That wouldn't explain why he reports the voltage across C808 is about -52V with about 30Vp-p ripple. I think he meant 0.0uf... and the rest of my post was with that thought in mind. -Chuck

Up to you. If you can do that with zero quality loss, please submit the new version to TekWiki (I believe you can get an editor account from Kurt). (I don't OCR anything myself, but if I recall

To debug shorts all together a milliohm meter is handy. HP3456A is good...but remember that it puts out a negative voltage when in ohms mode. Seeing the milliohms difference as you move a sharp

Hello Tomas, It may be a long shot, but here goes my idea... So you have a 7704A mainframe and no other (7K series) to compare to... and using the calibrator at highest speeds, the vertical steps are

Hi Chuck, I think he means it appears to have a dead short (or close to it) and this is why I say that: I have been following this 7603 thread, and had printed the power supply schematic out on large

If it helps, I had a 7603 fault due to one of those reservoir caps failing and, when I got round to checking them, most of the caps on that rectifier board were on their way out, so I changed them

Toby, There are three 466 manuals. If yours is the one named Tektronix 466 Service Manual (PDF, OCR) <http://w140.com/tekwiki/images/c/cc/070-1753-01.pdf>, I can improve it somewhat if you don't

I am not sure what you are saying when you say that C808 tests at 0.0 ohms. Do you perhaps mean 0.0 uf? Typically, when ripple gets to be that excessive, the capacitor's internal connection has been

I took a quick look at that portion of the schem. and noticed that. One thing I don't understand is on all of the schematics it has what looks like test points and they are labeled with a number

There's no mystery. The serial numbers were not coordinated between the manufacturing sites. Your scope was the 1239th 310A made on Guernsey, but there could have been a million units made in

I don't know about the 5xx scopes, but if you've worked on vintage radios you've probably seen cases where a leaky interstage coupling capacitor dumps a lot of positive bias onto a grid from the

Chuck, C808 on the -50 v unregulated is the only cap that tests at 0.0 Ohms and is the only one that doesn't charge up to some value using the cap test position on my Tek DMM916. I ordered some

I would not dissolve the cadmium yellow, just find something to pint it with to bind it in place. Like acrylic clear paint applied with a brush in a thin mix. Dissolving it will not yield results

Yeah, we're supposed to wear gloves when handling the green plated military connectors at work because they contain cadmium, but nobody does.   We do wash our hands afterward, though. Jim Sent

Thanks Jim ! Now that I know what it is... I can go ask the chemists out there what chemicals I might use to "neutralize"/dissolve it... well if there is one that is, crossing fingers ! :-/ Vincent

Cadmium! So common to electroplated hardware of the time.Toxic, don't eat, inhale, etc.  Wash hands.  Plants thatused to plate it here (US), were shut down by the 1970's JimMc

well that was a bodge assuming the s54 and d54 had anything in common ...s54 appears to have 105v and 12.5v supplies on the vertical . "Vertical Amplifier" section on page 8 has check and aligning

Hi Steve, I didn't want to open up the scope, as I have already a couple scopes I am working on at the moment, spread all over the bench... I wanted to keep the surprise of the 310A for later, when I

Scott, I would disagree on the 7M13... If you need to add a bit of documentation to a scope photo for inclusion in a report or for archival purposes, the 7M13 is absolutely great! I have a couple of

I agree except to emphasize that plastic-enclosed oiled paper (e.g. "Black Beauty" aka "bumblebee") are always bad and should be replaced. There are several in the Holdoff circuit which slow or