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
Need Help to ID this radio 11 tube Philco
If you want a radio that's difficult to work on, get a 37-620. The one side of the chassis is packed pretty tightly and ...Greg — 07:29 PM
Need Help to ID this radio 11 tube Philco
Philco 16 is not intimidating at all. Despite being an 11-tuber. 37-116 is indeed intimidating. 16 has good space unde...morzh — 04:11 PM
48-482 rear panel help
Thanks for the responses Gary and Bob. I'm a little surprised that there's no back panel - although I know older Philco'...keithchip — 04:09 PM
48-482 rear panel help
Gary is correct, there was not a rear panel on the 48-482. I restored one of those and its a great sounding radio that ...klondike98 — 03:24 PM
The list of my radio & TV collection!
A little light positivity in our feed... To nostalgic retro music... With English subtitles My new video on the contin...RadioSvit — 02:14 PM
My Philco 37-116 Restore
Ron and Mike I mentioned a 2 meg resistor not on the schematic. I stumbled on a changes note in Riders that mentioned th...dconant — 12:02 PM
Need Help to ID this radio 11 tube Philco
Here you go: Your the code 125Radioroslyn — 11:12 AM
My Philco 37-116 Restore
Hi Ron, Thanks for the input. I think I'm going to call it good enough. It does seem weird I can usually dial in othe...dconant — 08:01 AM
Need Help to ID this radio 11 tube Philco
Welcome, the radio looks intimating 11 tubes, wish you well.Jimradio — 07:49 AM
462ron
Hi Dan, it’s been 10 years since I restored the electronics on my 37-116 so I’m going on some foggy memories. I remember...462ron — 07:37 AM

[-]
Who's Online
There are currently 335 online users. [Complete List]
» 1 Member(s) | 334 Guest(s)
Avatar

>