I finished realigning this set with my new equipment and I am feeling great about how well it works. My BC is loud and clear. My SW works like a charm and I'm hearing stations all over the Bandwidth. So why the post?
I get motorboating on BC 1600 kc. I'm tempted to just not worry about it because it's nearly off the scale anyway and everything else works so good. Does anyone have any quick fixes for this? My alignment went well and I didn't even notice this until it was off the bench and sitting on top of the console of my other set. What causes motorboating anyway?
nom
Often enough my Zenith portables break into oscillation at the low end of the dial. This happens when the back is closed and the loop antenna is too close to the chassis. Otherwise the radios perform normally, and the loop is supposed to be where it is, so I'm not changing it. The oscillation can be eliminated by detuning the IF transformers, but it isn't worth the reduction in sensitivity.
T.
:If all is well otherwise, be sure that antenna wires are nowhere near speaker wires or any of the other tubes or wires. Poor shielding of tubes and circuitry could be another cause. All shared main power circuits must, of course, be adequately filtered (capacitors). Dried out electrolytics and capacitors of the wrong value (too small) will allow motorboating.
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:Often enough my Zenith portables break into oscillation at the low end of the dial. This happens when the back is closed and the loop antenna is too close to the chassis. Otherwise the radios perform normally, and the loop is supposed to be where it is, so I'm not changing it. The oscillation can be eliminated by detuning the IF transformers, but it isn't worth the reduction in sensitivity.
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:T.