12-04-2011, 04:31 PM
I have restored several of these, and believe me, they stand their own as sensitive AM receivers. You can dig up a free schematic on Nostalgia Air or for a better version visit http://www.philcorepairbench.com/index.htm - well worth the small fee charged.
Now then, you will want to do a wholesale replacement of all the electrolytic (very careful on polarity,)and paper capacitors in the set, and any out of tolerance carbon resistors (I replace 'em all, cheap enough.) If the candohm measures OK and has not any shorts to chassis, leave it in. Looks like you need tubes, none of them are rare or expensive. This forum has a WTB section, and someone may have a set available at a very reasonable cost. I'm tapped out on these at the moment.
The belt handle is usually rotten, and believe it or not, replacements are available, or you can make one out of a, well, belt.
The only tricky part is making sure the 8.5 volt DC filament supply does not run high, as the filaments in these battery/AC sets are very delicate. Today's line voltage is higher, so an additional series resistor might be needed to tame the power. You can do without the half wave rectifier (117Z3) and substitute a silicon diode. If you do this you will have to place an additional resistor in series at the beginning of the voltage divider and you will use a 10 watt chassis mount or sand resistor dressed to the chassis to dissipate heat.
The battery/AC interlock switch is also a real pain. If you want, you can just get rid of it, make the proper connections as if it wasn't there, and you'll be glad you did. That is unless you want to spend a bunch of money and time creating an ersatz AB battery pack, which of course could still be done. There are folks on this forum that make 'em.
Nice winter project, take your time. If you run into a real problem, like a wasted coil, these sets do come up all the time on Ebay, and can be had for not much money. I know we will be hearing from you soon.
I've all but hung up my mouse too, lapsed radio tinkerer for decades. Lots of us here.
Now then, you will want to do a wholesale replacement of all the electrolytic (very careful on polarity,)and paper capacitors in the set, and any out of tolerance carbon resistors (I replace 'em all, cheap enough.) If the candohm measures OK and has not any shorts to chassis, leave it in. Looks like you need tubes, none of them are rare or expensive. This forum has a WTB section, and someone may have a set available at a very reasonable cost. I'm tapped out on these at the moment.
The belt handle is usually rotten, and believe it or not, replacements are available, or you can make one out of a, well, belt.
The only tricky part is making sure the 8.5 volt DC filament supply does not run high, as the filaments in these battery/AC sets are very delicate. Today's line voltage is higher, so an additional series resistor might be needed to tame the power. You can do without the half wave rectifier (117Z3) and substitute a silicon diode. If you do this you will have to place an additional resistor in series at the beginning of the voltage divider and you will use a 10 watt chassis mount or sand resistor dressed to the chassis to dissipate heat.
The battery/AC interlock switch is also a real pain. If you want, you can just get rid of it, make the proper connections as if it wasn't there, and you'll be glad you did. That is unless you want to spend a bunch of money and time creating an ersatz AB battery pack, which of course could still be done. There are folks on this forum that make 'em.
Nice winter project, take your time. If you run into a real problem, like a wasted coil, these sets do come up all the time on Ebay, and can be had for not much money. I know we will be hearing from you soon.
I've all but hung up my mouse too, lapsed radio tinkerer for decades. Lots of us here.
