Thread Rating:
  • 0 Vote(s) - 0 Average
  • 1
  • 2
  • 3
  • 4
  • 5

Philco 37-660 Hum
#1

Finally got into working on this radio after a few years of ownership and letting it sit. Replaced Electrolytics - what a pain on the ones in the RF section!! I am now picking up stations very well but have a residual issue - low grade hum. This is not the obnoxious that existed before the original electro's were replaced but it is enough to be distracting. I have been going through replacing the other paper caps - and have not gotten into bakelites as of yet - could one of these be the culprits or is there something else I should be looking at?? Before I moved onto other projects I thought I'd look to the experts and see if I'm missing something that can bring this to a solid working state.
#2

If you haven't recapped the rest of the radio there maybe a leaky cap or two or three drawing excessive current. It is possible to have a bad tube with heater/cathode leakage. Check the 6F6 tubes, if one is really weak that could cause some hum. Just some thoughts.

Gregb
#3

Does the hum change when tuned in?
#4

The hum still exists when tuned in. I did notice when not on a station and varied the volume the hum would minimize then return. I'll look at the options described above and if any other suggestions feel free to chime in.

Tx. Mike
#5

What you have not answered is whether you did full recap.
#6

Gm

Did not do a full recap but did find issue- neg of 8uF electro caps was on chassis- once corrected now functions as should. I also as a precaution checked all tubes and all tested in tolerance.

Thank all for assist and direction!
#7

Are you sure the neg should not be on the chassis?
Post the link to the sch, it will make it easier.
Again.

Do the recap.
Do the recap.
Do the recap.




Users browsing this thread: 1 Guest(s)
[-]
Recent Posts
Philco 42-1008 conversion kit
I read about a kit to convert the variable speed changer in the Philco 42-1008 into a single speed unit.  That would rem...alangard — 09:30 PM
HiFi (Chifi) tube amp build - but my own design.
Tim Well...a chassis is metal. Magnetic or not, it does not matter. A transformer has some hum to it. It is natural....morzh — 08:40 PM
Shadow Meter Bulb
Ross I am not sure what current limiting effect the incandescent provides. They are two different parts of the sch...morzh — 08:31 PM
12' Philco
Bob Thanks for that photo. I have been looking for it, and I cannot find anythinmg on the web. I forgot it was here...morzh — 08:29 PM
Shadow Meter Bulb
I think after all has been said, I will use the same bulb that is specified for the dial pilot light which is a #55. I ...georgetownjohn — 07:31 PM
12' Philco
There was also this Philco! klondike98 — 07:25 PM
HiFi (Chifi) tube amp build - but my own design.
I expected a challenge and this is just part of it. But, it's also supposed to be fun, entertaining, informative and enj...TV MAN — 07:12 PM
Shadow Meter Bulb
Butting in here with a question. Since the shadow meter is connected directly to the 1st and 2nd I.F.'s wouldn't the met...RossH — 06:43 PM
HiFi (Chifi) tube amp build - but my own design.
Mike, Tim; you are about to enter the twilight zone. Doo doo doo doo, doo doo doo doo This is something alright. I'm go...RodB — 06:26 PM
HiFi (Chifi) tube amp build - but my own design.
:lol: We need to start a singing radio group! I play the guitar, so maybe get a few vocals? Anyways, Mike, I did try mou...TV MAN — 05:56 PM

[-]
Who's Online
There are currently no members online.

>