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-   -   Philco 38-12 radio (http://www.videokarma.org/showthread.php?t=270553)

timmy 06-10-2018 09:04 AM

Philco 38-12 radio
 
Well just picked this radio up and seems to be common one and chanced turning it on using an inverter and it's got the typical buzzing that am radios have but it didn't pickup any stations but I'm going to recap it. I'll have to chance this after recapping because I have no clue if the tubes are good or not since these tubes are so early I gave away my tube tester that would have tested these now I have none to test them with. If anyone knows these radios , is there any known problems with these radios that need special attention.

Zsuttle 06-10-2018 10:46 AM

Like most of the starter Philco sets, I think this one is relatively simplistic. Just don't forget about the bakelite capacitor block, If I recall correctly, this set uses one

dieseljeep 06-10-2018 10:47 AM

Quote:

Originally Posted by timmy (Post 3200693)
Well just picked this radio up and seems to be common one and chanced turning it on using an inverter and it's got the typical buzzing that am radios have but it didn't pickup any stations but I'm going to recap it. I'll have to chance this after recapping because I have no clue if the tubes are good or not since these tubes are so early I gave away my tube tester that would have tested these now I have none to test them with. If anyone knows these radios , is there any known problems with these radios that need special attention.

I have two in my collection!
Standard transformer powered five tube radio.
Initial check procedure: Remove 84 rectifier tube and see if the rest of the tubes light up, of course with power applied. Replace the electrolytic caps and the coupling cap from the 75 plate to the 41 output tube. Make sure the two resistors are good in the bias line. Then try it!
Tubes are the last things I worry about in a radio that basic.

jr_tech 06-10-2018 11:00 AM

Schematic here:

https://www.google.com/search?q=phil...O2nPfkz-m59jM:

I don't see any capacitor blocks... looks pretty simple.

jr

timmy 06-10-2018 12:40 PM

Quote:

Originally Posted by Zsuttle (Post 3200697)
Like most of the starter Philco sets, I think this one is relatively simplistic. Just don't forget about the bakelite capacitor block, If I recall correctly, this set uses one

What is that capacitor block which is listed as a compensator, whatever that is. :scratch2: how is anyone able to make out the colors for the values of the resistors in this radio, the colors are weird and don't make sense.

dieseljeep 06-10-2018 02:11 PM

Quote:

Originally Posted by jr_tech (Post 3200701)
Schematic here:

https://www.google.com/search?q=phil...O2nPfkz-m59jM:

I don't see any capacitor blocks... looks pretty simple.

jr

It looks like the power line filter is one of Philco's bakelite blocks.

dieseljeep 06-10-2018 02:18 PM

Quote:

Originally Posted by timmy (Post 3200714)
What is that capacitor block which is listed as a compensator, whatever that is. :scratch2: how is anyone able to make out the colors for the values of the resistors in this radio, the colors are weird and don't make sense.

Philco's name for trimmer condenser is compensator. Looks like the 2nd IF transformer is mounted on the back of the chassis with the compensator.
I don't remember the resistors used in the radio. Just use the schematic from Nostalgia Air.

Zsuttle 06-10-2018 05:37 PM

Quote:

Originally Posted by dieseljeep (Post 3200719)
It looks like the power line filter is one of Philco's bakelite blocks.

Yeah, that's the one I was referring to, however, I've had experience with Philco substituting items sometimes. I've found capacitor blocks where they shouldn't have been, and tubular caps the same. Could have been factory, or someone replacing with OEM parts, either way they were genuine philco stuff. Either way, they matched the schematic, though not the under chassis diagram provided.

Electronic M 06-10-2018 06:10 PM

Quote:

Originally Posted by Zsuttle (Post 3200730)
Yeah, that's the one I was referring to, however, I've had experience with Philco substituting items sometimes. I've found capacitor blocks where they shouldn't have been, and tubular caps the same. Could have been factory, or someone replacing with OEM parts, either way they were genuine philco stuff. Either way, they matched the schematic, though not the under chassis diagram provided.

ARF has a pretty good page under their resto section that translates the part numbers into cap values for the blocks (sadly it does a poor job for the ones that contain resistors and caps)....I just chip the tar out with a couple different sized screwdrivers and hide the new caps inside the block....Since the blocks act as terminal strips it is cheaper, simpler, and better looking to restuff them rather than replace with new terminal strips.

timmy 06-10-2018 06:21 PM

While this radio is really simple the schematic is not so clear as to the values of the resistors since some number 3s look like 5s because of ink bleed on the paper so I guess the best way is to try to compair the value of the resistor with what it shows on paper with adding more for drift. :yes:

dieseljeep 06-11-2018 11:05 AM

Quote:

Originally Posted by timmy (Post 3200734)
While this radio is really simple the schematic is not so clear as to the values of the resistors since some number 3s look like 5s because of ink bleed on the paper so I guess the best way is to try to compair the value of the resistor with what it shows on paper with adding more for drift. :yes:

There is very little problem reading the resistor values on the N/A Schematic, plus every part is listed by number on the parts list.
Philco is the one that started using the odd-at-the-time values of resistors, ie 47K instead of 50K, 2.2 K instead of 2K or 2.5K etc.
They claimed that some color codes were hard distinguish under the then-new Mercury Vapor lighting, being used in their plant.

timmy 06-11-2018 05:25 PM

Quote:

Originally Posted by dieseljeep (Post 3200765)
There is very little problem reading the resistor values on the N/A Schematic, plus every part is listed by number on the parts list.
Philco is the one that started using the odd-at-the-time values of resistors, ie 47K instead of 50K, 2.2 K instead of 2K or 2.5K etc.
They claimed that some color codes were hard distinguish under the then-new Mercury Vapor lighting, being used in their plant.

I have the NA schematic , even looking at it on line seemed Alittle bit of bleeding on the type. Well I don't have vapor lighting here, lol,lol :D

timmy 06-11-2018 08:41 PM

Quote:

Originally Posted by dieseljeep (Post 3200765)
There is very little problem reading the resistor values on the N/A Schematic, plus every part is listed by number on the parts list.
Philco is the one that started using the odd-at-the-time values of resistors, ie 47K instead of 50K, 2.2 K instead of 2K or 2.5K etc.
They claimed that some color codes were hard distinguish under the then-new Mercury Vapor lighting, being used in their plant.

Well I took out the 84 and the other 4 tubes do light. So now I'm off to check resistors and recap.

Electronic M 06-11-2018 11:47 PM

Most of the riders manuals were poorly scanned back in the 90's and no one ever bothered to fix that. The original books are much better, but the print is rather fine...One day I gotta get me the full paper riders.

dieseljeep 06-12-2018 10:35 AM

Quote:

Originally Posted by Electronic M (Post 3200811)
Most of the riders manuals were poorly scanned back in the 90's and no one ever bothered to fix that. The original books are much better, but the print is rather fine...One day I gotta get me the full paper riders.

Someone at the WARCI meet had some paper issues. That might've been the one you missed. I have some duplicates from the shop that closed down.
Let me know what ones you need.
BTW, the N/A scans are pretty good.


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