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

PHILCO 38-15 Mod notes?
#16

Thx all

So putting a 78 tube in and I will replace the 1M's and the 250K.
Can always put it back. If I have any issue's. I want to see the difference with the schematic and this Mod any way.

I will let the Phorum know.

Just want to confirm what I am reading.

Thx
#17

Take a look at this schematic:

http://www.nostalgiaair.org/PagesByModel...013233.pdf

It appears that the AVC circuit of this 38-10 model is wired the same way as what you now have (with 6Q7G instead of the 75, but same function). You can see the two 1 Meg resistors connected to the diode plate, with the mica cap connected to the IF coil.

The 250K triode plate load resistor should really not make any difference in operation.

Check the operation of the AVC, because if you remove the 1 Meg resistors, you may disable the AVC function.

Let us know what you find.
#18

Yes

I was just going to rewire per schematic.

I see that whom ever did this mod might of had some problems in the circuit.

So went to this to clean up his AVC.

I have ordered all the resistors.

I will just replace the ones there first see what I get on the radio.

Thank you Very much Mondial this does very clearly show what was done to the 38-15 I have.

Any issues I'll be back

Brad




Users browsing this thread: 1 Guest(s)
[-]
Recent Posts
Correct model 84 Ac plug an cord type
From what I read Philco went to using brown rubber power cords in 1936, so cloth was used in the 1935 and earlier models...Arran — 11:25 PM
Correct model 84 Ac plug an cord type
Hi Bruce, I have not worked on an 84, but in general, power cords for almost any radio prior to 1938 was cloth covered...MrFixr55 — 08:34 PM
Restoring Philco 38-14
OK, well, so after staring at the sch again, I realized the problem had to be the #12/12A padder. I put a scope on the o...morzh — 08:15 PM
Correct model 84 Ac plug an cord type
Hello Bruce, I mostly use brown far as my cloth powercords go ! Here is the plug that I have used bakelite Acorn style...radiorich — 08:05 PM
Correct model 84 Ac plug an cord type
Looking for as correct as can find the right Ac plug an the correct colored cloth line. Ive seen many old photos but mos...Bruce — 04:13 PM
Restoring Philco 38-14
Rod Two Y-caps make sense if you use them from L/N to the chassis; this is only makes sense in the transformer radios...morzh — 10:11 AM
Restoring Philco 38-14
Mike, I'm curious about a specific use of he Y cap. Lately I've seen a single cap across the power transformer primary. ...RodB — 09:01 AM
Restoring Philco 38-14
hello morzh , That sounds like a plan ! Sincerely Richardradiorich — 07:45 AM
Restoring Philco 38-14
Richard, It helped some, but I still had the whining when engaging the rear power strip (I did not realize it was fro...morzh — 07:07 AM
Restoring Philco 38-14
Hello morzh, Yes , that dreaded hum in my room where i do alighment I have my cable modem and router plus desktop plus ...radiorich — 11:25 PM

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

>