Topband: Eznec/ 4sq

[David Cole]

For many years I have run 4sq on both 80m and 40m - I currently run an 8 element vertical array for 80m and the centre mast is a top loaded vertical 85 foot vertical.

When resonating my 4sq verticals I have always disconnected three and resonated one vertical at a time to the target frequency for example 3.795 - this has worked well and without problem - I have used home made Hybrid and  Llewyn phasing networks.

I first started using  Eznec and modelling to understand how  the 8 Element array prior to Tony's article in NCJ  and during the development of the 80m version - Tony originally used 40m for his design.

Back to the 4 sq this leads me to my dilemma - If I model one element of a 4sq array and resonate it at 3.795 - using SWR to check no problem.

 I then bring in the other three element and enter sources of 0 degrees 2 elements at -90 and the front element at -180 when I check the resonance of the array the frequency drops far below 3.795.

 - at this point I would add that I was modelling a reduces height element of 41.5ft with 4 11ft 10inch top loading, could this be caused by the top loading increasing the mutual coupling and lowering the array frequency?

The end result is that the achieve an array resonant target of 3.795 I have to resonate the individual element at 4.105.

So the first question is WHY!!!!

Second question -  is how do I phase two four squares? do they have to be in line for my preferred direct NW from the UK which gives me in line SE for LP.

I am looking to achieve more forward gain than my 8 element array and two shortie type 4 sq's would be a good start.

If I can get to the bottom of all this then Shortie 160m 4sq will be possible.

If I have stated anything stupid or silly - remember I have been a ham for 51 years experiment experiment and more experiment is how we learn.

Thanks to everyone who helps me - from Dave in the UK