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

1948 Magnavox "Berkeley" Just Acquired!
#16

If you are planning on playing this radio to any extent, I would at least recommend changing the coupling caps connected to the control grids of the 6L6G output tubes. They are marked 35 (.03 uF) and 43 (0.1 uF) on the schematic. Any leakage through these caps will throw off the DC bias of the 6L6's causing them to draw excessive current. This could cause a runaway condition which could take out the tubes, output transformer and eventually the power supply.

You can restuff these two with modern film caps if you want to retain the original appearance.

http://www.nostalgiaair.org/PagesByModel...010334.pdf
#17

If you have not done so already, REPLACE THE POWER SUPPLY FILTER CONDENSERS !!! before you do anything else, before you turn it on again. They are the most likely to go, and if they do they can take the power transformer with them. Actually, I strongly suggest also replacing all the paper condensers, and checking all the resistors for out of spec ones and replace those too. Once done you will have a radio-phono which will be far more reliable, and probably only need a tube replaced now and then for the next half century.
#18

Thinking out loud maybe the reason the set looks so clean is somebody in the past restuffed the caps!
#19

I checked many of the caps and resistors, and it seems that the only caps that were bad were the across the line caps (there were 3 of them and they were all .02 µF 600V Micamold "Domino" style paper caps which were all leaking "wax" out of them, the rest of the paper caps measured fine yet using my Cornell-Dublier Capacitor Analyzer.

I agree with David that quite possibly this radio's cap's were restuffed sometime in the recent past as they tested little to no leakage, there was 2 paper caps that looked like they might of been later replacements, either that or they were sourced from a different source than the rest of the caps in this unit for some reason.




Users browsing this thread:
[-]
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 4798 online users. [Complete List]
» 2 Member(s) | 4796 Guest(s)
AvatarAvatar

>