Re: 425 Mil vertical module needed....seeking

Fabio Trevisan

Hello Jack,

What you refer to as 425 Mil is, for correctness sake, a 465M or an AN/USM 425.
It confused me at first, as I didn't recall there was ever a 425 oscilloscope.
For what I know, the 465M is electronically similar to the civilian 465 (but even at electronic diagram level, there ARE differences), but, for the sake of assemblies or sub-assemblies, they're essentially two completely different oscilloscopes (i.e the boards are physically different).

As mentioned on this ( page of the TekWiki website, the 465M is more similar to the civilian 455, than it is to the 465.
I can't really tell by how much they are similar, but you may be able to compare them by yourself by looking at the service manuals of both, which are available on the TekWiki website.
The page for the civilian 455 is here:

I don't know much of either (455 or 465M) but, coincidentally, there's a seller on a Brazilian auction site, selling the modules of a Tektronix 455:

I can't tell how similar those modules are (to your 465M) and if they can serve as parts donors, but if you find out that they may help, you can try to contact the seller, or I can help you with the purchase and shipping of the module (or the parts) to your location, for their advertised cost and shipping expenses to your place.

Note: I have no affiliation with the seller (and don't even know if I know them, since the auction site only reveals the seller after you purchase the item).

I normally wouldn't even make this offer, as shipping from Brazil is usually prohibitive and the parts are not even mine... But since you're so far away down under, I think that shipping from anywhere will be just as difficult.

Please let me know if you want my help, or maybe some other folks in the group will chime.



On Tue, Oct 30, 2018 at 06:52 PM, Jack wrote:

Hi. I'm a new member finding my way. I bought a lot of Tektronix scopes for
the services when with Defence during Vietnam era and visited Tektonix at
North Ryde (NSW)
to see about repairs to (I think it's a 564) I still have....still not working
I guess after having a new very high voltage insulated transformer wound for
CRT filament...two actually, the other must be around "somewhere". I
developed a healthy fear of Tektronic CRO's owing to the prices Tektronix
charged for repairs..

I have a 425 Mil with broken Vertical section It's unrepairable.
Whilst I could sooner or later find a parts CRO, sight unseen on eBay for
example, it may also be on the way out. I think the plastic used in Tektronix
may be the lowest quality amongst high quality devices , or maybe they just
specify 'shall be or a type formula and manufacture which will maintain all
utility until the end of time'

I was directed to your group (Hi...there) . To get to the essential point
Would some person have a reasonably low mileage vertical module, complete,
which I could buy? Please advise me if so....Australia would be best of course
but 'anywhere'. undo some confusion...I've been told 425 and 465 are
"intrinsically" the same CRO...obviously without the Mil labelling... . Does
that mean parts are interchangeable?

One reason I ask is that I was also told that the 425 being Military contract
and Mil Spec was built to be readily pulled down for field repairs. Is that
true?...Is that a quality the 465 does not replicate? if so it may mean that
...just as an example...the vertical amp module from a 465 may have some
mounting differences from the 425.

On the other hand it may not. Perhaps someone familiar with this type will
bring me to a state of awareness even wisdom regarding my CRO. ...oh... other
than having one channel down it seems to work ok and 'oh' again...when I
originally pulled it down a piece of curved springy metal fell out. Whence it
exactly originated I have no idea...'somewhere inside'. .It may be a method
of maintaining the case at frame potential, under pressure as one reassembles
the perhaps it 'jammed' between a plate on the chassis and the
bottom cover. It could have come from elsewhere or it might not be from the
CRO at all.....That said, Im pretty sure I saw an exploded view one time where
this curved metal piece as shown hanging in mid-air underneath the chassis.
Have I been able to find that particular exploded view again (that was 3 years
ago)...of course not!!

Any passing of knowledge wisdom common sense mindfulness and most of all
perhaps a complete vertical amplifier will be very well received.

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