Magnus, what everyone else said, plus, I have seen a few older Tek scopes with bad focus and/or intensity controls as well as HV divider resistors for the screens. If the HVs at the anode cap and cathode are good, then I would look there. The heater is, of course, at high voltage to prevent arcing to the cathode and it is run off a winding of the HV transformer. HV could be as much as 10kV, so be careful. > > Message: 8 > Date: Sat, 08 Nov 2008 01:30:17 +0100 > From: Magnus Danielson <[EMAIL PROTECTED]> > Subject: Re: [time-nuts] Tek 602, no trace > To: Discussion of precise time and frequency measurement > <[email protected]> > Message-ID: <[EMAIL PROTECTED]> > Content-Type: text/plain; charset=ISO-8859-1; format=flowed > > Richard Moore skrev: >> >> Magnus, a few thoughts that have most likely already occurred to >> you -- >> 1) HV supply failure -- I think it will be around 2 or 3kV if >> working. > > It's 3,9 kV. There is a test point, but I need to dig up a very old HV > probe lying around somewhere in the junk. Finally I get some use for > it... maybe > >> 2) X or Y deflection amp has failed, moving the trace offscreen. > > The X deflection amp seems to work at least. > >> 3) CRT heater dead. > > No, I have a very faint ligthening up on the screen which the > horizontal > control can move on or off screen. I need to shield the screen from > light to see it. It's so out of focus that it hits the full screen. > Could be an HV issue, but I am not sure at this moment. > >> Either 1 or 2 should be easy to detect. Having the manual will >> certainly help with repair. 3, however, is really discouraging. > > Certainly. I have enought of large scopes at a friends place to be > able > to salvage tubes before being tossed. I even think he still has the > spare tube NOS. :) > > Cheers, > Magnus > > End of time-nuts Digest, Vol 52, Issue 19 > *****************************************
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