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1936 60 alignment issues - Printable Version

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+--- Thread: 1936 60 alignment issues (/showthread.php?tid=8471)


1936 60 alignment issues - ipwizard - 01-13-2014

Hi folks I got a problem with this model 60 I'm working on right now. The set has been re capped, and I had to rewind the primary on the antenna coil.

I was able to peak the IF at 460kc, but when I try to peak the high freq at 1400 I only faintly hear the tone at the middle of the dial around 980 or so and adjusting the antenna or the HF trimmer on the tuner barely make any difference. I haven't made any adjustment to the wave trap, I'm not quite sure how to do that or if its even needed. I'm using my VTVM connected to the plate of the 42 as an output meter.

Anyone have any suggestion where I should look?

This is the correct schematic for this set: (click for larger pic)
[Image: http://www.philcoradio.com/tech/images/60g_sm.jpg]

And the Compensators:

[Image: http://www.philcoradio.com/tech/images/60bot3.jpg]

Thanks!

RE: 1936 60 alignment issues - morzh - 01-14-2014

Keith

1. have you measured your tubes?
2. Even if you did, have you made sure your pentagrid oscillates across the whole band?

RE: 1936 60 alignment issues - BrendaAnnD - 01-14-2014

Make sure that the osc. LF adjustment (#12) is tuned to 600 KHz, then go to check the high end of the dial. I know the manual usually says to do it the other way around, but if the LF padder is far enough off, you won't be able to get 1400 to tune in.

RE: 1936 60 alignment issues - BrendaAnnD - 01-14-2014

Also, to be sure, you are trying to adjust trimmer (6) to bring your 1400 KHz into alignment?

RE: 1936 60 alignment issues - Radioroslyn - 01-14-2014

Sounds like it's time to rewind the osc feedback coil.
Terry

RE: 1936 60 alignment issues - ipwizard - 01-17-2014

Thanks for the replies. Got tied up with work last couple days..

I found one problem, i forgot to re-solider the ground strap to the tuner screw. After I fixed that I was able to peak the #12 and the Antenna trimmer to 600kc. I tried to get the HF two play ball but no luck. I had my signal gen set to 1400 the dial set to 1400, and nothing I tried could get the high side to align.

I'm not sure how to check if the oscillator is running through out the band, at the low end I can pick up some stations, so it seems ok, but nothing on the high end.

RE: 1936 60 alignment issues - Mondial - 01-17-2014

You can check for oscillation by measuring the voltage across the oscillator grid leak resistor (10) of the 6A7 tube. When oscillating, there should be a negative voltage of several volts there all across the band. If you lose the negative voltage any time while tuning, then it is dropping out of oscillation at that point.

Make sure you connect a resistor of at least 100 K or so in series with the probe connected to the coil side of resistor 10 or you will load the RF circuit and possibly stop or reduce the oscillation.