Chazro

Hey this is a cool site…which I just discovered.
I’ve been doing Part 15 stuff for years. I have a permanent
AM antenna in my back yard and you can see the evolution of
it’s development here:

http://charliethompson.50megs.com/1610khz.htm

This antenna works well in spite of ground losses. In fact the
ground losses add to the radiation resistance to give me about
50 ohms at the feedpoint. Mind you the efficiency is not that

Hey this is a cool site…which I just discovered.
I’ve been doing Part 15 stuff for years. I have a permanent
AM antenna in my back yard and you can see the evolution of
it’s development here:

http://charliethompson.50megs.com/1610khz.htm

This antenna works well in spite of ground losses. In fact the
ground losses add to the radiation resistance to give me about
50 ohms at the feedpoint. Mind you the efficiency is not that
great due to the radiation resistance being a fraction of the
ground loss resistance ….but…when resonated….will give you
a 2+ mile range….hearable at 3 miles on your car radio when
running a 100mW transmitter output.

An improvement on this antenna design would be to add about
50 ground radials which will LOWER the feedpoint impedance at
resonance. Then you’ll need to add a matching coil at the antenna
input and re-tune the capacitor to get 50 ohms again. After this
is done the antenna current will be higher and the efficiency should
increase by at least a factor of two. If anyone out there makes these
improvements I’d like to hear about it. I may do the same to mine
as time permits.

Cheers,

-=Chazro=-