Date   

Re: Site moderator

Richard Knoppow
 

There is an address for the group owner at the bottom of each message I have no idea who this is.

On 8/22/2021 2:29 PM, Vince Vielhaber wrote:
Dennis or the group owner?

Vince.

On 08/22/2021 05:28 PM, ken chalfant wrote:
Greetings,

Does the site moderator (owner) have a dedicated email address for contacting “him” outside of the normal group traffic?

Thanks for your assistance.

Regards,

Ken




--
Richard Knoppow
dickburk@ix.netcom.com
WB6KBL


Re: Site moderator

ken chalfant
 

Hi Vince,

Thanks for your reply.

Before I post something I want to ask permission.

Who should I ask?

Ken

On 22Aug, 2021, at 3:29 PM, Vince Vielhaber <vev@michvhf.com> wrote:

Dennis or the group owner?

Vince.

On 08/22/2021 05:28 PM, ken chalfant wrote:
Greetings,

Does the site moderator (owner) have a dedicated email address for contacting “him” outside of the normal group traffic?

Thanks for your assistance.

Regards,

Ken



--
Michigan VHF Corporation -- nobucks dot net
K8ZW - https://na01.safelinks.protection.outlook.com/?url=http%3A%2F%2Fwww.hamradio.fun%2F&;data=04%7C01%7C%7Cf7c96e64816845da86b508d965b40555%7C84df9e7fe9f640afb435aaaaaaaaaaaa%7C1%7C0%7C637652646126404311%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&amp;sdata=OXucaMekE3nIygECK4T6OLnCLd0OY0Cc2f0bZ18%2FeDg%3D&amp;reserved=0





Re: Site moderator

John Griessen
 

Group Owner:TekScopes+owner@groups.io


Re: Site moderator

Vince Vielhaber
 

Dennis or the group owner?

Vince.

On 08/22/2021 05:28 PM, ken chalfant wrote:
Greetings,

Does the site moderator (owner) have a dedicated email address for contacting “him” outside of the normal group traffic?

Thanks for your assistance.

Regards,

Ken



--
Michigan VHF Corporation -- nobucks dot net
K8ZW - http://www.hamradio.fun


Site moderator

ken chalfant
 

Greetings,

Does the site moderator (owner) have a dedicated email address for contacting “him” outside of the normal group traffic?

Thanks for your assistance.

Regards,

Ken


Probe Comp Signal Ports on 76xx Scopes

 

I've wondered this for a long time, the probe compensation / calibration signal ports on the 76xx scopes, as well as on the 2200-series portable scopes (and others?) are small round sockets whose opening are maybe 1mm in diameter. You can fit a probe tip in the opening but it does not fit snugly, so you have to hold it there. I always assumed that was the correct use, but now that I have a 7603 and 7633 I'm wondering if I've been wrong.

Are there some kind of plugs or probe adapters that fit these sockets?

-- Jeff Dutky


Re: Tektronix 570 Curve Tracer

John Griessen
 

On 8/22/21 12:53 PM, Martin wrote:
my setup of a 576 with a Metrix U61 (tube analyzer (as heavy as the 576). Its perhaps the most versatile analyzer around. I just had to plug the base voltage into G1 and the collector voltage in the anode circuit. Had to take shielded cables, otherwise I got oscillations. The operation of the Metrix remains identical.
Seems much better than using the analyzer meters alone. Does your analyzer tell all the parameters of the DUT?


Tek 7103 found at auction in NM

John Griessen
 

On 8/22/21 1:09 PM, Clark Foley wrote:
I am not surprised that you found that unit in New Mexico. It was likely the property of Sandia National Labs or Los Alamos National Labs. The nuclear testing facilities in Nevada hosted many contractors such as EG&G and national lab personnel for conducting destructive transient measurements.
Yes, this had EG&G cal tags. Not sure if Sandia or Los Alamos origin though. The stuff comes form multiple companies wanting it off their books, some comes in oversize cardboard containers bigger than washing machine size, piled with microscopes and boxes and ??. Then Bentley Auction folks go through and photograph it for online only auctioning.

There were about 10 tons of env. chambers that disappeared between 7PM auction close and 2PM the next day when I picked up the 7103 scope -- some serious heavy buyers here in ABQ. Some of the old chambers with obsolete refrigerant may have gone to the scrap metal heap. Some nice controlled ovens got end user prices -- I missed out on a 575 deg F one with 40 step sequence ramp temp. controller.

The sticker on an Olympus BH microscope I won said US DOE contract xxxyyyxxx 1972 on a paper sticker that was done with a Selectric...
;-)


Re: What is a mod BG to 7103 or 7104?

Clark Foley
 

I am not surprised that you found that unit in New Mexico. It was likely the property of Sandia National Labs or Los Alamos National Labs. The nuclear testing facilities in Nevada hosted many contractors such as EG&G and national lab personnel for conducting destructive transient measurements. Although Tek 7912AD was popular in its day, a high-writing rate scope with a film camera configuration was more widely used. A lot of P11 phosphor tubes were sold for that purpose until the 7104/R7103 became available. The problem with hanging a film camera on the scope bezel was the weight of the camera and the vertical lift/drop of the transient event. The scopes were often housed in a big semi-rig trailer on the site. The underground event could easily lift and then drop the trailer. Technicians were elsewhere at the time. The torque would break the bezel or the front casting of the scope. Depending upon the camera used, often a custom device, the scope bezel would be replaced by a suitably stronger one but the scope casting had to come from the Tek factory.

This Mod BG unit might have been purchased with this use in mind in preparation for a test but not put to that particular use or the purchasing department required the mod for all R7103s.


Re: Tektronix 570 Curve Tracer

 

Adding to the discussion, my setup of a 576 with a Metrix U61 (tube analyzer (as heavy as the 576). Its perhaps the most versatile analyzer around. I just had to plug the base voltage into G1 and the collector voltage in the anode circuit. Had to take shielded cables, otherwise I got oscillations. The operation of the Metrix remains identical.

See the pic here... https://groups.io/g/TekScopes/album?id=267344 - nice to watch, indeed, analyzing an EL38.

cheers
Martin


Re: Manual for TM504A

Roy Thistle
 

On Sun, Aug 22, 2021 at 07:18 AM, Jared Cabot wrote:


Does anyone happen to have a manual to suit the TM504A?
There is some info about it in the TS-4353/U Distortion Test Set Op Manual... the plugins for the test set fit into a moded TM504A. The test set manual is on TekWiki
--
Roy Thistle


Re: Tektronix 570 Curve Tracer

John Griessen
 

On 8/22/21 9:38 AM, Glydeck via groups.io wrote:
here is my solution using my 575;
http://glydeck.blogspot.com/2012/01/testing-dual-triodes-with-tek-575.html
http://glydeck.blogspot.com/2012/02/testing-miniature-pentodes-with-tek-575.html
Thanks George KD6NEW,

I like the practicality of your adapter and using inexpensive 575 CTs! Is the 400V mod something you can add easily to a normal 575?

--
John


Re: Tektronix 570 Curve Tracer

Zentronics42@...
 

In terms of current gear. The "modern" way of testing would be with 2+ SMU's depending on the number of dynamic voltages you want to sweep. You can get one up to 1Kv for the anode voltage but you would need at minimum 2 smu's + a computer and the software to script the test but you are starting to talk about $20K just to start as the smu's are in the 5-12K range in price. This is the "cheap" solution, the parameter testers are in the if you have to ask don’t buy category. They use 4X SMU's and an integrated computer they do C-I curves as well as V-I curves that that is cool but out in the 6 figure range. I do have a few SMU's on the list to acquire for the lab but there are pushed out a bit. I'll stick with my restored 57X's. If you go the 576 route at the current time a dead (weak) tube is a show stopper. But there are some who are working on getting over that hurtle. To stretch the tub as much as possible there is a 3d printable viewing window for the 576 this totally encloses the display in a dark area so the intensity can be kept as low as possible and still be viewable.

Zen

-----Original Message-----
From: TekScopes@groups.io <TekScopes@groups.io> On Behalf Of David Simpson MM6ACI
Sent: Sunday, August 22, 2021 12:22 PM
To: TekScopes@groups.io
Subject: Re: [TekScopes] Tektronix 570 Curve Tracer

Many thanks Guys for the informative advice. Particularly regarding considering other models in the 57* family. As emissionlabs says, the AVO VCM163 is highly thought of here in the UK. Never owned one, but have owned a couple of CT160's in the past. Currently I use an AVO VCM MK3 which I restored, for "run of the mill" valve testing. (the CT160 is just a MK3/4 squeezed into a military grade clam-shell casing). But then, all of AVO's(and other UK manufacturer's, and Hickok's etc.) range of valve/tube testers all work using full-wave &/or half-wave mains frequency derived pulses on the working electrodes - Anode(Plate), Screen(G2) & Grid.
For several years I supplied a few folk in the UK vintage-radio fraternity with "Standardised" valves(ECC81's & 82's) using a hybridised CT160, but then some folk started to ask for standardised "power valves" - BT's & Pentodes. So, decided to build a fully DC Valve Tester which could determine mu & Gain "G" as well as just Gm. In addition, the bigger beasts - KT66's & 88's, etc., requiring matching of GM curves, could be supplied with A4 graphs.
Move foreward several years past "3 score years & ten" - getting older, eyes OK but they do get tired at times, wrist gets tired, and so on. Hence the thought of acquiring an item of vintage test equipment which could display a number of valve characteristics becomes rather attractive. From the pictures I've seen of a 570's CRT display, a decent digital camera or iPhone - should take some jolly nice pictures.
Again as "emissionlabs" says, buying an old clapped-out item is fraught with problems. For a 570, one would at least want the 5 transformers & the CRT working. Cosmetic & circuitry problems can be sorted with care and patience. I've already seen the strong warning in the 570's Manual about using the correct grade of solder, and soldering iron tips & temperature, when working on the ceramic tag strips. Back in the 60's & 70's I did work on RAF HP180A's, Collins 618T's, etc., so appreciate the high standard of US equipment.
Some folk might say ' why not buy something cheap & modern from China' using an LCD screen & a software package. No thank you. I'm just an old analogue guy with a 1960's, + or - ten years, mindset!

Regards, Dave


Tek TM500/5000 mating connectors

 

Noting all the ongoing comments on extenders, I do have 6 new factory parts, p/n 131-1078-00.
These are the heavy green 56 gold contact double-sided PC mounting connectors, with slots for keying tabs.

These also work for the 5000 series scope plug ins. You will notice these are wider and thicker than normal
edge connectors, this seems to be done for increased mechanical strength. The original maker may be CCC
as that is the only vendor marking on the part other than the Tek part number.

If you need one, email me off list, looking for US$15 each for these. I will toss them up on the stuff page with
pics later today.

All the best,
walter (walter2 -at- sphere.bc.ca)
sphere research corp.


Re: Tektronix 570 Curve Tracer

David Simpson MM6ACI
 

Many thanks Guys for the informative advice. Particularly regarding considering other models in the 57* family. As emissionlabs says, the AVO VCM163 is highly thought of here in the UK. Never owned one, but have owned a couple of CT160's in the past. Currently I use an AVO VCM MK3 which I restored, for "run of the mill" valve testing. (the CT160 is just a MK3/4 squeezed into a military grade clam-shell casing). But then, all of AVO's(and other UK manufacturer's, and Hickok's etc.) range of valve/tube testers all work using full-wave &/or half-wave mains frequency derived pulses on the working electrodes - Anode(Plate), Screen(G2) & Grid.
For several years I supplied a few folk in the UK vintage-radio fraternity with "Standardised" valves(ECC81's & 82's) using a hybridised CT160, but then some folk started to ask for standardised "power valves" - BT's & Pentodes. So, decided to build a fully DC Valve Tester which could determine mu & Gain "G" as well as just Gm. In addition, the bigger beasts - KT66's & 88's, etc., requiring matching of GM curves, could be supplied with A4 graphs.
Move foreward several years past "3 score years & ten" - getting older, eyes OK but they do get tired at times, wrist gets tired, and so on. Hence the thought of acquiring an item of vintage test equipment which could display a number of valve characteristics becomes rather attractive. From the pictures I've seen of a 570's CRT display, a decent digital camera or iPhone - should take some jolly nice pictures.
Again as "emissionlabs" says, buying an old clapped-out item is fraught with problems. For a 570, one would at least want the 5 transformers & the CRT working. Cosmetic & circuitry problems can be sorted with care and patience. I've already seen the strong warning in the 570's Manual about using the correct grade of solder, and soldering iron tips & temperature, when working on the ceramic tag strips. Back in the 60's & 70's I did work on RAF HP180A's, Collins 618T's, etc., so appreciate the high standard of US equipment.
Some folk might say ' why not buy something cheap & modern from China' using an LCD screen & a software package. No thank you. I'm just an old analogue guy with a 1960's, + or - ten years, mindset!

Regards, Dave


Re: Tektronix 570 Curve Tracer

Glydeck
 

Wow! Emissionslab, great page on the 576. Your repair notes will be super helpful. Great detail.

Chuck, Love your tube tester solution. Very nice documentation.

I’ve book marked both pages. For what it’s worth here is my solution using my 575;

http://glydeck.blogspot.com/2012/01/testing-dual-triodes-with-tek-575.html

http://glydeck.blogspot.com/2012/02/testing-miniature-pentodes-with-tek-575.html

The PDF files are on groups.io

https://groups.io/g/TekScopes/files/Tek575TestFixtures.pdf

https://groups.io/g/TekScopes/files/Tek575_TriodeTester.pdf

73s George KD6NEW

On Aug 22, 2021, at 7:40 AM, ChuckA <chuck@myvintagetv.com> wrote:

I bought a couple of Dennis's VTCT boards when he first produced them. I built a couple of crude adapters to use on my 576 which worked pretty well but were cumbersome to use.

I didn't like the use of a tube tester to get the required additions to make the adapter work so I decided to make a standalone unit to attach to the 576. After a couple of months and talking to Dennis about some issues I ran into, I came up with this:

http://www.myvintagetv.com/TEK576Tube.htm

Chuck

--
See Early TV at:

www.myvintagetv.com






Re: Tektronix 570 Curve Tracer

ChuckA
 

I bought a couple of Dennis's VTCT boards when he first produced them. I built a couple of crude adapters to use on my 576 which worked pretty well but were cumbersome to use.

I didn't like the use of a tube tester to get the required additions to make the adapter work so I decided to make a standalone unit to attach to the 576. After a couple of months and talking to Dennis about some issues I ran into, I came up with this:

http://www.myvintagetv.com/TEK576Tube.htm

Chuck

--
See Early TV at:

www.myvintagetv.com


Manual for TM504A

Jared Cabot
 

Hi,

Does anyone happen to have a manual to suit the TM504A?
I just picked one of these up today, but I can't find much online.

Thanks!
Jared


Re: What is a mod BG to 7103 or 7104?

John Griessen
 

On 8/21/21 5:22 PM, zenith5106 via groups.io wrote:
//
MOD BG includes modifying the 7104 by adding braces to
the front-panel casting and strengthening the mounting of the crt bezel.
//
/Håkan
Thanks Håkan! So that camera bezel was factory mounted. Mystery solved.


Re: 2236 Focus range.

Alex
 

This is a well known and documented problem in the 22xx line. There is a string of 5 (or 6) 510K resistors that over time change value and produce the focus problem in some cases even going off the potentiometer adjustment range. Just replace all resistors with metaI film types and 1-2W rating, and also make sure that each resistor is rated to handle at least 300V or more. Don't have any specific knowledge of the 2236, but for sure had to replace these resistors in two separate 2213A which basically are the same in this sense. Do a search here and I am sure you will find many other messages referring to this particular problem.

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