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FM reception is marginal for the stations we listen to. Have I tried a good antenna? Well I'm about to. Our main listening room is one story and shares a wall with the garage. There is an entry to the crawl space from the garage. I now have the first of 3 twinlead FM antennas installed. I pulled 3 lines for a planned 3 antennas. The first is a folded dipole about 10 ft. wide and is in place and in use. This will be my "omni" as it helps on most of the stations, but I will be adding 2 rhombics. fmfool shows that there are stations of interest on the compass at 325 deg. and 15 deg. There is 1 station at 15deg. just over a mile away, but I think we're actually too close, given the elevation difference. Next up is the first of the 2 rhombics. Looking at the 3 twin leads hanging out the wall, I'm thinking I should install a rotary switch in the wall to clean things up and select the antenna to the tuner.
The rhombics are straightforward, but working in the rafters is taxing. I sure hope it pays off with high fidelity FM.
Follow Ups:
is a good idea.
NASA used/uses them to fire signals at the moon and back.
Warmest
Tim Bailey
Skeptical Measurer & Audio Scrounger
I've read your posts about rhombics for so long I finally have to try it. I'm doing just over 22 ft. for each half.
11 feet per side?
:-)
Warmest
Tim Bailey
Skeptical Measurer & Audio Scrounger
I've got layout cord measured to 11'3" a side and the magnetic compass bearings from fmfool to guide me up in the attic.
Good luck! I hope it works well. If it is unshielded twin lead (shielded twin lead is rare) I hope you don't get too many problems from that. I probably would have used shielded cable as the feeder with unshielded twin lead only in the actual antenna construction.
You should follow this rule if you did not for the dipole: Cut a length of twin lead (for feedline) that is equal to or a multiple of the length calculated for the ant.
ET
For now the down lead is the unshielded twin lead. I presume rg6 or rg59 with a 300/75 balun on each end would be standard. I don't notice any artifacts on the folded dipole, The horizontal is 10ft with the twinlead through the wall to the receiver. I could replace the down leads if needed later.
Cool, hope it works well for you. "Sometimes" unshielded 300 ohm twin lead (shielded is hard to find BTW) has issues going near AC lines and other things in the wall.
If it works well then great. If there are some strange things going on try switching the feedline to perhaps coax as you can use the twin lead as a pull line for the new cable. I'd hate for you to try it and it make no difference or make it worse for some reason.
I wish I lived in an area where I could get some good FM. Nothing worth tuning in within 100 miles from here and if there were I'd have problems being in this narrow valley that is only a couple of hundred yards wide with sharp peaks of 1600-1800 on both the east and west side of me.
ET
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