Anyone who live in an apartment has to adjust to what the owner permit and the neighbours agree with. For me and many others it's therefore not about getting the “best” antennas, or even the best antennas we can afford. The “best” antenna for us is perhaps the antenna that make it possible to radiate any kind of signal (and to conduct this hobby) at all! This does not mean that we can't experiment with different types and concepts or that we will not strive for improvements. Even so, more than just the antenna, we have to find the best general solution to our antenna problems. A solution that has to fit within the limits of all the circumstances, restrictions and regulations we have.
When I first moved in the owner said a complete and total “NO!” to any kind of antenna hanging between the houses or standing on top of the roof. The only option left was to use a fishing-pole antenna on the balcony with counterweights inside of my apartment. I put it up when on the air and put it down when not, which was most of the time. Not a very good antenna at all, but it worked somehow for casual qso:s. I even worked some contests and managed to come number one in Sweden on 7 Mhz QRP.
I also tried with the ART073 from ECO Antenne; the trapped balcony antenna for the 10, 15, 20 and 40 meter bands. Put it on my balcony just outside the shack window. Didn't work for me, so I sold it after a while. I think that there was simply too much metal in the vicinity and surrounding it.
The big break came when the house was bought by a new company. Their attitude was more positive. I even got a written permission signed by the Big Boss to put up a off-center-fed dipole for 10-40 meters. What a difference it was! Much easier to get out and no hazzle with putting up and taking down the antenna all the time! Even if better than before, I found it far from perfect. As an improvement I tried a home-made vertical for 20 meters on top of the roof. It was indeed better, but it broke and fell down during a autumn storm, and that was the end of that!
A vertical seemed anyhow better than the off-center-fed dipole so I decided to try the Butternut HF6V. It had many good reviews and was said to be a good performer if only you had enough radials. Those are no problem at my location as you can put them flat on the roof and thus are almost invisible. Neither the owner of the house or the neighbours would take offence. I have 4 radials for 80 meters, 8 for 40, 8 for 30, 8 for 20 and 4 for 10 meters. I read on the Butternut Reflector that having the feeder parallel with the radials isn't an optimal solution. Strange things my happen. As I had a so called "line isolator" laying around I put it at the junction of the 75 ohm matching coax and the main transmission line. And what do you know! The antenna seemed to work a little bit better, particular on 20 meters. I don't know if it's just my imagination, but everything that make me do more qso:s during a contest is regarded as a positive; real or imagined, I don't care!
With this up on the roof performance was markedly better than the off-center-fed dipole. I could very well have left the off-center-fed dipole as a backup antenna, but the feeder coax was a major problem. Particularly during windy days, it was swinging violently in front of the windows of my neighbours. No good at all! Even I, myself, found it a bit annoying at times. So, I took it down and was left with only my HF6V thinking that it was the ultimate solution for me and the best I could ever get considering the circumstances. And I can indeed confirm that the HF6V is a very good antenna. With three supporting lines it has stood up to two of the worst storms we have had during the last 25 years without any problem at all. It certainly do not outperform a beam, but in spite of this enables me to achieve respectable positions in the qrp-category in contests. The sorry part about the HF6V is of course 80 meters. On that band the antenna is only 1/10th of the wavelength. The efficiency of the antenna is not overly good. Not that many of the 5 watts I put into it end up in the air.
For a long time I was thinking of different solutions to this problem. One idea was to put up a 13 meter vertical that would be a 5/8th of a wavelength on 20 meters and could be remotely tuned by base-loading for the other bands. I knew that a bare "stick" offends less than something thick and bulky on top of the roof of the house. I was sure that an extra five meters compared to the HF6V wouldn't be noticed very much. Being almost five meters longer/higher than the HF6V better efficiancy on 80 meter could be expected and more or less the same performance on the other bands. However, the whole thing seemed somehow a little cumbersome from a practical point of view. In the end I therefore was more and more considering just a monoband solution for 80 meters in order to “support” the vertical for that band. It followed that it would be some kind of horizontal antenna hanging between the top of my house and the house nearby. Any kind of dipole or of-center-fed antenna was, however, out of the question as it would mean a coax swinging in front of the windows of my neighbours. A long-wire would need counter-weights and could give both TVI and RF in the shack. Some other solution had to be found.
I finally found it at the web sait of AA5TB. It promised the performance a dipole without a feeder annoying the neighbours. Just what I was looking for! He also seemed to be a guy who knew what he was talking about! It was not just a whole lot of theoretical techno-babble or something he learnt from playing around with computer software. He had actually tried it out in his own back yard himself! If I, in addition, used the thin copperclad steel wire from DX-Wire it would be almost invisible to my neighbours. It all seemed just perfect!
Now when I have put it up, the end-fed half-wave dipole is beyond my expectations! With the HF6V I have never done more than 130 qso:s on 80 meters during a contest. During the first major contest with the end-fed half-wave dipole I made 220 qso:s on the same band! That's what I call a significant improvement!
The antenna has a SWR-minimum at 3538 kHz. SWR lower than 1:1,5 lies between 3503 and 3570 kHz and is lower than 1:2 up to 3590 kHz. Listening to other stations, the end-fed half-wave dipole seems to be stronger than, or at least as strong as, the HF6V to all stations up to a distance of about 1500 km. The closer the station is, the better do the dipole perform. For local contacts in Sweden a difference of up to 5 S-units have been reported by other stations. Furthermore, using the DX-Wire the antenna is indeed next to invisible. You actually have to know it's there to see it!
Of course there still remain some kind of antenna for 160 meters. At the moment I have nothing on that band. Trying to put up something for that band seems, however, to challenge the patience of my neighbours a bit too much. So better to just forget about that band alltoghether!
In the autumn of 2010 I begun to think about the “lack of punch” SM6VJA and I had noticed the HF6V had on 20 meters. It was just a feeling we had and nothing we could substantiate by any objective figures or reading.
Anyhow, I though that one cause might be the 75 ohm matching coax that is used to match the HF6V to 50 ohms on the 20 meter band. I set out to measure the exact electrical ¼ wave length of a RG-59. Originally there is a RG-11A/U, but you don´t need such a thick cable if you are only working QRP all the time. A RG-59 is quite enough!
Of course you can do this with a fancy antenna analyzer, but I don´t have one. Another way to measure the electrical ¼ wavelength is a setup like this: tranceiver ? SWR-meter ? 50 ohm dummy load, all connected by coax cable. Cut the coax cable between the SWR-meter and the 50 ohm dummy load, stripp the coax cable and soldered them together again, leaving the center conducter and the braid visible. I then connected the centre conductor of the 70 ohm coax to the centre conductor of the 50 ohm cable and the braid of the 70 ohm coax to the braid of the 50 ohm coax cable. Then short the braid to the centre conductor at the other end of the 70 ohm cable.
With this setup you get the least SWR-reading when when you have an exact ¼ wavelength of the 75 ohm cable. Note that the dip is very wide. You have to turn up your SWR-meter to maximum sensitivity to get any reading at all. In spite of this, and with a little bit of tinkering, you will get a reading and a fairly exact measurement of the electrical ¼ wavelength of your coax. For my RG-59 I got 3,70 meters at 14,030 kHz as opposed to the original 3,33 for the RG-11A/U that came with the antenna when I bought it. It is said that the shortening factor is 0,66 for these type of coaxes, but course this length will vary from coax type to coax type and from coax to coax of the same type. In addition one can expect a certain variation of the shortening factor or percentage of tolerance.
In any case, it´s always best to make an exact measurement of this piece of matching coax if you aim to get the absolute maximum from your antenna. For my HF6V the result was that the SWR – that with the old coax cable had varied between 1:1,5 to 1:2,0 on 20 meters – fell to 1:1,25 on 20 meters. This is not much – I know that! - but if you want to get everything you can from your antenna even a fraction of a watt extra into the air is worth the effort!
There is always ways you can improve your antennas even if you live with restrictions or other limitations. Getting better antennas do not have to mean replacing your dipoles or verticals with some beam. The fact that you can´t work all bands with good antennas does not mean that all hope is lost and that you can´t enjoy our hobby. You just have to accept the circumstances and make the best of them! Even with restrictions (at least in my country) you can often put up one good antenna for at least one band. A ground plane antenna is a very good antenna if it is put up “high and free”, for example on top of the house you are living in. You can make a simple wip from an old CB-antenna or an inexpensive fishing pole for either 20, 15 or 10 meters, have the radials put flat on the roof and have a very competitive antenna for very little money and that hardly can be seen by your neighbours. As I have said; it´s just a matter of making the best of your particular circumstances!
Update January 2014
I recently treated me with a YouKits FG-01 Antenna Analyzer. It is the later, “Mark II” version with a slightly bigger display and more memories. I have not used such a device before. I have relied on a simple SWR-meter and tril and error when adjusting my antennas.
I now realize that I have missed a lot in my life! Something that would have taken hours, if not a whole day, can with this device be made in a couple of minutes. As it is very small and portable I can now be at the antenna and directly see what the results of my tinkering is. As it has a small graphic disply you see directly “where you are”. As the impedance is shown you can see if you have to adjust the windings the transformer when tuning my EFHW-antennas, which is very helpful indeed.