Topband: New 160M high performance receiving antenna at W3LPL

[Dmitry Belousov]

George UA1DZ used this type of antenna since the late 70's. Unfortunately, George never
described his antennas in the literature. One of his antennas, was an 8-ele antenna
operating in the 14-28 MHz. Its descripted in Russian languagge and given in a
letter from George to one of hams.
It consisted  eight wideband vertical dipoles in a circle. Dipoles is unsimmetrical,
because it was necessary to get resistance of 100 ohms. All the elements are feeding
100 ohm cable. At the bottom of the dipole with the same cable George made a balun,
which delete the current asymmetry. Cables from all vibrators same length of 35
meters to come to George's shack, where connected to switch-phasing  device.
The scheme of this device is shown in the letter. The scheme provides switching
to 16 directions. As well, George thought, that in depending of the type of
condition in ionosphere it’s need to switch vertical angle of radiation. He was
to able to switch it on 0 degrees and 30 degrees. On Russian forums, not so long
ago was shown UA1DZ antenna in a model for MMANA analyzer (modeley by
VE7FDZ), which confirmed the high parameters of this antenna. In attachment – letter
of George with description of antenna, MMANA model file for this antenna,
printscreen of diagram and parameters of this antenna.


VG>  I was taught this kind of antenna during two semester course
VG> at radio department of Lvov Polytechnic at the begining of 70's. A
VG> lot of formulas and diagrams... 
VG> UA1DZ (SK) used this kind of array of 12 vertical elements on
VG> 20-10 meters. Unfortunately no information except the vertical
VG> element drawing remained.
VG> 73 Vic US5WE



VG> Вторник,  5 февраля 2013, 21:06 -08:00 от "Lee K7TJR" <k7tjr at msn.com>:
>>>The "Wullenwever" antenna was never a low-noise high performance antenna.
>> It was simply a system designed to find direction over a very wide frequency
>>range. The multitude of elements increased bandwidth, but the physical width
>>in wavelengths is the primary determinant of directivity.
>>
>>    While I will agree that the Wullenweber antenna was never designed to be a
>> low noise antenna, I fail to see why it is not. My copy of TM32-....... manual
>>on the US version shows some pretty good directivity specs. On the low band
>> starting at 2 MHZ the beamwidth was 11 degrees with the side lobes down a
>>minimum of 18dB. The maximum elevation was 30 degrees. Also the range
>> specified was 4000 nautical miles. And its outer element diameter was
>> 1116 feet. The 48 low band elements were 35 feet tall with a 120 foot tall
>>reflecting screen. Each element had a 19dB gain semiconductor amplifier with
>>a 7 dB noise figure. I agree also that not all the 48 elements were active
>> however the ones that are in a given direction produce some outstanding specs.
>>      So if I compare usual high performance low noise RX antennas to this large
>> antenna our directivity specs pale in comparison leading me to believe the RDF
>> of the "W" system surely would be greater than anything we could imagine with
>> our RX antennas. Nor does noise figure appear to be a concern.
>>     Or is my thinking corrupt?


-- 
Best regards,
 Dmitry                            mailto:ur4lrg at ukr.net