Date   

Re: 7A13 Funny Business

 

In retrospect that has to be what happened but the seller should have
said something before blindly shipping another unit.

On 15 Mar 2016 13:40:08 -0700, you wrote:

Dallas, let me be the devil's advocate. The S/N B240480 was visible in the picture, but on the other hand the listing ended saying "2 available, 3 sold". So you could know that the seller offered several units. Did you explicitly ask the seller to send the shown unit? Maybe when your complaint arrived the B24xxxx was sold already and he may have thought that B23xxxx would be close enough?

Albert


Re: 7A13 Funny Business

Richard R. Pope
 

Dallas,
It sounds like this seller is pulling some goofy stunts. I would
like to know who this person is so that I don't ever buy anything from
this person. The switching of the relays I don't know anything about
what will work.
Thanks,
rich!

On 3/15/2016 11:34 AM, dosmith54@... [TekScopes] wrote:



Which relays are the the most current revision? Strange that the lower
part numbers are on the higher SN.
The 7A13 with the higher SN is not functioning properly but the lower
one seems fine. Can the relays be switched? which one are the problem
ones?

Dallas


---In TekScopes@..., <dosmith54@...> wrote :

Hi All,


I just purchased a used 7A13 off of flee bay and the serial number was
B240480 in the picture.
But received SN: B103153 and has green PCB's and date code on semi
around 1983 with the date printed on the circuit board of 1983 and
relay series 300 & 400.


Complained to the seller and he said he would send the B240480, but
when received it was B238677 with semi date codes of 1978, brown PCB,
and relay series of 800 & 900. It also has a corroded black input
section cover ,the other is pristine and look like its been worked on,
missing connector header for the LED display, some kludge connection.


What gives, they switched out the serial number frame bracket?


Dallas





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


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


Re: 2465x A5 Crystal upgrade

Richard R. Pope
 

Mike,
Yep, having a scope and a frequency counter is really helpful. When I build an oscillator circuit I use my scope and frequency counter to fine tune the signal. I also put a variable capacitor in the circuit. Most of the time I use a canned oscillator rather than design and build a circuit. They are very accurate and stable. The cost is also moderate and usually less than what you would spend on your own design. If you factor in your time and labor the cost of your own circuit will almost always be many times a canned oscillator.
Thanks,
Richard R. Pope
President
Reedsburg Area Model Railroad Club, RAMRC
1230 19th Street #5
Reedsburg, WI 53959
608-768-7448
mechanic_2@...

On 3/15/2016 11:28 AM, 2465bct@... [TekScopes] wrote:
Menahem,

You are correct, but that doesn't take into account the additional capacitance
in the circuit, which is usually less than 5pF. That is why I went with 33pF
capacitors because that gives me 16.5pF plus the unknown extra capacitances.
It might even be better to use 33pF + 27pF or 30pF, or 30pF + 30pF. But, since
the capacitors vary by as much as 20%, all you can really do is to test the
output frequency once you make a good guess. Or have a tuneable capacitor.


Mike


Just for academics.....
If you use a 33pF and a 39pF (both commonly available values) - and I
would select an NP0 type - your load capacitance is 17.88pF.
Pretty close to the required 18pF.
Menahem


Re: 7A13 Funny Business

Albert Otten
 

Dallas, let me be the devil's advocate. The S/N B240480 was visible in the picture, but on the other hand the listing ended saying "2 available, 3 sold". So you could know that the seller offered several units. Did you explicitly ask the seller to send the shown unit? Maybe when your complaint arrived the B24xxxx was sold already and he may have thought that B23xxxx would be close enough?

Albert


Re: 2465x A5 Crystal upgrade

 

The 2247A and I assume 2252 have an external reference input for their
universal timer/counters.

Option 1E on the 2465B adds an external reference input to the
counter/timer/trigger included in option 06 and 09.

On Tue, 15 Mar 2016 16:21:39 -0400, you wrote:

If the scopes needed more accuracy or to be synced to other
instrumentation they would carry a Freq ref input (10Mhz perhaps) like a
SA or VNA or even Sig gens.
I see no input sig ref on any of my scopes. I know some high end
instruments have such an input.
Perhaps it boils down to the ppm drift of the crystal being too small to
chase down precision as other parts of the instrument would have errors
which would swamp any XO drift error.
Kinda like polishing your car to eke out extra mileage due to wind
friction loading when a worn valve seat, carbonized spark plug, poor
sensor grounding or any number of other issues can cause losses orders
of magnitude more than wind friction.


Re: 7A13 Funny Business

Richard R. Pope
 

Dallas,
I would say that that is what happened. I would also be concerned
that this person is selling stolen property. If I was you I would
contact the authorities. Yes, you might lose the equipment but that is
better than going to prison for receiving stolen property.
If it isn't stolen than this is a bad seller and I would return the
equipment for a full refund and then do business with another seller. I
have been buying and selling stuff on E-bay for decades and I have only
seen or heard about something like this happening a half a dozen times.
If you like the equipment and the wrong serial numbers aren't that big a
deal then keep the equipment and enjoy. These are my recommendations and
opinion. Others may or may not agree but that is ok. That is what
America is all about.
Thanks,
Richard R. Pope
President
Reedsburg Area Model Railroad Club, RAMRC
1230 19th Street #5
Reedsburg, WI 53959
608-768-7448
mechanic_2@...

On 3/15/2016 11:06 AM, dosmith54@... [TekScopes] wrote:

Hi All,


I just purchased a used 7A13 off of flee bay and the serial number was
B240480 in the picture.
But received SN: B103153 and has green PCB's and date code on semi
around 1983 with the date printed on the circuit board of 1983 and
relay series 300 & 400.


Complained to the seller and he said he would send the B240480, but
when received it was B238677 with semi date codes of 1978, brown PCB,
and relay series of 800 & 900. It also has a corroded black input
section cover ,the other is pristine and look like its been worked on,
missing connector header for the LED display, some kludge connection.


What gives, they switched out the serial number frame bracket?


Dallas




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


Re: 2465x A5 Crystal upgrade

mosaicmerc
 

If the scopes needed more accuracy or to be synced to other instrumentation they would carry a Freq ref input (10Mhz perhaps) like a SA or VNA or even Sig gens.
I see no input sig ref on any of my scopes. I know some high end instruments have such an input.
Perhaps it boils down to the ppm drift of the crystal being too small to chase down precision as other parts of the instrument would have errors which would swamp any XO drift error.
Kinda like polishing your car to eke out extra mileage due to wind friction loading when a worn valve seat, carbonized spark plug, poor sensor grounding or any number of other issues can cause losses orders of magnitude more than wind friction.


Re: 7A13 Funny Business

Dallas Smith
 

I will keep them for parts.
Dallas

I doubt it is stolen as one other poster suggested, and it is even more
unlikely you would ever be arrested for purchasing stolen property on
Ebay unless it could be proven that you had prior knowledge to that
fact, I could find no reference that anyone had ever been arrested as
such for an Ebay purchase, SELLING a known stolen item is another story
and several Ebay sellers have be caught6 and prosecuted for that

What is more likely that the seller ( or someone he purchased it from)
created a Frakenstein, i.e. Board from one unit placed in the body of
another to get it working. AS this gear gets older and older and parts
become more scarce this practice will flourish. Without the life history
of a unit it will get increasingly difficult to trace the source of what
happened before you or the seller had it.

That being said if the photo shows serial # B240480 and there is no
disclaimer that the item that the photo is "representative but not the
actual unit you will receive " ( I have seen this many times especially
if they are adverting that they have several of these for sale). I am a
big fan of working out things with the seller if it is an honest
mistake, However since he sent you two units neither of which was the
one in the picture time to minimize your losses and move on to find an
honest seller, Next you register a claim with Evil-Bay that the "item
you received was not a described" and ask for your money back. It will
take a few weeks but sounds like you would ultimately win. . I would not
deal with this seller anymore clearly best case he is ignorant about
what he is selling and worse case he is either stupid or Dishonest..

good luck my friend
--
Dave
Manuals@... mailto:Manuals@...
www.ArtekManuals.com

---
This email has been checked for viruses by Avast antivirus software.
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Re: 7A13 Funny Business

Bill (Doc) Courtright
 

FWIW my 7A13 Sn B242614 has a green board, 200 series relays and 80-81 date codes.
Looks like the seller might be doing rebuilds/repairs. This must be noted in the listing along with the fact of similar to pictured if not a picture of the listed item.
Bill,
KB3DKS

-----Original Message-----
From: dosmith54@... [TekScopes] <TekScopes@...>

Which relays are the the most current revision? Strange that the lower part numbers are on the higher SN.
The 7A13 with the higher SN is not functioning properly but the lower one seems fine. Can the relays be switched? which one are the problem ones?

Dallas

---In TekScopes@..., <dosmith54@...> wrote :

Hi All,

I just purchased a used 7A13 off of flee bay and the serial number was B240480 in the picture.
But received SN: B103153 and has green PCB's and date code on semi around 1983 with the date printed on the circuit board of 1983 and relay series 300 & 400.


Complained to the seller and he said he would send the B240480, but when received it was B238677 with semi date codes of 1978, brown PCB, and relay series of 800 & 900. It also has a corroded black input section cover ,the other is pristine and look like its been worked on, missing connector header for the LED display, some kludge connection.

What gives, they switched out the serial number frame bracket?

Dallas


Re: SMD test fixtures for curve tracers

John Miles
 

I won't spoil the surprise for the people doing the work, but there's
something being developed right now that will really give the Tek curve
tracers a new lease on life. Watch this space!



-- john, KE5FX (no affiliation with the project but very impressed with what
I've seen of it)



From: TekScopes@... [mailto:TekScopes@...]
Sent: Tuesday, March 15, 2016 12:02 PM
To: TekScopes@...
Subject: [TekScopes] SMD test fixtures for curve tracers





I have been trying to move into the SMD age.


Does anyone have an example of a DYI or economical SMD test fixture that one
can use for example on 2 and 3 leaded parts in a curve tracer?


Re: SMD test fixtures for curve tracers

John Gord
 

It looks like it is a stack of two boards. We only see one layer of each board.

--John Gord


---In TekScopes@..., <brad.thompson@...> wrote :

On 3/15/2016 3:06 PM, David DiGiacomo telists@... mailto:telists@... [TekScopes] wrote:
>
> On Tue, Mar 15, 2016 at 1:01 PM, <Kochcal@... mailto:Kochcal@...> wrote:
> >
> > I have been trying to move into the SMD age.
> >
> >
> > Does anyone have an example of a DYI or economical SMD test fixture
> that one can use for example on 2 and 3 leaded parts in a curve tracer?
>
> How about:
>
> http://www.ebay.com/itm/NEW-SOT23-SOT23-6-SOT23-6L-IC-Test-Socket-Programmer-Adapter-Burn-in-Socket-/271995317131 http://www.ebay.com/itm/NEW-SOT23-SOT23-6-SOT23-6L-IC-Test-Socket-Programmer-Adapter-Burn-in-Socket-/271995317131
>
> Hello--
Is it just me, or are there too-few connections visible on the adaptor's
PC board? It might be a three-layer board, but
somehow that would seem like overkill. Something doesn't look right.

73--

Brad AA1IP


Re: SMD test fixtures for curve tracers

Brad Thompson <brad.thompson@...>
 

On 3/15/2016 3:06 PM, David DiGiacomo telists@... [TekScopes] wrote:

On Tue, Mar 15, 2016 at 1:01 PM, <Kochcal@...> wrote:

I have been trying to move into the SMD age.


Does anyone have an example of a DYI or economical SMD test fixture
that one can use for example on 2 and 3 leaded parts in a curve tracer?

How about:

http://www.ebay.com/itm/NEW-SOT23-SOT23-6-SOT23-6L-IC-Test-Socket-Programmer-Adapter-Burn-in-Socket-/271995317131

Hello--
Is it just me, or are there too-few connections visible on the adaptor's PC board? It might be a three-layer board, but
somehow that would seem like overkill. Something doesn't look right.

73--

Brad AA1IP


Re: 7A13 Funny Business

Artek Manuals <manuals@...>
 

On 3/15/2016 2:34 PM, dosmith54@... [TekScopes] wrote:


Which relays are the the most current revision? Strange that the lower
part numbers are on the higher SN.
The 7A13 with the higher SN is not functioning properly but the lower
one seems fine. Can the relays be switched? which one are the problem ones?

Dallas


---In TekScopes@..., <dosmith54@...> wrote :

Hi All,


I just purchased a used 7A13 off of flee bay and the serial number was
B240480 in the picture.
But received SN: B103153 and has green PCB's and date code on semi
around 1983 with the date printed on the circuit board of 1983 and relay
series 300 & 400.


Complained to the seller and he said he would send the B240480, but when
received it was B238677 with semi date codes of 1978, brown PCB, and
relay series of 800 & 900. It also has a corroded black input section
cover ,the other is pristine and look like its been worked on, missing
connector header for the LED display, some kludge connection.


What gives, they switched out the serial number frame bracket?


Dallas
Dallas

I doubt it is stolen as one other poster suggested, and it is even more unlikely you would ever be arrested for purchasing stolen property on Ebay unless it could be proven that you had prior knowledge to that fact, I could find no reference that anyone had ever been arrested as such for an Ebay purchase, SELLING a known stolen item is another story and several Ebay sellers have be caught6 and prosecuted for that

What is more likely that the seller ( or someone he purchased it from) created a Frakenstein, i.e. Board from one unit placed in the body of another to get it working. AS this gear gets older and older and parts become more scarce this practice will flourish. Without the life history of a unit it will get increasingly difficult to trace the source of what happened before you or the seller had it.

That being said if the photo shows serial # B240480 and there is no disclaimer that the item that the photo is "representative but not the actual unit you will receive " ( I have seen this many times especially if they are adverting that they have several of these for sale). I am a big fan of working out things with the seller if it is an honest mistake, However since he sent you two units neither of which was the one in the picture time to minimize your losses and move on to find an honest seller, Next you register a claim with Evil-Bay that the "item you received was not a described" and ask for your money back. It will take a few weeks but sounds like you would ultimately win. . I would not deal with this seller anymore clearly best case he is ignorant about what he is selling and worse case he is either stupid or Dishonest..

good luck my friend
--
Dave
Manuals@...
www.ArtekManuals.com


Re: SMD test fixtures for curve tracers

David DiGiacomo
 

On Tue, Mar 15, 2016 at 1:01 PM, <Kochcal@...> wrote:

I have been trying to move into the SMD age.


Does anyone have an example of a DYI or economical SMD test fixture that one can use for example on 2 and 3 leaded parts in a curve tracer?
How about:

http://www.ebay.com/itm/NEW-SOT23-SOT23-6-SOT23-6L-IC-Test-Socket-Programmer-Adapter-Burn-in-Socket-/271995317131


Re: SMD test fixtures for curve tracers

stefan_trethan
 

For chip components there is a really neat LCR meter fixture by HP,
the part basically sits in a V groove and two rods come in from the
side, I'd really like to have that one. Maybe now I can 3d print it
;-)

I don't think there is a universal solution for the multitude of SMT
parts, I usually just tack wires on.

ST

On Tue, Mar 15, 2016 at 8:01 PM, Kochcal@... [TekScopes]
<TekScopes@...> wrote:
I have been trying to move into the SMD age.


Does anyone have an example of a DYI or economical SMD test fixture that one can use for example on 2 and 3 leaded parts in a curve tracer?


I have searched and not really come up with anything.


I have some really tiny grabbers but it's hard to get all three clips on, particularly if they have solder from being removed, and the parts tend to pop/wonder off and get lost.


Any other ideas?


John






------------------------------------
Posted by: Kochcal@...
------------------------------------


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

Yahoo Groups Links



SMD test fixtures for curve tracers

ykochcal
 

I have been trying to move into the SMD age.


Does anyone have an example of a DYI or economical SMD test fixture that one can use for example on 2 and 3 leaded parts in a curve tracer?


I have searched and not really come up with anything.


I have some really tiny grabbers but it's hard to get all three clips on, particularly if they have solder from being removed, and the parts tend to pop/wonder off and get lost.


Any other ideas?


John


Re: 7A13 Funny Business

Dallas Smith
 

Which relays are the the most current revision? Strange that the lower part numbers are on the higher SN.
The 7A13 with the higher SN is not functioning properly but the lower one seems fine. Can the relays be switched? which one are the problem ones?

Dallas


---In TekScopes@..., <dosmith54@...> wrote :

Hi All,


I just purchased a used 7A13 off of flee bay and the serial number was B240480 in the picture.
But received SN: B103153 and has green PCB's and date code on semi around 1983 with the date printed on the circuit board of 1983 and relay series 300 & 400.


Complained to the seller and he said he would send the B240480, but when received it was B238677 with semi date codes of 1978, brown PCB, and relay series of 800 & 900. It also has a corroded black input section cover ,the other is pristine and look like its been worked on, missing connector header for the LED display, some kludge connection.


What gives, they switched out the serial number frame bracket?


Dallas


Re: 2465x A5 Crystal upgrade

Michael
 

Menahem,

You are correct, but that doesn't take into account the additional capacitance
in the circuit, which is usually less than 5pF. That is why I went with 33pF
capacitors because that gives me 16.5pF plus the unknown extra capacitances.
It might even be better to use 33pF + 27pF or 30pF, or 30pF + 30pF. But, since
the capacitors vary by as much as 20%, all you can really do is to test the
output frequency once you make a good guess. Or have a tuneable capacitor.


Mike







Just for academics.....

If you use a 33pF and a 39pF (both commonly available values) - and I
would select an NP0 type - your load capacitance is 17.88pF.
Pretty close to the required 18pF.


Menahem







--
Best regards,
2465bct mailto:2465bct@...


Re: 7854 RAM card upgrade only - any interest?

Cliff Carrie
 

The Ebay listing I mentioned has a photo of the diagnostic card. There are 14 chips with 24 pins that look like ROM and are all labelled with different individual part numbers. There are also 2 empty 24 pin sockets. In addition , there are 5 chips with 16 pins along the connector edge that look like address decodes and bus drivers. The card is clearly made to go into the ROM socket, as it is keyed for this and has 44 edge contacts. I don't believe there is any RAM on it, because the ROM card socket does not present the lines needed by RAM. With so many ROM chips on the card, it is very possible that it uses some of the RAM address space.

The diagnostic version sticker on the Ebay 7854 sale is version 4, which is the same as on my 7854.


Cliff


Re: 2465x A5 Crystal upgrade

Chuck Harris
 

Manahem,

I am not sure why you are falling for this nonsense.

The crystal in the 2465 is just there to make the processor
run. The processor is not using it for any time critical
purposes... it needs a clock. The only reason they used
a crystal over a simpler RC oscillator is it allowed them
to run the microprocessor closer to its maximum speed over
all temperatures. If they used an RC oscillator there would
be some risk that it might run too fast and cause reliability
problems.

You could change the crystal 20% and never notice the change.
The crystal frequency has no affect on the scope's calibration.

The "square" crystal is a hybrid crystal oscillator. They
are smaller, and cheaper than using a separate HC17 crystal,
and a couple of invertors, and capacitors to make an oscillator.

They did it on some of the A5 boards because they ran out of
room.

-Chuck Harris

@yachadm [TekScopes] wrote:

Just for academics.....

If you use a 33pF and a 39pF (both commonly available values) - and I would select
an NP0 type - your load capacitance is 17.88pF. Pretty close to the required
18pF.


Menahem





------------------------------------ Posted by: @yachadm
------------------------------------


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

Yahoo Groups Links