HFU HF Underground
Technical Topics => Equipment => Topic started by: Dash Bronzehand on June 16, 2013, 0519 UTC
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ATM I am running a longwire antenna, a have a couple, this just happens to be it ATM.
It is made from RG58COAX cable, pretty ideal for SW/HF Frequencies. However i believe what you receive is dependent upon the length of the wire? the length is around 9 meters / 30 foot.
Am i right in saying only 20,17,15,12,10 METER bands are accessible through this?
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Just use a little receive antenna tuner on it :)
Peace!
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For receive only, 30 ft / 10 meters of wire should work OK throughout the HF spectrum. I've had good reception on antennas that were around that length.
You'll probably get more gain with a longer wire, though -- especially on the lower frequencies.
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I only use a longwire of 30 Ft. (off the ground 9 feet)due to restrictions--but also use a MFJ Versa Antenna Tuner 901B for the longwire and a MFJ -956 Band Tuner for the radio. Works well eeking out the faint signals. Regards... Steve
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Hi, don't forget the earthing, modern houses have kind of bonding, not sure what ? maybe some kind of counterpoise which is just a length of conducting wire related in wavelength to the bans in use. Maybe this is overkill I don't know.
Tuned loops are a smaller in size and can be directive, plenty info on You Tube...see if I'm allowed to put a link here.
MFJ do a ready made antenna, but its exspensive..look at the videos on You Tube, a trip to a local ham radio club could give a better ideas on antennas..heres a couple of links from you tube.http://www.youtube.com/watch?v=YswnVmAKSP0
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Tuned loops are a smaller in size and can be directive, plenty info on You Tube...
Tuned loops aka Resonant Loops (RLs) definitely can be smaller and definitely can be directive with some caveats. I have been a user of small RLs for a number of years and will attest to their performance, and also to their potential for further development.
There is a ton of material posted on the tubes, some of it good, some of it bad, some of it incomplete. To buy a RL, one has to deal with a very limited set of commercial offerings. To build a RL - Roll Your Own in MW parlance - all this information needs to be filtered carefully.
I do have a design for a RL which works very well for me from 90 to 41 meters, and that is pictured here:
(http://i1049.photobucket.com/albums/s387/jFarley44/TheLoop_zps9c4ceab2.jpg) (http://s1049.photobucket.com/user/jFarley44/media/TheLoop_zps9c4ceab2.jpg.html)
I would be more than happy to share that design with others, and I will start to tidy up things (schematics and drawings) so that this can be posted at some point in the future. In the short term, I think I will start a new thread in this Equipment section which will discuss some of the advantages/disadvantages of using a Resonant Loop, and what can realistically be expected.