02-23-2021, 08:19 PM
I am refurbishing a 1940 Philco 40-170CS I have the schematics. The radio was in a farmhouse with a wood stove so it was covered in soot. After cleaning the chassis with CRC I recapped and replaced two cracked resisters. Also some of the wiring insulation was cracked . I kept these wires but replaced the insulation with spaghetti tubing. Two tubes failed the life test and were replaced.
After slowly powering it up with a variac and dim bulb tester resister 20 overheated and it was clear from the dim bulb it was pulling more than 34 watts. The resister measured 1500 ohms but should be 1000 so I replaced it but still got the overheating. Also, the RF transformer was overheating I noticed when I disconnected the speaker the overheating stops and the wattage is better but most of the tubes don't light and without a speaker, I don't know if its working. I checked the speaker field ( Part 35) and it's within spec at 1700 ohms. Any suggestions?
After slowly powering it up with a variac and dim bulb tester resister 20 overheated and it was clear from the dim bulb it was pulling more than 34 watts. The resister measured 1500 ohms but should be 1000 so I replaced it but still got the overheating. Also, the RF transformer was overheating I noticed when I disconnected the speaker the overheating stops and the wattage is better but most of the tubes don't light and without a speaker, I don't know if its working. I checked the speaker field ( Part 35) and it's within spec at 1700 ohms. Any suggestions?
