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

What's Wrong With My Filament Circuit?
#1

Same 40-190.
http://www.nostalgiaair.org/PagesByModel...013339.pdf
I have about 9Vac on my filament circuit unloaded. But when I install the #47 dial lamp in its socket my voltage drops off into the mV range. The socket isn't shorted and has the same 9Vac on it until I install the lamp. I'm just getting the set checked out after a full restoration. The only tube installed is the rectifier so I could look at those voltages. They're good.

But what am I not seeing in my dial lamp/filament circuit? The lamp socket completes the circuit to ground. My ground is good. Icon_confused

EDIT: With my power transformer filament leads isolated I read an open across them. This isn't good but why do I see 9Vac when it's powered up?

Pepper

"It's Nice To Be Nice To The Nice"
Major Frank Burns Mash 4077th
#2

Open fil winding. You're seeing capacitive/inductive coupling to the open winding.
You are seeing a "ghost" voltage when no current is flowing (which can't due to open circuit).

Chuck
#3

Thanks Chuck! Kinda figured that. Icon_sad But already have the old one out which wasn't original to begin with and another from a parts set ready to go. Icon_smile Didn't like the one that was on there anyway. Someone had changed it and swapped the 84 rectifier for a 5Y3. The bad transformer was a 250-0-250 which I was told would work but the new one I'm putting on it is a little bigger and is 350-0-350. Had to remove 1/4" of chassis on the length but otherwise a good fit.

Pepper

"It's Nice To Be Nice To The Nice"
Major Frank Burns Mash 4077th




Users browsing this thread: 1 Guest(s)
[-]
Recent Posts
Philco Model 249 made in England
Thanks for the information MrFixr55.   It's tube amplification and not solid state. TOMfklown — 11:27 AM
Philco Model 249 made in England
Well, I’ll be! I learned something.jrblasde — 11:03 AM
Philco Model 249 made in England
Yes, Garrard was well-regarded for its standalones.morzh — 10:48 AM
Philco 46-480 Electronic Restoration
Quite the interesting stories, sir! Somewhat reminds me of my first job out of school (not that I worked in a similar fi...jrblasde — 09:33 AM
Philco model 40-100
Arran, I restored 2 Canadian battery-crank telephones for a friend a while ago, a Northern Electric (Canadian version of...MrFixr55 — 08:04 AM
Road Trip for a Philco 46-480
Beautiful work, a 79 year old radio brought back to life. The first FM radios for me, a little iffy, had some I just cou...Jimradio — 08:01 AM
Philco 46-480 Electronic Restoration
I was a field engineer for a biomedical company for many years. Many was the time that I was driving home from NYC in t...MrFixr55 — 06:40 AM
Philco 46-480 Electronic Restoration
Don't laugh folks, I have not been above taking a chassis into the bathtub (when Ms. Fixr was out of the house), taping ...MrFixr55 — 06:02 AM
Philco model 40-100
Marion; By "newer style" carbon resistors do you mean the molded type with coloured bands rather then the BE...Arran — 01:00 AM
Philco 46-480 Electronic Restoration
hello jrblasde , your radio sounds great well done !! I bought like 20 years ago a Philco 610b that someone had painte...radiorich — 11:50 PM

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

>