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

A Beginner's Journey: The Philco 40-190

I would advertise here for an output transformer. Also check out Playthings of the Past and John Kendall's site for your part.

It lives.



I'll work on the alignment later, after I inspect my signal generator; so far it would seem that the best thing to do would be to move the dial pointer about a half-inch on the string as that will bring the world into dial scale alignment. I may not even screw with it after that. Icon_smile

THANK YOU to all of you who walked me through my first radio!

Upon listening closely to my radio, it has a very low-volume but consistent 60 Hz (B-flat) hum coming out of the speaker, even with the volume all the way down. Is this normal, or indicative of needing the voice coil wires reversed?

Deckape, is the hum level changed at all by increasing the volume? If not, perhaps a little cathode to filament leak on one of the tubes in the audio output. The voice coil, a possibility if the wires were switched. If it has a hum bucking coil tied to the voice coil and things are turned around, it won't cut some of the induced hum from the field coil they have to be in opposition. Just my lame ideas. Congrats on getting this far!
Jerry

A friend in need is a pest!  Bill Slee ca 1970.

Agree, if the hum bucker winding is wired backwards you will get more not less hum. Can't hurt to reverse it and have a listen. All those old sets had some hum regardless. You can beef up the filter capacitors a little bit (say 10%) and as said, make sure your output tubes are not gassy, but there will still be a little hum or more likely interference from modern devices that simply didn't exist way back when.

Rectifiers will also cause a set to hum when they get weak....

I all but let the smoke out of the original rectifier by crossing a couple of wires in the rebuild--thankfully, I had a spare hanging about (And a Raytheon-branded tube, at that). The spare tested out stronger even to start with. I'll try swapping the wires out when I'm feeling adventurous (and have a few spare moments to devote to the pursuit). I guess I'm asking a bit of a useless question in wanting quantification when I'm the only one available to listen to the speaker. Icon_biggrin

All else fails, I'll swap the wires back.




Users browsing this thread: 1 Guest(s)
[-]
Recent Posts
Jackson 715 not working
Now that you posted the schematic, I don't know why that Sprague electrolytic cap is across the meter, as it is not indi...MrFixr55 — 05:51 PM
HiFi (Chifi) tube amp build - but my own design.
What may be lacking in the PP Tube amps may be the 2nd harmonics, which some, especially RCA back in the day called &quo...MrFixr55 — 05:32 PM
Jackson 715 not working
Usually in an emission tester, the tube under test is measured as if it were a diode. So, some testers connect all the g...RodB — 04:17 PM
Restoring Philco 37-604C
Yep. F5 is green, D5 is Red. Red is Bad. Green is Clean.morzh — 01:30 PM
Jackson 715 not working
I did start to do that but I stalled out because I could not figure out how the grid and plate get voltage. In this diag...daveone23 — 11:52 AM
Restoring Philco 37-604C
(Insert Homer Simpson "DOPF" Here.) When all fails, look at the can. Took the Ron Ramirez advice, red Caig D...MrFixr55 — 09:23 AM
Philco 91 Speaker Replacement
From your text I am not sure if you intend to use the existing speaker with a resistor instead of the field coil. It wo...morzh — 08:44 AM
Philco 91 Speaker Replacement
My field coil is bad. I am still hoping to find an original, but if I can't I will go with a fitting Philco speaker, 125...dconant — 08:34 AM
Philco 91 Speaker Replacement
As Rod said, it is OK to use a fitting speaker, and then look for an original one. If you buy a Hammond 125 output tr...morzh — 08:15 AM
Philco 91 Speaker Replacement
Yes, I often have to substitute, then keep an eye out for an original. In the meantime, the radio is working and being e...RodB — 08:02 AM

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

>