1. The PHILCO Phorum
  2. Philco Radio Discussions
  3. Philco Electronic Restoration

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

Linear Mode
Model 71 oscillator
WB5NEN
Junior Member
**
Posts: 13
Threads: 1
Joined: Aug 2020
City: Corrales State, Province, Country: NM
#4

09-07-2020, 05:16 PM
Steve and Terry,

It’s working. I noticed that, by touching the grid cap on the oscillator, it sprang to life. But next time, it was dead until I touched the grid cap again. Rinse, repeat. This struck me as odd, so I paralleled a resistor across the 15k cathode dogbone resistor (which actually measured 12.5K.) The  current value of these two resistors is 8.4K. Right now, that oscillator starts up automatically every time I turn the set on. But I’m leaving it on the bench for awhile. Fingers crossed.

I did remove and examine the oscillator coil. I just wanted to see it. It’s fine, as I suspected, because the large oscillator coil showed continuity and 4.3 ohms. The “input” coil From the RF stage in this radio is just a turn of wire...and one end is unterminated. It just floats.

Now, can someone educate me on this cathode resistor...I’m not clear on what I’ve done, or why. Sorry for the ignorance.

And thanks, gents.

Richard
Find
« Next Oldest | Next Newest »
Thread Closed


Messages In This Thread
Model 71 oscillator - by WB5NEN - 09-06-2020, 02:17 PM
RE: Model 71 oscillator - by Steve Davis - 09-06-2020, 10:16 PM
RE: Model 71 oscillator - by Radioroslyn - 09-07-2020, 08:39 AM
RE: Model 71 oscillator - by WB5NEN - 09-07-2020, 05:16 PM
RE: Model 71 oscillator - by WB5NEN - 09-07-2020, 07:32 PM
RE: Model 71 oscillator - by Radioroslyn - 09-07-2020, 07:53 PM
RE: Model 71 oscillator - by WB5NEN - 09-07-2020, 10:15 PM
RE: Model 71 oscillator - by WB5NEN - 09-08-2020, 01:57 PM
RE: Model 71 oscillator - by Radioroslyn - 09-08-2020, 07:58 PM
RE: Model 71 oscillator - by Steve Davis - 09-08-2020, 11:47 PM
RE: Model 71 oscillator - by WB5NEN - 09-09-2020, 04:19 PM
RE: Model 71 oscillator - by Radioroslyn - 09-09-2020, 06:57 PM
RE: Model 71 oscillator - by RodB - 09-09-2020, 07:00 PM
RE: Model 71 oscillator - by Radioroslyn - 09-09-2020, 08:49 PM
RE: Model 71 oscillator - by WB5NEN - 09-09-2020, 10:18 PM
RE: Model 71 oscillator - by Radioroslyn - 09-10-2020, 08:07 AM
RE: Model 71 oscillator - by WB5NEN - 09-10-2020, 08:50 AM
RE: Model 71 oscillator - by RodB - 09-10-2020, 08:57 AM
RE: Model 71 oscillator - by Radioroslyn - 09-10-2020, 10:34 AM
RE: Model 71 oscillator - by rfeenstra - 09-10-2020, 04:46 PM
RE: Model 71 oscillator - by WB5NEN - 09-10-2020, 10:43 PM
RE: Model 71 oscillator - by rfeenstra - 09-11-2020, 09:38 AM
RE: Model 71 oscillator - by WB5NEN - 09-11-2020, 10:07 AM
RE: Model 71 oscillator - by rfeenstra - 09-11-2020, 12:54 PM
RE: Model 71 oscillator - by rfeenstra - 09-11-2020, 01:05 PM
RE: Model 71 oscillator - by WB5NEN - 09-14-2020, 06:58 PM
RE: Model 71 oscillator - by Radioroslyn - 09-15-2020, 09:46 AM
RE: Model 71 oscillator - by WB5NEN - 09-15-2020, 12:00 PM
RE: Model 71 oscillator - by WB5NEN - 09-18-2020, 07:29 PM



Users browsing this thread: 2 Guest(s)
[-]
Recent Posts
Need to purchase some accessories for restoration of my Old Philco Radio
Hi Paulo, Welcome to the Philco Phorum. I can see why you want to find good reproduction parts. That is a bea...MrFixr55 — 11:10 PM
HiFi (Chifi) tube amp build - but my own design.
Tim, I have some bakelite sockets in my work shop that I can dig up. I believe quite a few are NOS. I will take photo...RodB — 10:03 PM
Philco 610B oscillator wiring
> The cathode as noted is wired directly to the ground side of the heater filament for that tube, not to the #17 and ...Radioroslyn — 08:12 PM
HiFi (Chifi) tube amp build - but my own design.
Tim; I noticed your post a little late, but I would take one of the junk sockets and try to break a chunk out of it wi...Arran — 08:07 PM
Need to purchase some accessories for restoration of my Old Philco Radio
Here is a list of resources found in our online library that you might find useful. Mike's Gobs of Knobs email addres...klondike98 — 01:46 PM
First Radio restoration
Hi Tubeman, Welcome to the Philco Phorum.  Phamily Phriendly Pfun with Phine Pholks Phull of Philco Phacts. (See a p...MrFixr55 — 12:33 PM
First Radio restoration
You could post in the WANTED ADs section here on the Phorum and see if anyone has an RF generator that they want to sell...klondike98 — 11:55 AM
Zenith H725
Good ideas, thank you Arrange and Rich. I have the adhesive aluminum foil already and can try that immediately. More ...EdHolland — 10:18 AM
Graphics for majestic 1050 dial glass.
Murf; I found this thread on the ARF, the first photo has a pretty good view of the dial glass. Regards ArranArran — 01:12 AM
Zenith H725
hello Ed, how about that speacial tape used for ducting it's like foil or how about thin piece of aluminum roof flash...radiorich — 12:19 AM

[-]
Who's Online
There are currently 2054 online users. [Complete List]
» 4 Member(s) | 2050 Guest(s)
AvatarAvatarAvatarAvatar

>
  1. The PHILCO Phorum
  2. Philco Radio Discussions
  3. Philco Electronic Restoration