08-02-2025, 05:01 PM
Hi all,
Well, I've got the compensator issues fixed. There were a couple more wiring issues on the A wafer. Turns out the BC band 1500KHz oscillator coil had no compensator connected across it. That compensator was connected in parallel to the BC band 580 KHz oscillator compensator. So that explains why neither of those did not work at all. In addition, I found that the BC band 1500 KHz compensator was not connected to anything. It had a wire connected to it, but the wire was cut off and not connected. Though that compensator did have a gimmick cap attached, not sure why. I connected the compensator to the C wafer and removed the gimmick cap. Found what might have been a cold solder joint on the SW band oscillator 12 Mhz compensator. Reflowed the joint, problem solved. So, now all the compensators work and I was able to calibrate the tuning so that the frequency generator tone was heard on the proper frequency. The SW and police bands were waaaay off, almost 2 Mhz on the SW band. So now the tuning tracking seems to work on all the bands. At least the AM band is correct. One of my local stations on AM 880 is now 880 on the dial, used to be over 900. I'll check this evening and see if WWV comes in on 10 MHz. Prior to this it came in on close to 12 MHz.
Still not quite sure about the AVC line, but haven't found anything amiss. I think a couple of local AM stations (really close and 50,000 watts) just overwhelm the AVC. The AVC seems to work better with stations that are not so close. Tuning across the AM band, the volume is controlled reasonably well with those stations that are not 5 miles away and pumping out 50,000 watts.
I think I'm calling the radio part done. Now I should work on the cabinet. Or maybe possibly move on to my Sky Rover. But I did just acquire a really nice Zenith chairside. But that's not for posting in the Philco Phorum!
Rich
Well, I've got the compensator issues fixed. There were a couple more wiring issues on the A wafer. Turns out the BC band 1500KHz oscillator coil had no compensator connected across it. That compensator was connected in parallel to the BC band 580 KHz oscillator compensator. So that explains why neither of those did not work at all. In addition, I found that the BC band 1500 KHz compensator was not connected to anything. It had a wire connected to it, but the wire was cut off and not connected. Though that compensator did have a gimmick cap attached, not sure why. I connected the compensator to the C wafer and removed the gimmick cap. Found what might have been a cold solder joint on the SW band oscillator 12 Mhz compensator. Reflowed the joint, problem solved. So, now all the compensators work and I was able to calibrate the tuning so that the frequency generator tone was heard on the proper frequency. The SW and police bands were waaaay off, almost 2 Mhz on the SW band. So now the tuning tracking seems to work on all the bands. At least the AM band is correct. One of my local stations on AM 880 is now 880 on the dial, used to be over 900. I'll check this evening and see if WWV comes in on 10 MHz. Prior to this it came in on close to 12 MHz.
Still not quite sure about the AVC line, but haven't found anything amiss. I think a couple of local AM stations (really close and 50,000 watts) just overwhelm the AVC. The AVC seems to work better with stations that are not so close. Tuning across the AM band, the volume is controlled reasonably well with those stations that are not 5 miles away and pumping out 50,000 watts.
I think I'm calling the radio part done. Now I should work on the cabinet. Or maybe possibly move on to my Sky Rover. But I did just acquire a really nice Zenith chairside. But that's not for posting in the Philco Phorum!
Rich




