What is the tube used for? It crosses to a 6ak8, so I suspect it may be a ratio detector/first AF for the FM section??<P>I'd opt for the closest modern value you can find; in this case 4.7mfd@160vdc. <P>Those caps, if round and clear, are probably polystryenes, and should be fine.<P>Peter<P>------------------<BR>

Ted, this is BAD advice but anything from about a 1 to 10 mf will work in that location.<BR>Yes, its positive may well go to the chassis. I recently replaced the 2uf in a ratio detector with a 10.<BR>That will get you moving until the correct part comes in.<BR>As for the testing part...yes, new mylars have extremely good leakage specs. The old paper ones, if they have as much as 700k leakage with the voltage from your meter, imagine how they may leak with REAL voltage applied. Thats not a valid test for good capacitors, only bad ones <BR>You can't really do much with electrolytics simply with a VOM/VTVM/DMM.<P><BR>-Bill<P>------------------<BR>

Hi Ted<P> Without load your voltage will be 1.4 times AC input. After tubes load it down shouldn't be a problem. <P> Would be a good idea to add a 47 ohm resistor in series with your diode bridge. Silicon diodes have a lower voltage drop then a selenium rectifier. <P> Try adding a .01 mfd @ 600 volt cap across your AC line or from AC line to chassis. This should eliminate hum heard on a station.<P> <P>------------------<BR>Norm

I hate to nitpick, but...<BR>Adding a 47 ohm resistor really won't do squat. If you figure the B+ draws say 50ma that gives you a drop of 2.35 volts. Hardly worth the trouble in a set where the B+ apparently is in the 175 volt range.<BR>Generally the resistor is handiest for surge limiting thru the diodes. But being a transformer set there's enough resistance/impedance already there to handle that function.<BR>OTOH, it won't hurt anything.<BR>(I had to say something to compensate for my earlier 'bad' advice) <P>-Bill<P><BR>------------------<BR>

The resistor will limit peaks seen by the diodes. It doesn't drop a lot of voltage but more than what is figured using ohms law. During peaks current is much higher than average draw of a radio. The resistor will also act as a fuse if a diode shorts. Agree a resistor is more effective in a radio without power transformer but could save it in case of a short. <P>------------------<BR>Norm

Ted, that 175 volts could have been simply due to bad selenium rectifiers but I still wouldn't expect 340 under load. Does the set have the 110/125 type of voltage taps?<BR><P>------------------<BR>

Hi Ted,<P>That EM85 to EM80 socket conversion can be a real brain bender. The last time I did it I wrote out step by step instructions to make it easier. Try this:<P>1. Remove the jumper wire between pin 7 and pin 9.<P>2. Remove the leg of the 470k or 500K resistor tied to pin 6 and solder it to pin 9. The resistor will now be across pins 7 and 9.<P>3. Take the wire (usually red) soldered to pin 6 and also solder it to pin 9. Pin 6 will now have nothing connected to it.<P>4.Move the wire that connects to ground on pin 3 to pin 2.<P>5. If there is a jumper between pin 3 & 4 remove it so nothing is connected to pin 3. Pins 2 and 4 will now be connected to ground<P>Pins read clockwise from the gap looking at the bottom of the socket. That should do it. It's made the job infinitely easier for me.<P>Mike<P>------------------<BR>

Ted,<P>My above post has been edited since Saturday night when I first posted it. It is now correct. Sorry!<P>Mike<P>------------------<BR>

On the 160 volt thing.<BR>I've lived in places where an 80 volt setting would have been just lovely on a radio because of chronic low voltage but thats not the type of thing I would expect a manufacturer to stick his neck out on.<BR>I've never heard a good explanation unless indeed there were places in Europe back then that used such voltage. I see such a tap (150 or 160) quite often on old eu radios.<BR>Maybe one of our european friends can clue us in?<P>-Bill<P>------------------<BR>