Date   
Programming Track Booster

acmee001
 

I have recently installed a a Soundtrax PTB-100 programming booster within my Digitrax setup because I thought it would assist with programming Blueline BLI. While the item functions as per the manual, I note that the JMRI program that I utilise to program locos, is coming up with the message that it is unable to identify the decoder.

This is happening with all decoders including the common - ones which normally would not present an issue to JMRI and the system.

Before I pull it out - has anyone experienced this and from a wiring perspective, have I created incompatibility issues with loadings and data handling? I use the Digitrax MS100 at about 16k baud as the interface and wondered whether there is a timing issue although this isn't mentioned in error codes.

I do have a loco buffer ready to install but not sure which way to proceed now.

thanks once again Stu

sound decoder issues - Lifelike Proto 2000

acmee001
 

Hi all

I have a Lifelike Proto SD9 sound unit (first runs)which has always operated properly. Recently, while running the loco came off the track but continued to operate at fast revs. Due to its (and my) location it took about 30 secs to isolate it. The DCC system did not see a short during this incident (Digitrax)

On re-running it, the sound revs, lights and all functions except the motor work. So the loco just sits. An internalexamination does not reveal any loose wires, mechanical malfunction or burnt boards etc.

Given some of the discussions I have noted, have I inadvertently overloaded the decoder? - and how can I check with an ohm meter (if that is possible)to validate my suspicions. In fact, are there any other checks that you would recommend that I undertake.

thanks for your time - regards Stu

Re: Rail Gaps Point of clarification

thomasmclae
 

I am a little confused too. We need to clarify what we are talking about. There are two types of "loop".
1. Regular loop. Same as out-of-the box circle or loop. Train goes in one direction. There is an inside and outside rail. (Track looks like "O")
2. Reversing loop. Track loops back to switch, and merges to one track. 'Left' track can be followed around to become 'Right' track. (track looks like "P")

For type 1, the only reason not to connect the buss as a loop would be signal interference, as the signal follows the wire and meets at the far edge of the loop. For this reason, having the buss and track gaped at some point on the layout may eliminate some odd errors. If you have no problems, don't worry about it.

For type 2, you need to wire the same as you would for DC, but maybe using a DCC reversing module instead of a dpdt switch. Polarity rules still apply.
Thomas

--- In WiringForDCC@..., "Harvey L. McRae" <hlmcrae@...> wrote:

Evidently you have not comprehended what I wrote. I'll persue this no further as it does not make sense to carry on this discussion.

Thanks.

Booster

gl.summers65 <gl.summers@...>
 

Just wandering what indicators would you look for to know if you need some boosters or not? Thanks Larry

Re: Rail Gaps

Harvey L. McRae
 

Evidently you have not comprehended what I wrote. I'll persue this no further as it does not make sense to carry on this discussion.

Thanks.

Harvey L. McRae,
838 McKenzie Rd.,
Kelowna, BC. V1X2B3,
www.webs.com/harriscreekcentral

----- Original Message -----
From: jrchaff2
To: WiringForDCC@...
Sent: Saturday, May 22, 2010 8:06 PM
Subject: [WiringForDCC] Re: Rail Gaps



This is one of those old wives tales with absolutely no basis
in fact or practice.

Harvey, for the life of me, I cannot understand your 'short'
logic. If the bus wires follow the track around, rail for rail,
there *cannot* be a short. Otherwise, the track itself would
short - which it obviously does not.

As for all the wordy pseudotechnobabble about frequencies,
the often heard 'bit collision' argument, etc etc - I'm
afraid there is no demonstrated, documented occurrence of
any problems traced to the 'complete loop' configuration.

Many words, little substance.

Our club operates with a complete loop in a near-square, about
30-35 feet on a side, with no DCC problems whatever. Last week,
testing this 'loop' theory, I unplugged the loop at the far
end - no discernible difference at all. (This was done because
I was having a different DCC-related problem, which turned out
to be something else entirely - of course.)

I would really like to see some solid evidence - not the
assumptions and suppositions often hear, but documented,
controlled test cases showing this supposed problem.

I doubt it exists.

If it did, we would all be having 'bit collisions' all the
time on all our layouts. DCC would come to a screeching halt
before it ever got going.

Sheesh.

Dick Chaffer / Bozeman, MT

--- In WiringForDCC@..., "Harvey L. McRae" <hlmcrae@...> wrote:
>
> I'll try and explain: First, with the track......You have a "North" rail
> and a "South" rail.
etc






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Re: Rail Gaps

Max Maginness <m.maginness@...>
 

If you are having no problems it's because the DCC standards designers did
not arrive at them by celebrating ignorance.



Max



From: WiringForDCC@... [mailto:WiringForDCC@...] On
Behalf Of jrchaff2
Sent: Saturday, May 22, 2010 8:07 PM
To: WiringForDCC@...
Subject: [WiringForDCC] Re: Rail Gaps





This is one of those old wives tales with absolutely no basis
in fact or practice.

Harvey, for the life of me, I cannot understand your 'short'
logic. If the bus wires follow the track around, rail for rail,
there *cannot* be a short. Otherwise, the track itself would
short - which it obviously does not.

As for all the wordy pseudotechnobabble about frequencies,
the often heard 'bit collision' argument, etc etc - I'm
afraid there is no demonstrated, documented occurrence of
any problems traced to the 'complete loop' configuration.

Many words, little substance.

Our club operates with a complete loop in a near-square, about
30-35 feet on a side, with no DCC problems whatever. Last week,
testing this 'loop' theory, I unplugged the loop at the far
end - no discernible difference at all. (This was done because
I was having a different DCC-related problem, which turned out
to be something else entirely - of course.)

I would really like to see some solid evidence - not the
assumptions and suppositions often hear, but documented,
controlled test cases showing this supposed problem.

I doubt it exists.

If it did, we would all be having 'bit collisions' all the
time on all our layouts. DCC would come to a screeching halt
before it ever got going.

Sheesh.

Dick Chaffer / Bozeman, MT

--- In WiringForDCC@... <mailto:WiringForDCC%40yahoogroups.com>
, "Harvey L. McRae" <hlmcrae@...> wrote:

I'll try and explain: First, with the track......You have a "North" rail
and a "South" rail.
etc



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Checked by AVG - www.avg.com
Version: 9.0.819 / Virus Database: 271.1.1/2870 - Release Date: 05/22/10
11:26:00

Re: Rail Gaps

jrchaff2 <jrchaff@...>
 

This is one of those old wives tales with absolutely no basis
in fact or practice.

Harvey, for the life of me, I cannot understand your 'short'
logic. If the bus wires follow the track around, rail for rail,
there *cannot* be a short. Otherwise, the track itself would
short - which it obviously does not.

As for all the wordy pseudotechnobabble about frequencies,
the often heard 'bit collision' argument, etc etc - I'm
afraid there is no demonstrated, documented occurrence of
any problems traced to the 'complete loop' configuration.

Many words, little substance.

Our club operates with a complete loop in a near-square, about
30-35 feet on a side, with no DCC problems whatever. Last week,
testing this 'loop' theory, I unplugged the loop at the far
end - no discernible difference at all. (This was done because
I was having a different DCC-related problem, which turned out
to be something else entirely - of course.)

I would really like to see some solid evidence - not the
assumptions and suppositions often hear, but documented,
controlled test cases showing this supposed problem.

I doubt it exists.

If it did, we would all be having 'bit collisions' all the
time on all our layouts. DCC would come to a screeching halt
before it ever got going.

Sheesh.

Dick Chaffer / Bozeman, MT

--- In WiringForDCC@..., "Harvey L. McRae" <hlmcrae@...> wrote:

I'll try and explain: First, with the track......You have a "North" rail
and a "South" rail.
etc

Re: Rail Gaps

georgebriscoe10
 

Sorry Harvey, I added that. I haven't joined the Buss wires but they are effectively joined by not having gaps in my rail loop. This is what concerned me................George.



To: WiringForDCC@...
From: hlmcrae@...
Date: Sat, 22 May 2010 16:33:51 -0700
Subject: Re: [WiringForDCC] Rail Gaps





Hi again: Re-read paragraph 3. I don't thin I said it was not recommended.
I just said there was no purpose in doing this.

Why no purpose!!!! or yet why not recommended !!!! if you are running
feeders to the loop, and you run a continuous bus line, you have just taken
out all your insulated joiners in the track.. That's where you will get the
dead short.

Harvey L. McRae,
838 McKenzie Rd.,
Kelowna, BC. V1X2B3,
www.webs.com/harriscreekcentral

----- Original Message -----
From: "George Briscoe" <georgebriscoe@...>
To: <wiringfordcc@...>
Sent: Saturday, May 22, 2010 2:53 PM
Subject: RE: [WiringForDCC] Rail Gaps


Harvey,



Thanks and I understand most of it. The one thing that still intrigues me
is summerised in your paragraph 3. If I twist the wires there will be no
short but it is recommended not to do this.


WHY? There seems no logic to this. Will I have or cause some problems in
the future?



I haven't actually connected the Buss wires but by NOT insulating the rail
loop at the end of the Buss runs I have effectively joined the Buss, or so
I would assume. And I will probably go ahead double gap the track at the
ends of the Buss runs according to Allan's recommendations. Everything
else I had read so far in his site makes sense.



The reality is the layout is running fine but when I came accross this
recommendation in Allan's site I began to wonder. Better to find out why
rather than to live in doubt is the way I think.



Regards.............George.


To: WiringForDCC@...
From: hlmcrae@...
Date: Sat, 22 May 2010 13:25:02 -0700
Subject: Re: [WiringForDCC] Rail Gaps





I'll try and explain: First, with the track......You have a "North" rail
and a "South" rail. We'll say the north rail is your POSITIVE the South is
the negative. O.k follow this around your loop to where you are going to
join back into the main track. If you did not use plastic insulators in
your track, the North rail would now be joining into the south rail ( A
positive going to a Negative) and you would have a dead short.

Now, car your bus wire through, we'll say you have a white and a black
buss
wire....If you take the two wires running paraller to each other without
making any twist in the wire the same as your track above, you would be
connecting a "black-Negative" with a white Positive. Thus a dead short.

If you put a twist in the wire to connect black to black and white to
white,
you create a complete loop without a short. But then what is the purpose
of
creating the loop in the bus other than to run your feeder wires up to the
track above.

You can't insulate the track and not the bus wire...In DC you have to have
a
dpdt switch so reverse the polarity... In DCC you work with an auto
reverser that changes the polirity in the decoder and not the track.

Does this help, or is it still clear as mud.

Hope it helps to clarify//

Harvey L. McRae,
838 McKenzie Rd.,
Kelowna, BC. V1X2B3,
www.webs.com/harriscreekcentral

----- Original Message -----
From: "George Briscoe" <georgebriscoe@...>
To: <wiringfordcc@...>
Sent: Saturday, May 22, 2010 12:37 PM
Subject: RE: [WiringForDCC] Rail Gaps

Don,

Thanks for the detailed reply although it still hasn't answered my
question
completely. I think I will have to learn how to be more specific when I
ask
a question of the group.

In the end what I would like to know, and understand, is why we should not
make "loops" in a Buss. Following is a paragraph from Alan's site,

"1. Even if your layout is a loop, don't join the ends of your bus in a
loop. If your loop is one big block, put one pair of insulated joiners in
the track above where the ends of your bus are so that your layout doesn't
form an electrical loop with joined ends."

This is really what I am looking for an answer to. I have been through
Alan's site and cannot find a reason why we should not do this. I know
there
is a logical reason for this recommendation and out of curiosity I would
like to know the answer.

Thanks................George.

To: WiringForDCC@...
From: dvollrath@...
Date: Fri, 21 May 2010 17:23:42 -0500
Subject: RE: [WiringForDCC] Rail Gaps

George, in your hypothetical case of one continuous rail loop with
absolutely no insulating gaps but with multiple track feeders along the
way,
it won't make much difference if the DCC bus under the table is a
continuous
loop or actually broken up into left and right directional runs from some
central point. Multiple power drops to the non-insulated track loop
essentially connects them together. If each of those left & right bus runs
however has its own PSX circuit greaker, then you would not want the
connections to track rails connecting the two far ends of the busses
together... Otherwise you defeat the purpose of putting the breakers in...
Which is to isolate shorts to a smaller portion of the layout. With your
scenario, a short anywhere in the track loop will always cause one, then
both breakers to trip, dropping power to the whole layout. Each breaker
power district should have insulating gaps at both ends in order to
separate
it from other districts.
DonV

-----Original Message-----
From: WiringForDCC@... [mailto:WiringForDCC@...]
On
Behalf Of George Briscoe
Sent: Friday, May 21, 2010 10:17 AM
To: wiringfordcc@...
Subject: RE: [WiringForDCC] Rail Gaps

Dear All,

Thanks for the responses. I think my description lacks a bit of clarity.
Hard to describe a layout in words. Let's take a hypothetical situation
and
see if I can explain it better.

Single loop with feed from one end. Buss extends from feed point in both
directions around the loop, via PSX, but is not joined at the ends. The
rail
loop is not gapped though.

How important is it to gap the rails to match the Buss gaps? In Alan's
site
it suggests both should be gapped. What are the consequences of not
gapping
the rail other than it effectively cancels out the gap in the buss
feeders?

Regards..............George.

To: WiringForDCC@...
From: dvollrath@...
Date: Thu, 20 May 2010 15:49:32 -0500
Subject: RE: [WiringForDCC] Rail Gaps

Nope... Err, sort of. But if your track loops are already broken up into
several isolated sections fed by separate PSX units, the rails don't form
a
continuous electrical loop around the layout either. Any given section of
track is being fed from either the 'left' or 'right' power bus.

If it works OK, there is no need to mess with it.
DonV

-----Original Message-----
From: WiringForDCC@... [mailto:WiringForDCC@...]
On
Behalf Of georgebriscoe10
Sent: Thursday, May 20, 2010 2:46 PM
To: WiringForDCC@...
Subject: [WiringForDCC] Rail Gaps

Hi All,

Just joined this group. Have recently got back into model railroading and
have discovered DCC. Doing okay so far but have a question, particularly
for
Alan, about rail gapping. I have read most of "Wiring for DCC" and this
particular recommendation intrigues me.

Have a simple set-up. Live in a smallish apartment. Double loop with
crossovers and two sets of sidings off the inner loop. The two loops and
two
sets of sidings are insulated from each other and protected from short
circuit by 4 PSX units.

My question relates to the "gapping" of the rails to match the Buss wires
I
have installed. My "Busses" run left and right from one side without
joining.

How important is it to "gap" the rails to match the "gap" in the Buss?
Everything is working okay at the moment so I do not see the need to gap
the
rails to match the Buss. Is there something that I am missing?

Regards..............George.

------------------------------------

http://www.WiringForDCC.comYahoo! Groups Links

__________________________________________________________
Need a new place to live? Find it on Domain.com.au
http://clk.atdmt.com/NMN/go/157631292/direct/01/



------------------------------------

http://www.WiringForDCC.comYahoo! Groups Links

__________________________________________________________
New, Used, Demo, Dealer or Private? Find it at CarPoint.com.au
http://clk.atdmt.com/NMN/go/206222968/direct/01/

[Non-text portions of this message have been removed]

------------------------------------

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__________________________________________________________
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------------------------------------

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11:26:00





_________________________________________________________________
View photos of singles in your area! Looking for a hot date?
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[Non-text portions of this message have been removed]

Re: Rail Gaps

Harvey L. McRae
 

Hi again: Re-read paragraph 3. I don't thin I said it was not recommended. I just said there was no purpose in doing this.

Why no purpose!!!! or yet why not recommended !!!! if you are running feeders to the loop, and you run a continuous bus line, you have just taken out all your insulated joiners in the track.. That's where you will get the dead short.


Harvey L. McRae,
838 McKenzie Rd.,
Kelowna, BC. V1X2B3,
www.webs.com/harriscreekcentral

----- Original Message -----
From: "George Briscoe" <georgebriscoe@...>
To: <wiringfordcc@...>
Sent: Saturday, May 22, 2010 2:53 PM
Subject: RE: [WiringForDCC] Rail Gaps



Harvey,



Thanks and I understand most of it. The one thing that still intrigues me is summerised in your paragraph 3. If I twist the wires there will be no short but it is recommended not to do this.


WHY? There seems no logic to this. Will I have or cause some problems in the future?



I haven't actually connected the Buss wires but by NOT insulating the rail loop at the end of the Buss runs I have effectively joined the Buss, or so I would assume. And I will probably go ahead double gap the track at the ends of the Buss runs according to Allan's recommendations. Everything else I had read so far in his site makes sense.



The reality is the layout is running fine but when I came accross this recommendation in Allan's site I began to wonder. Better to find out why rather than to live in doubt is the way I think.



Regards.............George.


To: WiringForDCC@...
From: hlmcrae@...
Date: Sat, 22 May 2010 13:25:02 -0700
Subject: Re: [WiringForDCC] Rail Gaps





I'll try and explain: First, with the track......You have a "North" rail
and a "South" rail. We'll say the north rail is your POSITIVE the South is
the negative. O.k follow this around your loop to where you are going to
join back into the main track. If you did not use plastic insulators in
your track, the North rail would now be joining into the south rail ( A
positive going to a Negative) and you would have a dead short.

Now, car your bus wire through, we'll say you have a white and a black buss
wire....If you take the two wires running paraller to each other without
making any twist in the wire the same as your track above, you would be
connecting a "black-Negative" with a white Positive. Thus a dead short.

If you put a twist in the wire to connect black to black and white to white,
you create a complete loop without a short. But then what is the purpose of
creating the loop in the bus other than to run your feeder wires up to the
track above.

You can't insulate the track and not the bus wire...In DC you have to have a
dpdt switch so reverse the polarity... In DCC you work with an auto
reverser that changes the polirity in the decoder and not the track.

Does this help, or is it still clear as mud.

Hope it helps to clarify//

Harvey L. McRae,
838 McKenzie Rd.,
Kelowna, BC. V1X2B3,
www.webs.com/harriscreekcentral

----- Original Message -----
From: "George Briscoe" <georgebriscoe@...>
To: <wiringfordcc@...>
Sent: Saturday, May 22, 2010 12:37 PM
Subject: RE: [WiringForDCC] Rail Gaps

Don,

Thanks for the detailed reply although it still hasn't answered my question
completely. I think I will have to learn how to be more specific when I ask
a question of the group.

In the end what I would like to know, and understand, is why we should not
make "loops" in a Buss. Following is a paragraph from Alan's site,

"1. Even if your layout is a loop, don't join the ends of your bus in a
loop. If your loop is one big block, put one pair of insulated joiners in
the track above where the ends of your bus are so that your layout doesn't
form an electrical loop with joined ends."

This is really what I am looking for an answer to. I have been through
Alan's site and cannot find a reason why we should not do this. I know there
is a logical reason for this recommendation and out of curiosity I would
like to know the answer.

Thanks................George.

To: WiringForDCC@...
From: dvollrath@...
Date: Fri, 21 May 2010 17:23:42 -0500
Subject: RE: [WiringForDCC] Rail Gaps

George, in your hypothetical case of one continuous rail loop with
absolutely no insulating gaps but with multiple track feeders along the way,
it won't make much difference if the DCC bus under the table is a continuous
loop or actually broken up into left and right directional runs from some
central point. Multiple power drops to the non-insulated track loop
essentially connects them together. If each of those left & right bus runs
however has its own PSX circuit greaker, then you would not want the
connections to track rails connecting the two far ends of the busses
together... Otherwise you defeat the purpose of putting the breakers in...
Which is to isolate shorts to a smaller portion of the layout. With your
scenario, a short anywhere in the track loop will always cause one, then
both breakers to trip, dropping power to the whole layout. Each breaker
power district should have insulating gaps at both ends in order to separate
it from other districts.
DonV

-----Original Message-----
From: WiringForDCC@... [mailto:WiringForDCC@...] On
Behalf Of George Briscoe
Sent: Friday, May 21, 2010 10:17 AM
To: wiringfordcc@...
Subject: RE: [WiringForDCC] Rail Gaps

Dear All,

Thanks for the responses. I think my description lacks a bit of clarity.
Hard to describe a layout in words. Let's take a hypothetical situation and
see if I can explain it better.

Single loop with feed from one end. Buss extends from feed point in both
directions around the loop, via PSX, but is not joined at the ends. The rail
loop is not gapped though.

How important is it to gap the rails to match the Buss gaps? In Alan's site
it suggests both should be gapped. What are the consequences of not gapping
the rail other than it effectively cancels out the gap in the buss feeders?

Regards..............George.

To: WiringForDCC@...
From: dvollrath@...
Date: Thu, 20 May 2010 15:49:32 -0500
Subject: RE: [WiringForDCC] Rail Gaps

Nope... Err, sort of. But if your track loops are already broken up into
several isolated sections fed by separate PSX units, the rails don't form a
continuous electrical loop around the layout either. Any given section of
track is being fed from either the 'left' or 'right' power bus.

If it works OK, there is no need to mess with it.
DonV

-----Original Message-----
From: WiringForDCC@... [mailto:WiringForDCC@...] On
Behalf Of georgebriscoe10
Sent: Thursday, May 20, 2010 2:46 PM
To: WiringForDCC@...
Subject: [WiringForDCC] Rail Gaps

Hi All,

Just joined this group. Have recently got back into model railroading and
have discovered DCC. Doing okay so far but have a question, particularly for
Alan, about rail gapping. I have read most of "Wiring for DCC" and this
particular recommendation intrigues me.

Have a simple set-up. Live in a smallish apartment. Double loop with
crossovers and two sets of sidings off the inner loop. The two loops and two
sets of sidings are insulated from each other and protected from short
circuit by 4 PSX units.

My question relates to the "gapping" of the rails to match the Buss wires I
have installed. My "Busses" run left and right from one side without
joining.

How important is it to "gap" the rails to match the "gap" in the Buss?
Everything is working okay at the moment so I do not see the need to gap the
rails to match the Buss. Is there something that I am missing?

Regards..............George.

------------------------------------

http://www.WiringForDCC.comYahoo! Groups Links

__________________________________________________________
Need a new place to live? Find it on Domain.com.au
http://clk.atdmt.com/NMN/go/157631292/direct/01/


------------------------------------

http://www.WiringForDCC.comYahoo! Groups Links

__________________________________________________________
New, Used, Demo, Dealer or Private? Find it at CarPoint.com.au
http://clk.atdmt.com/NMN/go/206222968/direct/01/


------------------------------------

http://www.WiringForDCC.comYahoo! Groups Links

----------------------------------------------------------

No virus found in this incoming message.
Checked by AVG - www.avg.com
Version: 9.0.819 / Virus Database: 271.1.1/2888 - Release Date: 05/21/10
11:26:00





_________________________________________________________________
If It Exists, You'll Find it on SEEK. Australia's #1 job site
http://clk.atdmt.com/NMN/go/157639755/direct/01/




------------------------------------

http://www.WiringForDCC.comYahoo! Groups Links



--------------------------------------------------------------------------------



No virus found in this incoming message.
Checked by AVG - www.avg.com
Version: 9.0.819 / Virus Database: 271.1.1/2888 - Release Date: 05/21/10 11:26:00

Re: Rail Gaps

georgebriscoe10
 

Thanks Don,



This make sense. I knew there would be a reason for this but I needed to know. I am not having problems at present as my Busses are short but I will follow the advice of the experts and gap my rails so I do not form a "loop". The TV analogy is a good one. I have experienced ghosting with analogue TV and went to great lengths to minimise it.



In future I will try and get to the point a little quicker. It takes some time to learn how to post messages on forum such as this..................George.







To: WiringForDCC@...
From: dvollrath@...
Date: Sat, 22 May 2010 17:31:52 -0500
Subject: RE: [WiringForDCC] Rail Gaps





George - to answer your specific question: "In the end what I would like to know, and understand, is why we should not make "loops" in a Buss." The answer depends greatly on the length of the wire and track forming the loop.

DCC is made up of multiple frequencies of AC voltage. Loco decoders are watching for fast transitions in voltage polarity to determine digital coded communication commands sent down the bus. There is a definite propagation speed of the signal down any wire or cable... including the track. Decoders in the loco rely on receiving a 'clean' signal in order to decipher the DCC commands. When/If you make a large loop of continuous track or wire, and place the loco say 1/4 of the way around the loop, signals arriving via the short path will be mixed with signals arriving slightly later via the longer path. This can create multiple signal 'ghosting' effects, destroying the ability to cleanly receive the signal (remember that from analog TV?). Power to operate the loco will still be there, but communication may be temporarily lost. Simply not connecting the power bus and track into a continuous loop eliminates that possibility. How long must the loop be before this becomes a problem is somewhat dependant on your wiring method and brand/model of the decoder. If the loop is made up of only 30 ft of track I would not expect any issues. If the loop is 300 ft of track long there may be a different answer. Easy to ensure that it will always work by simply providing a break in the 'almost' loop of bus wiring and track.
DonV

-----Original Message-----
From: WiringForDCC@... [mailto:WiringForDCC@...] On Behalf Of George Briscoe
Sent: Saturday, May 22, 2010 2:38 PM
To: wiringfordcc@...
Subject: RE: [WiringForDCC] Rail Gaps

Don,

Thanks for the detailed reply although it still hasn't answered my question completely. I think I will have to learn how to be more specific when I ask a question of the group.

"1. Even if your layout is a loop, don't join the ends of your bus in a loop. If your loop is one big block, put one pair of insulated joiners in the track above where the ends of your bus are so that your layout doesn't form an electrical loop with joined ends."

This is really what I am looking for an answer to. I have been through Alan's site and cannot find a reason why we should not do this. I know there is a logical reason for this recommendation and out of curiosity I would like to know the answer.

Thanks................George.

To: WiringForDCC@...
From: dvollrath@...
Date: Fri, 21 May 2010 17:23:42 -0500
Subject: RE: [WiringForDCC] Rail Gaps

George, in your hypothetical case of one continuous rail loop with absolutely no insulating gaps but with multiple track feeders along the way, it won't make much difference if the DCC bus under the table is a continuous loop or actually broken up into left and right directional runs from some central point. Multiple power drops to the non-insulated track loop essentially connects them together. If each of those left & right bus runs however has its own PSX circuit greaker, then you would not want the connections to track rails connecting the two far ends of the busses together... Otherwise you defeat the purpose of putting the breakers in... Which is to isolate shorts to a smaller portion of the layout. With your scenario, a short anywhere in the track loop will always cause one, then both breakers to trip, dropping power to the whole layout. Each breaker power district should have insulating gaps at both ends in order to separate it from other districts.
DonV

-----Original Message-----
From: WiringForDCC@... [mailto:WiringForDCC@...] On Behalf Of George Briscoe
Sent: Friday, May 21, 2010 10:17 AM
To: wiringfordcc@...
Subject: RE: [WiringForDCC] Rail Gaps

Dear All,

Thanks for the responses. I think my description lacks a bit of clarity. Hard to describe a layout in words. Let's take a hypothetical situation and see if I can explain it better.

Single loop with feed from one end. Buss extends from feed point in both directions around the loop, via PSX, but is not joined at the ends. The rail loop is not gapped though.

How important is it to gap the rails to match the Buss gaps? In Alan's site it suggests both should be gapped. What are the consequences of not gapping the rail other than it effectively cancels out the gap in the buss feeders?

Regards..............George.

To: WiringForDCC@...
From: dvollrath@...
Date: Thu, 20 May 2010 15:49:32 -0500
Subject: RE: [WiringForDCC] Rail Gaps

Nope... Err, sort of. But if your track loops are already broken up into several isolated sections fed by separate PSX units, the rails don't form a continuous electrical loop around the layout either. Any given section of track is being fed from either the 'left' or 'right' power bus.

If it works OK, there is no need to mess with it.
DonV

-----Original Message-----
From: WiringForDCC@... [mailto:WiringForDCC@...] On Behalf Of georgebriscoe10
Sent: Thursday, May 20, 2010 2:46 PM
To: WiringForDCC@...
Subject: [WiringForDCC] Rail Gaps

Hi All,

Just joined this group. Have recently got back into model railroading and have discovered DCC. Doing okay so far but have a question, particularly for Alan, about rail gapping. I have read most of "Wiring for DCC" and this particular recommendation intrigues me.

Have a simple set-up. Live in a smallish apartment. Double loop with crossovers and two sets of sidings off the inner loop. The two loops and two sets of sidings are insulated from each other and protected from short circuit by 4 PSX units.

My question relates to the "gapping" of the rails to match the Buss wires I have installed. My "Busses" run left and right from one side without joining.

How important is it to "gap" the rails to match the "gap" in the Buss? Everything is working okay at the moment so I do not see the need to gap the rails to match the Buss. Is there something that I am missing?

Regards..............George.

------------------------------------

http://www.WiringForDCC.comYahoo! Groups Links

__________________________________________________________
Need a new place to live? Find it on Domain.com.au http://clk.atdmt.com/NMN/go/157631292/direct/01/



------------------------------------

http://www.WiringForDCC.comYahoo! Groups Links


__________________________________________________________
New, Used, Demo, Dealer or Private? Find it at CarPoint.com.au http://clk.atdmt.com/NMN/go/206222968/direct/01/

[Non-text portions of this message have been removed]

------------------------------------

http://www.WiringForDCC.comYahoo! Groups Links





_________________________________________________________________
New, Used, Demo, Dealer or Private? Find it at CarPoint.com.au
http://clk.atdmt.com/NMN/go/206222968/direct/01/

[Non-text portions of this message have been removed]

Re: Rail Gaps

Vollrath, Don <dvollrath@...>
 

George - to answer your specific question: "In the end what I would like to know, and understand, is why we should not make "loops" in a Buss." The answer depends greatly on the length of the wire and track forming the loop.

DCC is made up of multiple frequencies of AC voltage. Loco decoders are watching for fast transitions in voltage polarity to determine digital coded communication commands sent down the bus. There is a definite propagation speed of the signal down any wire or cable... including the track. Decoders in the loco rely on receiving a 'clean' signal in order to decipher the DCC commands. When/If you make a large loop of continuous track or wire, and place the loco say 1/4 of the way around the loop, signals arriving via the short path will be mixed with signals arriving slightly later via the longer path. This can create multiple signal 'ghosting' effects, destroying the ability to cleanly receive the signal (remember that from analog TV?). Power to operate the loco will still be there, but communication may be temporarily lost. Simply not connecting the power bus and track into a continuous loop eliminates that possibility. How long must the loop be before this becomes a problem is somewhat dependant on your wiring method and brand/model of the decoder. If the loop is made up of only 30 ft of track I would not expect any issues. If the loop is 300 ft of track long there may be a different answer. Easy to ensure that it will always work by simply providing a break in the 'almost' loop of bus wiring and track.
DonV

-----Original Message-----
From: WiringForDCC@... [mailto:WiringForDCC@...] On Behalf Of George Briscoe
Sent: Saturday, May 22, 2010 2:38 PM
To: wiringfordcc@...
Subject: RE: [WiringForDCC] Rail Gaps


Don,



Thanks for the detailed reply although it still hasn't answered my question completely. I think I will have to learn how to be more specific when I ask a question of the group.







"1. Even if your layout is a loop, don't join the ends of your bus in a loop. If your loop is one big block, put one pair of insulated joiners in the track above where the ends of your bus are so that your layout doesn't form an electrical loop with joined ends."



This is really what I am looking for an answer to. I have been through Alan's site and cannot find a reason why we should not do this. I know there is a logical reason for this recommendation and out of curiosity I would like to know the answer.



Thanks................George.


To: WiringForDCC@...
From: dvollrath@...
Date: Fri, 21 May 2010 17:23:42 -0500
Subject: RE: [WiringForDCC] Rail Gaps





George, in your hypothetical case of one continuous rail loop with absolutely no insulating gaps but with multiple track feeders along the way, it won't make much difference if the DCC bus under the table is a continuous loop or actually broken up into left and right directional runs from some central point. Multiple power drops to the non-insulated track loop essentially connects them together. If each of those left & right bus runs however has its own PSX circuit greaker, then you would not want the connections to track rails connecting the two far ends of the busses together... Otherwise you defeat the purpose of putting the breakers in... Which is to isolate shorts to a smaller portion of the layout. With your scenario, a short anywhere in the track loop will always cause one, then both breakers to trip, dropping power to the whole layout. Each breaker power district should have insulating gaps at both ends in order to separate it from other districts.
DonV

-----Original Message-----
From: WiringForDCC@... [mailto:WiringForDCC@...] On Behalf Of George Briscoe
Sent: Friday, May 21, 2010 10:17 AM
To: wiringfordcc@...
Subject: RE: [WiringForDCC] Rail Gaps

Dear All,

Thanks for the responses. I think my description lacks a bit of clarity. Hard to describe a layout in words. Let's take a hypothetical situation and see if I can explain it better.

Single loop with feed from one end. Buss extends from feed point in both directions around the loop, via PSX, but is not joined at the ends. The rail loop is not gapped though.

How important is it to gap the rails to match the Buss gaps? In Alan's site it suggests both should be gapped. What are the consequences of not gapping the rail other than it effectively cancels out the gap in the buss feeders?

Regards..............George.

To: WiringForDCC@...
From: dvollrath@...
Date: Thu, 20 May 2010 15:49:32 -0500
Subject: RE: [WiringForDCC] Rail Gaps

Nope... Err, sort of. But if your track loops are already broken up into several isolated sections fed by separate PSX units, the rails don't form a continuous electrical loop around the layout either. Any given section of track is being fed from either the 'left' or 'right' power bus.

If it works OK, there is no need to mess with it.
DonV

-----Original Message-----
From: WiringForDCC@... [mailto:WiringForDCC@...] On Behalf Of georgebriscoe10
Sent: Thursday, May 20, 2010 2:46 PM
To: WiringForDCC@...
Subject: [WiringForDCC] Rail Gaps

Hi All,

Just joined this group. Have recently got back into model railroading and have discovered DCC. Doing okay so far but have a question, particularly for Alan, about rail gapping. I have read most of "Wiring for DCC" and this particular recommendation intrigues me.

Have a simple set-up. Live in a smallish apartment. Double loop with crossovers and two sets of sidings off the inner loop. The two loops and two sets of sidings are insulated from each other and protected from short circuit by 4 PSX units.

My question relates to the "gapping" of the rails to match the Buss wires I have installed. My "Busses" run left and right from one side without joining.

How important is it to "gap" the rails to match the "gap" in the Buss? Everything is working okay at the moment so I do not see the need to gap the rails to match the Buss. Is there something that I am missing?

Regards..............George.

------------------------------------

http://www.WiringForDCC.comYahoo! Groups Links


__________________________________________________________
Need a new place to live? Find it on Domain.com.au http://clk.atdmt.com/NMN/go/157631292/direct/01/

[Non-text portions of this message have been removed]

------------------------------------

http://www.WiringForDCC.comYahoo! Groups Links





_________________________________________________________________
New, Used, Demo, Dealer or Private? Find it at CarPoint.com.au http://clk.atdmt.com/NMN/go/206222968/direct/01/





------------------------------------

http://www.WiringForDCC.comYahoo! Groups Links

Re: Rail Gaps

georgebriscoe10
 

Harvey,



Thanks and I understand most of it. The one thing that still intrigues me is summerised in your paragraph 3. If I twist the wires there will be no short but it is recommended not to do this.


WHY? There seems no logic to this. Will I have or cause some problems in the future?



I haven't actually connected the Buss wires but by NOT insulating the rail loop at the end of the Buss runs I have effectively joined the Buss, or so I would assume. And I will probably go ahead double gap the track at the ends of the Buss runs according to Allan's recommendations. Everything else I had read so far in his site makes sense.



The reality is the layout is running fine but when I came accross this recommendation in Allan's site I began to wonder. Better to find out why rather than to live in doubt is the way I think.



Regards.............George.


To: WiringForDCC@...
From: hlmcrae@...
Date: Sat, 22 May 2010 13:25:02 -0700
Subject: Re: [WiringForDCC] Rail Gaps





I'll try and explain: First, with the track......You have a "North" rail
and a "South" rail. We'll say the north rail is your POSITIVE the South is
the negative. O.k follow this around your loop to where you are going to
join back into the main track. If you did not use plastic insulators in
your track, the North rail would now be joining into the south rail ( A
positive going to a Negative) and you would have a dead short.

Now, car your bus wire through, we'll say you have a white and a black buss
wire....If you take the two wires running paraller to each other without
making any twist in the wire the same as your track above, you would be
connecting a "black-Negative" with a white Positive. Thus a dead short.

If you put a twist in the wire to connect black to black and white to white,
you create a complete loop without a short. But then what is the purpose of
creating the loop in the bus other than to run your feeder wires up to the
track above.

You can't insulate the track and not the bus wire...In DC you have to have a
dpdt switch so reverse the polarity... In DCC you work with an auto
reverser that changes the polirity in the decoder and not the track.

Does this help, or is it still clear as mud.

Hope it helps to clarify//

Harvey L. McRae,
838 McKenzie Rd.,
Kelowna, BC. V1X2B3,
www.webs.com/harriscreekcentral

----- Original Message -----
From: "George Briscoe" <georgebriscoe@...>
To: <wiringfordcc@...>
Sent: Saturday, May 22, 2010 12:37 PM
Subject: RE: [WiringForDCC] Rail Gaps

Don,

Thanks for the detailed reply although it still hasn't answered my question
completely. I think I will have to learn how to be more specific when I ask
a question of the group.

In the end what I would like to know, and understand, is why we should not
make "loops" in a Buss. Following is a paragraph from Alan's site,

"1. Even if your layout is a loop, don't join the ends of your bus in a
loop. If your loop is one big block, put one pair of insulated joiners in
the track above where the ends of your bus are so that your layout doesn't
form an electrical loop with joined ends."

This is really what I am looking for an answer to. I have been through
Alan's site and cannot find a reason why we should not do this. I know there
is a logical reason for this recommendation and out of curiosity I would
like to know the answer.

Thanks................George.

To: WiringForDCC@...
From: dvollrath@...
Date: Fri, 21 May 2010 17:23:42 -0500
Subject: RE: [WiringForDCC] Rail Gaps

George, in your hypothetical case of one continuous rail loop with
absolutely no insulating gaps but with multiple track feeders along the way,
it won't make much difference if the DCC bus under the table is a continuous
loop or actually broken up into left and right directional runs from some
central point. Multiple power drops to the non-insulated track loop
essentially connects them together. If each of those left & right bus runs
however has its own PSX circuit greaker, then you would not want the
connections to track rails connecting the two far ends of the busses
together... Otherwise you defeat the purpose of putting the breakers in...
Which is to isolate shorts to a smaller portion of the layout. With your
scenario, a short anywhere in the track loop will always cause one, then
both breakers to trip, dropping power to the whole layout. Each breaker
power district should have insulating gaps at both ends in order to separate
it from other districts.
DonV

-----Original Message-----
From: WiringForDCC@... [mailto:WiringForDCC@...] On
Behalf Of George Briscoe
Sent: Friday, May 21, 2010 10:17 AM
To: wiringfordcc@...
Subject: RE: [WiringForDCC] Rail Gaps

Dear All,

Thanks for the responses. I think my description lacks a bit of clarity.
Hard to describe a layout in words. Let's take a hypothetical situation and
see if I can explain it better.

Single loop with feed from one end. Buss extends from feed point in both
directions around the loop, via PSX, but is not joined at the ends. The rail
loop is not gapped though.

How important is it to gap the rails to match the Buss gaps? In Alan's site
it suggests both should be gapped. What are the consequences of not gapping
the rail other than it effectively cancels out the gap in the buss feeders?

Regards..............George.

To: WiringForDCC@...
From: dvollrath@...
Date: Thu, 20 May 2010 15:49:32 -0500
Subject: RE: [WiringForDCC] Rail Gaps

Nope... Err, sort of. But if your track loops are already broken up into
several isolated sections fed by separate PSX units, the rails don't form a
continuous electrical loop around the layout either. Any given section of
track is being fed from either the 'left' or 'right' power bus.

If it works OK, there is no need to mess with it.
DonV

-----Original Message-----
From: WiringForDCC@... [mailto:WiringForDCC@...] On
Behalf Of georgebriscoe10
Sent: Thursday, May 20, 2010 2:46 PM
To: WiringForDCC@...
Subject: [WiringForDCC] Rail Gaps

Hi All,

Just joined this group. Have recently got back into model railroading and
have discovered DCC. Doing okay so far but have a question, particularly for
Alan, about rail gapping. I have read most of "Wiring for DCC" and this
particular recommendation intrigues me.

Have a simple set-up. Live in a smallish apartment. Double loop with
crossovers and two sets of sidings off the inner loop. The two loops and two
sets of sidings are insulated from each other and protected from short
circuit by 4 PSX units.

My question relates to the "gapping" of the rails to match the Buss wires I
have installed. My "Busses" run left and right from one side without
joining.

How important is it to "gap" the rails to match the "gap" in the Buss?
Everything is working okay at the moment so I do not see the need to gap the
rails to match the Buss. Is there something that I am missing?

Regards..............George.

------------------------------------

http://www.WiringForDCC.comYahoo! Groups Links

__________________________________________________________
Need a new place to live? Find it on Domain.com.au
http://clk.atdmt.com/NMN/go/157631292/direct/01/

[Non-text portions of this message have been removed]

------------------------------------

http://www.WiringForDCC.comYahoo! Groups Links

__________________________________________________________
New, Used, Demo, Dealer or Private? Find it at CarPoint.com.au
http://clk.atdmt.com/NMN/go/206222968/direct/01/

[Non-text portions of this message have been removed]

------------------------------------

http://www.WiringForDCC.comYahoo! Groups Links

----------------------------------------------------------

No virus found in this incoming message.
Checked by AVG - www.avg.com
Version: 9.0.819 / Virus Database: 271.1.1/2888 - Release Date: 05/21/10
11:26:00





_________________________________________________________________
If It Exists, You'll Find it on SEEK. Australia's #1 job site
http://clk.atdmt.com/NMN/go/157639755/direct/01/

Re: Rail Gaps

Harvey L. McRae
 

I'll try and explain: First, with the track......You have a "North" rail and a "South" rail. We'll say the north rail is your POSITIVE the South is the negative. O.k follow this around your loop to where you are going to join back into the main track. If you did not use plastic insulators in your track, the North rail would now be joining into the south rail ( A positive going to a Negative) and you would have a dead short.

Now, car your bus wire through, we'll say you have a white and a black buss wire....If you take the two wires running paraller to each other without making any twist in the wire the same as your track above, you would be connecting a "black-Negative" with a white Positive. Thus a dead short.

If you put a twist in the wire to connect black to black and white to white, you create a complete loop without a short. But then what is the purpose of creating the loop in the bus other than to run your feeder wires up to the track above.

You can't insulate the track and not the bus wire...In DC you have to have a dpdt switch so reverse the polarity... In DCC you work with an auto reverser that changes the polirity in the decoder and not the track.

Does this help, or is it still clear as mud.

Hope it helps to clarify//


Harvey L. McRae,
838 McKenzie Rd.,
Kelowna, BC. V1X2B3,
www.webs.com/harriscreekcentral

----- Original Message -----
From: "George Briscoe" <georgebriscoe@...>
To: <wiringfordcc@...>
Sent: Saturday, May 22, 2010 12:37 PM
Subject: RE: [WiringForDCC] Rail Gaps



Don,



Thanks for the detailed reply although it still hasn't answered my question completely. I think I will have to learn how to be more specific when I ask a question of the group.



In the end what I would like to know, and understand, is why we should not make "loops" in a Buss. Following is a paragraph from Alan's site,




"1. Even if your layout is a loop, don't join the ends of your bus in a loop. If your loop is one big block, put one pair of insulated joiners in the track above where the ends of your bus are so that your layout doesn't form an electrical loop with joined ends."



This is really what I am looking for an answer to. I have been through Alan's site and cannot find a reason why we should not do this. I know there is a logical reason for this recommendation and out of curiosity I would like to know the answer.



Thanks................George.


To: WiringForDCC@...
From: dvollrath@...
Date: Fri, 21 May 2010 17:23:42 -0500
Subject: RE: [WiringForDCC] Rail Gaps





George, in your hypothetical case of one continuous rail loop with absolutely no insulating gaps but with multiple track feeders along the way, it won't make much difference if the DCC bus under the table is a continuous loop or actually broken up into left and right directional runs from some central point. Multiple power drops to the non-insulated track loop essentially connects them together. If each of those left & right bus runs however has its own PSX circuit greaker, then you would not want the connections to track rails connecting the two far ends of the busses together... Otherwise you defeat the purpose of putting the breakers in... Which is to isolate shorts to a smaller portion of the layout. With your scenario, a short anywhere in the track loop will always cause one, then both breakers to trip, dropping power to the whole layout. Each breaker power district should have insulating gaps at both ends in order to separate it from other districts.
DonV

-----Original Message-----
From: WiringForDCC@... [mailto:WiringForDCC@...] On Behalf Of George Briscoe
Sent: Friday, May 21, 2010 10:17 AM
To: wiringfordcc@...
Subject: RE: [WiringForDCC] Rail Gaps

Dear All,

Thanks for the responses. I think my description lacks a bit of clarity. Hard to describe a layout in words. Let's take a hypothetical situation and see if I can explain it better.

Single loop with feed from one end. Buss extends from feed point in both directions around the loop, via PSX, but is not joined at the ends. The rail loop is not gapped though.

How important is it to gap the rails to match the Buss gaps? In Alan's site it suggests both should be gapped. What are the consequences of not gapping the rail other than it effectively cancels out the gap in the buss feeders?

Regards..............George.

To: WiringForDCC@...
From: dvollrath@...
Date: Thu, 20 May 2010 15:49:32 -0500
Subject: RE: [WiringForDCC] Rail Gaps

Nope... Err, sort of. But if your track loops are already broken up into several isolated sections fed by separate PSX units, the rails don't form a continuous electrical loop around the layout either. Any given section of track is being fed from either the 'left' or 'right' power bus.

If it works OK, there is no need to mess with it.
DonV

-----Original Message-----
From: WiringForDCC@... [mailto:WiringForDCC@...] On Behalf Of georgebriscoe10
Sent: Thursday, May 20, 2010 2:46 PM
To: WiringForDCC@...
Subject: [WiringForDCC] Rail Gaps

Hi All,

Just joined this group. Have recently got back into model railroading and have discovered DCC. Doing okay so far but have a question, particularly for Alan, about rail gapping. I have read most of "Wiring for DCC" and this particular recommendation intrigues me.

Have a simple set-up. Live in a smallish apartment. Double loop with crossovers and two sets of sidings off the inner loop. The two loops and two sets of sidings are insulated from each other and protected from short circuit by 4 PSX units.

My question relates to the "gapping" of the rails to match the Buss wires I have installed. My "Busses" run left and right from one side without joining.

How important is it to "gap" the rails to match the "gap" in the Buss? Everything is working okay at the moment so I do not see the need to gap the rails to match the Buss. Is there something that I am missing?

Regards..............George.

------------------------------------

http://www.WiringForDCC.comYahoo! Groups Links


__________________________________________________________
Need a new place to live? Find it on Domain.com.au http://clk.atdmt.com/NMN/go/157631292/direct/01/



------------------------------------

http://www.WiringForDCC.comYahoo! Groups Links





_________________________________________________________________
New, Used, Demo, Dealer or Private? Find it at CarPoint.com.au
http://clk.atdmt.com/NMN/go/206222968/direct/01/





------------------------------------

http://www.WiringForDCC.comYahoo! Groups Links





--------------------------------------------------------------------------------



No virus found in this incoming message.
Checked by AVG - www.avg.com
Version: 9.0.819 / Virus Database: 271.1.1/2888 - Release Date: 05/21/10 11:26:00

Re: Rail Gaps

georgebriscoe10
 

Don,



Thanks for the detailed reply although it still hasn't answered my question completely. I think I will have to learn how to be more specific when I ask a question of the group.



In the end what I would like to know, and understand, is why we should not make "loops" in a Buss. Following is a paragraph from Alan's site,




"1. Even if your layout is a loop, donít join the ends of your bus in a loop. If your loop is one big block, put one pair of insulated joiners in the track above where the ends of your bus are so that your layout doesnít form an electrical loop with joined ends."



This is really what I am looking for an answer to. I have been through Alan's site and cannot find a reason why we should not do this. I know there is a logical reason for this recommendation and out of curiosity I would like to know the answer.



Thanks................George.


To: WiringForDCC@...
From: dvollrath@...
Date: Fri, 21 May 2010 17:23:42 -0500
Subject: RE: [WiringForDCC] Rail Gaps





George, in your hypothetical case of one continuous rail loop with absolutely no insulating gaps but with multiple track feeders along the way, it won't make much difference if the DCC bus under the table is a continuous loop or actually broken up into left and right directional runs from some central point. Multiple power drops to the non-insulated track loop essentially connects them together. If each of those left & right bus runs however has its own PSX circuit greaker, then you would not want the connections to track rails connecting the two far ends of the busses together... Otherwise you defeat the purpose of putting the breakers in... Which is to isolate shorts to a smaller portion of the layout. With your scenario, a short anywhere in the track loop will always cause one, then both breakers to trip, dropping power to the whole layout. Each breaker power district should have insulating gaps at both ends in order to separate it from other districts.
DonV

-----Original Message-----
From: WiringForDCC@... [mailto:WiringForDCC@...] On Behalf Of George Briscoe
Sent: Friday, May 21, 2010 10:17 AM
To: wiringfordcc@...
Subject: RE: [WiringForDCC] Rail Gaps

Dear All,

Thanks for the responses. I think my description lacks a bit of clarity. Hard to describe a layout in words. Let's take a hypothetical situation and see if I can explain it better.

Single loop with feed from one end. Buss extends from feed point in both directions around the loop, via PSX, but is not joined at the ends. The rail loop is not gapped though.

How important is it to gap the rails to match the Buss gaps? In Alan's site it suggests both should be gapped. What are the consequences of not gapping the rail other than it effectively cancels out the gap in the buss feeders?

Regards..............George.

To: WiringForDCC@...
From: dvollrath@...
Date: Thu, 20 May 2010 15:49:32 -0500
Subject: RE: [WiringForDCC] Rail Gaps

Nope... Err, sort of. But if your track loops are already broken up into several isolated sections fed by separate PSX units, the rails don't form a continuous electrical loop around the layout either. Any given section of track is being fed from either the 'left' or 'right' power bus.

If it works OK, there is no need to mess with it.
DonV

-----Original Message-----
From: WiringForDCC@... [mailto:WiringForDCC@...] On Behalf Of georgebriscoe10
Sent: Thursday, May 20, 2010 2:46 PM
To: WiringForDCC@...
Subject: [WiringForDCC] Rail Gaps

Hi All,

Just joined this group. Have recently got back into model railroading and have discovered DCC. Doing okay so far but have a question, particularly for Alan, about rail gapping. I have read most of "Wiring for DCC" and this particular recommendation intrigues me.

Have a simple set-up. Live in a smallish apartment. Double loop with crossovers and two sets of sidings off the inner loop. The two loops and two sets of sidings are insulated from each other and protected from short circuit by 4 PSX units.

My question relates to the "gapping" of the rails to match the Buss wires I have installed. My "Busses" run left and right from one side without joining.

How important is it to "gap" the rails to match the "gap" in the Buss? Everything is working okay at the moment so I do not see the need to gap the rails to match the Buss. Is there something that I am missing?

Regards..............George.

------------------------------------

http://www.WiringForDCC.comYahoo! Groups Links


__________________________________________________________
Need a new place to live? Find it on Domain.com.au http://clk.atdmt.com/NMN/go/157631292/direct/01/

[Non-text portions of this message have been removed]

------------------------------------

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Re: Rail Gaps

Vollrath, Don <dvollrath@...>
 

George, in your hypothetical case of one continuous rail loop with absolutely no insulating gaps but with multiple track feeders along the way, it won't make much difference if the DCC bus under the table is a continuous loop or actually broken up into left and right directional runs from some central point. Multiple power drops to the non-insulated track loop essentially connects them together. If each of those left & right bus runs however has its own PSX circuit greaker, then you would not want the connections to track rails connecting the two far ends of the busses together... Otherwise you defeat the purpose of putting the breakers in... Which is to isolate shorts to a smaller portion of the layout. With your scenario, a short anywhere in the track loop will always cause one, then both breakers to trip, dropping power to the whole layout. Each breaker power district should have insulating gaps at both ends in order to separate it from other districts.
DonV

-----Original Message-----
From: WiringForDCC@... [mailto:WiringForDCC@...] On Behalf Of George Briscoe
Sent: Friday, May 21, 2010 10:17 AM
To: wiringfordcc@...
Subject: RE: [WiringForDCC] Rail Gaps


Dear All,



Thanks for the responses. I think my description lacks a bit of clarity. Hard to describe a layout in words. Let's take a hypothetical situation and see if I can explain it better.



Single loop with feed from one end. Buss extends from feed point in both directions around the loop, via PSX, but is not joined at the ends. The rail loop is not gapped though.



How important is it to gap the rails to match the Buss gaps? In Alan's site it suggests both should be gapped. What are the consequences of not gapping the rail other than it effectively cancels out the gap in the buss feeders?



Regards..............George.







To: WiringForDCC@...
From: dvollrath@...
Date: Thu, 20 May 2010 15:49:32 -0500
Subject: RE: [WiringForDCC] Rail Gaps





Nope... Err, sort of. But if your track loops are already broken up into several isolated sections fed by separate PSX units, the rails don't form a continuous electrical loop around the layout either. Any given section of track is being fed from either the 'left' or 'right' power bus.

If it works OK, there is no need to mess with it.
DonV

-----Original Message-----
From: WiringForDCC@... [mailto:WiringForDCC@...] On Behalf Of georgebriscoe10
Sent: Thursday, May 20, 2010 2:46 PM
To: WiringForDCC@...
Subject: [WiringForDCC] Rail Gaps

Hi All,

Just joined this group. Have recently got back into model railroading and have discovered DCC. Doing okay so far but have a question, particularly for Alan, about rail gapping. I have read most of "Wiring for DCC" and this particular recommendation intrigues me.

Have a simple set-up. Live in a smallish apartment. Double loop with crossovers and two sets of sidings off the inner loop. The two loops and two sets of sidings are insulated from each other and protected from short circuit by 4 PSX units.

My question relates to the "gapping" of the rails to match the Buss wires I have installed. My "Busses" run left and right from one side without joining.

How important is it to "gap" the rails to match the "gap" in the Buss? Everything is working okay at the moment so I do not see the need to gap the rails to match the Buss. Is there something that I am missing?

Regards..............George.

------------------------------------

http://www.WiringForDCC.comYahoo! Groups Links





_________________________________________________________________
Need a new place to live? Find it on Domain.com.au http://clk.atdmt.com/NMN/go/157631292/direct/01/

[Non-text portions of this message have been removed]



------------------------------------

http://www.WiringForDCC.comYahoo! Groups Links

Re: Rail Gaps

georgebriscoe10
 

Dear All,



Thanks for the responses. I think my description lacks a bit of clarity. Hard to describe a layout in words. Let's take a hypothetical situation and see if I can explain it better.



Single loop with feed from one end. Buss extends from feed point in both directions around the loop, via PSX, but is not joined at the ends. The rail loop is not gapped though.



How important is it to gap the rails to match the Buss gaps? In Alan's site it suggests both should be gapped. What are the consequences of not gapping the rail other than it effectively cancels out the gap in the buss feeders?



Regards..............George.







To: WiringForDCC@...
From: dvollrath@...
Date: Thu, 20 May 2010 15:49:32 -0500
Subject: RE: [WiringForDCC] Rail Gaps





Nope... Err, sort of. But if your track loops are already broken up into several isolated sections fed by separate PSX units, the rails don't form a continuous electrical loop around the layout either. Any given section of track is being fed from either the 'left' or 'right' power bus.

If it works OK, there is no need to mess with it.
DonV

-----Original Message-----
From: WiringForDCC@... [mailto:WiringForDCC@...] On Behalf Of georgebriscoe10
Sent: Thursday, May 20, 2010 2:46 PM
To: WiringForDCC@...
Subject: [WiringForDCC] Rail Gaps

Hi All,

Just joined this group. Have recently got back into model railroading and have discovered DCC. Doing okay so far but have a question, particularly for Alan, about rail gapping. I have read most of "Wiring for DCC" and this particular recommendation intrigues me.

Have a simple set-up. Live in a smallish apartment. Double loop with crossovers and two sets of sidings off the inner loop. The two loops and two sets of sidings are insulated from each other and protected from short circuit by 4 PSX units.

My question relates to the "gapping" of the rails to match the Buss wires I have installed. My "Busses" run left and right from one side without joining.

How important is it to "gap" the rails to match the "gap" in the Buss? Everything is working okay at the moment so I do not see the need to gap the rails to match the Buss. Is there something that I am missing?

Regards..............George.

------------------------------------

http://www.WiringForDCC.comYahoo! Groups Links





_________________________________________________________________
Need a new place to live? Find it on Domain.com.au
http://clk.atdmt.com/NMN/go/157631292/direct/01/

Re: My 1st DCC layout

Vollrath, Don <dvollrath@...>
 

Patrick, If you are already planning on needing a 5A booster, circuit protectors and reversers, why start with the PowerCab? Spring for the PowerPro system control station, booster, ProCab and 5A power supply right away. The main advantage is ease (and cost) of further expansion you are likely to want next - including radio, a PC link to DecoderPro for loco programming, macros and use with multiple cabs. Look at the Team Digital SMD82 to control multiple switch machines.

-----Original Message-----
From: WiringForDCC@... [mailto:WiringForDCC@...] On Behalf Of PATRICK B
Sent: Friday, May 21, 2010 8:42 AM
To: WiringForDCC@...
Subject: [WiringForDCC] My 1st DCC layout

I am building my 1st DCC layout.
I will use a NCE Power Cab and eventually add a SB3a 5A booster.
What recommendations for circuit protection?
I will also need some reverse loop protectors.
I am looking at the PSX-4, PSX-AR, EB-3 (not for Power Cab), CP6.
What is the best way to protect the blocks?
I will have ~ 10 blocks with a double track.
I will also need an interface with the Tortoise switch machines.
Am I over complicating this?
Thanks for any help.



------------------------------------

http://www.WiringForDCC.comYahoo! Groups Links

Re: DCC "friendly" turn-outs with minimal wiring

Vollrath, Don <dvollrath@...>
 

Practically all commercial turnouts made for 2-rail running will work. But as Doug said, all of them rely somehow on metal to metal contact imbedded in plastic and/or the rail points touching the stock rails and/or moving pivots to carry electrical power to the inner rails and/or frog. Therein lies the rub of reliability. The electrical connections sometimes become intermittent with age and oxidation/dirt. Many units have insulated frogs. Some frogs can be energized only when you provide an external wiring means to switch power polarity in accordance with the throw bar position. In part, the wiring-for-DCC method is to use soldered connection to positively provide electricl power to every important piece of rail. Why don't the manufacturers do that? Ease of assembly and Cost.
I use some Atlas code 83 #4 dead-frog turnouts as is. Most work OK for modern diesels with all wheel pick-up. However I have found a few that had poor electrical connections to the point rails and have added a soldered in flexible wire to provide positive power. Some steam locos with engine-tender pick-up will stall on the dead frog. Walther's/Shinohara with live frogs work OK, especially with an aux switch and wire to power the frog and point rails, even if they are not totally DCC friendly.
DonV

-----Original Message-----
From: WiringForDCC@... [mailto:WiringForDCC@...] On Behalf Of MauriceG
Sent: Thursday, May 20, 2010 8:04 PM
To: WiringForDCC@...
Subject: [WiringForDCC] DCC "friendly" turn-outs with minimal wiring

I am currently building a new layout in HO scale, which I want to wire for DCC. The choice of turn-outs is where I am confused. It seems that every brand I have looked at will require additional wiring to work. My layout will have at least one area of crowded switching where slow movement of multiple turn-outs will be done. All of my turn-outs will be hand-thrown. My motive power is exclusively 4 axle diesel switchers. If all the research I have currently done is correct, shorts in the area of the frog are a major concern. What I can't understand is why no manufacturer makes a turn-out that switches polarity of the frog based on position of the points without the need of additional wiring and hardware. Is there any brand of turn-out that will work in my situation without additional hardware or wiring? For the sake of this discussion, I only need #4 frog angle turn-outs.

Please forgive my ignorance if I have over-looked anything. Thanks in advance for any replies.



------------------------------------

http://www.WiringForDCC.comYahoo! Groups Links

My 1st DCC layout

PATRICK B
 

I am building my 1st DCC layout.
I will use a NCE Power Cab and eventually add a SB3a 5A booster.
What recommendations for circuit protection?
I will also need some reverse loop protectors.
I am looking at the PSX-4, PSX-AR, EB-3 (not for Power Cab), CP6.
What is the best way to protect the blocks?
I will have ~ 10 blocks with a double track.
I will also need an interface with the Tortoise switch machines.
Am I over complicating this?
Thanks for any help.

Re: DCC "friendly" turn-outs with minimal wiring

Doug Stuard <dstuard@...>
 

If there is no additional wiring or hardware, then it must be the points themselves, making contact with the adjacent stock rail, that provides power to the frog. This type of turnout is as old as the hills and has proven to have significant reliability issues as the point to stock rail contact area is prone to dirt and contamination, resulting in erratic operation. To solve this, hand throws and switch machines have provided auxiliary contacts to switch frog power, and have been doing so for as long as I have been in MRRing (don't ask <G>).

If you are going to use hand throws, I would recommend the Caboose Industries ground throw which includes aux contacts for this purpose, the Blue Point manual actuator, or the Humpyard Purveyance throw which can be similarly equipped.

Doug Stuard

--- In WiringForDCC@..., "MauriceG" <maurice@...> wrote:

I am currently building a new layout in HO scale, which I want to wire for DCC. The choice of turn-outs is where I am confused. It seems that every brand I have looked at will require additional wiring to work. My layout will have at least one area of crowded switching where slow movement of multiple turn-outs will be done. All of my turn-outs will be hand-thrown. My motive power is exclusively 4 axle diesel switchers. If all the research I have currently done is correct, shorts in the area of the frog are a major concern. What I can't understand is why no manufacturer makes a turn-out that switches polarity of the frog based on position of the points without the need of additional wiring and hardware. Is there any brand of turn-out that will work in my situation without additional hardware or wiring? For the sake of this discussion, I only need #4 frog angle turn-outs.

Please forgive my ignorance if I have over-looked anything. Thanks in advance for any replies.