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

Modified 54C - Oscillator Issue
#1

Just for fun, I decided to try and see if I could convert a 54C to use octal tubes in order to eliminate the two large dropping resistors. It was mostly successful.

Mostly?

Well, now the thing will not tune correctly. The oscillator is working, but is way, way out of range - beyond a simple alignment issue.

Our local AM station at 990 kc won't even come in. Stations which should be on the higher end of the band are coming in on the lower end.

IFs are properly aligned at 460 kc.

Please look over the modified schematic below, and then tell me -

Would you consider this to be an oscillator coil issue? Or is there something else I am missing here?

Thanks. Oh, and you can compare the schematic below with the original 54 schematic which may be found here.

   

--
Ron Ramirez
Ferdinand IN


Messages In This Thread
Modified 54C - Oscillator Issue - by Ron Ramirez - 11-20-2021, 11:59 PM
RE: Modified 54C - Oscillator Issue - by OZ4 - 11-21-2021, 01:12 PM
RE: Modified 54C - Oscillator Issue - by OZ4 - 11-21-2021, 01:26 PM
RE: Modified 54C - Oscillator Issue - by MrFixr55 - 11-21-2021, 05:12 PM
RE: Modified 54C - Oscillator Issue - by morzh - 11-21-2021, 06:10 PM



Users browsing this thread: 1 Guest(s)
[-]
Recent Posts
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
Zenith H725
Ed; One material that I have seen, but never tried for this was material for making exhaust gaskets, it's similar to ...Arran — 11:42 PM
Zenith H725
I just remembered, I have some hi temp silicone rubber material which could do the trick. Or a piece of FR4 laminate. Th...EdHolland — 08:39 PM
Zenith H725
The PSU filter cap arrived today (thank you USPS!) so I will work on that later. Meanwhile, I have the dial, speaker...EdHolland — 06:42 PM
Philco 610B oscillator wiring
Thanks Terry. After checking my notes I think I recorded about -10v at the 6A7 G4/control grid. The screen grid (G3 &...Tubester — 05:59 PM

[-]
Who's Online
There are currently 1516 online users. [Complete List]
» 1 Member(s) | 1515 Guest(s)
Avatar

>