Welcome Guest! Be sure you know and follow the Phorum Rules before posting. Thank you and Enjoy! (January 12) x

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

38-12 can caps?
#1

Ok This one has 2 can caps one is 12 mfd @450v the other is 4 mfd @450V In the picture below the cap in green has a negative lead and the center is for positive but the one in red seems to only have positive(center post) is the negative attached to the outside of the can and attached to the chassis if so where can I attach the negative?Thanks Doug
[Image: http://i1095.photobucket.com/albums/i474...hoto01.jpg]
#2

(03-06-2012, 09:01 PM)fixinmyphilco Wrote:  Ok This one has 2 can caps one is 12 mfd @450v the other is 4 mfd @450V In the picture below the cap in green has a negative lead and the center is for positive but the one in red seems to only have positive(center post) is the negative attached to the outside of the can and attached to the chassis if so where can I attach the negative?Thanks Doug
[Image: http://i1095.photobucket.com/albums/i474...hoto01.jpg]

That's because the one circled in red is grounded to the chassis and the one circled in green has a floating ground. This was a very common practice in 1930s radios, the reason they would do this is so they could install a fixed bias network between the center tap of the high voltage winding and the chassis.
Regards
Arran
#3

So if I rebuild the can I can just make sure the negative lead is touching the outside of the can or if I by-pass it the negative would just connect to the chassis perhaps where the paper cap next to it there connects to the chassis?
(03-06-2012, 09:20 PM)Arran Wrote:  
(03-06-2012, 09:01 PM)fixinmyphilco Wrote:  Ok This one has 2 can caps one is 12 mfd @450v the other is 4 mfd @450V In the picture below the cap in green has a negative lead and the center is for positive but the one in red seems to only have positive(center post) is the negative attached to the outside of the can and attached to the chassis if so where can I attach the negative?Thanks Doug
[Image: http://i1095.photobucket.com/albums/i474...hoto01.jpg]

That's because the one circled in red is grounded to the chassis and the one circled in green has a floating ground. This was a very common practice in 1930s radios, the reason they would do this is so they could install a fixed bias network between the center tap of the high voltage winding and the chassis.
Regards
Arran





Users browsing this thread: 1 Guest(s)
[-]
Recent Posts
91H Code 126 Restore
Well I'm making good progress. All the bakelite blocks have been recapped.  I found that using a heat gun and skinny ...RealRider — 02:35 PM
Philco model 60
>>and found that the field coil is bad. Should be 1140 ohms, tests at 1.1k ohms. You have one stringent crit...morzh — 02:07 PM
Philco model 60
Yes I was there. I got some real bargains there. Plus a Zenith 7G605 clipper that I have been trying to find for a fair ...Radios1340 — 01:46 PM
The speaker table error?
G  10-1/2"       65, 76, 87, 95 Push-Pull 45's 2766 0.7 550 3200 H   10-1/2"    77, 96 Push-Pull...morzh — 09:26 PM
A Marconi model 86
I have a Stromberg, one of the early ones, seems early 30s. This is what I call a back breaker. None of the early Philc...morzh — 08:28 PM
A Marconi model 86
A backbreaker.....PaulPaul Philco322 — 08:12 PM
A Marconi model 86
>>What a behemoth! A Juggernaut.morzh — 07:47 PM
Philco 70 antenna lead
I am not sure I understood about the coils and the mush. I looked an more than one coil in 20, 70, 90, 60, Zeniths and ...morzh — 07:46 PM
A Marconi model 86
:e_biggrin: What a behemoth!  I hope the final result is as much a quality sounding example!  Keep us posted on your pro...GarySP — 07:32 PM
A Marconi model 86
I should add that the double conversion may only be used on the shortwave bands, but I haven't looked at the schematic t...Arran — 07:27 PM

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

>