Topband: DHDL

Sun Jun 30 13:29:14 EDT 2019

Two things:
1. The antenna does not become "useless" when the loops are longer than 1/4 
wave. It just won't work as a DHDL, but may still be useful as a low noise 
RX antenna.
2. The DHDL is actually two loops, and each loops should be shorter than 1/4 
wave. Note that there is nothing special about the dimensions. You could 
make it smaller, to make it more suitable for 80 and 40. The dimensions 
originally published were set to maximize the signal output on 160.
One thing that's important: the two loops should be exactly the same size 
(within a couple of inches)! You can easily achieve that my moving the 
central crossing to the exact center.

On Sun, 30 Jun 2019 18:03:23 +0200
  Martin <dm4im at> wrote:
> Topbanders,
> just read a few articles about DHDL antennas. One article states, the cut off frequency where the antenna becomes useless is when the overall length of wire reaches a 1/4WL. In my understanding the original dimensions , 2*7.5m vertical plus 22m horizontal plus 2*13.3m sloping wires equals 63meters, which is already a lot longer than 1/4WL on 160m. What did i miss?
> -- 
> Ohne CW ist es nur CB..
> 73, Martin DM4iM
> _________________
> Searchable Archives: - Topband Reflector

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