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

Help with Troubleshooting on a Philco 71
#10

Hey Jon,

As a beginner first starting out, early '30s radios are going to be a lot of guess work for you (voltage & resistance wise) because of the "limited" info on *All* schematics. You're goin' have to get use to it if these are the years you prefer.8)

As you get more restorations under your beltIcon_smile like a lot of forum members here have, you become accustom to what certain resistances (ohms) should be from most coils (oscillating transformers). Bob Anderson had to make some of these assumptions when fixin' his Brunswick 5KR.

Philco IS Very Good in the late 30s & early 40s at labeling their schematics better. Better Than Most at the time. Coil terminal #s & ohm values between each pair of terminal windings. Anything with more than 4 terminals you practically have to pull the whole coil out of the radio to see what terminals are paired with each other to get a good ohm reading.

At this point you can visually inspect the coils & hopefully IF there is a break it is right by the terminal to where it Was soldered. Acid flux over the years ate away at this small diameter enameled wire.

The leads (wire) going to these small value ohm coils should at least be unsolderd to get a Good ohm reading, that a Noob would be comfortable with. Just like resistors, if over in value change them., under in value, need to disconnect one side to get their true value.

Now there are goin' be some that will tell you that you don't have to disconnect the coils to get That True Reading that you can be confident about, & that maybe true if you're a veteran at these, but they forget what it was like when they were a noob, And....

If YA All don't believe me,
Just take a looksey at Bob's last video on his 15DX.Icon_smile He disconnected one side of the shadow meter so he could get an accurate reading. John(badrestorer) also done that on the shouldered tombstone he re-did.

I've been switching 3 of them around, on these 3 650Bs this last week. One Was OpenIcon_sad All 3 were wired in differently. All produced under code 121.Icon_wink

Gotta Love PhilcosIcon_thumbup
Lloyd
_____________________________________________________________

Ooohhh Noooo, What’s the Matter NOW?? It WAS Working GREAT before I “FIXED IT”!!


Messages In This Thread
RE: Help with Troubleshooting on a Philco 71 - by CrumblingWires - 08-05-2012, 12:48 AM



Users browsing this thread: 2 Guest(s)
[-]
Recent Posts
Philco 42-390, code 121 speaker
Using a 5W  1.5k  ceramic resistor in place of the field coil and using a 4 ohm PM speaker, I was able to bring the radi...Stevelog — 02:57 PM
Philco 60 Squealing
I have taken out the 2nd IF and found a problem or not. I believe the coils are litz wire. There is a very small strand ...dconant — 02:13 PM
1930s Stromberg-Carlson Tombstone Radio need help identifying model number
Hi Cap'n Clock, Unfortunately, I do not have this radio.  This is a shame because this should be a good performer.  2A5...MrFixr55 — 06:48 AM
American Bosch Model 802 auto radio
I think it would come under either American Bosch or United American Bosch. American Bosch made sets for the American We...Arran — 05:53 AM
trying to identify this wire type
Thanks to all for the feedback. As Arran said, it is probably an older replacement and yes it has a grid cap so I will ...georgetownjohn — 09:32 PM
trying to identify this wire type
It's possible that the red wire, actually a grid cap lead, is a very old replacement, I can't remember seeing a pre 1939...Arran — 09:18 PM
Gilfillan Brothers Car Radio?
Hi everyone,  Special thanks to Joe Rossi for tracking down this obscure radio and thanks to others who took up the hun...Antipodal — 08:15 PM
trying to identify this wire type
Here's one source for your wire of many. Take care and BE HEALTHY! Gary P.S. Can't get the right color you need? I ...GarySP — 06:40 PM
trying to identify this wire type
...and modern wire of the appropriate gauges and insulation V-rating (300V minimum, usually shown right on the wire) is ...morzh — 05:47 PM
1930s Stromberg-Carlson Tombstone Radio need help identifying model number
I have a question about this radio, is there anyone that has access to this radio that has an intact unmolested speaker ...captainclock1988 — 04:28 PM

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

>