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Philco 41-295 Restor/Service Bulletin 365
#1

I need some help. The radio needs all rubber wiring replaced. Is 300 v pvc coated 20 ga copper strand is OK? A quick check of the secondary open circuit voltage off the center tap gives 313 vac. I think the power supply should have caps at 350 vdc.

The electrolytic on the service bulletin call for 18 and 25 uf but no voltage rating. The cans in the set appear original and are 25 and 40 uf at 475 volts. The b+ is supposed to be 245 VDC. What caps would you use?

There is an error in the bulletin, the parts show a 115 ohm resister but the schem shows 150 ohm and that is what is in the bias circuit of the power supply.

There is a red wire soldered to the tuning capacitor but is broken off and I have no idea where it is attached. The schematic shows connections to the band switch. Any ideas?

Does anyone have any ideas about the wire color coding?

The set has white and red on the tube filaments and dial lights, some blue and green on the band switch and IF cans.

There are 4 dial lights; two 34-2064 that I believe are type 44 6.3vac/.25a and two 34-2141 that I believe are type 47 6.3vac/l15a. Not sure about the 2141’s.
#2

On your wire 300v rating should be fine. I have used wire from Napa auto parts with no trobule. It's made by Belden and comes in as small as 20awg. Colors red,black,yellow,green, and I think blue.

On the filter caps I always use at least 450v rating unless it some special bias bypass cap. On start up the voltage can go much higher until the filaments warm up. 

On your other questions, I defer to someone more knowledgeable.

Oh and it helps if you post a link to the schematic.

Chris
newbie 2nd class

!!!!!!!!!!!!!!!!!!!RESISTANCE IS FUTILE!!!!!!!!!!!!!!!!!!!!!!  
                           /\/\/\/\/\/\/\/\/\
                                                     
                                 [Image: http://philcoradio.com/phorum/images/smi...on_eek.gif]  Chris
#3

millevolt,
I used 20 & 30 ufd @450VDC for C83 & C80. The voltage on C80 will go well over 350VDC upon initial power up.
Normally it runs about 320-325 VDC after warmup. Yes, the tuning cap osc. section goes to bandswitch wafer A&B
pin 12. The tuning cap aerial section goes to bandswitch wafer D pin 12..... Getting to this pin with the bandswitch in the chassis is very difficult if not impossible. I removed the bandswitch to replace the rubber wires in my 41-295.
Nessitated making comprehensive wiring lists and studying the schematic closely and was time consuming...had to replace a broken B wafer anyway. There is a gimmick wire on top of the tuner cap also where one end is not connected by design.
You can use all #44 lamps o.k. R82a is 150 ohm, I used a 5 W to replace it....the parts list is incorrect. Just follow the original color code if you wish...not that important. Not a easy set to work on...lots of components but works well when completed. John
#4

   

THIS IS A PIC OF THE TUNING CAP WIRE TO NOWHERE  THE WIRE ON THE RIGHT IS PART OF ONE OF THE DIAL LAMP WIRES.
#5

These look like stator wires.
Look in the sch.
#6

(12-27-2014, 02:02 PM)millievolt Wrote:  THIS IS A PIC OF THE TUNING CAP WIRE TO NOWHERE  THE WIRE ON THE RIGHT IS PART OF ONE OF THE DIAL LAMP WIRES.

That's the 'gimmick' wire I referred to. It is normal...just resleeve the rubber insulation, if cracked with heat shrink.
John 




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