Big changes (Sept 2014) over the summer of 2014 - a completely new array - two phased four squares for 80m and two phased four squares for 40m - more infomation to follow -
At 19th.October 2014 the second 80m four square is finished and working - both arrays are fed with hybrid phasing units home made on home made PCB - both arrays have 8 directions.
A very interesting point is that my 80m verticals are only 40ft high and top loaded - 40m are 25ft and again top loaded, after many eznec models and one dx season it was found that full size verticals make little difference to short verticals - (other UK stations are also using short verticals) - the difference is points of a db and not discernable at the received end.
On long path last season a distance of some 21000miles my short vertical four square produced the same reports as other UK stations using full size elements.
As there were 4 completely separate 8 direction boards and 4 hybrid phasing boards to make it was decided for ease of construction to use PCB's.
The two pictures below show one of the four waterproof boxes that contain the 90/180 and 110 degree phase shift required for diagonal and off the side directions, together with the 8 directional switching, note there are 4 additional relays that short one end of the 90 degree phasing lines - this method make the other end of the line open circuit the result is invisible elements until chosen by the central control PCB lower down the page. Those familier to hybrids will note the additional reactance across the dump load together with compensation inductance and capacitance, thes components allow fine tuning of the array and its possible to vary the centre element for best front to back - The lowest dump power is 1.8% when all elements are at 1-1-1-1 however I change my current to 0.95 on the centre element which increase the dump slightly.
20th October 2014 work starts on the control PCB - this is a complex board that has many functions.All elements are floating and invisible to each other. The arrays are approximately 750 feet from the shack. There is 500 feet of 18 way control cable. Over 1000 feet of plastic trunking encases the cables - this is due to Rabbits that seem to like my cable.
The control centre board enables the following to happen from the shack and completely self cotained.
Selection of any four square for either 40 or 80m either singly or as a phased pair.Switches on the elements needed for the chosen configuration.Switches in the end fire delay line for NE and SW and moves the delay depening on direction. Switches in the LC network to allow matching of the the two 50 ohm feeders from each four square for broadside directions. The delay and LC matching networks are of course different for each band - these combinations are again selected automaticaly.
There are 14 double pole relays in the Control Centre PCB -
PC Boards are made easily and etched in Ferric Chloride solution - I do not use a CAD program all my PCB layouts are first made on scaps of paper - then I use a simple paint program that comes with Windows to make the final design, this is then lazer copied to press n peel - the resulting image is then pressed onto the board using a press originally designed for T shirt transfers - board are 100% everytime.
Above is the finished Central Control board with 50/25 LC matching circuits for 40 and 80 together with the end fire delay circuits again 40 and 80.
Sunday 26th October 2014 Central Control board under test before installing into the arrays - carefull checking of the complex circuits resulted in 100% success - next fine day installation - at last - then all I have left is to buld the two 40m phasing boards and the two 8 direction relay boards.
Monday 3rd November 2014 80m - both arrays now working and under test - Control Box installed and working 100%. Tomorrow - I start on finising the 40m arrays, below is a photo at sunset of one of the two 40m four squares - clearly showing the four capacity hats - note also how flat the terrain is - the sun is just setting - all directions are flat so take of is excellent.
Sunset over one of the two four squares for 40m.
Please visit again as I will be uploading photos of all the boards together with more information.
90 foot free standing Titanex vertical for 160m and a Optibeam OBW 10-5 for HF bands. For local contacts I use a 264foot Doublet at 60 feet.
I have traded in new and used ham gear for some 52 years and trade under the banner of RCQ Communications Limited from my warehouse near Kings Lynn - both old and new equipment is catered for and I advertise in RadCom, Practical Wireless and RAOTA - I am also have an Agency with ML&S and can supply most equipment to the UK mainland - next day delivery .
Please visit my website http://www.g3rcq.co.uk
I have been licenced for 52 years - thanks for looking me up on QRZ
Thats me winding up the second vertical for 160m - Titanex free standing 90 foot - tuned against 75 quarter wave radials
Left to right G4AMN G3RCQ G4PEL
80m DX gathering at G3RCQ's QTH 2012
1403367 Last modified: 2014-11-03 18:16:42, 6383 bytes
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