Topics

1S1 sampling unit; (also 7B53AN & 7A18 plugins)


 

Hi all,
just acquired the above (but missed out on the actual TEK scope), all at a local recycling centre.
Would like to buy a TEK scope, working or not, in which I can use the 1S1.
Is anyone prepared to dispose of a suitable TEK scope? Plus carriage to Oz at cost.
Alternatively there is a Heathkit IO-14 (8MHz, valves/tubes, triggers to 2.5 MHz) on its way to me.
Maybe I could use the 1S1 in this, with suitable connections? I have the IO-14 schematic, but Heathkit Manuals have now been commercialised.
Any advice appreciated.
Thanks & Regards
David C.


Colin Herbert
 

Hi,
I have a copy of the IO-14 scope schematic as 4 gif files. I could email it to you if you are interested, but I don't think it would be easy (or useful) to try to connect it to a 1S1. You really need a 500-series Tek scope to use it. Others may have different ideas.
Colin.

-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of @dc888
Sent: 31 August 2020 06:04
To: TekScopes@groups.io
Subject: [TekScopes] 1S1 sampling unit; (also 7B53AN & 7A18 plugins)

Hi all,
just acquired the above (but missed out on the actual TEK scope), all at a local recycling centre.
Would like to buy a TEK scope, working or not, in which I can use the 1S1.
Is anyone prepared to dispose of a suitable TEK scope? Plus carriage to Oz at cost.
Alternatively there is a Heathkit IO-14 (8MHz, valves/tubes, triggers to 2.5 MHz) on its way to me.
Maybe I could use the 1S1 in this, with suitable connections? I have the IO-14 schematic, but Heathkit Manuals have now been commercialised.
Any advice appreciated.
Thanks & Regards
David C.


Dave Wise
 

It might be possible to power a 1S1 from an IO-14 scope but IMO it's deep into "not worth the effort" territory. Do it right and get a Tek mainframe.

The 1S1 is a fine sampling system but be aware that it contains a number of different types of tunnel diode which are not known for reliability. Plus it's easy to burn out the sampling diodes. Expect some serious troubleshooting before it's working. You'll need to build or buy a fast-rise pulser to do some of the common adjustments.

HTH,
Dave Wise
________________________________________
From: TekScopes@groups.io <TekScopes@groups.io> on behalf of Colin Herbert via groups.io <colingherbert=blueyonder.co.uk@groups.io>
Sent: Monday, August 31, 2020 10:51 AM
To: TekScopes@groups.io
Subject: Re: [TekScopes] 1S1 sampling unit; (also 7B53AN & 7A18 plugins)

Hi,
I have a copy of the IO-14 scope schematic as 4 gif files. I could email it to you if you are interested, but I don't think it would be easy (or useful) to try to connect it to a 1S1. You really need a 500-series Tek scope to use it. Others may have different ideas.
Colin.

-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of @dc888
Sent: 31 August 2020 06:04
To: TekScopes@groups.io
Subject: [TekScopes] 1S1 sampling unit; (also 7B53AN & 7A18 plugins)

Hi all,
just acquired the above (but missed out on the actual TEK scope), all at a local recycling centre.
Would like to buy a TEK scope, working or not, in which I can use the 1S1.
Is anyone prepared to dispose of a suitable TEK scope? Plus carriage to Oz at cost.
Alternatively there is a Heathkit IO-14 (8MHz, valves/tubes, triggers to 2.5 MHz) on its way to me.
Maybe I could use the 1S1 in this, with suitable connections? I have the IO-14 schematic, but Heathkit Manuals have now been commercialised.
Any advice appreciated.
Thanks & Regards
David C.


 

Thanks all for advice. Yes would love to get a 500-series TEK! A 535 (?) in particular, just before the multi-tubed Y amp version.
Forgot to mention I have TEK TAS465; HP1640A and Hantek 200MHz digital available as test gear.
Didn't see a 'reply' icon previously, no idea why not.
Valves (tubes) keep you warm in the winter.
Regards


 

On Tue, Sep 1, 2020 at 01:26 AM, David Collier wrote:


Forgot to mention I have TEK TAS465; HP1640A and Hantek 200MHz digital
available as test gear.
Isn't that an HP 1740A 'scope?

Didn't see a 'reply' icon previously, no idea why not.
You won't see the Reply icon unless logged in.

Raymond


snapdiode
 

The 1S1 is a fine sampler when it works. It is however what I would call "high strung". It has a way of failing in interesting and completely different ways all the time.

It is also not easy to troubleshoot because of the feedback loops and complex sequence of events.

You could keep an eye out for this

http://w140.com/tekwiki/wiki/132

Then you could also power up the four times faster and also more reliable 1S2 should you find one.

Maybe you already know the 1S1 has a 50 ohm input, keep an eye out for these fun accessories:

800MHz+ active probe
http://w140.com/tekwiki/wiki/P6032
https://www.ebay.ca/itm/TEKTRONIX-P6032-CATHODE-FOLLOWER-PROBE-HIGH-FREQUENCY-w-010-351-010-352-TIPS/233581462952?hash=item36628a45a8:g:YioAAOSwoWtetA8w

TDR pulser add-on
http://w140.com/tekwiki/wiki/281
https://www.ebay.ca/itm/Tektronix-Model-A-Type-281-TDR-Pulser/113909473593?hash=item1a8588a139:g:L6YAAOSwCHhdk3jh

Hi-Z probe adapter
http://w140.com/tekwiki/wiki/282
https://www.ebay.ca/itm/Tektronix-282-015-0074-00-Probe-Power-Adapter/291628446566?hash=item43e668f366:g:ftMAAOSwwE5WXKFP

Somebody, I don't know who (but he smells good), bought all of these things the picosecond they hit eBay so they are more expensive now.

These things are all over half a century old now so they are brittle and stinky and probably don't work.

But they are fun!

You can also start here and build your own adapter

https://www.ebay.com/itm/Amphenol-16-Contact-Female-Panel-Rack-Connector-PN-26-190-16/264245712294?epid=1708024957&hash=item3d864595a6:g:uPMAAMXQPatTJ2Nq


Morris Odell
 

I wouldn't even think of interfacing the 1S1 with anything other than a 530,540.550 series Tek scope. It's a complex interface, involving not just the connector but several different power supplies ranging from 6.3 volts up to 500 volts. The plugin also has to sink 150 mA at 75 volts from the mainframe. The differential output of the plugin has a 67 volt common mode component that matches the input requirement of the 500 series Tek vertical amplifiers. Some of the 540/550 series also had a sync interface. The only thing you can do is keep your eyes peeled for a suitable mainframe. The most desirable one IMHO is the 547 although it is prone to the HV transformer thermal runaway problem. The 535A which does not have that problem would be the next best.

Good Luck!

Morris


Tom Phillips
 

I was given an old 547 that was set for scrapping. It that had some high
voltage issue. The tubes were partially pulled but it seems intact
otherwise.

I'm located in Austin Tx if anyone wants to come pick it up.


 

My mistake: HP1740A.
I get the impression vintage TEK scopes are ten times the price they were ten years ago, and now rare. My HP1740A was from a recycling centre for next to nothing, just needed switch cleaner.
And thanks for the recent information: very useful.
Regards
David Collier


snapdiode
 

Lots of vintage stuff pricing is quite high these days. I also collect 8 bit computer junk and for example a digital doorstop like a Commodore 16 is priced in the 400-500$ US range these days.

On the Tektronix side I've noticed far fewer letter series plugins these days. Sampling and spectrum analyzers are rarely seen now IME.

I guess all the ones worth snapping up have been snapped up, certainly by one person (who could it be) who has a closet full of them and never uses them...


Thomas Garson
 

David,

Hopefully there is an active HP group where you can get more informed assistance on your 1740A.

I will say this: Many years ago,  I purchased a used HP all vacuum tube oscilloscope, which was initially a fine instrument. However, after a week or two, it stopped working. I opened it up and discovered that the deflection amplifier output tubes, which ran quite hot, were in sockets which were attached directly, and only, to a large printed circuit board. Those tubes were literally falling through holes in the PCB which were the result of the heat from the tubes dessicating all of the resin from the board over how many years old (Probably 10 to 12) it was.

Fortunately for me, I had purchased the it from a reputable dealer who, upon return of the HP o'scope, allowed me to apply 100% of its purchase price towards a used Tektronix 561A, along with a variety of plugins. I still have the 561A. It now lives in my closet, along with the plugins, having been supplanted by 46x, 5000 and 7000 series instruments. It still works and I had to dig it out last year to use as my 5000 required repair. The 561A did yeoman work once again, helping me to repair its somewhat newer brethren.

I guess the moral of this story is that HP was capable of, and did, build some excellently performing oscilloscopes, but their idea of quality construction wasn't even in the same league as Tektronix. This is why you see very few classic HP scopes. Worldwide, aerospace and military buyers prized the reliability and longevity of Tek o'scopes so, over the years, they purchased them by the hundreds of thousands. Also, because Tek o'scopes were so long lived, many survived long enough to be retired due to obsolescence, not failure, and surplussed out.

Regarding the 1740A: Just as the much older model of my experience, it is not exceptionally solidly built. Beware the Schadow push button switches. They are commercial grade parts and notorious for having corrosion build up on the contacts. They can be serviced but its not a congenial process, requiring the use of some somewhat nasty solvent based chemicals and a tiny bit of VERY fine abrasive powder which must be completely removed once its done its work.

Thomas Garson

Aural Technology, Ashland, OR

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

On 9/1/20 3:55 PM, David Collier wrote:

My mistake: HP1740A.
I get the impression vintage TEK scopes are ten times the price they were ten years ago, and now rare. My HP1740A was from a recycling centre for next to nothing, just needed switch cleaner.
And thanks for the recent information: very useful.
Regards
David Collier




Garth Daddy
 

Where are you located?


 

Hi Garth,
I'm in Canberra (Oz).
Some US sellers won't ship to Oz, a few charge ridiculous shipping of US$400 to 500, which is where they hope to profit!
A Heathkit IO-14 from USA is costing me US$50 carriage via the Global Shipping Program, which seems very inexpensive.
David C.


 

Thanks Thomas,
Happy to swap my HP1740A for a Tek!


Harvey White
 

I once had a Heathkit OM3, which had a horrible hum problem (eventually).  I solved it by running the filaments off DC.  If you ever have that problem, I can suggest it.  The IO-14 was billed as a lab scope, I think.

Harvey

On 9/2/2020 9:19 PM, David Collier wrote:
Hi Garth,
I'm in Canberra (Oz).
Some US sellers won't ship to Oz, a few charge ridiculous shipping of US$400 to 500, which is where they hope to profit!
A Heathkit IO-14 from USA is costing me US$50 carriage via the Global Shipping Program, which seems very inexpensive.
David C.



Jim Ford
 

I believe it, Harvey.  A former coworker had experimented with tubes, and he said that while you can run the filaments from A.C., try D.C. for audio; you'll like it.Jim Ford Sent from my Verizon, Samsung Galaxy smartphone

-------- Original message --------From: Harvey White <madyn@...> Date: 9/2/20 7:01 PM (GMT-08:00) To: TekScopes@groups.io Subject: Re: [TekScopes] 1S1 sampling unit; (also 7B53AN & 7A18 plugins) I once had a Heathkit OM3, which had a horrible hum problem (eventually).  I solved it by running the filaments off DC.  If you ever have that problem, I can suggest it.  The IO-14 was billed as a lab scope, I think.HarveyOn 9/2/2020 9:19 PM, David Collier wrote:> Hi Garth,> I'm in Canberra (Oz).> Some US sellers won't ship to Oz, a few charge ridiculous shipping of US$400 to 500, which is where they hope to profit!> A Heathkit IO-14 from USA is costing me US$50 carriage via the Global Shipping Program, which seems very inexpensive.> David C.>> >>


snapdiode
 

Oh and you might want an extender cable too, for when you need to repair it (and you will).

I recommend you read the circuit description of the manual and study the schematics.

Use this PDF

http://bama.edebris.com/download/tek/1s1/Tek1S1_Manual_print.pdf

Text-searchable and nice clear schematics and graphs.


Ravi Moghe
 

There is a group HP-Agilent-Keysight-equipment@groups.io, dedicated to HP equipments.

Warm Regards,


Garth Daddy
 

Hi David C
I do not know where my messages go to on this site, I have sent a couple of them re your 1S1.
I am in Gosford and have a 545B scope.Email me if you are interested.


 

Hi Garth,
Yes am interested! Dunno how to get your email address presently, mine is @dc888
Regards,
David Collier