[Antennas] Hanging more wire.

2004年2月17日 23:39:28 -0500

Correction on the "All" frequencies: I think it has a little trouble
loading on one of the WARC bands, but I don't remember which. I think
it is 17 Meters though.
Buck
> -----Original Message-----
> From: NA4FM (Buck) [mailto:[email protected]] 
> Sent: Tuesday, February 17, 2004 11:21 PM
> To: 'Dan Evans'; 'antennas'
> Subject: RE: [Antennas] Hanging more wire.
>>> Are you able to add 45' of wire to one side of the feed line? 
> If so, you will have approximately a 1/2 wave 80 meter 
> off-center fed doublet which should load on all bands from 
> 3.5 - 30 MHz. Also, remove as much coax as possible between 
> the ladder line and the rig. If you need to feed the ladder 
> line into the house, say through a window, use two pieces of 
> coax (any type). Connect the ladder line to the center 
> conductors and short the outside braids of the two coaxes 
> together to have a binocular looking piece for feeding the 
> line into the house. Then connect ladder line all the way to 
> the rig if possible, or, as previously suggested, no more 
> than 6 inches. Your antenna tuner should do the matching for 
> you. If you use a balun, use a 4:1 rather than a 1:1. You 
> should be just as well without the balun though as the tuner 
> will match the load for you in the rig.
>> If you need a space-saving antenna, check out the G5RV 
> design. I think it is close to the same size as you are 
> using but tunes 75/80 much better than the one you have.
>> Good luck
> Buck
>> > -----Original Message-----
> > From: Dan Evans [mailto:[email protected]]
> > Sent: Tuesday, February 17, 2004 5:56 PM
> > To: antennas
> > Subject: [Antennas] Hanging more wire.
> > 
> > 
> > To hang more wire, or less wire?
> > 
> > I have an 88' ladder line fed dipole, up in the trees about
> > 45'. It works pretty well on 40 & 20, but doesn't tune well 
> > on 75m, being a bit short. I'm using the internal tuner in my 
> > '746, about 10' of rg213, 1:1 balun, and probably 60' of 
> > 450ohm ladder line.
> > 
> > I would like to get better results on 75m, and still use it
> > on 40 & 20. [I have a vertical that does a decent job on 10 
> > & 15]. What I would like to do is extend the dipole into a 
> > loop for 75m. But, living on a 100'x60' lot, I just don't 
> > quite have the real estate. What I can do is make a loop 
> > that is about 200' [at the same 45' average height], or I 
> > could lengthen the current 88' dipole to 130' and give it a 
> > "Z" shape.
> > 
> > I could also go with the 200' loop, and add a 'stub' of
> > ladder line to load it for 75m....
> > 
> > What do you think? Hang more wire, or less wire?
> > 
> > Any suggestions greatly appreciated:-)
> > 
> > 73
> > Dan
> > 
> > Dan Evans K9ZF
> > Scottsburg, IN 47170
> > {EM78}
> > K9ZF /R no budget Rover
> > ex-N9RLA
> > Check out the Rover Resource Page at: http://www.qsl.net/n9rla
> > QRP-l #1269
> > Central States VHF Society
> > IN-Ham list administrator
> > 
> > 
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