[TowerTalk] Unique Inv L...Help!

[Jim Brown]

On Thu, 1 Jan 2009 12:55:51 -0800 (PST), Edward Sylvester wrote:

>I have compared the two and I prefer the dipole.  The LW couples 
>into anything electronic and I hesitate to use it because it 
causes
>interference.  It's also noisier and is virtually the same as the 
>dipole, in terms of signal output.

>Hence, it's somewhat of a disappointment.  Plus, my signal on 
160m
>is anemic.  Thinking I can convert this into an Inverted L for a 
>better DX antenna.

I didn't near you mention radials under the LW. Both of your 
complaints are exactly what one would expect without radials. 
Antennas do NOT work against "ground," they work against a 
reference plane that completes the antenna and serves as a return 
for both antenna current and the fields associated with the 
antenna. The EARTH is very lossy, so is a lousy return. That's why 
your transmit signal is weak. 

The most likely reason you're "getting into everything 
electronic" is that the all the wiring in your shack and home is 
forced to carry that antenna return current (and field). That 
current is exciting pin 1 problems in that equipment, and also 
coupling into wiring within the equipment. 

Your inverted L could be an excellent antenna if you finished 
building it -- that is, installing radials. Until you do, you have 
only half of an antenna. This antenna should be fed with coax. 
Study the ARRL Antenna Book and the ON4UN book (both published by 
ARRL) for more on this. 

As long as this antenna is NOT close to a half wave (or full 
wave), you should be able to tune it with a decent antenna tuner. 
The closer it is to a quarter wave, the more likely it will be 
that you can load it with the auto tuner built into a rig. Loss in 
coax is negligible on 80 and 160, which are the bands where an 
antenna like this really shines. 

Finally, don't expect an antenna like this to be quiet on RX. If 
you want a good RX antenna, BUILD an RX antenna. Study those two 
books for specific advice. 

73,

Jim Brown K9YC