41-221

 


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Philco 41-221  

Manufactured about April 1941

 

This radio receives both Broadcast and Short Wave band.  

 

Most of the insulation has deteriorated and is crumbling off.  About 30% is OK.  Philco seemed to use two types of rubber for insulation.  It was 1940-40 during WW2 when this radio was manufactured.  Materials were in short supply for consumer goods.  This is a rather common occurrence with radios manufactured during these years.  

Schematic here.

IMG_6132.JPG (111943 bytes) IMG_6129.JPG (165129 bytes)

Cabinet to be refinished.

IMG_6130.JPG (154265 bytes)

A new dial scale cover will be ordered.  

IMG_6131.JPG (124546 bytes) IMG_6128.JPG (163167 bytes) IMG_6133.JPG (174875 bytes)
IMG_6134.JPG (159110 bytes) IMG_6135.JPG (204530 bytes)

All tubes tested good. 

IMG_6136.JPG (175850 bytes)

A twisted wire capacitor gimmick.  It measures about 5 to 7 pf.  It is not on the schematic.  That internal resistor gets replace too. 

IMG_6138.JPG (176613 bytes)

Good Tools and test gear is essential to an accurate capacitor fabrication. 

IMG_6139.JPG (179518 bytes)


The old dial cord is frayed. 

IMG_6140.JPG (166363 bytes)

New dial cord.  The chassis was treated to Brasso and Elbow Grease to remove the dirt.  

IMG_6141.JPG (119504 bytes) IMG_6142.JPG (222599 bytes) 

I can not get the AM band to go below 580khz. I started with heating the coils and extra cleaning then heating of the band switch. Next is to clip measure and replace the mica and ceramic caps.  

Fixed it with the proper value of resistor #21.  I goofed and installed 10X too small. 

IMG_6144.JPG (197211 bytes)

Yep. Made by Micamold.  It is marked on the back.  There is paper inside this cap.  But replacement did not restore the frequency coverage.

IMG_6143.JPG (189052 bytes)

I replaced all the mica caps.  Still not low enough.  I have ordered a new 14AF7 oscillator tube.  This is about the last thing to replace that affects frequency spread. 

 

No change with different tubes.

There is an outside chance it may be the tuning capacitor rotor ground.  It depends on under the chassis mounting screw connection.  This could be causing problems.  I will add a separate ground strap.  

 

No change with ground strap. 

IMG_6135crop.JPG (38867 bytes)

Unused ground connection.  Age and wear may have compromised the ground.  I did burnish and clean the wiping surfaces early on in the restoration.  A bad oscillator tube can also cause this problem. 

RE-ASSEMBLY

IMG_6236.JPG (176213 bytes)

Band indicator filled in with black paint.

IMG_6237.JPG (204183 bytes) IMG_6238.JPG (319361 bytes)

New Dial scale cover on the left. 

IMG_6239.JPG (436831 bytes)

New parts under chassis.

IMG_6240.JPG (199270 bytes)

Rear view.

IMG_6241.JPG (193131 bytes)

Front View of completed radio. 

IMG_6242.JPG (149244 bytes)

Tom* did the refinishing.

IMG_6243.JPG (146411 bytes) IMG_6244.JPG (171061 bytes)

Rear cover.

IMG_6246.JPG (27224 bytes)

Lights out.  

   
           

* I have a friend Tom that is doing most of my refinishing since late 2009. Wood finishing has been his profession and he is much faster than me. It takes Tom a fraction of the time to accomplish (strip, stain, color blend, repair, finish, etc) what takes me a week to do. 

 Tom is an artist!  Click on this paragraph and go to his new web site.  

There is always a few chassis that just don't make it easy to align.   I have not been defeated yet!  R21 had the wrong value installed and replacing the 14AF7 rendered the radio stable, no squegging.  Once replaced all aligned in easily.

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