Welcome Guest! Be sure you know and follow the Phorum Rules before posting. Thank you and Enjoy! (January 12, 2025) x

Thread Closed

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: 1 Guest(s)
[-]
Recent Posts
Philco 71 Code 125
Hello,  I am in need of a schematic for this radio. Mine has the three separate circular tube shields and a shadow me...dconant — 08:06 AM
Stromberg Carlson 1500 Squeal
And life just keeps getting more complicated.dconant — 07:57 AM
54C Complete Teardown/Rebuild
Hello Roy, here is this one sincerely Richardradiorich — 12:45 AM
54C Complete Teardown/Rebuild
Richard, Had grabbed it already but thank you just the same.  I find myself wanting to find some way to block out the...glyphmon — 12:03 AM
54C Complete Teardown/Rebuild
Hello roy, here is a link to the schematic . Sincerely Richardradiorich — 11:54 PM
54C Complete Teardown/Rebuild
Richard, The Silvertone 2014 also is a transformerless set, so I am incorporating a 1:1 600 ohm audio isolation transfo...glyphmon — 11:37 PM
Preliminary work on wife's Silvertone 2014
Did an alignment today which was interesting.  IF alignment went great, almost all was already spot-on.  Adjusting on th...glyphmon — 11:35 PM
54C Complete Teardown/Rebuild
The main problem with adding a Bluetooth input is that this set lacks a traditional power transformer to isolate it from...radiorich — 11:19 PM
54C Cabinet Refinish
I started stripping this cabinet before it got super chilly out because I knew I wasn't going to be able to work on ...glyphmon — 11:18 PM
54C Complete Teardown/Rebuild
While I'm waiting to wrap up the final steps on my wife's Silvertone 2014, I started disassembly on the next project.  O...glyphmon — 11:07 PM

[-]
Who's Online
There are currently 1335 online users. [Complete List]
» 2 Member(s) | 1333 Guest(s)
AvatarAvatar

>