Topband: T Vertical feed

[Jim Brown]

On 1/26/2012 1:48 PM, ct1ilt at sapo.pt wrote:
> I measured the impedance at the base and it is Z = 23 + 9j with VSWR
> of 2 to 1.

If that is a good measurement, i wouldn't bother with a matching network.

> The VSWR after 50m of coaxial cable and a home made 1:1 balun (made
> with coax) is 1.7 to 1.

What do you mean by "balun?"  Did you wind turns of the coax around a 
ferrite core?  That is NOT a balun, it is a common mode choke. Some 
people who don't know better call it a "current balun."  A common mode 
choke like this does NOT affect the VSWR or the loss in the coax (except 
for the small additional length of coax it takes to wind the choke).

Based on your VSWR measurement and your impedance measurement, I'd say 
you're in pretty good shape, at least from the perspective of matching 
to the TX.  Good luck in the contest.

73, Jim K9YC  (California, Near SF)