Login  Register

Re: OT antenna question

Posted by John Oppenheimer on May 28, 2018; 5:39pm
URL: http://elecraft.85.s1.nabble.com/OT-antenna-question-tp7641318p7641320.html

Hi Mike,

An EZNEC model using 30 feet AGL and Q=200 for the coils, has a very
close match the the reported values.

20M, the antenna does not seem to degrade form a simple dipole with a
Gain of about 6 dBi at about 30 degrees elevation.

80M, it's about 5 dBi at 90 degrees elevation. Expected from a low
dipole. The impedance at resonance is about 25 Ohm, so should have a SWR
about 2. A lower measured SWR may be the result of other system loses.

I'd suggest this antenna is a good option for the constraints imposed.

John KN5L

On 05/28/2018 11:39 AM, Michael Blake wrote:
> The center sections of the dipole are tuned for resonance at about 14.15 MHz and the end sections, past the loading inductors on each dipole leg, are tuned for resonance a 3.7 MHz.  The resonance dips at both frequencies are quite sharp and the SWR on both bands is less than 1.5 to 1.
______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to [hidden email]