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Philco 38-5 shadow meter
#1

Circuit diagram for this radio is at http://www.nostalgiaair.org/PagesByModel...013252.pdf

I have completed restoration of this radio with new electrolytics and replacement of paper caps and out of spec resistors. It is playing good. My question is about the "shadow meter", item 27 on the circuit diagram and parts list. This is supposed to provide some type of visual tuning but I see no change in the shadow when tuning a station. How is this supposed to function and are there any ways to test it. The coil portion of the meter measures about 1450 ohms.

Thanks, Bob
#2

See Service Tip No. 1 on my website.

http://www.philcorepairbench.com/tips/svctip01.htm

Chuck
#3

is the vane stuck? did you replace the bulb? I've got a 38-5 & mine is working. I could measure the resistance in the coil if you like, I don't remember what it was off hand. by the way.. it's a bit of a chore to "adjust" the light and projection on these. also, you might want to buy a handful of 44 bulbs for it. you want to find the bulb with the flattest filament and make sure it's vertical to the slit in the back of the shadow meter. otherwise the shadow will be blurry.
#4

You do not need any secial bulb. The checking and adjusting proceures, as well as troubleshooting are all in that article on Chuck's website.

Make sure your

1. Coil has resistance (in 1 or 2 kOhm range)
2. Vane moves freely (take the cover off and gently touch the vane, see if it moves)
3. Your magnet is magnetized. The pocedure of re-magnetizing is available at the same place.

Some Advice: when you ak many-many questions at once, you scare yourself. Get methodical, follow the procedure, do not try to think many steps ahead as you simply do not know the answers, it might be something simple.
#5

Bob, your doing fine. Your coil seems to have the right resistance, good! Morzh's #2 and 3 are the next steps. Follow Chuck's suggestions. Keep in mind that the action of the meter is dependent on the strength of the signal being received, not necessarily the "volume" of the radio although certainly related. It measures the current flow to the plates of the tubes in the front end of the radio. A good antenna is needed for it to move properly. We are guessing (good guess) a sticky vane or weak magnet. With a strong local station you should get some movement. Hence try 2 and 3.
Good luck Jerry

A friend in need is a pest!  Bill Slee ca 1970.




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