[TenTec] 17 Meter Antenna

[george fritkin via TenTec]

Really, did you measure the impedance at the feed point?
George, W6GF 

     On Sunday, November 23, 2014 8:50 AM, Rick - DJ0IP / NJ0IP <Rick at DJ0IP.de> wrote:
   

 GM George,

The advantage of this type of delta loop is, at low heights, the loop fed vertically polarized has a lower radiation angle than the dipole. The dipole will have to be raised a lot higher to match its radiation pattern.  The loop is also more broad banded.  Its advantage over a quarter wave vertical is, you don't need to put lay a bunch of radials, which often can be a nuisance.

As for how to feed it, well I have been feeding loops like this for 35 years and they have been giving me outstanding results.  That does not mean a perfect match but good enough to use without a matchbox.  Of course the impedance varies with height above ground.

If you have a better idea on how to feed it, please share it with us.
I'm always happy to learn something new.

My source of information on how to feed this type of antenna is from DL1BU (SK, and ex- chief technical Engineer of the DARC) in his article on loops, printed in the 1979 issue of CQDL magazine, page 154. 

73 - Rick, DJ0IP
(Nr. Frankfurt am Main)


-----Original Message-----
From: TenTec [mailto:tentec-bounces at contesting.com] On Behalf Of george fritkin via TenTec
Sent: Sunday, November 23, 2014 4:40 PM
To: Discussion of Ten-Tec Equipment
Subject: Re: [TenTec] 17 Meter Antenna

Delta loops show marginal gain over a dipole (1.1db), and are much more of a pain to erect.  As far as noise no real proof that is true.  And one more thing, feeding with 1/4 wave of 72ohm is more voodoo engineering you find here George, W6GF 

    On Saturday, November 22, 2014 11:18 PM, Rick - DJ0IP / NJ0IP <Rick at DJ0IP.de> wrote:
  

 Use a telescoping fiberglass pole.
They don't have to be very high.
25 ft. is high enough if you make the horizontal bit a little longer.
That still leaves about 7 or 8' under the antenna so that people can walk under it.
Scott (W4PA) sells 40' poles.  One of those would be perfect.

73 - Rick, DJ0IP
(Nr. Frankfurt am Main)


-----Original Message-----
From: TenTec [mailto:tentec-bounces at contesting.com] On Behalf Of Reed
Sent: Sunday, November 23, 2014 4:17 AM
To: tentec at contesting.com
Subject: [TenTec] 17 Meter Antenna

I'm sure Gary they are the best antenna for the dollar, but not enough trees here for support.  I was raised on a farm & my late father, W4PFP & elmer, had some serious wire antennas.  I miss the real estate, but not the farming.

Reed  W4JZ


Reed,
    I had a 80M Delta loop up for quite a few years. It worked extremely well. Very quiet. It was fed in the corner with 75 ohm coax, then 50 ohm to the shack. My matching piece of 75 ohm coax was abt
46.5 feet long (1/4 wave x velocity factor of the cable). I'd put another up but all my trees have grown up.

Gary - KN0V


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