Zenith 2250R

[Electronic M]

Two things that may be worth doing towards the end of fixing the low HV: 1.) If you haven't done this yet and have several good 1B3s try swapping different ones in (tube testers while good at IDing dead HV rects are a poor indicator of how good they will do in a set). 2.) If a tube rect does not help try an SS HV rect...They made SS plug-in R-3A3s that will work in place of a 1B3, or if that is hard to get 5KV (or higher) PIV rated diodes are inexpensive online I'd grab 3-4 5KV diodes, string them in series and install them in place of the tube...Elimination of the HV rect tube filament load from the fly by switching to SS rect may bring the HV to spec.

[Kevin Kuehn]

Originally Posted by Electronic M

Elimination of the HV rect tube filament load from the fly by switching to SS rect may bring the HV to spec.

And don't forget there was some discrepancy between Riders and SAM's as to what the HV rectifiers series filament dropping resistor was suppose to be in this set. An ohm or two can make a big difference when it comes to a low voltage heater.

[Zsuttle]

Alright, so I substituted a brand new (5 in carton) 1X2B in for the HV rect. and I'm still having issues. The HV is still low, I'll probably try replacing it with the 1.2 ohm, though the one currently in the set is a 3.3 ohm. If that doesn't work, I'll try the solid state idea.

[Kevin Kuehn]

For a quick test you can tack a second 3.3 ohm in parallel. That way you'll save all the work of removing the original in the event that it makes no difference. However there's also the concern of keeping the solder joins round and smooth in that high voltage area. Sharp points are more prone to arcing.

[Zsuttle]

Well, I was able to get a pretty decent picture and did my best to adjust it. Is the ion trap supposed to be so close to the focus magnet? The only way I can get a picture is either pushing it right next to the focus coil or almost to the end of the neck. I thought it was supposed to be midway on the tube.

I had to order the resistors because I didn't have any that low.
Thanks for everyone's help so far,
Zach