09-05-2014, 07:12 PM
thanks for the quick replies guys!
i wonder if it helps for me to mention that there seems to be no trace of any static or actual signal in the speaker, just the hum.
just putting that out there...
as for the condenser caps, i should have worded that differently.
im speaking about the trimmer caps on the back panel that are used to align the radio.
one of the sheets i have for this radio called them condenser caps.
i did NOT replace these.
one of them is missing the nut though. will have to find one.
on the hum issue; the only two caps that are polarized are the 4uF and the 8uF.
(i used a 4.7 and a 10)
these are indeed oriented the correct way, but i did want to mention that i may have done something a little strange when it came to the negative side of the filter caps.
it looked to me from the schematic that the negative leads of the 4 and 8uF caps did not go to chassis ground, and were isolated from it.
the 325 ohm resistor and .015uF cap gave me this impression.
so i soldered the negative lead of the new 10uF cap to the negative tab of the original 8uF cap, and did the same with the new 4.7uF cap to the negative tab of the original 4uF cap.
i left the original caps in place for looks, but there is nothing connected to the center "nut".
so, could i have inadvertently done something wrong here?
thanks for all the help so far.
when i get home from work tonight, i will remove each tube one at a time as suggested. (except for the output tube; i get the impression that removing that tube and turning the set on is a bad idea)
and i will measure the resistance of all the coils in the radio again also.
two things i have not done yet, that i really should have, was to measure the resistance of the coils on the speaker and the power transformer itself. oops!
still open to any more things to try tonight.
LC
i wonder if it helps for me to mention that there seems to be no trace of any static or actual signal in the speaker, just the hum.
just putting that out there...
as for the condenser caps, i should have worded that differently.
im speaking about the trimmer caps on the back panel that are used to align the radio.
one of the sheets i have for this radio called them condenser caps.
i did NOT replace these.
one of them is missing the nut though. will have to find one.
on the hum issue; the only two caps that are polarized are the 4uF and the 8uF.
(i used a 4.7 and a 10)
these are indeed oriented the correct way, but i did want to mention that i may have done something a little strange when it came to the negative side of the filter caps.
it looked to me from the schematic that the negative leads of the 4 and 8uF caps did not go to chassis ground, and were isolated from it.
the 325 ohm resistor and .015uF cap gave me this impression.
so i soldered the negative lead of the new 10uF cap to the negative tab of the original 8uF cap, and did the same with the new 4.7uF cap to the negative tab of the original 4uF cap.
i left the original caps in place for looks, but there is nothing connected to the center "nut".
so, could i have inadvertently done something wrong here?
thanks for all the help so far.
when i get home from work tonight, i will remove each tube one at a time as suggested. (except for the output tube; i get the impression that removing that tube and turning the set on is a bad idea)
and i will measure the resistance of all the coils in the radio again also.
two things i have not done yet, that i really should have, was to measure the resistance of the coils on the speaker and the power transformer itself. oops!
still open to any more things to try tonight.
LC
