On 6/2/2026 12:25 PM, k1zm--- via Topband wrote:
A couple of weeks ago I gave a speech at the Topband DInner in DAYTON - and one of the
things I talked about was this 160m RX antenna called the DHDL - or "Double Half
Delta Loop".
I will comment on my personal experience using this antenna for RX on 160m -
but for those who want to r
So now then - What works on 160m RX "FOR THE REST OF US" - who are not lucky
enough to be a HAVE with lots of land and resources?
Excuse me, but I happen to have 20 acres.
For me, it is the AA7JV DHDL ***without question*** and I will next comment on
my personal experiences with this antenna.
One last point:
means that you do NEED a TON of Rx pre-amplifier gain to make them
hear well on 160m.
THE DHDL ALSO NEEDS LOTS OF PREAMPLIFIER GAIN IN ORDER TO HEAR WELL!! You cannot just hook up a feedline to your RX and expect it to work its magic. Here I use an old AMECO PLF2 or a Gary Nichols KD9SV 160m preamp - which is then coupled into the RX - and I can vary the gain as needed using either preamp,
Here at K1ZM - My take on the DHDL is that it performs about as well as a 600
ft beverage - and that's good enough for me to hear well on Topband in most
cases.
Jeff K1ZM/VY2ZMCape Cod Mass.
Email: [email protected]
Maybe you can school me on DHDL construction.
A few years ago, I built one according to published design articles.
It appeared to work in terms of front to back ratio.
However, it never produced a noticeable improvement in signal to noise
ratio compared to the 90 foot vertical TX antenna used as a RX antenna.
Which BTW, was about 1000 feet away from the DHDL.
This was the same problem I had with various beverages I erected.
I believe my problem with the beverages could be attributed to my very
high ground conductivity. Driving a beverage with a signal generator
and then using a current probe along the wire indicates that the current
has dropped to a negligible value after a few hundred feet. At my QTH
a 600 foot Beverage would be a waste of wire. I am wondering if the
ground conductivity is also causing the problem with the DHDL.
I am also wondering about your comment concerning pre-amps with a ton of
gain. Correct me if I am wrong, but once you have enough pre-amp gain
to overcome the noise of the pre-amp in the radio, more gain doesn't
help. In any event, the amount of noise coming off of the DHDL easily
exceeded the noise of my radio's preamp. Just for good measure, I tried
a very high quality commercial preamp and it didn't matter. This was
the same thing I experienced with beverage antennas. Possibly my high
ground conductivity produces a very high noise level from ground wave
propagation of local noise.
Can you recommend any corrective action I could take to fix the DHDL?
Thanks.
73
Rick N6RK
_________________
Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
