08-31-2014, 06:27 PM
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
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
