Very good. I haven't worked on radios for donkey's but it seemed that when initially changing between 455 and 262kHz IF there was little difference to the tone volume, prior to realignment, possibly indicating the IF filtering was too broad. Though this may be a misconception due to my rapidly fading memory, I do recall that early car radios were always very poor without the correct antennas.
@ralphj4012 keep in mind the volume regardless of tuning is adjustable via volume pot. At 455kHz and 1kHz mod @90% I couldn't align below (I think) .03-.02 vpk-pk (maybe it was higher than that), but at 262kHz I was able to get a tone at a much lower input level. That being said the IF cans are fairly broad filters and they shouldn't be. The cans should provide overall selectivity and to a degree assist with sensitivity (outside of the transistors), right? I just took the reception issue as mostly a sensitivity issue and my assumption is that I needed a better antenna. There were definitely some adjustable trimmer caps that needed replacement. I also didn't really bother testing a lot of components because the customer wasn't looking for a full restoration. Mainly because they just wanted to use it with Bluetooth. The checkout using my SigGen as a low amplitude RF radio station at the end was as far as I could really go. As a guy who loves radios, it was a bit sad for me. However, I know the customer was happy to have the Bluetooth functionality so that at least was a plus. Always appreciate your insight! Keep injecting whatever and whenever.
Very good. I haven't worked on radios for donkey's but it seemed that when initially changing between 455 and 262kHz IF there was little difference to the tone volume, prior to realignment, possibly indicating the IF filtering was too broad. Though this may be a misconception due to my rapidly fading memory, I do recall that early car radios were always very poor without the correct antennas.
@ralphj4012 keep in mind the volume regardless of tuning is adjustable via volume pot. At 455kHz and 1kHz mod @90% I couldn't align below (I think) .03-.02 vpk-pk (maybe it was higher than that), but at 262kHz I was able to get a tone at a much lower input level. That being said the IF cans are fairly broad filters and they shouldn't be. The cans should provide overall selectivity and to a degree assist with sensitivity (outside of the transistors), right? I just took the reception issue as mostly a sensitivity issue and my assumption is that I needed a better antenna. There were definitely some adjustable trimmer caps that needed replacement. I also didn't really bother testing a lot of components because the customer wasn't looking for a full restoration. Mainly because they just wanted to use it with Bluetooth. The checkout using my SigGen as a low amplitude RF radio station at the end was as far as I could really go. As a guy who loves radios, it was a bit sad for me. However, I know the customer was happy to have the Bluetooth functionality so that at least was a plus. Always appreciate your insight! Keep injecting whatever and whenever.