Topband: Help on 4 Squares

David Cole g3rcq at
Fri Feb 22 15:18:53 EST 2008

Hi all - I have some questions regarding four squares - My career was in commerce and not electronics so please excuse what may seem silly questions. Tom W8JI advocates that the normal 90/180 phasing is not the optimum - the 117/234 phasing gives more gain whilst making the lobes narrower which means to get the full effect there needs to be 8 selectable directions instead of 4 - I wish to follow Tom's suggestions - but I am unsure of the following - is the size of the 4 square fixed by the frequency or does the different phasing mean that the sides are of a diffent length?The four quarter wave feed lines I presume are longer to accomodate the 117 instead of 90 - is that correct? If so - to get the 234 phase do I put a twice the length of the feeds to each vertical in series with the front vertical?With the longer feeds to each antenna will the same current / voltage rules still apply in the same way as if they were quarter wave feedlines?Sourcing vacuum
 relays is a problem - can anyone pass on where in the world I can get 10 DPST 1 4PST and 3 SPST - if  I cannot locate vacuum relays and I revert to normal relays then what current rating should I use - I guess this is allied to the RF current going into each antenna - assume 400watts as this is the UK max - any help would be appreciated - regards Dave G3RCQ

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