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

Replacing a Field Coil with a PM Speaker - Please Help
#16

Good point on getting 89 Ohms for a VC. There is also Ni Chrome Icon_lol

0.89 Ohm VC resistance on a tube amp has a bad smell also.Icon_crazy

Can someone with a good 84B measure the VC resistance?Icon_redface

Ron probably knows without looking
#17

Once upon a time, eletrolytic capacitors were more expensive than chokes, and coil magnets were better than the "permanent" magnets of their time.

So in fxing up an ld set that doesn't care how how you got there, inexpensive larger value capacitors, resistors if needed, and permanent magnet speakers can be used.
#18

Sparky

why exactly are you going to fry anything? and where is that 11:1 ratio came fom?
Again, the speaker voice coil in 84 is 0.89 Ohm (zero point eight nine), not eighty nine ohm.

And so it is more or less in all old early Philcos: 90, 20, 70, 111, 95 and such.
The transformer they use in 2x71A or 2x45 pushpulls are more or less 100:1 ratio hich will turn 0.89 ohm into 8.9 kOhm impedance that ain't gonn burn anything.

So I m not sure what the post was about, but clearly no one uses 1:11 rAtio an 0.89 ohms there for 42 tube.
#19

My 84b had hum to it was caused by a bad ground on the detector tube it was the rivet on the the tube socket that was used for the ground.
#20

Seems like I remember someone having a bad gnd at the rivet on the #42 socket too.
GL
Terry




Users browsing this thread:
[-]
Recent Posts
Philco 91 Restore Code ??
Can someone tell me if my 42 tubes are connected triode or pentode in fixed or cathode bias? How could I tell by looking...dconant — 10:47 AM
Philco 40-120C Restoration
Hello David, that is great news about the tubes source being local ! Sounds like you got good start on the radio . ...radiorich — 09:41 AM
An attempt to remove the Field Coil from a G speaker
Mike; I've only run into a speaker with an open filed coil twice, and they were on newer speakers from the 1940s. One ...Arran — 12:48 AM
An attempt to remove the Field Coil from a G speaker
Arran Yes, this is my plan for now and what do I got to lose, this is not even the speaker from this radio, but one o...morzh — 10:44 PM
An attempt to remove the Field Coil from a G speaker
Mike;  I would unwrap the field coil, and see if maybe there a break near one of the ends, like where the coil wire att...Arran — 10:23 PM
An attempt to remove the Field Coil from a G speaker
...and this is what I did. I fed a little LT into the screwholes with a small brush, and a little on the rim next to the...morzh — 09:52 PM
Philco 40-120C Restoration
I combined the two 40-120C threads together as we like to keep the discussion of the same radio together. It helps with...klondike98 — 09:36 PM
Philco 40-120C Weak, Distorted Ouput
Just checked were I buy tubes price is four dollars. So living in Florid we have a local source for tubes. David    David — 09:14 PM
Philco 40-120C Weak, Distorted Ouput
The higher voltage may be due to higher mains voltage. My mains run 120-125AC when the set was new mains would be 110-11...David — 09:09 PM
Philco 40-120C Weak, Distorted Ouput
Thank you for your reply. I pulled a speaker from a Philco 41-221 and received the same result. I used a signal tracer t...bluecap — 08:45 PM

[-]
Who's Online
There are currently 4258 online users. [Complete List]
» 1 Member(s) | 4257 Guest(s)
Avatar

>