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- April 24, 2011 at 1:32 am #7737
I found this really good websites about antennas. http://www.northcountryradio.com/Kitpages/am88.htm
I found this really good websites about antennas. http://www.northcountryradio.com/Kitpages/am88.htm
On the web site there is a page called long wire antenna. Could this type antenna be used with the Talking House Transmitter? I think it can plug into the wire antenna port on the transmitter.April 24, 2011 at 2:23 pm #21746mram1500
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Total posts : 45366Try it, but most likely it won’t perform very well.
For starters, the Talking House auto-antenna tuner is designed to work with about 10 feet of wire. If the “long wire” antenna is some multiple it might tune up. Otherwise, the tuner will error out not being able to tune the wire.
Next, the “long wire” will most likely be horizontal and not very high. It will exhibit directional characteristics with many null points meaning the signal will be very weak in several directions, strong in others.
But hey, try it! Sometimes some unusual combination of variables will work just fine.
Don’t forget to try the “remote ATU” connection. That is a direct output that does not use the internal auto-tuner. And, you could home-brew a simple tuner to resonate the “long wire.”
April 25, 2011 at 5:33 am #21758Ken Norris
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Total posts : 45366“Could this type antenna be used with the Talking House Transmitter?”
In a word … absolutely not.
1) Take a look at the last paragraph … this is intended as a receiver antenna. To transmit on such an antenna it would need to be 1/4 wave, or about 150 feet, and it would be horizontally polarized, and, most of all …
2) It’s illegal … Part 15 transmitter systems cannot have an antenna longer than 3 meters (about 10′) INCLUDING the transmission line and the ground lead. Somehow, the TH was certified to use its ATU/antenna with a 75ohm TV cable, probably because the tuner is not inside the cabinet (except with the 10′ wire antenna that hooks up to a different part of the circuit as mentioned below).
“I think it can plug into the wire antenna port on the transmitter.”
You mean the connection for the 10′ wire antenna that comes with it? NO-NO … the circuitry inside is for matching the 10′ wire. You don’t want to change the length of that wire at all.
The F connector for the external antenna system is another story. You still can’t hook up an antenna longer than 3 meters, which is very short for mid-band wavelengths, especially since the output to final can’t be more than 100 mw (or 1/10th watt), but you can purchase the ATU for the TH tx, or maybe build one.
The whole idea of unlicensed radio is about preventing interference with licensed radio, or with other appliances which might receive it unintentionally, so it is severely restricted. I’m mostly OK with that, because it makes it all the more challenging,
April 25, 2011 at 12:53 pm #21760mram1500
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Total posts : 45366It would be considered illegal under Part 15.219. But from the experimenters viewpoint, it would be fun to try – temporarily.
You could claim operation under Part 15.209 which does not limit the antenna system but rather the field strength. And if/when they do come around to inspect they will cite Part 15.209 anyway and nail you for excessive field strength.
Long wire antennas can be used as transmitting antennas but as I previously stated you would need some type of tuner to resonate the antenna if not the proper length. Otherwise the mismatch between the transmitter and antenna impedance would reduce the field strength considerably. Which then again, you could be legal but end up with about 200 feet of range.
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