I do that all the time. You would be committing a very dangerous act if you were to work on the power supply while it was installed in the scope. To make the supply work, you need a dummy load. The

Wondering if anyone has been able to test the 2465B power supply boards (A1A2, A3) together, without reinstalling into the scope? This would allow checking the supply voltages and ripple to at least

Oh, I missed that it was the resistor's paint. They are toast, and must be replaced. I thought he was talking about the solder mask paint. -Chuck Harris Ed Breya via groups.io wrote:

If the over-coating on these SMDs has floated or burned off, then it's likely due to being undercut by the corrosive, leaked electrolyte. This stuff can travel considerable distance by capillary

The problem was indeed caused by defective trimcaps: I started by replacing 4 (four !) open trimcaps in Ch2, made preliminary adjustments and took another picture. See album. I'd never have thought

I understand and I figured out what made me think otherwise. It is the generic picture of a multiplier they have on the semiconductor manual at the top of that page! Lesson learnt.

Dennis, Did you ever make duplicates of that early 7804N conversion board (K7-1286-XA)? Clark

DW, My "ZERO Line trace" stays flat, right against the bottom of the CRT graticule. When testing a transistor with the steps set to 1, I see two lines, the first is that "zero line trace" at the

Michael, Thanks for the reply. From what you observed I am not getting the same results. The phenomenon I am experiencing seems to be an issue with improper biasing on the base terminal. When you

A schematic for the -00 version of the board is in the datasheet link on the TekWiki page to which Dennis pointed. DaveD

Hi Eric, I can't help with a schematic, but there is some information on this card on TekWiki at http://w140.com/tekwiki/wiki/067-0912-00 Dennis Tillman W7pF

I am thinking about trying to tackle a calibration on my 7854. I have confirmed that the digital and analog sections are out of adjustment. The digital section is about .8 division left of center. In

They did not use the same part number for two different parts. The 455 and 465M both use the U550 designation in their schematics, both use the identical TEK part # 152-0635-00. 152-0635-00 is the

Thanks Chuck 73 Richard W4MCD

This is my newest 7A26 (main PCB code 670-2549-21)! S/N 709928, so Heerenveen. It's the only one in my collection with a green PCB and 155-0078's with date code "429", I guess that's 8429. Raymond

Hi Roger, Since these components constitute most of the common parts, I had done some testing in that area. I checked Vbe across Q820 / Q840, Q860 / Q880 and they were correct. I pulled Q860 and Q880

Hi John, I know the problem with the trimmer caps. I found several that had no effect, initially blaming that on the lack of HF content in the signal as it appears and not expecting a multi-device

Hi John, Both edges show the same behavior. Raymond

Omit, previous message as I see your title, plainly states, "available for free".... Still waking up, here. Good price for a hobbyist with little to spare. Best email is Cjuried@... and phone is

Sure. Cjuried@... how much are you a asking?  Chris Juried, WRCB719 FCC Licensed RF Coordinator Audio Engineering Society (AES) Member   InfoComm-Recognized AV