Hi group,

I've been using a Tee-antenna for Navtex reception on 518 KHz for about
6 months now. Details are he
http://users.pandora.be/dirk.claessens2/NAVTEX/Tee-antenna.jpg

I'm very pleased with the results, the thing just works. Almost no
local QRM pickup, low noise. I was able to decode really weak Navtex
stations in Florida, Puerto Rico, Bahrein. ( I'm living near Antwerp,
Belgium).

But is this a really optimal antenna setup - given the obvious real
estate limitations of my back garden?

When I feed the antenna data into 4NEC2, the following data result:

Z = 241-j1812 Gain = -28.6 dB SWR = 278
I'm assuming that the mismatch is "solved" by the use of the 4:1 UnUn..

If I model a base loading coil of +/- 550 microH , the following
results:
Z = 165-j14 Gain = -26.9 dB SWR = 3.3

Question 1: Is installing a base loading coil worth the trouble for
receive-only purposes?

Question 2: Should I still use the balun?


Thanks for any advice.

Cheers - Dirk