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Old 12-29-2013, 03:26 PM
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Winky Dink Winky Dink is offline
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Join Date: Apr 2010
Location: Meridian, Idaho.
Posts: 583
More Progress and Some Photos

I'm figuring out a few things myself.

The set came with an 89 replacing a 78 as an IF or RF amp. I replaced it with a good 78, and that eliminated a loud hum.

Most B-C voltages were 30% higher than Philco specs. Rectifier was putting out 410 volts instead of the specified 300v. Switched in different used 80 and the output went down to 330v most tube voltages are reasonable.

Made my first foray into alignment. Spent hours trying to make the signal generator give an audible output before I determined that the connecting cable was defective. I adjusted each capacitor to obtain max noise (AM band only).

So now I have a usable radio with fair-to-poor AM reception and some extraneous noises.

Now I'm stuck on a couple of B-C voltage issues. Here's the latest test results:



I can't figure out why the voltage to the plate on 85 is so low. All components test OK, and I've even tried replacing the resistors 48 and 49 with new ones. Would it be worthwhile (or risky?) trying a lower resistance for the 99K resistor?



Full schematic:

https://picasaweb.google.com/lh/phot...eat=directlink

If you're interested at all, here's a small album detailing replacement of missing condenser cans:

https://picasaweb.google.com/coldrb/...eat=directlink
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