"Roy Lewallen" wrote in message
...
Jerry Martes wrote:

I'd have expected the "gain" to be closer to 4 1/2 db over the 1/4 wave
stub over a ground. is it easy to show where i've missed something?


I think it should be more like 3 dB, but hadn't said anything until I had
a chance to model it. The quarter wave stub doesn't radiate significantly,
so it can be ignored. A half wavelength element should have about 1.5 dB
gain over a quarter wave. Two of them would give another 3 dB if it
weren't for mutual coupling, but the mutual coupling of collinear elements
reduces the gain to about 1.5 dB over a single element. (See for example
Fig. 39 on p. 8-35 of the ARRL Antenna Book, 20th Edition; look up
Collinear, Gain and directivity in the index of other editions; or model
it with your favorite program.)

Roy Lewallen, W7EL

Thanks Roy

Your posts always add alot to my understanding. I appreciate your taking
time to evaluate this antenna and then pass the information on to the group.

Jerry