[Hallicrafters] Sky Challenger rectifier tube glowing cherry red

[Bob Young]

Hi All,

I picked up a Sky Challenger and powered it up slowly on a variac, the 
output was very weak and the rectifier plates were glowing cherry red. I 
tried a different rectifier tube brought it up again and this one started to 
arc a bit at around 70 V. I assume I have a shorted filter cap and haven't 
had the time to test it further. Any other ideas? What resistance would a 
shorted or partially shorted filter cap read on a multimeter, incidentally 
there was no hum.

I just bought an Eico 950B resistance capacitance comparator bridge,, it 
needs a "comparator prototype or standard"?
Anyone familiar with this thing, and what is the comparator it needs? a 
known capacitance?

Bob Young
Millbury, Ma