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Model 048 set tester restoration help
#1

Well finally got the batter packs for this unit and need some pointers on some of the components. First their is a metal box just above the meter this is a 1 mfd capacitor. I tested it and it is still good. Should it be replaced ? I assume its like radio restoration and I should.It does not give the voltage rating on the parts list .What would be a good voltage rating for the cap?
Also a black bakealite box with three wires emitting from it one terminal to ground terminal post .Middle terminal to a rf choke I believe. and last to one of the pin of the 30 tube. Part number on component is 6287-F .The unit is in very good shape and would like to give it life again....
Thank you.
#2

The cap shpould be replaced. The original was probably a 400 volt part, can't cross ref the part number here at work in the service bulletin for the 048. Use a 630 volt film replacement. Put the new cap into the old shell, a la the Bakelite Block re-stuff method.

Chuck
#3

Thanks very much.Its all progress one step at a time. The only item I see on the parts list that might be the unknown part number is a terminal block.This component seems like it has more of a purpose.I was abel to get the ohm meter working and zero'd.
#4

Well took a few minits and researched your web site and found the page with the bypass condensors and does not give the number 6287-F but the image is identical .I will tets the condensor and see.
#5

The 6287-F bakelite block condenser is a DUAL 0.15uf unit, used for bypassing the RF generator section.
Common terminal for the two caps (ground in the schematic) is closest to mounting screw hole.
Center and end terminals are the other ends of the two caps. Re-stuff with new 200-400 volt film types.

No need to touch the mica 1800pF. cap, unless it's leaky (rarely). ALL resistors in there are suspect due to age drift. Check all of them. If any ore outside the +/-20% tolerance, replace for proper calibration.

Parts list calls out odd resistances for the voltmeter ranges, so if you need to replace any, use the closeset 2% value.
#6

Thanks Chuck.I will check the resistance tolerances today. I also read on your site that some of these bakelite condensors also had resistors built into them.The other cap that is in the metal box is rated as a 1UF is the tolerance for this +/- 20 % . I haven't got a 1 uf on hand.I also noted in the parts list that the set came with some leads and some sort of universal adapters. In your vast library of Philco service data, would you have any info on these items.Or know of anyone who would have such items for sale ....
#7

Just parallel two .47/400 caps for the 1uF. Tolerance not cirtical.
The test leads were just that, leads with clips, probes, term adaptors.
Any good test lead set can be used. Just re-do the meter ends to mate with the pin jacks used.

Chuck




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