Thanks to the manual provided by Jim and the HV test gear provided by Alan Wolke, I was able to finish the troubleshoot on the broken Tek 465. It is the HV multiplier, U1432. The cathode voltage is supposed to be -2450. It initially tested at -1000. The manual calls for a jumper to be removed to take the HV Multiplier out of the circuit. As soon as I did that, the cathode voltage went to -2500. Bingo.
Now I have to get a replacement for U1432. Any carcasses laying around?
Thanks guys.
Bill,
ReplyDeleteTake this with a grain of salt.
I believe that the part is a 6x multiplier: 2500v in to 15000v out.
I found an old post where somebody build their own:
"I have taken some X-Rays from one part and found that it is X6 multiplier, in contrast of the majority think to be X3. There are 6 diodes and 6 capacitors inside the block connected as a X6 multiplier.
The capacitors are all 1400pF x 10KV and the diodes are BY8212 from Philps, 12Kv x 5mA. There are a lot of similar capacitors and diodes to sell on Ebay, and you can use these parts also."
The topology they are using is "Cockroft-Walton voltage multiplier".
BE CAREFUL!
http://tech.groups.yahoo.com/group/TekScopes/
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