OH6NIO yagi antennas

Where all this started?

I was born in 1964 and I was already interested in radios and electronics as a schoolboy. In the end of 70's I started DX-listening, and I listened to the Short-wave broadcasting station around the world with a Yaesu FRG-7700 communications receiver and a wire antenna. Later I found out that there would be a ham radio course in my town. I took the course but I did not try to pass the examination. That time the schoolwork took most of my spare time.

In the Army

Later when I served my military duty in Finnish defense forces as a radio operator I learned CW, and I got interested in ham radio once again. I had two friends there who were ham radio operators, and they also increased my motivation to become one. In those days if one had already passed the second-class radio operator examination one could apply for a military radio amateur license, which allowed one to work on 40m and 80m CW from the special military club station. Many other radio operators took part in the examination just because they would get one-day holiday if they passed. I worked some 300 QSOs from OI6AX. During that time I also passed the first class radio operator examination, and therefore with a special permission I could take part in the general class amateur radio examination, which I took later in November 1985 and passed. In those days here in Finland one had to first pass the so called novice examination, then get enough experience by working many CW QSOs before one could upgrade to general class, which gives the highest privileges to a ham radio operator in Finland.

The first touch into the world of contesting

A good friend of mine Ari, OH6XA introduced me to contesting. He had a 24m high tower with monobanders on 20-10m. When I admired his setup I thought that he had a very big station. I received my license in December 1985 but I had to wait 5 months before I was issued my own call sign! It felt like the longest 5 months that I have ever waited. I immediately started to work on HF from our local club station OH6AP. I also started to build a modest station at my parents QTH. My first contest was WPX SSB in 1986. I worked some 350 QSOs from the club station OH6AP because I did not yet have a call of my own! The score was not very big because the antenna was just a dipole for 20m band but I was hooked. It was such an excitement to work into the states, Alaska, Japan and all other more exotic places in such a short time. My operating was 100% search and pounce because there was just an old TS520 without any voice-keyers available at the club.

Some antenna experimentations at OH6NIO

When I finally received my call sign in the last day of May in 1986 I already had worked both WPX SSB and CW from our club, and I had gained some experience in contesting. My first station was very modest. The radio was an old tube radio TS510, and antenna was just a G5RV. I could work mostly Europe and one of the few strongest DX-stations. It was solar minimum so DX was not so plenty. I later tried a vertical on 20m and a wire LPDA pointed to JA. I started to get more DX QSOs especially on 15m with the LPDA. I had also built a wire LPDA for 7-30MHz at my fathers house, mainly as a receive antenna in early 1985. It was pointed to USA. Later I could occasionally try working some DX from there. My first QSO to USA on 40m was worked with that antenna.

The joy of the first tower

Working on my first tower.

In November 1986 I finally got my first tower installed at my parents property. The tower was only 17m high but it did not matter because it would be much better setup than my old G5RV. My first antenna was a rotary 12-element log periodic. I did not have any amplifier, so I worked just with only 100W. The beam really opened the bands very differently than my G5RV. Now I could hear stations from USA loud and clear and the Caribbean stations had never been that strong. I did not yet miss any amplifiers. In 1987 I started to build an amplifier to boost my signal. It was using four PL519 TV sweep tubes. OH6XA was just building one himself so I also got also interested in building an amplifier. The first contest where I tested the amplifier was WPX SSB 1987. It was a thrill because I usually worked any station with just one call. Later in 1987 I disassembled my log periodic beam because I wanted to build monoband yagis with more gain. So before the end of the year I had a 4-element yagi on 20m and an interlaced beam on 15m and 10m (4el/3el). On 40m I had a delta loop, and on 80m I had a half sloper. At that time I was trying to participate in every contest I possibly could.

Busy at the club station OH6AP

The single band fever

The new locations

After I was finished with my electrical engineering studies in 1991 I moved into Oulu in northern Finland where I had no opportunity to build any station. I had to drive back home for 4 hours to be able to get on the air. This was a bit too tiring. In 1992 I started to build a station with Mark, OH6MMC at his QTH. It would "only" take 3 hours to get on the air. Mark had already an 18m high tower on top of a small hill with a good takeoff in any direction. His QTH is rural and surrounded by fields. There are not too many neighbors nearby which makes his QTH an ideal place for working contests. The first setup was ready in August 1992. When we were finally able to make some QSOs with our new setup we were very much satisfied with our efforts. All higher bands worked just beautifully. It was a lot of fun to work into USA on 15m receiving 59++ reports.

The antennas were:

• 10m band 5 element monoband yagi @ 21m
• 15m band 5 element monoband yagi @ 27m
• 20m band 5 element monoband yagi @ 24m
• 40m band delta loops and a dipole
• 80m band 1/4 wave vertical with 60 radials
• 160m band Inverted Vee

The quest for the lost sunspots

In 1993 we started a new project on a fully rotatable 42m tall tower at OH6MMC. Actually we welded two towers together, one for Mark and one for myself. The guy wire bearings were our own unique design. The other tower and the antennas were stored for the future at Marks QTH. We had an ambitious project for 15m. We wanted to build a quartet of 5 element yagis. 20 elements on 15m sure sound nice. But it was even better when we were able to work all those west coast guys on our late evenings. Already in 1993 the sunspots were down from the previous years but the stack really shined and opened the band. When the tower was finished it supported following antennas:

• 10m band 5 element monoband yagi @ 30m
• 15m band 4x5 element monoband yagis @ 18/27/36/45m
• 20m band 2x5 element monoband yagis @ 24/39m
• 40m band dipole
• 80m band 1/4 wave vertical with 60 radials and slopers
• 160m band inverted vee apex @ 36m

The new contest QTH

My existing QTH is located in Mieto, which is a small village located in a small town of Kurikka in the west part of Finland in the southern Ostro-Bothnia region some 350 km north west from the capital Helsinki. I moved into this QTH in the summer of 1996.

My house in Mieto near Kurikka.

The surrounding area is rural, so I do not have any restrictions on antennas. Although my property is not very wide, I have installed three towers so far. My first tower was installed in October 1996, and it is a "Finnish standard" 42m tall fully rotatable tower based on a rear axle of a van. I missed CQWW SSB that year but I was happy when I was able to work in the CQWW CW contest later in November when I had my 40m beam completed but not raised yet. It was still waiting on the ground. Anyway it was a big thrill to finally work a contest from home. The second smaller tower, which was put up in 1997 is fixed and it has a rotating mast on top of it. The rotator is now broken and I am planning to turn the antennas (a 4 element 10m and a 2 element 40m Cushcraft) fixed into Japan. Both towers and all antennas are homemade (except for the Cushcraft). My good friend Mark OH6MMC and I have built and installed the antennas. Without Marks help it could not have been possible to do the entire job. There have also been sometimes other friends helping us with the antennas but we have done most of the work together.

A more scientific approach to antenna design

I have experimented with different antenna configurations over the years and I have designed all of the home-brew yagi antennas with Yagi Optimizer (YO) 6.07 by K6STI. I also use programmes like Antenna Optimizer (AO) and Nec/Wires by K6STI. As YO allows only modeling of yagi type of antennas with the element lengths close to a half wavelength I model other type of antennas like verticals and quads etc. with AO. I use NEC/Wires to verify models, which are too close to ground for AO. If an antenna is less than 0.2 wavelengths above the ground the results that AO gives are too optimistic because AO assumes that the antenna is above perfect ground and the ground losses are omitted. When I modeled a 2-element delta loop for 80m band which is only 18m high AO showed approximately 4dB gain compared to an inverted vee at 30m high. When the model was checked with NEC/Wires against the real ground the gain of the array was really even below the inverted vee due to the high ground losses! The only benefit in this case was the improved signal to noise ratio if the antenna was aimed to DX. Great care should be taken when designing antennas close to the lossy ground.

The big tower

My 42m fully rotatable tower.

My taller tower 42m/140ft, which is fully rotatable, is supporting following antennas:

• 10m band 5 element monoband yagi @ 39m
• 15m band 5 over 5 element monoband yagis @ 33m & 42m
• 20m band 4 over 4 element monoband yagis @ 23m & 36m
• 40m band 2 element full size yagi @ 21m
• 160m band inverted vee dipole on the higher guy wires feed point @ 33m

The second tower

My fixed tower with a rotator and rotating mast on top.

• 10m band 4 element rotatable monoband yagi @ 35m
• 10m band 3 element monoband yagi @ 12m pointed to Europe
• 15m band 5 element monoband yagi @ 21m pointed to Japan
• 20m band 3 element monoband yagi @ 28m pointed to Japan
• 20m band 3 element monoband yagi @ 18m pointed to Europe
• 40m band 2 element rotatable Cushcraft @ 33m
• 80m band inverted vee @ 28m

The multiplier tower

My third tower is a small 12m high tower with a Tail twister rotator, monoband yagis for 20-10m and dipoles for 40m and 80m bands. I have also a Wire vertical for 80m band some 30m/100ft away from the tower. I have planned to use this tower mainly with the second radio or as a multiplier station. The tower is located far away from the other towers to keep the interference as low as possible. It is supporting following antennas:

• 10m band 4 element monoband yagi @ 16m
• 15m band 4 element monoband yagi @ 14m
• 20m band 3 element monoband yagi @ 12m
• 40m/80m band inverted vee @ 10m mainly for domestic contacts

I have already made a lot of comparisons between my bigger setup and the multiplier setup and I have realized that this small setup is working surprisingly well. At least 10m and 15m work very well during the prime opening times. Especially the Far East is usually coming very loud. USA is also quite close to the higher antennas. Later in the afternoon the higher antennas usually produce signals that are 2 S-units stronger. During disturbed conditions the multiplier setup is usually much weaker than the higher antennas. In my opinion even the 20m 3 element yagi works also fine considering that it is only 12m high. I have not made very many comparisons on 20m so I must wait and see some further results.

The SO2R concept

The operating techniques

OH6NIO: OH6NIO OH6NIO test (7 seconds which can be used to listen on the second radio)
DX: N6NIO (3 seconds)
OH6NIO: N6NIO 5NN 15 (5 seconds which can be used to listen on the second radio)
DX: TU 5NN 03 (4 seconds)
OH6NIO: TU OH6NIO (4 seconds which can be used to listen on the second radio)

This whole sequence takes 23 seconds from which 16 seconds can be used to listen to the second radio. This makes almost 42 minutes of listening time on the second radio every hour. It means that you would have more than 33 hours of extra time to listen into the second radio during a 48-hour contest just like CQWW. If you could even work 10 QSOs/h (one qso every 6th minute) with the second radio it would increase the QSO-count in CQWW by 480 QSOs! In a contest situation nothing goes as smoothly as in this example and sooner or later the fatigue makes it even more difficult. However you can work substantial amount of QSOs by using the second radio very actively. It is difficult to maintain a high rate like more than 120 QSOs/h on the run radio if the second radio is used actively at the same time. I believe that it is easier to start just to look for new multipliers on critical times when the run radio rate is something like 60 QSOs/h. I believe that in some of the low power categories where the pile-up rates are around 60QSOs/h the second radio can be very productive but if the rate drops too low S&P-technique maybe gives a better result.

The benefits of networking in SO2R concept

Beaming simultaneously into multiple directions

Sometimes when the band is open to multiple directions this arrangement helps me to increase the number of the contacts and multipliers and I don't have to waste time by turning my antennas all the time. Until now I have split the power 50-50, but my intention is to use 80-20 ratio in some contests to get more power to the main direction.

When I am using the power-dividing ratio of 50-50 it means that my power into both directions drops by 3 dB, which is sometimes too much especially if you are trying to copy an extremely weak signal from USA. One disadvantage of beaming two direction is that the signal to noise ratio deteriorates. The QRM from the other direction can completely cover some of the weaker signals that will not be noticed and worked. One trick that I have not yet tried is to automatically drop one direction after a short delay. The ear is a very delicate instrument and it immediately notices if there was a caller who disappeared after the delay even though the signal is very weak.

My multiplier tower.

If you have some long boom monoband beams they usually have a very narrow beam width and if the antenna is pointed away from Europe your signal will be very weak in Europe. This leads often into a situation where someone is trying to take over your frequency. Then you try to turn the antenna into Europe and try to scare the poor operator away. This means that some of the operating time is wasted and in the worst case you may end up losing your frequency if the other operator won't go away. In CQWW it is sometimes very difficult to find a good spot. One advantage of dividing power is that you can make the impression of a big signal by dividing some of the power into Europe. The stations are now not very willing to take over your frequency when your signal is much stronger. In this situation the QRM from Europe is often covering the weak DX. One other trick is to divide the power only during transmission and listen only with the DX-antenna. One can also delay the Europe antenna during receive cycle so that it drops off after a short delay and the Europe QRM is gone. In this way one can immediately hear if a weak station from Europe or south that is not audible with the DX-antenna is coming back.

We are allowed to run 1kW in Finland so dividing power by 80-20 ratio would mean 800W into USA and 200W into Europe or Japan. Usually 200W is more than enough to raise the interest of these callers. If I drop power from 1kW to 800W the difference is less than 1 dB and it is very difficult to notice but when I am running 200W to the other direction it makes a big difference. Usually if a monoband yagi is pointed into USA, Europe is then maybe some 30dB or more weaker (side rejection of the yagi). It means that if I run 1kW and I am beaming into USA direction it is comparable to the situation where I am running 30dB weaker power into Europe. In this case -30dB equals 1W! Less than QRP! The existing system (50-50 ratio) has also worked very well in low-power (100W) categories, which means 50W to both directions. So when I am running 80-20 ratio at high power I am putting out 200W into Europe or Japan which means that the power is still 6db stronger than when I am now running on low-power (50-50 ratio).

The station automation

My goal is to automate all possible functions at my station so that I can concentrate on the operating. This also reduces the risk of an equipment failure. Can you remember how many times you have transmitted into a wrong antenna when you are very tired in those early morning hours in a long contest? Using two radios even complicate the situation so automation is a must if you are going to use this concept successfully.

The new possibilities

I recently bought an FT-1000MP that can receive two different frequencies on the same band. This feature can be utilized especially in a single band contest when you must call CQ almost all the time. Constant CQing is needed to keep the rate up and to keep a clear frequency. Once you leave your frequency it is immediately occupied by someone else and then it is very difficult to find a clear spot on a crowded band. With the sub-VFO you can look for the new multipliers or the stations that you have not worked before without the risk of losing your running frequency. There are many stations on the air from exotic places just calling CQ for a couple of hours. If you cannot work them when they are active you might miss some really juicy multipliers.

One nice thing about this technique is that you don't need to build any new antennas and you don't have to buy a new radio. I have even tried to listen on a different band with the sub-VFO but the signals are very much attenuated because the sub-VFO shares the front-end filters with the main VFO. So if you are running on 20m band (with the main VFO) and listening with the sub-VFO on 15m there will be the 20m band pass filter selected to both VFOs. This means a lot of attenuation on receive on 15m band. This technique can only be used to work stations that are strong enough. In FT-1000MP there are two connectors for the antenna namely A and B. In the previous scenario one can use antenna A (monoband yagi) on 20m (main VFO) and antenna B on 15m (sub-VFO). With a tribander one can just use antenna A.

I believe that the optimal score can be reached by using a second radio as a multiplier radio to increase the multipliers on the different bands than where the run radio is. The sub-VFO can be used to pick up the multipliers on the running band. I have already made some tests with my multiplier tower and it looks like I could even be able to use the multiplier setup on the same band with the run radio. The distance between my running towers and the multiplier tower is 90m...120m and when I am running USA I am pointing away from the multiplier tower.

Reducing the interference

Low power contesting

Some people live in densely populated areas with a lot of people and their electronic consumer devices around. In this kind of environment it is sometimes difficult due to TVI or RFI problems to run the contests with high power. Luckily there are now many contests that have got the low power category. I have not too many neighbors so TVI is not a big problem here but I have participated in some contests with low power just for the fun of it. Usually low power refers to a power level that is not exceeding 100W. So it means that you run just with the transceiver without the linear amplifier. Just remember to turn the power down if you are using an IC781, FT1000 or some other rigs that are capable of running 200W. One advantage of LP is that you don't have to buy an expensive, heavy and ugly (in the xyl's opinion :-) linear amplifier that usually occupies a lot of room. The operating room stays much cooler when there is no linear amplifier heating the room. Warm room on a Sunday morning makes you feel sooooo tired!

Ken K1EA, Teijo OH6NIO and Bob N6TV at the WRTC 2002 camp in Himos.

The logging programmes and the hardware

Although I have never used TR by N6TR some people really like it. It has a built in keyer, which you can use by hooking up your keying paddle into the LPT-port of your computer. This feature is not available in CT. EI5DI's Super Duper available free of charge for IOTA and some other limited contests. A full version covering more contests is available for a small fee. I might be wrong but this logger does not have capability of networking computers.

I have also used logging programmes made by UA1AAF. He has built some simple and easy to use programmes which are available free of charge on the web. I have just recently used his programme to work the European HF Championship contest. LA0FX has also published some of his free loggers on the web. There were loggers for SAC and some Polish contests. All of these programmes run quite well in a very modest computer because they are DOS-programmes.

There is also Windows logging programme by N1MM available free of charge on the web. This programme requires a more modern computer but it looks a fine logger. It has two visible band maps for radio A and B, which is cool. I have downloaded the programme and opened it once but have no further experience of it yet. One other Windows contest logger is Writelog, which you must pay for. Some people have changed to Writelog and they have been quite satisfied. I believe that this programme also requires a more modern computer.

My contest computers are old 486 machines, which do not have much of value for other use. Similar computers one can obtain very cheap. I only paid 25 euros for one of them a couple of years ago. In the modern radios there is usually a built in keyer but if you use a logging programme for keying CW the internal keyer must be disabled. IC765 has two different connectors for CW. One connector is for straight key or computer keying and the other one is for a keying paddle like Bencher, which uses the built-in keyer of the radio.

A contester usually works a lot of nice DX and also receives a lot of QSL cards from many award chasers. It really helps a lot to have a good logging programme that can keep track of the different awards like DXCC, WAZ, WAS etc. It is also much easier if the programme prints out all the QSL cards that the other people are requesting.

My solution for post contest functions like QSLing and award chasing is an excellent programme called DX 4 Windows. DX4Win has a very good support, cheap upgrades (most of the upgrades are free) and a large group of users subscribing to an e-mail reflector ready to help in case of the trouble. You can connect your radios, rotators and packet radio cluster etc. into DX4Win. It really makes working DX a lot of fun. It covers many different awards and user can configure more awards. Useful cluster spots (useless spots are filtered) are marked with different colors to make it easier to notice a brand new country or a band country etc. It has also a built-in interface for PSK and a gray-line map. As it is windows software it requires a modern computer. This product is a real bargain. I have been more than satisfied with this product and I would gladly have paid more for it. I have already some 240 000 QSOs in the database and it works like a charm on my 900MHz Duron.

My shack today

My shack looked like this some 5 years ago.

In my shack I have the following radios: an FT-1000MP as the main radio, an ICOM IC765 as a multiplier radio, a Kenwood TS830S as a multiplier radio and an ICOM IC706mkII which is hooked up on packet. I also work some 6m QSOs with the IC706. I am planning to replace the IC706 with another radio more suitable to packet use. My main amplifier is a home-brew design using a pair of 3-500ZG. Then I have some tubes like 4CX1000A and Russian GU-43 and GU-78b, which I may use in the future, projects. I have also a home-brew MOSFET amplifier that is capable of putting out about 600W. I still need to do some more tests with it before I can use it in the contests. I will use it with my second radio because it will allow me to instantly switch between different bands to look for some new multipliers while I have my first radio running a pile-up. It means that when I hook-up my packet radio system I will have a fully automatic multiplier station that will put the radio on the DX-spot frequency with a single keystroke. I will probably try to utilize it in the assisted or multi-single category.

Some of my future projects

What keeps me running?

Teijo, OH6NIO oh6nio@sral.fi

Visit OH6NIO Home Page for more info.

Visit also home pages of other OH6 Big Guns:

OH6 Amateurs Homepages
OH6AC Home Page
OH6OS Home Page
OH6RX Home Page
OH6MMC Home Page
Location of all these stations on the map.