On 6 jul, 15:34, Michael wrote:
Has anyone here actually built a Lazy H for 10 meters that worked?
In my previous post there was alot of references to published material
on the Internet as well as alot of people using computer modeling
software to check out the antenna. I've already done all that, but
when I actually tried to build the antenna on 10 meters it did not
work. It's performance was awful. When I try to tune it up on the
antenna tuner (Dentron MT-3000a) the antenna adjustment on my tuner is
almost all the way over to the right, and the transmitter adjustment
was tweaked a little over to the right as well. I decided to try a
different antenna tuner, so I hooked up my Drake MN-75 antenna tuner
with the 4:1 balun installed and was once again I had to just about
max out one of the variable capacitors to bring the SWR down. Once
the SWR was down the receive was still way behind the Solarcon
Max-2000 and the 10 meter horizontal dipole.
Has anyone actually built one of these and made it work well on 10
meters? If so how did you feed it/match it?

Michael

Hello Michael,

The concept can work at any radio frequency. I didn't build them on
10m, but I did on 433 MHz, 868MHz and 2450 MHz (over a reflecting
plane to get unidirectional pattern), both with 0.5lambda spacing and
more (to get more gain, and some side lobes).

There is one difference with respect to your setup. I designed for 50
Ohm input impedance in the middle so that I have no high VSWR on the
feed cable. Depending on the thickness of the radiating elements you
may have a VSWR of about 15 on your 450 Ohms feed line.

When the distance from end of radiator to feedpoint is about
0.5lambda, the impedance is real and low (about 30 Ohms, depending in
thickness of radiators). This interfaces good with a 50 Ohm coax. 2
years ago a planned to build one for NVIS operation at 80m (pastoral
wet soil as reflector). I didn't build it as the HW dipole with 3
reflecting wires did perform more then well.

I concluded from your posting that you simulate also. I think your
problem is in the matching and tuning. So try to lower the VSWR in the
feed line and or examine your tuner.

Best regards,

Wim
PA3DJS
www.tetech.nl
When your remove abc, the address is valid.