开云体育

A giant rubber band also works to hold the plugin in to the connector. Hobby stores sometimes sell them.

There may be something wrong with your TM501 connector if the extender card falls out. I can't recall ever having a problem with this style of connector in over 40 years of using them. The original design is by Cinch. I think Tek used Edac brand connectors but the design is the same. All of the green Cinch connectors I ever used hold on to a PC Board of the right thickness very tenaciously. The nominal board thickness is 0.061 inch. Check that your extender card is that thick. If it still falls out take a careful look at the green connector.

I stripped my TM501 down to the bare bones. Just removing the cover gave me access to some of the plugin but the side frames kept getting in the way to I cut the entire side frames off right back at the connector PC Board with a hacksaw. If I were to do this again I would have allowed about an extra inch forward of the connector because the two pass transistors are mounted down at the bottom by the connector and this way you won't have to move them.

I use this completely open frame supply all the time when testing or building TM500 plugins. There are problems with my "hack job" which you should be aware of:
1) When the TM501 power supply section is upright the front of the plugin needs a small support of 1/4". PostIt notes work perfect because you can peel off a 1/4" stack from the rest of the pile for this purpose.
2) When the TM501 is on its side the front of the plugin has to be supported with a 1" spacer if the supply is on its left side or 1/4" spacer if the power supply is on its right side.
3) You may want to move the power switch since the pull switch is in an awkward position after you make these changes. I used a small C&K DPST switch mounted on a bracket on one of the screws holding the transformer in place. It was handy and it was up top. I also put a pilot on it so I know when power is applied to the TM500 and its plugin.
4) If I was really smart (apparently I'm not since I only realized this years after cutting up my TM501) I would also cut down the cover so that it completely covered the power supply section from wandering hands. I haven't yet been shocked from my open frame TM501 supply but it's only a matter of time before I am reminded that I am not nearly as smart as I think I am.

Was I a bad person for desecrating a TM501?

Dennis Tillman W7PF

I'll cite one example of a mod not having a 2-letter identifier. On at
least some of the 7L12, 13, and 14 spectrum analyzers, before Option 39 was
available the same effect could be had as "Mod 139U" or something similar.
I can send a picture of the label if you don't believe me.

Dave Casey

Hi H?kan,
All of the instruments that I know of which have been modified have a Tek label that says something like "MOD WN". The MOD is always identified by two letters on every plugin that has a mod. I have never seen MODs listed by Tek part numbers.

In fact until now I didn't know there were part numbers for the MODs at all. Brian Henry put a copy of the Tek Modified Products list (June 1978) in the archives some years ago. It is at

/g/TekScopes/files/%28Modified%20Products%29.pdf


You can see from Brian's Modified Products list that there was almost no consistency in how MODs were numbered. I understood from talking to several people that the MODs were not well "controlled" by some centralized authority. As a result a lot of documentation relating to the MOS was lost. Your list with the standard part numbers suggests otherwise. Maybe there was a system after all and someone was responsible for issuing these part numbers (Deane Kidd?). Is there a way to cross reference a MOD identifier from Brian's document such as "MOD WN" to a 040-xxxx-xx number from your list? Your list gives very little information about what the MOD does compared to Brian's document.

Good luck getting your Microfiche copier repaired. Bummer that it broke!

Dennis Tillman W7PF

Hi Velik,

You did a great job! These look as good as the original skirt from Tek.
I am very impressed with how all three dial's turned out.

There are many times when members need to make replacement skirt's with scales on them for their equipment.

Would it be possible for you to write up a step by step procedure for how you did these lovely scales for your curve tracer. As you write it keep in mind that other people may have a different number of choices on the skirt of their dial, different size skirts, and/or different settings on the skirts. I can help with the final edits if you need to finish the step by step directions on how you did it.

Dennis Tillman W7PF

Sadly, nothing under ?100 on fleaBay :-(

Anything in the DIY arena ??

Dave

Try ebay.
Bob

Can anyone suggest a source of the above ??

DC to 20MHz would be more than adequate.

I don't even need a high voltage device - 30V would be OK, 100V would be
better.

I'd even consider a DIY or kit implementation.

Any suggestions?

TIA
Dave

I'm looking for that disc for a AWG 2040.

Michael Lynch

From My I-Phone

mlynch002@...

479-477-1115

A while back I found a guy named Bob Haas, who was selling molded 400 series feet on eBay, try and make up some 314 feet (same as the 335.) I sent him a couple of feet and he made a couple of sets for me but he said they were too hard to make and weren't of the quality he could sell. I'd be interested in how this goes and might be interested in a set myself.

Thanks,
John Clark

________________________________
From: [email protected] <[email protected]> on behalf of Phillip Potter <p.potter@...>
Sent: Thursday, March 1, 2018 4:56 PM
To: [email protected]
Subject: Re: [TekScopes] Back feet for 335 scope

Hi Jeff,

Are you N0dy? If so, I just emailed you about your 400 series feet.

If your process is nondestructive, maybe we can get Lee H. (on list) to
volunteer his one surviving complete foot for measurement...

I have a picture of the foot, upon which I have drawn (crudely) the
measurements, that I will put that in my folder on the server:

/g/TekScopes/photo/33014/2?p=Name,,,20,1,0,0

If it comes to pass that Lee would allow you to measure and print out
feet... he should probably be the one to receive your kind offer of
printed feet, not me, but I would buy a set from you.

Phil



On 3/1/2018 1:36 PM, Jeff Davis wrote:

Hi all,


I'd be willing to undertake the 3D modelling and printing with a durable nylon material if I could get my hands on a reasonable existing foot to take measurements from. I've already developed models of 465/475 and 453/454 feet that are near identical replacements for the existing feet.


In exchange for the use of your foot, I'd be happy to provide a set of nylon printed feet gratis to upgrade your existing feet. I would then make these feet available to the community through the same channels I use for my 465/475 and 453/454 feet.


PM me if interested.


Thanks,
Jeff


________________________________
From: [email protected] <[email protected]> on behalf of Phillip Potter <p.potter@...>
Sent: Thursday, March 1, 2018 12:34 PM
To: [email protected]
Subject: [TekScopes] Back feet for 335 scope

Hello all,

The feet on the rear of my 335 are crumbling apart, literally!

I talked to Walter at Sphere and he has nothing even close, and searches
on the net reveal nothing... so, I am coming to the group to see if
there might happen to be someone who has any extra rear feet (Tek PN
348-0425-00) or even just one, that could be spared (or loaned?) to me
as an example of a complete foot? I don't know if they could be 3-D
printed or cast, but I don't have even one that is complete... mine are
all crumbled.

Here is a picture of what it looks like (borrowed from the internet):



Thanks for any suggestion or help you can provide.

Phil

Jeff, the foot is packaged up in a USPS Small Flat Rate box. Hopefully I will remember to mail it tomorrow and you will likely have it Monday. You should have received an email from the USPS with the tracking number; if not yet then you should when they have the package. Just remember to save my shipping label for the return address.

Now to find a source for 2445 and 2430A feet....

Hi Rick,
This would be a much cheaper, do it yourself, alternative that would take you a few minutes to make.
Buy this resistor and put it on a dual banana plug:
Through Hole, 1W, 600ohms, 1%, $0.25 each, Mouser #71-CMF60600R00FKR6



Dennis Tillman W7PF

Siggi,

At the bottom of H?kan's page that I linked in:

"NOTE: Since my Microfiche copier recently broke down I will not be able to provide any scans, at least not for some time.
This message will be removed if and when I either have it repaired or acquired another on.
Updated Feb 27 2018"

His webpage says that he does have additional information that he hasn't scanned and uploaded, but it looks like that process is on hold until further notice since it's all on microfishe.

In the meantime, I'll keep searching for more databases of documentation in hopes of finding something that lists the options for various pieces of equipment. I know that's precisely what we're looking to accomplish on TekWiki, but my guess is that someone's already done exactly that or at least started to. Otherwise, it's on to catalog surfing and seeking out "with options" service manuals to reference, which is going to be extremely time consuming.

Brian

Hey Brian,

H?kan is a member here - at least he was before the relocation to groups.io.
He's frequently helped out other Tek enthusiasts with this and that,
sometimes by consulting his microfiche stash. Maybe he has summaries of
instrument options in his stash.
We might ask, I guess.

Siggi

On Thu, 1 Mar 2018 at 17:44 Brian Bloom via Groups.Io <analogaddict013=
[email protected]> wrote:

Found a large list of Tek MODS and their relative documentation:

On Thu, 1 Mar 2018 at 17:21 Francesco <madowax@...> wrote:

Thanks Siggi, I have just tested every resistor you listed out of circuit,
they all test good and they are still in spec even the 1% tolerance ones, I
replaced R1878 when I received the scope, the previous owner butchered it,
probably the grid bias problem was there when he sold the scope, I also
replaced c1991, just to be sure it wasn't leaking. The only thing I found a
bit strange is the waveform from pin 7 of high voltage trasformer, the
sinewave seems a bit asymmetrical, however -300v test point is exactly at
-300V. Thanks again.
Regards
Francesco.

Hey Francesco,

well, now that you know the resistor values for sure, the next step would
be to measure the voltage drop over them in-circuit. I'd suggest leaving
the scope running for 10-15 minutes before you do so, as it's easier to get
consistent measurements that way. Alternatively you could short the
slow-start capacitor to get a consistent measurement in the stone-cold
state.

If you measure and report the voltage drops over R1994, R1881 and R1992, we
can do a bit of math and see whether the currents make sensible values.
Is it reasonable for you to do this with the grid bias pot at min and max
settings?

Note that resistors can go wonky in weird ways. In my 485, I found a
resistor that measured in spec on my DMM, but had voltage-dependent
resistance in circuit. A bit of a head-scratcher that one :).

Siggi

Found a large list of Tek MODS and their relative documentation:

The simple answer to this is that unless the output is terminated with 600 ohms it will be +6dB too high. Get yourself a BNC Y attachment and a 600 ohm attenuator from BroadWave Technologies, and be calibrated forever afterward!

EJP

Lee...

Thank you for your willingness to help out a fellow Tek 335 owner in need!!? :)

Thank you, Jeff, for offering your service, as well...

If I can help with postage or ?, please email me off list and I will be especially happy to assist in any way I can.

Phil

Hi Lee,


Thanks! I'll get to work on it as soon as the foot arrives!


My address:


Jeff Davis

12 Galora Lane

Ladera Ranch, CA 92694


319-431-3846 (cell)


Regards,
Jeff


________________________________
From: [email protected] <[email protected]> on behalf of Lee Houde <houdatto@...>
Sent: Thursday, March 1, 2018 2:26 PM
To: [email protected]
Subject: Re: [TekScopes] Back feet for 335 scope

Phillip Potter, Jeff Davis N0DY -

It would appear you two are on the same page so I would be more that willing to send my one good 335 foot to Jeff for modeling and creation of new feet. Jeff if you will pm me your address off group I will get the foot out in the mail ASAP.

Lee NV8YH

Phillip Potter, Jeff Davis N0DY -

It would appear you two are on the same page so I would be more that willing to send my one good 335 foot to Jeff for modeling and creation of new feet. Jeff if you will pm me your address off group I will get the foot out in the mail ASAP.

Lee NV8YH

Thanks Siggi, I have just tested every resistor you listed out of circuit, they all test good and they are still in spec even the 1% tolerance ones, I replaced R1878 when I received the scope, the previous owner butchered it, probably the grid bias problem was there when he sold the scope, I also replaced c1991, just to be sure it wasn't leaking. The only thing I found a bit strange is the waveform from pin 7 of high voltage trasformer, the sinewave seems a bit asymmetrical, however -300v test point is exactly at -300V. Thanks again.
Regards
Francesco.