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

Weird Symptom 42-355
#1

A few years ago I recapped a 42-355, and it worked perfectly for a long time.  In the last few months it's developed a strange problem.

Every now and then, when listening to one of the push-button preset stations, suddenly the sound will drop out.  Sometimes I can hear faint signals from other stations if I turn the volume up, but they are definitely the not station I was listening to when it dropped out.  Other push buttons work fine, just not the one I was listening to when the signal dropped out.  So I think the LO is temporarily retuning itself from the preset frequency, not just losing contact with the band switch / push button block.

The only thing that will reliably bring back the signal from the push-button preset station is to push the AM band dial tuning button, then tune it manually to the station I was listening to, and then push the preset button for that station again.  Works every time.

After that, all the push buttons and the dial tuning work as designed until the next time.  If I push the AM band selector button but don't tune it to the frequency of the push button that dropped out, it still doesn't work.  Somehow the dial tuning has to be set to the same frequency as the button preset.  But once the preset station comes back, it doesn't matter what I do with the dial tuning, until the next time it drops out.

I'm sure this symptom has affected buttons 2 and 5, and probably 3 at one time or another.  I rarely listen to the other presets.

Any ideas?   Why the dial tuning has to be tuned to the preset frequency to restore the button preset is beyond me.

John Honeycutt
#2

Deoxit.




Users browsing this thread: 1 Guest(s)
[-]
Recent Posts
1949 Motorola 5A9M
bob  Nice work on battery . If you don't. Have terminals i have a few spares  Samsam — 02:12 AM
1949 Motorola 5A9M
hello mr Fixr, for sure !! I have some radios that I need to make some batteries for too. Sincerely richardradiorich — 12:33 AM
1949 Motorola 5A9M
Dittos, sweet b on the battery. Love the "9 Lives" logo, remembered from my childhood. Other neat ones are t...MrFixr55 — 11:24 PM
Philco 46-1209 strange behavior
Hi Morzh, Dunno if the AC EMI caps are an issue. I never liked the concept but never had an issue with these causin...MrFixr55 — 11:21 PM
Philco 46-1209 strange behavior
And no hum without the 7AF7? Not common but I am thinking heater - cathode short. This would introduce hum in this sta...MrFixr55 — 11:14 PM
schematics
Those filter caps in the cardboard tube are easy to restuff, especially the kind with the rolled over end. You don't hav...Arran — 09:56 PM
Philco Model 16 wiring question
If you have 5 wires, do this: The wires that go to thick-wire wound winding are the filament. If you do not know wha...morzh — 09:03 PM
Philco Model 16 wiring question
I recently acquired a Philco Model 16 Code 126. I removed the power transformer to place heat shrink on some very bad...bobclausen — 08:23 PM
1949 Motorola 5A9M
Hello Bob, That battery looks great nice job ! Sincerely Richardradiorich — 08:20 PM
1949 Motorola 5A9M
Yes, I plan to put a Velcro closer on the top.klondike98 — 07:28 PM

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

>