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

Philco 71 restoration
#28

An osc is a amp with a small amount the output fed back to the input. Among homebrewers it all ways seems when building something that is suppose to oscillate it amplifies and vise versa.
How your set does it is a bit of the energy from the cathode is coupled inductively to the plate though the coil. With the cathode coil open two things happen. One no feedback/no oscillation. Two the 36 tube has no dc ground so it won't draw much it any current. So it won't amplify very well either.
Make sense?
Terry 'gte
PS
Short answer is yes.

When my pals were reading comic books
I was down in the basement in my dad's
workshop. Perusing his Sam's Photofoacts
Vol 1-50 admiring the old set and trying to
figure out what all those squiggly meant.
Circa 1966
Now I think I've got!

Terry


Messages In This Thread
Philco 71 restoration - by ipwizard - 09-29-2011, 12:48 AM
RE: Philco 71 restoration - by ipwizard - 03-02-2012, 06:09 PM
Re: Man this thing is a nightmare - by ipwizard - 09-29-2011, 01:36 AM
Re: Man this thing is a nightmare - by ipwizard - 09-29-2011, 10:14 PM
Re: Man this thing is a nightmare - by ipwizard - 10-06-2011, 12:29 AM
Re: Man this thing is a nightmare - by Arran - 10-06-2011, 02:24 AM
Re: Man this thing is a nightmare - by rghines1 - 10-06-2011, 10:20 AM
Re: Man this thing is a nightmare - by exray - 10-06-2011, 12:41 PM
Re: Man this thing is a nightmare - by ipwizard - 10-08-2011, 10:34 PM
Re: Man this thing is a nightmare - by Marsupial - 10-08-2011, 11:52 PM
Re: Man this thing is a nightmare - by exray - 10-09-2011, 05:56 AM
Re: Man this thing is a nightmare - by ipwizard - 10-10-2011, 01:40 PM
Re: Philco 71 restoration - by ipwizard - 10-31-2011, 05:10 PM
Re: Philco 71 restoration - by 7estatdef - 10-31-2011, 08:48 PM
Re: Philco 71 restoration - by 7estatdef - 10-31-2011, 09:00 PM
Re: Philco 71 restoration - by ipwizard - 11-01-2011, 01:03 AM
Re: Philco 71 restoration - by ipwizard - 11-01-2011, 01:06 AM
Re: Philco 71 restoration - by 7estatdef - 11-01-2011, 10:58 PM
Re: Philco 71 restoration - by ipwizard - 11-03-2011, 01:03 AM
Re: Philco 71 restoration - by 7estatdef - 11-03-2011, 02:59 AM
Re: Philco 71 restoration - by codefox1 - 11-03-2011, 10:04 AM
Re: Philco 71 restoration - by ipwizard - 11-03-2011, 06:00 PM
Re: Philco 71 restoration - by 7estatdef - 11-03-2011, 06:26 PM
Re: Philco 71 restoration - by ipwizard - 11-03-2011, 06:31 PM
Re: Philco 71 restoration - by 7estatdef - 11-03-2011, 06:42 PM
Re: Philco 71 restoration - by ipwizard - 11-03-2011, 07:40 PM
Re: Philco 71 restoration - by 7estatdef - 11-03-2011, 08:39 PM
Re: Philco 71 restoration - by ipwizard - 11-03-2011, 09:38 PM
Re: Philco 71 restoration - by ipwizard - 11-04-2011, 12:29 AM
Re: Philco 71 restoration - by ipwizard - 11-04-2011, 02:33 PM
Re: Philco 71 restoration - by ipwizard - 11-30-2011, 11:56 PM
Re: Philco 71 restoration - by TA Forbes - 12-01-2011, 12:37 AM
Re: Philco 71 restoration - by TA Forbes - 12-02-2011, 09:54 PM
Re: Philco 71 restoration - by codefox1 - 12-03-2011, 11:48 AM
Re: Philco 71 restoration - by ipwizard - 12-04-2011, 03:03 PM
Re: Philco 71 restoration - by ipwizard - 12-23-2011, 04:36 AM



Users browsing this thread: 7 Guest(s)
[-]
Recent Posts
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
Philco 70 antenna lead
Yes, that wire will not pick up much interference as routed - the RF at that level won't be affected, and if you have st...radio1 — 07:26 PM

[-]
Who's Online
There are currently 7587 online users. [Complete List]
» 3 Member(s) | 7584 Guest(s)
AvatarAvatarAvatar

>