Having witnessed the performance of numerous 4-Square antennas on 80m I decided that to be serious about searching out DX on the band it was the antenna that I had to have. On many occassions I have heard people working DX and giving good reports when I could hardly hear them and I'm sure that their success has been mainly due to the performance of a 4-Square array. I know that propagation can vary considerably over relatively short distances sometimes and without having the required antennas switchable at my location it is impossible to make any accurate comparison. However, I have heard relatively local stations being able to hear and work DX that I could not even hear on enough occassions to convince me that a 4-Square is a "must have". Also the numerous front to back comparisons I have heard demonstrated on the air are quite amazing.
In April 2008 I managed to negotiate and agree a suitable location to erect a 4-Square with my landlady (God bless her!) and construction was started as soon as possible.
Thanks must go to Wyn, GW4RIB, for his help and information regarding the construction of his 4-Square. Mine is heavily based on his and if I manage to put out half as good a signal as Wyn does then I will be very pleased. Having experienced so many problems with the guying of my single vertical (trees on the property prevent the optimum siting of guy ropes) Wyn's free standing verticals seem to be the ideal solution.
I am using a Comtek ACB-4 Hybrid Phasing Coupler and took delivery of that in early May 2008.
The verticals are supported by 5" x 5" pressure treated wooden posts. Each post is 3m long and have been set in 75cm of concrete leaving 2.25m above ground. The verticals themselves are made in three sections - the bottom section is 2.5" o.d. aluminium tubing 0.25" wall thickness and 2.5m long, the middle section is a standard aluminium scaffold pole 6.4m long and 49mm o.d. and the top section is a Spiderbeam 12m telescopic fibre glass pole. I have fed a length of 4mm wire up the centre of the Spiderbeam, knotted at the top and sealed with self amalgamating tape. Each section of the Spiderbeams has been secured by fastening hose clamps to the very bottom of each section to prevent it "collapsing" back into the next - I have heard that some people just secure them with tape but I found from experience that the taped joints eventually move. Spiderbeam do sell a "kit" of hose clamps with rubber inserts especially for this job - I just used a selection of hose clamps from my local motor accessory shop. The 4mm wire makes the Spiderbeam a pretty tight fit on top of the scaffold pole but with a bit of perseverance I have them far enough on to the pole to support it. For extra security and stability I have put a stainless steel bolt through both and used large washers (repair washers from the motor accessory shop again!), bent to fit the curvature of the pole, to spread the load and prevent damage to the fibre glass. The bottom of the wire is connected to the top of the pole using a stainless steel bolt. The top of the bottom section of tubing has been drilled and tapped in two locations to take M8 bolts and these keep the scaffold pole secure in the bottom section and should make adjustment of the overall height of the verticals a simple job.
The verticals are fastened to the wooden posts by means of two stainless steel brackets that are each secured by 8 x 3" coach bolts and the vertical is attached to the brackets using 65mm 'U' bolts (exhaust clamps from your local motor parts supplier). The bottom bracket has a hinged bottom section and the top brackets have slotted holes to enable adjustment in two directions to ensure that the antenna is perfectly vertical. I am currently investigating a method of attaching a winch to the post to aid erection - if I am successful I will probably put a winch on each so that they can easily be lowered in the event of very high winds.
As of April 2009 I have 25 radials per vertical.
Click on the thumbnails below to view a full sized image.
29th April 2008 I purchased a winch today, mounted it on one of the posts and winched up the first vertical. After securing the winch it took less than ten minutes to get the vertical upright and bolted in position! Excellent - I have now ordered another three winches, one for each vertical. I will put up the remaining three verticals next weekend (3/4 May 2008) and then the hard work with the ground system starts. Photos of the winch and vertical below.
Latest News - 5th May 2008 My Comtek phasing unit arrived on Saturday 3rd May. All four verticals are up now and at the moment they each have 6 radials. Each vertical's SWR is 1:1 at 3.720 MHz and one of them was used on Saturday night with pleasing results. I have ordered 75 Ohm coax for the connections to the phasing unit so hopefully I will be on the air using my new 4-Square sometime next weekend - please look out for me somewhere in the DX window on the night of Saturday 10th May.
The photos above show the last vertical of the 4-Square going up. The winch makes it a really easy job to get the verticals upright - I can winch them up with one hand easily.
Finally, the photos above show the completed 4-Square (apart from the ground system of course, is a four square ground system ever completed??!!) and the Comtek phasing unit.
The above photos show the effects of 25-30mph gusts of wind on the verticals - as soon as the wind drops they are perfectly vertical again!
7th May 2008 - now started work on the feed lines and each vertical has 8 radials. It's all looking good to be testing on Saturday 10th May 2008.
8th May 2008 - managed to get everything connected up for testing. Initial reports and performance very good especially considering that there are only 8 radials on each vertical and, at the moment, there are no radials within the array. 5 9 ++ reports from W2VP, N2RK and W1VO and the front to back seems very good.
9th May 2008 - VK4WR, VK4CZ & VK3PA .... my first VK4 and VK3 on 80m. Why didn't I put up a 4-square before??
10th May 2008 - Early morning QSO with ZL4DH. I realised that I had the wrong coax for the feed lines - RG59, velocity factor .66 and they should be 75 ohm coax with velocity factor around .80 Phone call to Wyn (GW4RIB) to find out where he got his feed line resulted in a trip out to spend some more money!! Thankfully not too much! Feed lines now all replaced with the correct spec coax. Each vertical now has 10 radials.
w/e 17th & 18th May 2008 - Martin, 2E1FVS, came to visit me for the weekend and brought fresh stock of wire for the ground system. Daytime was spent tidying up the radial connections and burying more wire - each vertical now has 12 radials and the nights were spent looking for DX. I could hardly get a look in on the rig!! Martin was on the mic a lot of the time which caused a little confusion for some of the stations that have worked me before!! Over the two nights we made around 75 DX QSO's mainly North America but also ZS6, PY2, PY5, WP4 & V5/DJ6OV for a new DXCC. My total DXCC is now 141.
26th May 2008 - Put down 8 additional radials, 4 on each of the two northern verticals. They now have 16 radials each while the 2 southern verticals still have 12. Winds have been gusting up to 50mph today! The fibre glass top sections dance around quite a bit when the wind blows but as soon as it drops they are bolt upright again. Comtek have now placed a link to this page on their web site - I have the honour of being the first "DX" station featured on their site!
My advice to anyone considering antennas for 80m would definately be if you have room for a 4-Square then go for it!! Don't do what I did and try a single vertical to see how it performs and then think about adding to it later. Just take the plunge and go the whole hog and get four of them up. I guarantee that once you have a 4-Square up and running you will wonder why on earth you didn't do it years ago!!
I know we are not all lucky enough to have the space available for a 4-Square - if you don't then I can highly recommend a single vertical and a K9AY receive antenna. The K9AY outperforms a single vertical on receive - I worked plenty that I could hardly hear on the single vertical but, having made comparisons of the receive performance between the K9AY and the 4-Square, the 4-Square wins hands down every time.
Credits
GW4RIB, Wyn - for advice, details about his 4-Square and encouragement. Thank you Wyn.
W2VP, John - for advice, encouragement and numerous QSO's many starting over an hour before his sunset. Thank you JC!
PA0GMW, Paul - for inspiration! Thank you Paul.... if I get reports only 2 or 3 S points down on yours I'll be happy!!
2E1FVS, Martin - for sourcing "old stock" wire for the ground system and help with the construction ..... top man!
Comtek - for an excellent product!
Spiderbeam - for an excellent product and prompt service.
XL Scaffolding - for the supply of scaffold poles - thank you.
Last but by no means least my landlady, Min, for allowing me to erect my 4-Square on her land ... at no extra cost, what a star!!