Wednesday, August 15, 2018

My Screwdriver Antenna Experiences



Even On A Compact SUV


Some of you may be familiar with the Hi-Q line of mobile HF antennas. SEPAR has several, a choice prompted by the need for a relatively compact, portable HF antenna that is quick to set-up in the field, at least until a more robust antenna can he erected. As an RV’er I decided that I needed a usable mobile HF antenna that I could erect quickly, but that would provide me with a worthwhile HF experience. There is nothing worse than spending hours at the radio and not hearing a soul on the air!

In order, my criteria were:

  • Performance 
  • Size;
  • Ease of set-up (not necessarily speed);
  • Ruggedness; and
  • Solid mount

I researched a number of mobile HF antennas including the Buddipole and Tarheel products. Not to bad-mouth these other products, but I tried both and was not satisfied that they would meet my expectations. I was impressed by the quality of construction and military spec components of the Hi-Q. Performance reports were good (provided it is properly installed) and it met my needs for ease of transport and mounting.

Hi-Q antennas are made in the workshop of Charlie Gyenes, W6HIQ, VA7HIQ in Wildomar, CA about 150 Km SE of Los Angeles. Charlie has been supplying these antennas for over 20 years and is a supplier to the US military and NASA. I visited Charlie to pick up my Hi-Q  and he is an interesting, though opinionated fellow who came to the US from Hungary via Canada during the 1956 revolution. Charlie worked for Boeing before setting out on his own.

Charlies’s workshop is modest, consisting of a medium sized building beside his home. When I visited, he had about 20 Hi-Q’s ready to go. He also showed me several military antennas—ruggedized versions of the Hi-Q, and a huge VLF antenna which was to be installed aboard a US Navy submarine. His test equipment is impressive and his greatest joy is in developing new concepts which can be incorporated into his antenna designs. I mentioned Charlie was opinionated… he pulls no punches when describing his competition and he is obviously very proud of his product. 

Before we left, Charlie’s wife, a lovely lady, insisted on preparing lunch before we headed out with the antenna. 

Some Mis-steps

Arriving at our Palm Springs RV Resort, I set up the antenna on a satellite stand, a setup we had used with SEPAR at community displays. This antenna is a typical screwdriver design, the coil being contained in a 20cm diameter plastic housing. A rotor moves up or down the inside of the coil to decrease or increase the virtual length of the antenna, thereby tuning it to the appropriate frequency. To complete that process, the user can use something as simple as a toggle switch, a turns counter, or a third party automatic antenna tuner. I had opted to purchase Charlie’s turns counter, basically a switch box with an LED numeric display that shows how many turns are in the antenna circuit. This worked but I found it less precise and it was easy to under or overshoot the target frequency with just one rotation. 

Palm Springs is in a ‘bowl’, surrounded by tall mountains, I found that the antenna performed well for strong stations within 1000 Km, but was not stellar for DX.

The ‘Right’ Set-up

This year we sold the RV but I still wanted to be able to travel with the Hi-Q to operate mobile. We stay in an RV Resort with antenna restrictions, but they do not cover antennas on vehicles. We often travel with bicycles and my wife suggested I find a way to mount it on the car’s bike carrier (see photo below). This also permitted me to easily remove either just the antenna or the rack and antenna. I added a ground strap to the frame and also added a current balun to the feedline. Additionally, I extend about 20ft of plain hookup wire directly out from the rear of the vehicle... kind of a counterpoise. With this revised setup and my Icom 7000 (100 Watts max.) I worked the CQ WW DX contest. What a difference! Granted the conditions were excellent and even the high bands were open but the results were immediate and surpassed any previous use of the Hi-Q. I worked stations throughout the US, Canada and the Caribbean. I also worked Portugal, Mexico, Japan and added two new countries, Curacao and Cape Verde—the latter my first African contact. On all bands I got an SWR less than 1.6 and as low as 1.1 on 20m.

I’ve  now purchased the automatic tuner for use with my Icom, a purchase that I hope will ease tuning and further improve my portable station. Given my recent experience, I’d recommend this set-up for anyone with strata restrictions wishing to operate HF.

More info at: http://www.hiqantennas.com/

The Hi-Q with whip is 12' high
The bicycle mount provides enough height to
work HF, even on the low bands







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