Date   
Re: SG5030 and SG504 leveling heads

 

Indeed and finding a modern replacement for those latching relays isn't easy! I looked at making an SG5030 head replacement, but no-one at the time had a dead levelling head and I also hadn't got an SG5030 to test against.

Could I do one - yes. If you want to use anything from the original SG504 head design you'll find the write up on my website:

<http://perdrix.co.uk/SG504Head/index.htm>

If you do go down that route I have hand drawn schematic from the original designer that shows a few component value changes from mine.

David

-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of Egge Siert
Sent: 05 January 2020 08:31
To: TekScopes@groups.io
Subject: Re: [TekScopes] SG5030 and SG504 leveling heads

Hi Melvin,

Maybe you allready know? Out of some private correspondence with another TekScopes member:

" NOOT: the 015-2350-01 SG5030 Leveling Head has indeed the same RF switches as the earlier mentioned CG's and DC's. Also it has the same Hybrid as used in the SG504 Leveling Head. "

Greetings,

Egge Siert

Re: Logic families

Mlynch001
 

Arden,

True. However, in the context of much of the equipment that many of us are dealing with, these older forms of logic are most relevant. This is why I read and try to understand posts, such as Eric’s. So the historical part is nice to know. But understanding how the early forms work is essential to the understanding of the later versions. That is why I enjoy herring from people, such as yourself, and others on this forum who have a better understanding of the subject.

Thank you
--
Michael Lynch
Dardanelle, AR

Re: SG5030 and SG504 leveling heads

Egge Siert
 

Hi Melvin,

Maybe you allready know? Out of some private correspondence with another TekScopes member:

" NOOT: the 015-2350-01 SG5030 Leveling Head has indeed the same RF switches as the earlier mentioned CG's and DC's. Also it has the same Hybrid as used in the SG504 Leveling Head. "

Greetings,

Egge Siert

Re: TDS694C 50 Ohm Overload

EricJ
 

They were about $5 apiece when I bought them IIRC, and there are 4 per board I think.  It has been a while. It's a slightly finicky job, the joints are not very easy to reach and the boards are very fragile being ceramic.

As far as Ebay sellers checking things,  you will probably not have much luck there unless the seller is somewhat knowledgeable about the scope. You might be able to guide one through running SPC and checking the error log.

--Eric

On Jan 4, 2020 9:14 PM, "Reginald Beardsley via Groups.Io" <pulaskite=yahoo.com@groups.io> wrote:




On Sat, Jan  4, 2020 at 05:30 PM, EricJ wrote:


A lot of SPC fails on TDS scopes seem to be related to contact
resistance in
the switching relays on the hybrid acquisition boards. I have a TDS754D
that
had that problem. Changing the relays solved it.

--Eric

On Jan 4, 2020 4:00 PM, "Reginald Beardsley via Groups.Io"
<pulaskite=yahoo.com@groups.io> wrote:




If it works on the higher setting, the problem is in the input section
ahead of the ADC.  I'd look for a burned 50 ohm resistor. Or perhaps a
cracked solder joint.

I saw several of these on ebay with the SPC fail, but had been unable
to
find any information about what might be wrong with such a unit.  How
did
you get the input damage information?

Reg





How hard is it to get replacement relays and what do they cost?

Is there a blog post about reviving these things?

And what do you ask an ebay seller to do to find out the status of  an
item?

Thanks,
Reg

Reg





Re: TDS694C 50 Ohm Overload

EricJ
 

If that is the case then looks like you need to continue looking for that parts donor. Do you know if a TDS644b shares that part? I saw one for sale the other day.

--Eric

On Jan 4, 2020 5:54 PM, Stephen Hanselman <kc4sw.io@...> wrote:




I think, underline think, that a good number of those fails are due to bad
relay contacts but cannot prove that yet.

Regards,

Stephen Hanselman
Datagate Systems, LLC
On Jan 4, 2020, at 14:01, Reginald Beardsley via Groups.Io
<pulaskite=yahoo.com@groups.io> wrote:

If it works on the higher setting, the problem is in the input section
ahead of the ADC.  I'd look for a burned 50 ohm resistor. Or perhaps a
cracked solder joint.

I saw several of these on ebay with the SPC fail, but had been unable to
find any information about what might be wrong with such a unit.  How did
you get the input damage information?

Reg






Re: Tektronix 570 Vacuum Tube Curve Tracer on eBay

Jamie Ostrowski
 

Ha, interesting story. Yeah, I didn't even notice it was an actual auction.
I would be surprised if anyone bids on that, but I could be wrong! Will be
interesting to see what happens.

On Sun, Jan 5, 2020 at 12:16 AM John Williams <books4you@...> wrote:

Maybe a lot of people have a car that cost less. And that is not a BIN
price but an auction. So the seller clearly hopes to get more than the 4K
for this one.

One time I was delivering an oscilloscope I had sold locally to a guy.
When I walked into his office there sitting on a table was a pristine 570.
I stupidly blurted out that “those are worth over $2000!” But I didn’t have
the money to buy it so I left. But after some more sales I did have a bit
of a nest egg and went back to see if he would sell it. When I asked him
what he would take for it, he said “$2000.” Nice going. But I did buy it
and again stupidly later sold it. I would like to still have it just to own
it. I wonder if he will get bids.



Re: Tektronix 570 Vacuum Tube Curve Tracer on eBay

John Williams
 

Maybe a lot of people have a car that cost less. And that is not a BIN price but an auction. So the seller clearly hopes to get more than the 4K for this one.

One time I was delivering an oscilloscope I had sold locally to a guy. When I walked into his office there sitting on a table was a pristine 570. I stupidly blurted out that “those are worth over $2000!” But I didn’t have the money to buy it so I left. But after some more sales I did have a bit of a nest egg and went back to see if he would sell it. When I asked him what he would take for it, he said “$2000.” Nice going. But I did buy it and again stupidly later sold it. I would like to still have it just to own it. I wonder if he will get bids.

Re: Trying to bring back a AA501

KeepIt SimpleStupid
 

On Saturday, January 4, 2020, 10:31:47 PM EST, Mlynch001 <@mlynch001> wrote:

OK, learned something.  LSTTL and TTL are different animals?  SN74HC175N Will drive 10 outputs of LSTTL.    Just trying to learn how logic works, I will likely encounter a similar issue in the future.

Thanks! 
--
Michael Lynch
Dardanelle, AR

Re: Logic families

Dave Seiter
 

I too would like to see a comprehensive guide to the earliest logic families, from RTL to the mid seventies.  Sure, they are slow, power hungry, etc but they are interesting historically (and you never know when you might run into them).  Some families appear to be short-lived or had few members, and data sheets can be difficult to find for the more unusual parts.  
-Dave

On Saturday, January 4, 2020, 08:18:30 PM PST, Mlynch001 <@mlynch001> wrote:


Covers the very modern series of logic families.  It seems to be a little short on the older families.  I don’t see many of these listed.  Those families are the ones that I am more interested in.  I have an older TI Logic Cross reference that crosses over many of the older Logic IC’s.  I still appreciate any information where logic is concerned.  There are so many sub-divisions within TTL alone, understanding them all is confusing to say the least.  I appreciate any lessons that I can learn.
--
Michael Lynch
Dardanelle, AR

Re: Logic families

KB6NAX
 

RTL and DTL are obsolete, too slow, too few functions, too power hungry, no longer made. Look up ancient data sheets.

Arden

-----Original Message-----
From: Dean Davidson via Groups.Io
Sent: Saturday, January 04, 2020 8:05 PM
To: TekScopes@groups.io
Subject: Re: [TekScopes] Logic families



On 5/01/2020 13:58, KB6NAX wrote:
Here's a comprehensive overview of the various logic families (long URL):

https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=19&cad=rja&uact=8&ved=2ahUKEwjBrqSQuevmAhVoB50JHRjTC4MQFjASegQIBxAC&url=http%3A%2F%2Fwww.ti.com%2Flit%2Fsdyu001&usg=AOvVaw25lGF9wfK6uX4gPjvyvJpf
No that very comprehensive. What about DTL & RTL???
Dean

Re: Logic families

KB6NAX
 

It was just a quickie off of Google.

Arden

-----Original Message-----
From: Mlynch001
Sent: Saturday, January 04, 2020 7:33 PM
To: TekScopes@groups.io
Subject: Re: [TekScopes] Logic families

Arden,

THANKS! much appreciated.

--
Michael Lynch
Dardanelle, AR

Re: Tektronix 570 Vacuum Tube Curve Tracer on eBay

Dan Cordova
 

For less than $200, I put together a Dennis Tillman VTCT board, and modified my Hickok Tube Tester to use with my Tektronix 575 curve tracer.  I also made the Daniel Schoo designed triode and pentode adapters for the Tektronix 576 Curve Tracer at work.  
I'm also not sure all my tubes and stereo gear are worth ~$4000 all together.    ;)

On Saturday, January 4, 2020, 08:25:27 PM PST, Roy Morgan <k1lky68@...> wrote:

Gee.  Only ten bucks less than four thousand dollar$. Too bad he doesn't have two - one for spare.

Roy Morgan
K1LKY Western Mass

On Jan 4, 2020, at 11:02 PM, John Williams <books4you@...> wrote:

https://www.ebay.com/itm/Tektronix-570-Vacuum-Tube-Curve-Tracer-w-manual/333465990412?hash=item4da41f350c:g:~hMAAOSwpj1eETIK


Re: Tektronix 570 Vacuum Tube Curve Tracer on eBay

Jamie Ostrowski
 

When the prices get that high, at some point you need to ask yourself how
much it would cost to build one from scratch!

On Sat, Jan 4, 2020 at 10:25 PM Roy Morgan <k1lky68@...> wrote:

Gee. Only ten bucks less than four thousand dollar$. Too bad he doesn't
have two - one for spare.

Roy Morgan
K1LKY Western Mass

On Jan 4, 2020, at 11:02 PM, John Williams <books4you@...> wrote:


https://www.ebay.com/itm/Tektronix-570-Vacuum-Tube-Curve-Tracer-w-manual/333465990412?hash=item4da41f350c:g:~hMAAOSwpj1eETIK




Re: Tektronix 570 Vacuum Tube Curve Tracer on eBay

Roy Morgan
 

Gee. Only ten bucks less than four thousand dollar$. Too bad he doesn't have two - one for spare.

Roy Morgan
K1LKY Western Mass

Re: Logic families

Mlynch001
 

Covers the very modern series of logic families. It seems to be a little short on the older families. I don’t see many of these listed. Those families are the ones that I am more interested in. I have an older TI Logic Cross reference that crosses over many of the older Logic IC’s. I still appreciate any information where logic is concerned. There are so many sub-divisions within TTL alone, understanding them all is confusing to say the least. I appreciate any lessons that I can learn.
--
Michael Lynch
Dardanelle, AR

Re: Logic families

Dean Davidson
 

On 5/01/2020 13:58, KB6NAX wrote:
Here's a comprehensive overview of the various logic families (long URL):
https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=19&cad=rja&uact=8&ved=2ahUKEwjBrqSQuevmAhVoB50JHRjTC4MQFjASegQIBxAC&url=http%3A%2F%2Fwww.ti.com%2Flit%2Fsdyu001&usg=AOvVaw25lGF9wfK6uX4gPjvyvJpf
No that very comprehensive. What about DTL & RTL???
Dean

Tektronix 570 Vacuum Tube Curve Tracer on eBay

John Williams
 

Re: Logic families

Mlynch001
 

Arden,

THANKS! much appreciated.

--
Michael Lynch
Dardanelle, AR

Re: Trying to bring back a AA501

Mlynch001
 

OK, learned something. LSTTL and TTL are different animals? SN74HC175N Will drive 10 outputs of LSTTL. Just trying to learn how logic works, I will likely encounter a similar issue in the future.

Thanks!
--
Michael Lynch
Dardanelle, AR

Re: TDS694C 50 Ohm Overload

Reginald Beardsley
 

On Sat, Jan 4, 2020 at 05:30 PM, EricJ wrote:


A lot of SPC fails on TDS scopes seem to be related to contact resistance in
the switching relays on the hybrid acquisition boards. I have a TDS754D that
had that problem. Changing the relays solved it.

--Eric

On Jan 4, 2020 4:00 PM, "Reginald Beardsley via Groups.Io"
<pulaskite=yahoo.com@groups.io> wrote:




If it works on the higher setting, the problem is in the input section
ahead of the ADC.  I'd look for a burned 50 ohm resistor. Or perhaps a
cracked solder joint.

I saw several of these on ebay with the SPC fail, but had been unable to
find any information about what might be wrong with such a unit.  How did
you get the input damage information?

Reg





How hard is it to get replacement relays and what do they cost?

Is there a blog post about reviving these things?

And what do you ask an ebay seller to do to find out the status of an item?

Thanks,
Reg

Reg