Simple vs Sophisticated ... or my take on amateur radio satellites .                 GM1SXX  24 Nov 2006

AMSAT-NA seem to be pursuing a policy of moving to higher frequencies and not supporting 'low-tech' satellite solutions, but there are exceptions. The exceptions centre around providing FM (!!!) satellites for beginners. I don't intend to get into the reasons why I think FM is not a clever use of satellite resources, enough has been said elsewhere.

In contrast, AMSAT-ELSEWHERE does seem to support the concept if not always the hardware, to provide satellite access via the lower frequency bands. This is nothing new. In fact the debate of VHF/UHF vs SHF has rumbled on for  many years, especially within Europe where there is still a great deal of support for satellites operating on 70Cms and below. Over in India, the Indian government under the auspices of ISRO and with a bit of help from William, PE1RAH (for the redundant transponder which he designed, built and paid for) put its money in this particular basket in the recent past with the gift of HM-1, also known as HAMSAT and by AMSAT-NA as VO52 to the amateur satellite community. The Japanese also had good success with the Fuji OSCARs, of which FO-29 is still functional. Prior to that, the Russians had a hugely successful and popular range of amateur satellites in the RS (Radio Sport) series. These were arguably the most popular LEO birds of all time. Sadly, whether we like it or not, the amateur satellite scene is now strongly US dominated and they have little interest in the lower bands.

Much has been made by AMSAT-NA, and also other AMSAT groups about the benefits of moving to SHF. The usual reasons stated are smaller antennas, lower noise, fewer band intruders and so on. Against this must be set the cost of re-equipping all the stations involved. In the past, the cost was largely downplayed. Suggestions to use modified Drake and other TV converters for 2.4Ghz receive are all very fine but most of these devices are not ideal for use in this application without quite a bit of work to improve their performance. Many satellite operators are simply not interested in tweaking hardware. They'd either rather use what they've already bought and paid for or buy a system off the shelf. Previous birds carrying 2.4Ghz downlinks have not lived up to expectations and much of the equipment bought to date lies in cupboards collecting dust. I too equipped for 1.3/2.4Ghz and it wasn't particularly cheap.    The fact is that I had a lot more fun on the lower frequencies.

I now read that one of the reasons for a shift to SHF is to support medium speed emergency communications. Another reason for sure is the shrinking size of AMSAT satellites generally. Where to fit antennas? Having a requirement or perceived need to provide 'medium speed' emergency communications compromises what can be done in other areas. It also forces the operating frequency upwards because of bandwidth requirements. This would appear to be in direct opposition for the wishes of many radio amateurs who want simply to communicate by voice using the minimum of equipment. Until a few weeks ago, I had no idea that 'medium speed emergency communications' in some part drove the selection process. This contrasts strongly with what most users want, namely a means to communicate at low cost (relatively speaking).

The reality is that there are already commercial comsats in place capable of providing medium speed emergency communications via radiotelephone terminal,at a price. Nowadays I'm even told there are inexpensive cellphones capable of communications to many parts of the globe. Should AMSAT-NA even be trying to provide a free alternative when the 'cost' of doing this is so high? It's a bit like throwing out the baby with the bathwater. On one hand, the purpose of the amateur radio satellites is so that we can communicate but a perceived need for providing 'medium speed emergency communications' appears to be driving the choice of bands used. Surely the primary purpose of an amateur satellite is amateur communications with everything else it may be able to provide being secondary in importance? I'm all for altruism, but not when it at least in part drives the band selection process. I wonder why the Europeans don't seem to have this particular problem? It this something specific to the USA? I'm all for helping to provide emergency cover, but not to the detriment of the primary mission.

It's blindingly obvious at least in the UK that most users want low-tech satellite solutions. We all know that 2M and 70Cms are not ideal bands. This is old old news. We don't need to hear it ad nauseum. We know the problems, but we still want satellites to operate there. There are intruders, noise levels are higher than we'd like, antennas are big etc etc.... but who cares, it's what people want. It also works. The most popular analogue satellite at the moment seems to be HM-1 / HAMSAT.

There seems to be a conflict of interests within AMSAT generally (not just AMSAT-NA), with the users wanting low tech solutions while the designers and builders want ever more complex systems. To a degree, this is understandable. The designers don't want to go where they have already been but the end users are the ones picking up the tab and surely the designers/builders should be building for the users irrespective of what the designers would like?

I don't see much point in the designers and builders producing sophisticated hardware that the end users don't want or need. The very successful HM-1/HAMSAT bird is a simple satellite yet is immensely popular. It only carries a redundant transponder pair. It could be even simpler still and yet perform the same mission. The point I'm making here is that the builders and designers are after new challenges while the users in general lean the other way, toward low-tech simplicity. It's my personal opinion that we need more easy to use birds like the simple low-tech RS satellites that were so popular in the past.

It's one thing to embrace new technology but the users generally seem to want something completely different. That something is simplicity and the tradeoff between accessibility and performance. Of the fact that there is strong support for modes U/V, and especially in Europe, among the AMSAT membership there is little doubt.

FM satellites seem to be an US led anomaly. The reality is that FM is just about the least effective transmission mode to use on any transponder. AMSAT-NA must be aware of this fact but FM satellites are now a fact of life. In the UK, AMSAT-UK donated to the AO51 fund followed by a sizeable number of members leaving in disgust (as I also did) at the squandering of valuable resources on inappropriate technology. A  listen to the AO51 downlink will readily demonstrate the folly of FM transponders.

Alllan Copland
GM1SXX