05-14-2008, 05:09 PM
Okay. Here are the factory specs for the electrolytics used in Model 42-365:
(37) Dual, 8 and 8 uF, 475 volts (per 1946 replacement 40-3003) - Part No. 30-2476
(60) 12 uF, 400 volts - Part No. 30-2471
Now let's look at the circuit. The input filter (60) sees 320 volts across it according to the schematic. Given today's higher line voltages, and using modern, more sensitive multimeters that do not load down the circuit under test, that voltage may actually be around 350 or so.
Output filter (37A) shows 190 volts across it; you can count on 225 or so.
The extra electrolytic for the B+ line applied to the plates of the mixer and oscillator tubes shows 160 volts across it. In reality, that is probably in the neighborhood of 175.
Thus, armed with this information, it is safe to assume that 450 volt electrolytics will be just fine for this radio. In fact you could probably get by with 300 volt electrolytics for the two 8 uF units, but to simplify things, you may wish to go ahead and use 450 volts.
8 and 12 uF are no longer standard values. 10 uF will be fine as substitutes for all three.
(37) Dual, 8 and 8 uF, 475 volts (per 1946 replacement 40-3003) - Part No. 30-2476
(60) 12 uF, 400 volts - Part No. 30-2471
Now let's look at the circuit. The input filter (60) sees 320 volts across it according to the schematic. Given today's higher line voltages, and using modern, more sensitive multimeters that do not load down the circuit under test, that voltage may actually be around 350 or so.
Output filter (37A) shows 190 volts across it; you can count on 225 or so.
The extra electrolytic for the B+ line applied to the plates of the mixer and oscillator tubes shows 160 volts across it. In reality, that is probably in the neighborhood of 175.
Thus, armed with this information, it is safe to assume that 450 volt electrolytics will be just fine for this radio. In fact you could probably get by with 300 volt electrolytics for the two 8 uF units, but to simplify things, you may wish to go ahead and use 450 volts.
8 and 12 uF are no longer standard values. 10 uF will be fine as substitutes for all three.
--
Ron Ramirez
Ferdinand IN
