09-09-2024, 07:04 PM
I am on the fence about restoring this 38-14 I got during the last Kutztown.
http://www.nostalgiaair.org/PagesByModel...013238.pdf
I paid maybe $15 for it. A fairly durty backelite case, but the chassis is clean enough.
This will require lots of cleaning, especially the case.
No original caps, the tubulars all were replaced by the black beauties; the electrolytics are paper-cartridge axials.
Now the question: I decided to check the speaker first. The transformer is good, the cone is good, the FC is 23 kOhm. According to the sch it is 3 kOhm.
It is not open, it is 23K. I cannot imagine the failure of a wirewound coil where it does not get open, but develops 23K resistance.
The speaker seems to be original Philco; same cone assembly as in 38-12, and the FC looks the same, except the resistance value.
The coil in 38-14 is in parallel to the first rectifier cap and is not used as the filter; they have a separate choke for it. So, naturally, it is expected to be a higher resistance than in the 38-12 (3K vs 1.5K). But 23K?
So, my question is: has someone encounter this before and can 23 kOhm FC resistance be legit? If not, at this point starting this radio makes little sense for me.
PS> I thought, why not check my old idea of mounting a strong RE magnet to the centerpole and replace the FC as the magnet (it is not being utilized as the filter). Well, tomorrow is another day.
http://www.nostalgiaair.org/PagesByModel...013238.pdf
I paid maybe $15 for it. A fairly durty backelite case, but the chassis is clean enough.
This will require lots of cleaning, especially the case.
No original caps, the tubulars all were replaced by the black beauties; the electrolytics are paper-cartridge axials.
Now the question: I decided to check the speaker first. The transformer is good, the cone is good, the FC is 23 kOhm. According to the sch it is 3 kOhm.
It is not open, it is 23K. I cannot imagine the failure of a wirewound coil where it does not get open, but develops 23K resistance.
The speaker seems to be original Philco; same cone assembly as in 38-12, and the FC looks the same, except the resistance value.
The coil in 38-14 is in parallel to the first rectifier cap and is not used as the filter; they have a separate choke for it. So, naturally, it is expected to be a higher resistance than in the 38-12 (3K vs 1.5K). But 23K?
So, my question is: has someone encounter this before and can 23 kOhm FC resistance be legit? If not, at this point starting this radio makes little sense for me.
PS> I thought, why not check my old idea of mounting a strong RE magnet to the centerpole and replace the FC as the magnet (it is not being utilized as the filter). Well, tomorrow is another day.
People who do not drink, do not smoke, do not eat red meat will one day feel really stupid lying there and dying from nothing.