05-11-2017, 10:15 PM
part 2 of today.
prior to my discovering how to fix the volume issue, i thought that since my R102 that was getting really hot, i retofitted in a multi-tap resistor in my pic. end to end its 611 ohms.
i relocated one of the wires to give me 400 ohms in an effort to see if this got rid of the hum and my minor lack of high high volume.
I am so lucky i stayed with the radio for a while when i connected to the 400 ohm side, i was tinkering around and wow!!, my transformer was getting very very unusually hot!! Laser temp gun said it was 168 deg F.
my goal was to introduce 400 ohms to see if this would fix my volume problem and maybe my hum.
this did nothing for the hum or volume. It resulted in my 6k6 pin 3 sitting on 305volts and pin 4 getting to around 260v.
when i found the transformer was getting too hot i reverted back to 611 ohms side of my R102.
It occured to me that i have an opportunity to let heat out of the transformer easily because one side comes off whithout any wiring conflicts.
i removed the one side cover of the power transformer.
i drilled a hole on each side down low.
the purpose i feel for these two holes is to allow the heat convection to suck air in,, then the opening at the top acts as a chimney.
I hacksawed a slot along the top and sorta bent it out a tad so nothing can drop into the transformer giving it an awning so to speak.
now when there is a heat issue, a lot of it can get out instead of being trapped and such.
now i cant find any spot on the transformer that is over 115 deg f.
the vast majority of the heat introduced on the power transformer is sourced from radiant heat off the rectifier tube and the 6k6's on the other side you cant see.
what i do know is that 300 ohms is wrong for the code 125 update.. 500 ohms is ok,, and 600 or so is working for me. just my 2c worth but its been a good trial and error on the part of an amature here who knows little about these sets , but thanks to the help here, im getting more comfortable.
prior to my discovering how to fix the volume issue, i thought that since my R102 that was getting really hot, i retofitted in a multi-tap resistor in my pic. end to end its 611 ohms.
i relocated one of the wires to give me 400 ohms in an effort to see if this got rid of the hum and my minor lack of high high volume.
I am so lucky i stayed with the radio for a while when i connected to the 400 ohm side, i was tinkering around and wow!!, my transformer was getting very very unusually hot!! Laser temp gun said it was 168 deg F.
my goal was to introduce 400 ohms to see if this would fix my volume problem and maybe my hum.
this did nothing for the hum or volume. It resulted in my 6k6 pin 3 sitting on 305volts and pin 4 getting to around 260v.
when i found the transformer was getting too hot i reverted back to 611 ohms side of my R102.
It occured to me that i have an opportunity to let heat out of the transformer easily because one side comes off whithout any wiring conflicts.
i removed the one side cover of the power transformer.
i drilled a hole on each side down low.
the purpose i feel for these two holes is to allow the heat convection to suck air in,, then the opening at the top acts as a chimney.
I hacksawed a slot along the top and sorta bent it out a tad so nothing can drop into the transformer giving it an awning so to speak.
now when there is a heat issue, a lot of it can get out instead of being trapped and such.
now i cant find any spot on the transformer that is over 115 deg f.
the vast majority of the heat introduced on the power transformer is sourced from radiant heat off the rectifier tube and the 6k6's on the other side you cant see.
what i do know is that 300 ohms is wrong for the code 125 update.. 500 ohms is ok,, and 600 or so is working for me. just my 2c worth but its been a good trial and error on the part of an amature here who knows little about these sets , but thanks to the help here, im getting more comfortable.