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I can answer questions (1) and (2):
(1) A type 55 bulb was originally used behind the dial. Without looking, I do not remember if the four automatic tuning bulbs are #44 or #55; I suspect the former since the shells are "pinched" on the four automatic tuning lamp assemblies, this would make it very difficult to install #55 bulbs. Frankly, I would use LEDs, but that's my preference...
(2) Yes - bend those lamp assemblies so they are aimed toward the reflector ring.
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Ron Ramirez
Ferdinand IN
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The pilot light is listed as 34-2039 on service bulletin #268.
According to
http://www.philcorepairbench.com/lamps.htm that's a #55.
The part number of the individual flood lamps aren't given as far as I could find, but the 37-116 I have is very similar and uses #55 for all of them.
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Question #3:
[Image:
http://i326.photobucket.com/albums/k420/...g~original]
It's sort of hard to explain without taking an
Automatic Tuning assembly apart and taking lots of pictures. The only Philco I own with
Automatic Tuning is my 38-690, and I really do not wish to disassemble it right now.
But the photo above may help.
As you can see by the red arrow, the tab of that movable muting contact should ride inside the slot the arrow is pointing to. There should be a fiber washer in front of that movable contact which insulates it from the movable metal piece in front of it. With the tab inside that slot, when the little knob is pushed in to operate the
automatic tuning mechnism, the tab shorts to the movable metal piece, thus shorting out the set's audio.
I hope this helps.
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Ron Ramirez
Ferdinand IN
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The 37-116 schematic gives part number 34-2039 for the four
automatic tuning lamps...so Nathan is correct.
Now that I think about it, I have removed #55 lamps from those sockets in the past...but as the black reflectors are pinched, that made it very hard to remove them.
I would still use four-chip LEDs such as the warm white versions of these from Pinball Life:
http://www.pinballlife.com/index.php?p=product&id=2561
The ad copy reads:
Quote:Don't be fooled by the low cost of these LEDs, they are the latest, greatest, brightest 4-SMD-LED bulbs on the market, we guarantee it or your money back!
And that is not just marketing hyperbole. They are somewhat brighter than #55 bulbs...just enough to make the difference between seeing the dial and not seeing the dial very well on a dial scale that has darkened with age.
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Ron Ramirez
Ferdinand IN
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Thank you for the link. I have no problem with using LEDs
Also thank you for the information about the muting switch. That jogged my memory that my 37-690 has the same
automatic tuning mechanism. I have yet to do any work on it but think I'll pop the lid on it's
tuning mechanism and do a little comparison.
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(This post was last modified: 01-16-2016, 11:56 PM by
Bob Andersen.)
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Thanks for the pictures. I am at the Napoleon Blown-apart stage right now with the three chassis disconnected mechanically from each other and I am methodically going through the paper and bakelite block capacitors and replacing with film as well as adding in some stuff from the service bulletin.
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09-17-2018, 07:44 PM
I have found a way to restuff C81, the 0.05 µF tone control capacitor that connects to one of the 6F6G output tube plates. If you imagine the output transformer to be a seesaw with the centre tap at the rated 250 volts, one tube conducting fully could force the other plate up to 2 x B+. You might get away with a standard 600 or 630 volt capacitor here but leakage inductance could force the voltage above that and I like to use a generous derating for film capacitors. I have connected a pair of WIMA box capacitors of 0.1 µF 630 volts each in series to make a 0.05 µF capacitor rated at 1260 volts, reducing the stress on everything. I have added some tape across the capacitor connections and the 3/16 inch height of the boss plus the thickness of the star washer keeps it well off the chassis.
[Image:
https://i.postimg.cc/28sgbTmR/IMG_0656.jpg]
(This post was last modified: 09-17-2018, 07:46 PM by
amptramp.)