12-31-2010, 01:06 PM
Concerns R100, a 220 ohm resistor across the first two filter capacitors. Is this a 1 watt or 2 watt resistor?
48-464 resistor question
12-31-2010, 01:06 PM
Concerns R100, a 220 ohm resistor across the first two filter capacitors. Is this a 1 watt or 2 watt resistor?
12-31-2010, 07:12 PM
I think I would go with 2 watts. The dissipation calculates out to a hair over 1 watt at DC but there is still some peak AC variation at that point.
12-31-2010, 08:39 PM
The parts list calls for part no. 66-1224340, which translates to 220 ohms, 1 watt:
http://www.philcoradio.com/tech/resistor.htm However, I agree with Exray that you should use a 2 watt resistor in its place. -- Ron Ramirez Ferdinand IN
01-01-2011, 09:53 PM
Thats what I thought. Now I need to go find a 2 watter. Thanks.
01-03-2011, 04:09 PM
I often put 1 watt resistors in series or parallel to dissipate larger amounts of power. If you put two 110 ohm resistors in series, each will dissipate half the total power, and the total resistance will be 220 ohms. Two 440 ohm resistors in parallel will accomplish the same result, but 440 ohm isn't a common value.
Philco bias resistors (such as the Candohms) are sometimes odd values that aren't easy to find today, so I often put two or even three smaller value resistors in series to obtain the same resulting resistance as the original. I try to use resistors that are as close as possible to the same value while summing to the desired resistance so that each will dissipate close to the same proportion of the power. I've done this with several radios without problems. If you can find a 220 ohm wire-wound resistor in two watts or greater, you are probably better off, since their inductance should theoretically help with filtering. John Honeycutt
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