[loosecannon]

ok, things are moving along nicely.

got the pot and switch ordered from Gary. (thanks to ccomer1955)

got some grill cloth on the way also.

sorry about the confusion on the gimmick. the reason i was confused was because there were two different ways of doing it described, and the second one did not involve actually wrapping the wire around the wiper wire.
yes, i understand the concept of creating a very small value capacitor by twisting the insulated wire together.
(but what thickness should the insulation be as this will affect the capacitance value!? just kidding!)

most of the old wiring seems to be fine. the insulation is brittle, but the copper inside is still in relatively good shape.
i have measured the resistances of all the coils and they all check out reasonably within specs. (thank goodness this radio was stored in a dry location in the deserts of the south west)

i found the volume control wiring confusing until i realized that its not actually a volume control. it is an RF gain!!! (well, somewhat of one anyway)
i was assuming it would be an audio taper pot because it was a volume control, but the fact that the antenna goes to one terminal had me scratching my head for a while. now it makes sense that it would be a linear taper pot.

that does lead me to one question though.
there are two wires coming out for the antenna, one antenna lead and one ground lead.
my question is, were these intended to be used with a loop antenna?
my guess is no, and that the ground wire went to a cold water pipe or was one side of a dipole style antenna.
just wanted some input from those who have more of a history with these types of radios. (im only 39)

i wont be doing a cabinet restoration, as the customer doesnt want to pay for all that, but i would like to give the original finish a good cleaning without rubbing off any of the original stain. (if thats what it is)

so, can anyonoe suggest a good cleaning product and process?

thanks for all the input so far.
its been really fun not worrying about burning up PC board traces!
Matt

[Warren]

I have just one comment. You said the old wiring the insulation is brittle but the wire inside seems good. That is usually the case, the wire is good but when the insulation is brittle it will flake off somewhere and the "good" wire underneath will short out on something. If the insulation is coming off you really need to either replace the wiring or use shrink tubing over it to protect from a short.

[exray]

that does lead me to one question though.
there are two wires coming out for the antenna, one antenna lead and one ground lead.
my question is, were these intended to be used with a loop antenna?
my guess is no, and that the ground wire went to a cold water pipe or was one side of a dipole style antenna.
just wanted some input from those who have more of a history with these types of radios. (im only 39)

No, not made for a loop. Made for a 'random wire' and ground connection. Random wire translates to 'anything you want to hook to it' A reasonable length of wire outdoors will serve as an excellent antenna. Could be half of a dipole, etc.

[loosecannon]

thanks for the replies guys!

yes, i have been using heat shrink tubing on the wires that have breaks in the insulation.

i am replacing any wire that has to move around, such as speaker leads and control grid caps.

thanks also on the antenna clarification.
Matt

[exray]

So, can anyone suggest a good cleaning product and process?

Gojo gets rave reviews. They have about a dozen different products but the common, non-abrasive one apparently is favored. Maybe others can provide some reviews.

[jerryhawthorne]

Gojo hand cleaner (without pumice) seems favored. Apply with 0000 steel wool and repeat until it comes off clean on a clean rag. A proper "scratch" removal product to even things out and then a couple rounds of Johnson Paste seems to be what is known as "The Treatment". Do a search for this here or on the other forum. The process has been described several times and the result is stunning. Check out some results!

http://radioheaven.homestead.com/The_Treatment.html
Jerry

[mikethedruid]

I use pure gum spirits of turpentine on 0000 steel wool, working lightly and slowly in little circles to remove the "dead finish." It works well, and only takes off the old wax and oxidized varnish. Be sure to work the cracks and crevices in the woodwork design, but be careful. And let it dry at least a few days before putting on any further finish.

[loosecannon]

thanks guys,

from what has been suggested here along with what i have learned by searching the phorum; i think i am just going to clean the cabinet with the pumice free gojo cleaner, and then wipe some "howards" on it.

again, im not going to be "restoring" the cabinet, just cleaning it up to make it look nicer.

always open to more suggestions though!
Matt

[jerryhawthorne]

LC, I think you on the right road. Others have other ideas and great. It seems this works the best. Show some pictures as you move along.
Best, Jerry

[loosecannon]

hi all,

well i finished the component replacement yesterday as i received the correct volume pot from Gary at play things of the past. (thank goodness for him, as i dont think there was another one available anywhere!)

i connected the speaker, turned the unit on, and------ all i get is a loud hum from the speaker.

tuning control makes no difference, and neither does the volume control.

just to give you guys all the info, here is what has been replaced:

all components except for the variable tuning capacitor, and the tuning condenser caps on the back have been replaced. (i have checked the wiring and it is correct as per the "philco 80" schematic)

all tubes were replaced with tubes i bought on ebay. (im pretty savvy with ebay and made sure that the people i bought them from were reputable and stated that the tubes tested in good/ excellent condition)

i measured the resistance of all the coils while all the parts were removed and they all seemed to be within specs, but i have been soldering on them quite a bit while installing the components, so i guess one could have opened up from too much heat.

can i measure the coil resistances with all the components in the radio?

is there a list of correct voltages for the tube sockets?

any other ideas?

i did not test the volume pot i received, and i will do this right away just to eliminate it.

thanks for any advice, the expertise on this site is invaluable to a guy in my shoes!

LC

[morzh]

1. "the tuning condenser caps on the back have been replaced" - what are those and why replace them?

2. can i measure the coil resistances with all the components in the radio? - Yes You can measure coils in-circuit.

[jerryhawthorne]

LC, it certainly sounds like you may have some unfiltered B+ meaning some caps in backwards perhaps or miss wired. With the volume control on the antenna it is not helping isolating the problem. Check your caps again try pulling the second detector tube and turn the set on. Still hum? At least that will tell you a little more information. If you have hum, it is from the amplifier section. Probably something in the filtering section of the power supply. If you don't have the hum, try pulling one tube at a time from right to left on the schematic to see if it goes away. A cheap easy way to look for isolating the problem. I could be a cathode to filament leakage in any of the tubes putting some A/C into the the signal path. If you can pull tubes one at a time and still have the hum (not the output tube) it is no doubt bad filtering in the power supply

[loosecannon]

thanks for the quick replies guys!

i wonder if it helps for me to mention that there seems to be no trace of any static or actual signal in the speaker, just the hum.
just putting that out there...

as for the condenser caps, i should have worded that differently.
im speaking about the trimmer caps on the back panel that are used to align the radio.
one of the sheets i have for this radio called them condenser caps.

i did NOT replace these.
one of them is missing the nut though. will have to find one.


on the hum issue; the only two caps that are polarized are the 4uF and the 8uF.
(i used a 4.7 and a 10)

these are indeed oriented the correct way, but i did want to mention that i may have done something a little strange when it came to the negative side of the filter caps.

it looked to me from the schematic that the negative leads of the 4 and 8uF caps did not go to chassis ground, and were isolated from it.
the 325 ohm resistor and .015uF cap gave me this impression.
so i soldered the negative lead of the new 10uF cap to the negative tab of the original 8uF cap, and did the same with the new 4.7uF cap to the negative tab of the original 4uF cap.
i left the original caps in place for looks, but there is nothing connected to the center "nut".

so, could i have inadvertently done something wrong here?

thanks for all the help so far.

when i get home from work tonight, i will remove each tube one at a time as suggested. (except for the output tube; i get the impression that removing that tube and turning the set on is a bad idea)

and i will measure the resistance of all the coils in the radio again also.

two things i have not done yet, that i really should have, was to measure the resistance of the coils on the speaker and the power transformer itself. oops!

still open to any more things to try tonight.
LC

[morzh]

You probably do not need to measure power transformer or speaker coils. You would have some good manifestation of them being bad.

See if the insulation around old electrolytics is intact and their cans are indeed insulated fom chassis (should be 300 Ohm in between either of them), and are connectedto each other.

[exray]

im speaking about the trimmer caps on the back panel that are used to align the radio.
one of the sheets i have for this radio called them condenser caps.

i did NOT replace these.
one of them is missing the nut though. will have to find one.

That's not your immediate problem but its definitely an issue that will need to be resolved. Make sure the mica sheet is still between the plates of the trimmer.