Future Plans

Like all good radio amateurs I have plans for the future. My equipment is more or less complete, I have adequate power levels on the bands that I am interested in, and I have no plans to go much further with them at the moment. This does not stop me from dreaming about future projects that may not be realisable at the moment, but may be at some later date.

Moonbounce - EME

I would love to get active on EME. I did some calculations about path losses and equipment capabilities, and produced an Excel spreadsheet with the correct data, it can be found here. To me it seems the easiest bands to get active on are 23cms and 3cms, neither require huge investments in power or antennas. At present 23cms is the easiest of the two bands mostly because of the availability of cheap power compared to 3cms, although the antennas are a little larger.

Taking 23cms as an example, I learned that the "average" 23cms EME station uses 500 Watts and has a 5m dish. If we take that as a baseline, then running 100W to a 3m dish would be able to work such stations. If we investigate more efficient modes than CW, for example JT44, then such a small system becomes capable of working average sized systems easily. There is a report in the 432MHz and Above EME News of a test between K2UYH and OH3MCK using JT44 on 23cms using a very small system at the Finns end (40W and 25dBi of antenna gain), K2UYH has a 10m dish. In due course I intend to do a JT44 test with HB9Q who has a 15m dish. This was one of my main reasons why I developed JT44 for Linux.

Now that I have returned to the UK I am now in a position to start building an EME station. I have a GS15B PA from Mats KD5FZX which just needs a power supply to work, before that is working I would probably press my solid-state 100W amplifier into service to get me going. For the feed I will use the new Septum Plate feed design by OK1DFC is a very interesting design and the analysis of it by W1GHZ makes it sounds even more interesting. I think initially I would go for a stressed dish design as it can be very lightweight and won't cause too many tears to be shed if it falls down. The pre-amp is a WD5AGO design and is pretty close to being state of the art with a reasonable budget.

Automated Propagation Monitoring

A long time ago, I wondered about the possibility of building some form of activity/propagation monitoring system. With the advent of modern hardware and software, it is now possible. My plan was to have a system that ran for 24 hours a day (or at least when I was not active personally) that would monitor beacons on various bands and build a picture of conditions. The main element of this become available a few years ago, a computer controlled radio, the Icom IC-PCR1000, which I bought in May 2002. My intention was to have a number of omni-directional antennas for various bands and then use the IC-PCR1000 to scan for selected beacons throughout the day and to log the information to a PC. The lack of gain of an omni-directional antenna is a disadvantage but it could still return useful information.

The above idea was formulated with respect to searching for Tropospheric propagation rather than Rain Scatter or Sporadic E. The radio has turned out to be a very flexible and interesting tool. There is now a generation of Software Defined Radios that promise almost total flexibility and these could be used as both incredibly powerful monitoring receivers and other things.

In these days of Packet Clusters and on-line chats the need for automated propagation monitoring has somewhat gone. We even have advanced warning of many propagation modes bar Sporadic E, so that you don't have to spend time listening to the radio. This in many ways is a bad thing as activity has gone down and people are waiting for DX to appear instead of chatting on the band.

6/3cms System Enhancements

My 6/3cms system is now almost optimum. The dish is as large as I can reasonably use, I have as much power, if not more, than most people on 3cms and the system is proven. I can think of only two more enhancements that I would like to make to the system in order to squeeze the last dB out of it. The first is the addition of G8ACE OCXOs to both 6cms and 3cms to give me more accurate frequency setting, and to remove the drift I experience when I transmit. I already have many of the parts that I need, I still need to get some heating plates made and then it is a matter of construction. For various reasons I have decided that this is a Winter project when it doesn't matter if the system is unavailable for a while. What complicates it, is that I have to modify the transverters to accept external oscillator inputs and this requires some surgery on them, not a nice thought. In order to reduce the mechanical work, I have bought some single-hole SMC sockets to fit instead of the more normal SMA. At the same time I am going to use a 432MHz IF instead of 144MHz.

The other enhancement is simpler. I want to change the layout of the semi-rigid cable and the co-ax relays in the transverters to remove some connectors from the system and some small pieces of semi-rigid cable. I hope that I may be able to win about 1dB by this change. All I need is to get some more UT141 SMA plugs and some time to do it. I hope to have this done within a few weeks, although the change will not be particularly great, it could be important in weak signal tropo work.

I am also thinking about changing my dish feeds again. Although I have been happy with my DD7MH dual band feed, a test result from Martlesham 2003 appears to show that they don't illuminate dishes as well as I had thought. A change to a more conventional horn feed could net me many dB's of gain without any other system changes. If the results from Martlesham are to be believed then maybe 6dB more system gain could be obtained.

Digital Modes

I am fascinated with what is now possible with digital modes. By this I don't mean packet radio which ceased to be interesting a long time ago. I am interested in using modern techniques to get signals through when they appear to be below the noise floor, and techniques that are completely new to amateur radio like Digital Voice. Further details of this side of the hobby are to be found on my Software page.

VLF (136 kHz)

Since returning to the UK I have been thinking about getting started on VLF. In many ways it is just as chanllenging as microwaves but from a different point of view. Although the transmitters and receivers are simple, the aerials are a challenge for people with normal gardens, and the signal detection mechanisms are very interesting indeed. Many of the same techniques that are common to EME are used also by VLF operators, including the TMO reporting system.

It will be interestig to operate on a band where a new set of 500 Watt PA transistors cost only £4 or so to replace. I hate to think how much the final transistor in my 3cms 10W PA would cost to replace.

Last updated on 15.8.2004