06-09-2020, 08:14 PM
So I put this radio back on the bench. I played with the dial lamp - it was all the way in. I found a different 47 lamp that was slightly longer and had the filament way out at the end. It improved the dial lighting a bit.
I hooked the IF section up to the spectrum analyzer to see what I could do with the response curve. Here are the results:
IF peaked per alignment instructions. At 6 db down the bandwidth is about +-3.5k.
I looked at doing this. At 6db down, bandwidth would be about+- 7K but the sensitivity is down a lot.
I settled in on this. At 6db down, bandwidth is about +- 6k.
At the loss of quite a bit of sensitivity, I gained a fair amount of bandwidth. Still not as good as the Philco 37-116. The radio does sound better with my HiFi transmitter, though. That's the way I usually use my AM sets. If I listen to real broadcasts, it's usually talk radio so the high frequencies are not needed.
Kind of fun to play with!
I hooked the IF section up to the spectrum analyzer to see what I could do with the response curve. Here are the results:
IF peaked per alignment instructions. At 6 db down the bandwidth is about +-3.5k.
I looked at doing this. At 6db down, bandwidth would be about+- 7K but the sensitivity is down a lot.
I settled in on this. At 6db down, bandwidth is about +- 6k.
At the loss of quite a bit of sensitivity, I gained a fair amount of bandwidth. Still not as good as the Philco 37-116. The radio does sound better with my HiFi transmitter, though. That's the way I usually use my AM sets. If I listen to real broadcasts, it's usually talk radio so the high frequencies are not needed.
Kind of fun to play with!
