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Post by jimhenry2000 on Jul 16, 2017 2:33:01 GMT
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Post by Boomer on Jul 16, 2017 13:01:42 GMT
Those are good, because they pick up signals outside of the house, and farther from noise sources like lighting and transformers. I've used old fashioned longwire antennas for that, but these might be better, as amplified antennas, and with the shielded lead-in.
One thing I use a lot for reception is a Terk loop antenna, you'd see them as Select-a-Tenna in the ads in radio magazines. It's a gray circle with a tuner on it, and you put it near the radio and adjust the tuner to peak up the station. It works well, so selective it even can narrow the audio bandwidth of a station, though when you're trying to bring up a distant noisy station, that doesn't seem to be a big problem. I even use the loop outside!
If the active antennas really work, maybe I'll try one or look for plans. I don't need anything for HF or FM, so it should be simpler for just mediumwave use.
Likely the active antenna is the short whip feeding a very high impedance amplifier. I'd need a bandpass filter for 500 to 1800, and a way to couple the result to a receiver indoors, like a small untuned loop as a link sitting by the radio. Maybe even better, a loopstick and tuning cap system by the radio, link fed by the active antenna.
Boomer
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Post by mark on Jul 16, 2017 15:58:13 GMT
Yes, that tuned loop is the best for AM. Ive used this and so simple anyone can do it. But convincing someone to get this to hear your part 15 station better, that's another thing.
Mark
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