View Single Post
  #30   Report Post  
Old February 3rd 07, 03:35 PM posted to rec.radio.amateur.antenna
Ian Jackson Ian Jackson is offline
external usenet poster
 
First recorded activity by RadioBanter: Oct 2006
Posts: 89
Default Matching Issue ........... I think!

In message , Cecil
Moore writes
Ian Jackson wrote:
I don't understand that, Cecil. Yes, the stub will be a halfwave on
40m, and therefore add a low impedance in parallel with the antenna
feedpoint. Depending on the exact resonant length of the stub, the
impedance will be either a very low value resistor, a low value
inductor, or a large value capacitor. None of these is going to help
to convert the resistive part of the input impedance of the antenna to
something around 50 ohms.


You're right, Ian. I was trying to apply the same
principles that causes the stub to turn a full-wave
40m loop into a 1/2WL 75m dipole and had a senior
moment. But that idea would work with RG-174. With
a 3 dB loss in the stub, the impedance looking into
the stub would be around 50 ohms. :-)


I'm not an antenna person, Cecil. Are you going to do the hono(u)rable
thing and calculate the dimensions?
Ian
--