01-13-2018, 03:09 PM
After speaking with a new member abt his set he was a little hesitant to service it himself so I offered. Normally I don't take in service work but I was getting tired of beating my head against the wall on a couple '40s Philco sets (I hate loctal tubes and their worthless sockets!) so it was a nice reprieve to work on something nice and simple.
So the chassis was sent along w/a bevy of batteries. First order of business was to replace the battery cable and ant/gnd wiring. Next where the caps and checking the resistors. All where close to tolerance. Strung up some batteries and tried to wake her up. Heavy sleeper didn't want to wake up. Did some checking to find that the off/on switch on the filament side was open. A jumper fixed that temporarily and gave it another try. It sprang to life and was working w/a few gremlins.
Volume control was very noisy and only turned about 40% of it normal rotation. Out and apart came the control used a little bit of WD-40 on the pot and contact cleaner on the switch section. Bart (the Simpson 260) said it was ok. I believed him. Back it went and work fine. The rotation issue was caused by the actuator for the off/on flag it was hitting the bracket for the dial. With a little manipulation was able to clear up path for the actuator. Did the IF and RF alignment. Plays swell! I was curious about how much current was it using from the B batteries. Well the answer is about 6ma on a strong signal and about 6.25ma on weak signals do to the avc action. That works out to about .5 watt total power consumed. Sounds like just about all of it is used in the audio output stage as it plays pretty loud for a farm set. The more important question does it draw any current when it's turned off as this will run the batteries down. Nope no current when off.
Was listening to CHML out of Canada last night.
Next step is to figure out how to make up a friendly battery pack. Have to buy some 9v battery snap connectors and make some sort of connector to fit the old A/B battery plug. Have to see what I've got in my bag of tricks.
So the chassis was sent along w/a bevy of batteries. First order of business was to replace the battery cable and ant/gnd wiring. Next where the caps and checking the resistors. All where close to tolerance. Strung up some batteries and tried to wake her up. Heavy sleeper didn't want to wake up. Did some checking to find that the off/on switch on the filament side was open. A jumper fixed that temporarily and gave it another try. It sprang to life and was working w/a few gremlins.
Volume control was very noisy and only turned about 40% of it normal rotation. Out and apart came the control used a little bit of WD-40 on the pot and contact cleaner on the switch section. Bart (the Simpson 260) said it was ok. I believed him. Back it went and work fine. The rotation issue was caused by the actuator for the off/on flag it was hitting the bracket for the dial. With a little manipulation was able to clear up path for the actuator. Did the IF and RF alignment. Plays swell! I was curious about how much current was it using from the B batteries. Well the answer is about 6ma on a strong signal and about 6.25ma on weak signals do to the avc action. That works out to about .5 watt total power consumed. Sounds like just about all of it is used in the audio output stage as it plays pretty loud for a farm set. The more important question does it draw any current when it's turned off as this will run the batteries down. Nope no current when off.
Was listening to CHML out of Canada last night.
Next step is to figure out how to make up a friendly battery pack. Have to buy some 9v battery snap connectors and make some sort of connector to fit the old A/B battery plug. Have to see what I've got in my bag of tricks.
When my pals were reading comic books
I was down in the basement in my dad's
workshop. Perusing his Sam's Photofoacts
Vol 1-50 admiring the old set and trying to
figure out what all those squiggly meant.
Circa 1966
Now I think I've got!
Terry
