Re: Shipped They Are

Michael W. Lynch


THANKS for all your efforts! Looking forward to receiving mine in the mail.


Michael Lynch
Dardanelle, AR

Re: Tm500 Extender on eBay

Michael W. Lynch

I do not have the luxury of owning so many different examples of TEK extenders and the "Original Tek produced extenders" were all monstrously expensive when I went looking. Therefore, I ended up purchasing an excellent 3rd party flexible extender that includes test points and LED power indicators in its design.

To Walter's point about pricing, I bought 2 of these aforementioned "flex kits" for about the price of this one extender, and as I said, perhaps the seller was "too cheap" on the flex extender kits.

Walter is correct, plugging the flex extender into a loaded mainframe requires that an adjacent plugin be removed to insert the extender, not a big deal for me.

However, the flex extender allows the Device under repair to be moved and turned to almost any position when you are working on it; a considerable plus, in my opinion.

The flex extender also allows people with limited bench space to position the Plugin to take advantage of said limited space.

While the mainframe connectors certainly are quite robust, the rigid connector still will impart far more force on the connector and on the PC board of the extender itself. This would need to be dealt with in some form or fashion.

The quality appears to be very good, I have no concerns about that, other than what I have previously stated. If the chamfer did happen to be missing, that could be remedied with a few strokes of a file.

If I did not already have extenders, I would jump on one of these myself. If you are going to work on these TM500 plug ins, sooner or later you will need an extender or two (in some cases).

All in all, I do not find the selling price to be out of line in today's market. The seller deserves to make a profit and he must price the item accordingly (for the reasons that Walter mentions), especially with E-Bay taking their 12.35% cut.

I certainly appreciate Walter and his well reasoned comments and experience on this topic. looking forward to hearing his opinion after he tests one of these in person.

Another .02 cents added to the pot.
Michael Lynch
Dardanelle, AR

Lot of threads on 24xxB but few on 24xx"A" ...

Ulf Kylenfall


Over the years, I have seen and read a lot of threads about 24xxB but very few regarding the "A"
version. Are there any similar "ouch" information apart from immediate replacment of
the RIFA capacitors in the AC power line filtering?


Ulf Kylenfall

Re: Shipped They Are


Thank you so much Larry for your work making this happen! Looking forward to stuffing the boards.

Re: Stan Griffiths estate sale


David &/or others:

Could someone make contact with the daughters or the administrative person and get a Phone# or email address,
to allow us to contact them ?

-- Clearly there is interest in this collection.

For whatever reason, I am unable to click and 'connect' with any of the facebook or other hyperlinks.
They just don't work with my browser.

thank you,

Re: Hey this isn't even on Tekwiki!

snapdiode <snapdiode@...>

I just ctrl-f the main page and found nothing relevant for 183.

Re: Hey this isn't even on Tekwiki!


It's listed under "183"

Re: Tm500 Extender on eBay


A few comments on the ebay extender (which I have nothing to do with personally).

1. the edge fingers *ARE* chamfered, it is clearly shown in the pic, and it even says so in the text. I found all the bashing of that card on this topic totally uncalled for, and especially ironic considering that all the TM500 tester kits just delivered *ARE NOT *chamfered. I see that was "solved" by a few hits with a file, but apparently such a fix was not deemed possible for this extender card.

2. that rear backplane connector is strong as an ox. I have trouble picturing the case where it will be destroyed by this card. It is MUCH stronger than the 7K backplane connectors.

3. It would be EASY to add a correct height side plate or plates via stand-offs to fit into the cage height (maybe put some nylon edge guard on it to make it slide easier), to act as a strain absorber and positioner. it may  also be possible to just add a bit of nylon edge grommet to the board itself to do this, making any flexing on the connector a non-issue.

4. I own literally every extender that has been made for TM500/5K/7K plug-ins in cable and rigid styles, original and 3rd party. They all have their features and detractions. The actual Tek flexible cable for TM500 repair is Ok, but would have REALLY benefited from some status LEDs for power supply status (to quickly check all the fuse conditions), and it is incredibly hard to insert that short edge connector into the frame unless the adjacent plug ins are removed first, an issue this long card avoids.

5. The current long extender being offered seems pretty good to me, I would have added power supply LEDs, and polyswitches to the DC supply lines (can't be done on the AC lines except by fuses) to prevent damaged plug-ins from cratering the frame, but that could in fact be added easily.  A little bit of mechanical support to engage the frame for stress relief, and voila, total happiness could be yours.

6. The price is not bad, that is a LOT of PCB area, with  GOLD chamfered edge fingers, solder mask and slots, all extra cost adders for fab. I'm going to buy one and test it for myself to see how it compares to the cable types.
I should point out that very similar VME single connector extenders are hundreds of dollars (I have those too),
so I don't really begrudge the maker a some extra revenue for his time and design.

just my $0.02 worth on this topic.

all the best,
walter (walter2 -at-
sphere research corp.

PS: Tons of power supplies and audio goodies being added daily to the *stuff season page*, it's almost  ready to go,
and you can grab stuff now. Vu-data items added to the Tek section.

Walter Shawlee 2
Sphere Research Corp. 3394 Sunnyside Rd.
West Kelowna, BC, V1Z 2V4 CANADA
Phone: +1 (250-769-1834 -:-
+We're all in one boat, no matter how it looks to you. (WS2)
+All you need is love. (John Lennon)
+But, that doesn't mean other things don't come in handy. (WS2)
+Nature is trying very hard to make us succeed, but nature does not depend on us.
We are not the only experiment. (R. Buckminster Fuller)

Re: Looking for 067-0625-00 Peak-to-Peak Detector Photos

Jared Cabot

Do you remember how the signal passed through from the cavity to the PCB?
It appears there is a feed-through capacitor for each diode maybe? Do you remember if the 50ohm resistor had this too or if it was just passing through a simple hole?


On Fri, Feb 12, 2021 at 12:00 PM, Kerry Burns wrote:

As far as I can remember it was fairly simple – as per the third photo in
the album (the one with the red tape). The 50ohm resistor is soldered directly
to the centre pin of the GR-874 and the two diodes to the ground.  Despite
the warnings in the manual about disturbing this RF cavity, my peak detector
seemed to test ok after the repair.  I had no choice anyway as the 50 ohm
resistor was broken in half.  I was just careful to select the new resistor
to measure as close as possible to the correct value.


Re: Hey this isn't even on Tekwiki!


Thanks 🙏

Hey this isn't even on Tekwiki!

snapdiode <snapdiode@...>

Also an interesting "salvage" stamp from Tek itself all over the thing.

Re: Spectrum analyzer Tektronix 7L13 on mainframe Tektronix 7603


Hi everyone,
I reassembled the TR503, connected it to 7L13 (SA) and I have the signal on the screen of the SA.
With the MAX span / div the trace drops a bit from 1 GHz to 1.8 GHz but it is in the 2 dB, so I think acceptable, with 50 MHz of span / div the trace on the screen is a straight line. I can get a decent adjustment of the TRACKING ADJUST on the TR503 with the resolution at 300 Hz on the 7L13, but at 30 Hz the adjustment is not enough, maybe some calibration needs to be revised.

I also have two doubts: when I redid the calibration procedure of the BPF four cavity filter, I got the curve centered, but very narrow, from the manual it seemed about 20 MHz wide while to me it is around 2 MHz and I was unable to widen it acting on the BPF filter settings. The other question is about the 7L13: is the PHASE LOCK active with the selector positioned up or down?
When I place it high below a white dot appears.

Thanks for your help

Re: Stan Griffiths estate sale

Lawrance A. Schneider

How many of us are there in this group? Is there any possibility of 'grouping' and buying all of this? Storing it where? The time line is absurd. Living in Maine, I'll never see any of it. I see the laments of those that have seen this. Does anyone know where the 'slip-sticks' are being presented?


Re: Waking a slumbering 475

Weathers, W

On Thu, Feb 11, 2021 at 01:24 PM, Roy Thistle wrote:

On Wed, Feb 10, 2021 at 07:36 AM, Torch wrote:

Before giving it to me, the owner plugged it in and turned it on
That's usually what inexperienced sellers do with these old Tek scopes (unless
you can catch them before they do it.)
I'd say, if you got one (buyer or seller)... don't plug it in, until you check
it out.
This is interesting. So what is the right way to have it checked out if it should not be plugged in and powered up?

If the tantalum caps fail short, should they be measured prior to running?

Re: 465B strange ripple


It means it is picked up inside the scope.

I second the external effect, I had something similar with a luminescent tube that I replaced by an LED tube when working on my 475A.

With both inputs at GND, could you try to temporarily ground the point where the attenuator is connected to the input amplifier? (Near that flying resistor/capacitor combo?)

That way you can eliminate if it is the amplifier or the attenuator part that's picking up the ripple.


Re: Tm500 Extender on eBay


So if I bought one of these extenders and filed chamfers on either side of each key slot, would that make these safe to insert?

This sort of extender seems guaranteed to experience torque since it has nothing to engage the slot guides, and it sounds like a little torque can also damage the mainframe slots.

I'm not too concerned about the price (have you SEEN what a 7000-series flexible extender costs?!?), and this is only $10 more than what appears to be a genuine Tektronix TM500 extender (which, oddly, doesn't have any key slots cut in the card edge connector). The genuine Tek extender also does not engage the guides, so I assume that it will also tend to be torqued on insertion. Is there something else that makes this modern extender unsuitable?

-- Jeff Dutky

Re: TM50X DC ripple?

Ed Breya

Oops - forgot a sentence at the end: When it's sufficiently loaded, you may see volts of ripple, making it easy to assess the condition of the caps, or compare different ones.


Re: TM50X DC ripple?

Ed Breya

The no-load, or light-load mV-ish ripple measurements on the raw DC supplies don't mean much unless you consider the possible conditions and worst-case scenario, although they may be an acceptable indicator of the caps being OK or not. If you're designing something to work reliably over the full range of possible conditions, it's good to use the TM5000 specs. The worst-case bottom of ripple is at highest ambient temperature, lowest line voltage, lowest line frequency, and maximum load. The maximum load is difficult to define. We used 8 V and 26 V to be slightly above worst-case TM500 BOR, as the minimum DC outputs in the TM5000 mainframes. That represents the minimum overhead you'll have for linear regulators. In reality, you likely won't reach worst-case, but it's good to be aware of it.

So, don't bother with no-load ripple - put a bunch of plug-ins in there to get a better idea of what to expect.


Re: Looking for 067-0625-00 Peak-to-Peak Detector Photos

Kerry Burns

As far as I can remember it was fairly simple – as per the third photo in the album (the one with the red tape). The 50ohm resistor is soldered directly to the centre pin of the GR-874 and the two diodes to the ground.  Despite the warnings in the manual about disturbing this RF cavity, my peak detector seemed to test ok after the repair.  I had no choice anyway as the 50 ohm resistor was broken in half.  I was just careful to select the new resistor to measure as close as possible to the correct value.


From: <> on behalf of "Jared Cabot via" <jaredcabot@...>
Reply to: <>
Date: Friday, 12 February 2021 at 1:35 pm
To: <>
Subject: Re: [TekScopes] Looking for 067-0625-00 Peak-to-Peak Detector Photos

Great! Thanks for that, pretty much exactly what I was looking for.

Do you remember what the other side of the cavity looked like with the connection to the input jack?



Re: Tm500 Extender on eBay

Jared Cabot

Or counting on percieved scarcity to increase value... :D

Which reminds me, I need to finish my design of the extender I was working on....

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