[TowerTalk] Receive 4-Square

[Roger Parsons via TowerTalk]

Many thanks to all who replied to me both directly and to this reflector.

Firstly, I have some egg on my face. One of the verticals had a corroded connection, and on fixing that the array seems to work significantly better. I am pretty confident that the system is now working as it should.


I have had the system for several years, but until this summer I did not use the 'crossfire phasing' technique so it was really quite narrowband. I very much take on board the need to evaluate it over a lengthy period - I find that even my long Beverages sometimes have zero directivity. Last evening it had an F/B ratio varying between 15dB+ and very little on W1BB.


The hybrid combiners used are not quadrature hybrids - they (ideally) have zero phase shift between input and output. The phase shift comes from the two lengths of URM70 (75 Ohm cable) shown on the schematic as 60 and 120 degrees, and the element phases should be 0/120/240 degrees. As the verticals are heavily resistively loaded there is very little mutual coupling which greatly simplifies design.

Thanks again to all

73 Roger
VE3ZI