Model 43 Alignment Issues - Printable Version
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Model 43 Alignment Issues - jhgrahamjr - 04-18-2015
Hi Folks,
I have finished re-capping my Model 43, and finally got around to the alignment. I followed the directions in the Service Guide, basically. I've run into a few issues which I can't figure out! Your comments will be very much appreciated. I am using a Triplett 3432-A signal generator, and a little frequency counter to fine tune it before I use it, so I'm confident the signal is accurate. I was told to adjust the dial, with the tuning capacitor plates totally closed, with the pointer flush with the the line at the left end of the dial scale, around 550 KHz.
1) When I went to adjust the 1400 KHz trimmer for the broadcast band, I couldn't hear the signal generator modulated signal at all. When I tune between 1300 and 1400 KHz on the broadcast band, the radio goes from static to very quiet, anyway. I can't find any plates touching on the tuning condenser... I ended up adjusting the trimmer for maximum volume for a station I found around 1200 KHz. I didn't know what else to do.
2) It seemed to take quite a bit of adjusting of the wavetrap trimmer to get minimal output volume at 450 KHz. Not sure if that bodes ill or not...
3) I found the 700 KHz signal with the Philco dial set around 750 KHz, and adjusted it there for maximum volume.
4) It's really annoying, but dial settings match up like this with a few stations:
First band: KFI AM 640 with dial set at 670 KHz
Second band: a station with frequency 1570 KHz when dial is set to 1650 KHz
Third band: too noisy to find any stations
Fourth band: WWV comes in with dial set at 14.6 MHz and 16.4 MHz
Is the situation hopeless? It's so annoying to have a useless tuning dial...
Thanks!
Jim
RE: Model 43 Alignment Issues - morzh - 04-18-2015
A really stupid question, when your pointer is to the left position, is the tuning cap fully meshed? Pointers do move.
A wavetrap means nothing today, no use for it.
Is your counter accurate?
RE: Model 43 Alignment Issues - Ron Ramirez - 04-18-2015
(04-18-2015, 08:02 PM)morzh Wrote: Pointers do move.
Not when it's a Model 43, or the vast majority of pre-1939 Philcos - you have to move the dial scale while the pointer remains stationary. The scale must be aligned to the line to the left of 55 on the first band, with the tuning condenser fully meshed.
RE: Model 43 Alignment Issues - morzh - 04-19-2015
(04-18-2015, 10:19 PM)Ron Ramirez Wrote: The scale must be aligned to the line to the left of 55 on the first band, with the tuning condenser fully meshed.
Well, that was the gist of my lengthy and partly erroneous statement.
RE: Model 43 Alignment Issues - jhgrahamjr - 04-24-2015
(04-18-2015, 10:19 PM)Ron Ramirez Wrote:(04-18-2015, 08:02 PM)morzh Wrote: Pointers do move.
Not when it's a Model 43, or the vast majority of pre-1939 Philcos - you have to move the dial scale while the pointer remains stationary. The scale must be aligned to the line to the left of 55 on the first band, with the tuning condenser fully meshed.
Thank you, Ron!
Well, yes, my dial scale was adjusted to the line to the left of 55 on the first band. Yesterday, by tinkering and trial and error, I discovered the source of my "alignment" issues.
The trimmer on the klunky "trimmer/inductor" assembly connected to the top of the antenna transformer housing needed adjusting.
Adjusting it to almost minimum capacitance resulted in: 1) no more "dead" spots on the dial; 2) perfect match between station frequencies and dial readings. What a relief!
I hope no one will find the following observations "stupid", so I will apologize to the pros in advance for that. I am not a radio/electronics expert, only very interested in learning more about Philco restoration.
Anyway, that trimmer/inductor assembly was the source of earlier problems during the restoration also. There were initial issues with buzzing, popping, etc. at various points on the low band. After a lot of exploration and trial and error, I found that if I soldered a wire between the leads of the inductor portion of the assembly, to short it out, that the popping/buzzing problem disappeared. I know this may defy logic, but it worked, and continues to work. Just thought I'd put this out there in case anyone else encounters the problem.
Thanks for your kind attention and assistance!
Jim