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The Postal Stork dropped a Dynaco FM1

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guitargrump

Active Member
Friday the postal stork's dropped me off a new baby project a Dynaco FM1.

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  • Media owner guitargrump
  • Date added
  • Comments 2
Dynaco FM1 sitting on a Magnavox Astrosonic console

The radio is in good general condition a bit dirty... The radio works surprisingly well for a antique... It has a nice warm sounding ambience... Just what I love...

I made it a quick dipole antenna and it's amazing how many stations it picked up with a simple wire dipole antenna indoors...

The radio is a hummer, you have to keep it's volume up over half or the humming is audible you can still hear it in the pauses...

Anyway I was hoping someone had it's schematics...:)

That and maybe some prior wisdom so I can just fix it...

I believe that this hobby is a pretty deep rabbit hole... And the rabbits are hungry...:jump:
 
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looks like a fm3 to me.if the tag on the back says fm 1then it has been probally converted to stereo with the addition of the multiplex board.
 
Thank You so much:) the bottom plate says fm1 it has two outputs labeled A and B... there's no other tags
 
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if it was a full conversion your tuning eye tube will be different than the one in the original Fm1 .Also the plastic around the tuning eye tube should have stereo on it .
 
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Inside of a FM1

I popped the top for a quick inside picture

The tuning eye lense has the word stereo on it...

I have been listening to PBS WV it's definitely very good sounding I like the Red Barn Show on Sunday evening live country mountain music...

Sounds as good or better as the radio in my Silvertone console in the shop...

Except for the Humm at lower radio volume it's a winner
 
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Enjoyed reading through the manual...I see this tuner can be aligned without additional test equipment - using only the magic tuning eye -- brilliant !
 
kappclark said:
Enjoyed reading through the manual...I see this tuner can be aligned without additional test equipment - using only the magic tuning eye -- brilliant !
Click to expand...

Be aware that the FM-1/3 no-instrument alignment procedure assumes that the IF transformers are “new” and are pre-aligned fairly closely to 10.7MHz. Drift over the decades as well as user alignment attempts frequently invalidate this assumption. Net result is that an old FM-1/3 tuner *can* benefit significantly from an instrument alignment as described in the construction/user manual.
 
kappclark said:
Enjoyed reading through the manual...I see this tuner can be aligned without additional test equipment - using only the magic tuning eye -- brilliant !
Click to expand...
It's not the easiest to do though. I restored one with all new caps, resistors, power supply and even custom made PEC's. Someone had tried to align it before I got it. I've tried several times following the alignment directions and it's still not right. I haven't had any luck finding someone to realign it.
 
Lavane said:
It's not the easiest to do though. I restored one with all new caps, resistors, power supply and even custom made PEC's. Someone had tried to align it before I got it. I've tried several times following the alignment directions and it's still not right. I haven't had any luck finding someone to realign it.
Click to expand...

You could be experiencing the 10.7MHz issue I noted above. Or, another issue I’ve run across with a couple of FM-1/3s is the failure of the little silver mica caps internal to the IF cans. Depending on failure mode, the result is either a continuous static or crashing noise or inability to peak the signal. The fix for these problems requires surgery on the offending can to remove the bad caps and replace with new caps. This is tedious, delicate, time consuming work. Considering the quality of most FM programming and signal today, this problem if encountered makes restoration of the Dyna tuner either a labor of love or not worthwhile. FWIW, the bad IF/discriminator caps situation is not confined to Dyna tuners.
 
Tuners in general are voo-doo and black magic to me. Other than restore the power supplies I generally leave the rest alone. The exception was the FM-3. It was easy enough to replace out of spec resistors, caps etc. But the rest is beyond me. It's gotten hard to find anyone capable to align and work on them. I picked up a second one really cheap as a parts unit, but it had the flat top transformers and inductors. And several had broken slugs or frozen.
 
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