The adjustiwave antenna system is an efficient adjustable quarter wave vertical antenna that can be used anywhere between 3.5Mhz and 148Mhz (80m to 2m). Resonance is achieved by either extending or retracting the antenna wires via a reel and pulley system. Primarily designed for use on the Amateur Radio bands but due to its continuous frequency coverage it is also ideal for any other radio communication services. Primarily designed for portable operation but also ideal for fixed installations.

How many antenna systems do you know of that can be used anywhere between 3.5Mhz and 148Mhz, set up in less than 20 minutes, perform as a quarter wave vertical and handle 1Kw plus?

No more Tuners! How often do we make compromises in order to work multiple bands with 1 antenna? Due to the adjustiwaves reel and pulley system, a near perfect match (SWR 1.5:1 or better) can be reached on the desired frequency you want to operate on.

Made as standard with an adjustable radial which enables rapid deployment. The system can be set up for operation is less than 20 minutes! For better efficiency, a radial plate & radials can be utilised.

Operate lower than 7Mhz with only 10 – 11 meters overall height by linear loading the driven element. Overall height is reduced drastically (by up to 50%) which allows the use of cheaper shorter antenna masts/supports. How much efficiency do you lose by linear loading? I’ve done some modeling with MMANA Basic but I think its ability is somewhat limited. When you model linear loading. MMANA shows its actually 0.4db better than a standard vertical at 5 degrees. Do I beleive this? The jury is out but I think the difference its negligible in real terms.

Standard 80m 1/4 wave ground mounted vertical antenna with 32 radials

Adjustiwave Development

The idea for adjustiwave antenna was first thought about in early 2019. I moved to my new QTH in 2015 but unfortunatly I didnt have the space to get my Hexbeam and 80m horizontal operational again. I persevered with a fan dipole for some time before changing to the GM0ONX Inverted L Antenna. The inverted L allowed me access to the top end of 80m but I didnt get the perforamce from it I expected, not to mention the S7 of QRM, Performance on 40m wasnt much better. I beleive this down to how I had it set up and lack of radials.

I came to the conclusion that if I wanted to work some DX then I would have to go portable. I looked at various ideas – dipoles, verticals, delta loops, long wires etc etc. Nothing ticked all the boxes for me. I needed an antenna that was quick and easy to set up for operation and covered all the HF bands with full performance(or as close to it). I looked at all commercial options but everything was either not suitable or too expensive. I knew what I wanted, I just had to source the parts I needed. This proved much harder than that first invisaged.

Wire choice – For the adjustiwave to work you need wire that conducts on its outer diameter, Your wire will create unwanted inductance otherwise. I learned this the hard way when I initially tested using an enamelled copper wire. I then tried Stainless Steel wire which ended up being the final choice, not before trying a couple of others. Next up was kevlar cored tinned copper braided wire, This was my preferred choice (I still use this on my MK2) but at almost £1 a meter and you also need to strip the outer coating off its a non starter when you compare cost vs performance. Galvanised steel wire was tried next, my thinking was the losses would be less than stainless steel. Unfortunately I couldnt get a match. the SWR wouldnt go lower than 2:1. That meant going back to Stainless Steel again.

Reel Choice – Of all the adjustiwaves components, these took the longest time to source. Being a keen fisherman I knew that a wide arbour fly fishing reel should be ideal. Finding a cost effective reel isnt as easy as you think (plus you need 4 off). I spent a month non stop researching when I happened to visit my parents and came across my Dads old Compo 69 fly reels. He happened to have 4 spare. I use these on my MK2 yet. For the MK3 I managed to source affordable fly spools. I dont expect these to last forever. I may have to look at turning my own eventually.