What is AO-27?

AO-27 is actually an amateur satellite operating piggy-back on a commercial satellite, EYESAT-1. Compared to most amateur satellites, AO-27 are fairly simply. It contains a modest amount of packet equipment, which is only used for maintenance purposes. The rest of the time, it acts like a low power cross-band repeater operating on a limited basis.

What's the excitement about AO-27?

It is the first of a new breed of amateur satellite which does not require elaborate or expensive equipment to operate. One does not need equipment which is generally only useful for HF or weak signal work to access AO-27. Instead, it places a premium on cleverness, operator skill and on acting in a courtious and considerate manner, rather than on sophisticated antenna systems and expensive equipment. Many excellent operators are operating QRP on AO-27, with good signal on as little as 1/2 watt. You won't be able to 'work the world' on AO-27, but for purposes of comparison, those in the North America can reasonably expect 48 States with a reasonable amount of dilligence (and all 50 from the western states).

What are the limitations of AO-27?

AO-27 is not easy to hear, but it has a very sensitive and wideband receiver. That generally means that if you can hear it, you can work it. But only one person can talk at a time, and it is in a low earth orbit, which means it's only overhead for about 15 minutes at a time. It takes about 100 minutes to circle the earth.

AO-27 shares power with the commercial satellite, and since it is a secondary payload, it only operates during daylight hours in the Northern Hemisphere, world-wide. So the folks "down under" are out of luck, but you can operate out of Moscow just as well as you can out of Texas. It's in a sun-synchronous orbit, which means goes overhead at roughly the same time every day (+/- 50 minutes). So, you'll get at least two usable passes a day on AO-27, generally between 9 am and noon local standard time, irrespective of where in the Northern Hemisphere you live! So if you can take off as much time each day as the average smoker spends on his tobacco habit, you should be able to work at least one pass a day.

But AO-27 is very popular, and that's the other big problem you'll face. Not everyone can work it on weekdays, so weekends can be very crowded. It can almost as bad on weekday passes which cover very wide areas, for example, transcontinental passes over the United States. That's where skill and consideration come in. We'll talk about this in detail later. And you can't rag-chew on AO-27 -- most QSO's are 'contest style', and if there are more than a few people on, you can't have what many people consider a decent QSO on AO-27.

If you really like to talk, AO-27 is not for you. You should get the equipment to work AO-40, or one of the other satellites with linear transponders (AO-10, FO-20, FO-29, or RS-12/13). Otherwise, please learn CW and get a license to operate HF. You'll really enjoy it and you can talk to the world. AO-27 is a good challenge for those of us who like to work with minimal equipment and prefer to place an emphasis on skill over a sophisticated and/or expensive station.

Briefly, what is needed to talk on AO-27?

First, patience, a sense of humor and willngness to co-operate. The other basic requirement is an amateur radio license of Technical class or better. As far as equipment is concern, you can do with less, but i can assure you that you'll be happy with this: And in terms of equipment, you'll competitive with the best operators on AO-27, because that's what they use!

Where to go from here?

People will be coming here with different interests and levels of experience. If you're interesting in getting started, there's more on what is needed to talk on AO-27. If you have the proper equipment already and want to know how to use it, here's information on working an AO-27 pass. Additional topics are remain to be written. Such topics may include working AO-27 with existing equipment, how get predictions, transcribing tapes of AO-27 passes, printing your own QSL cards, awards and contests, going beyond AO-27, and future satellites [currently rather outdated].

See also AO-27 TEPR States Explained at the AMSAT WWW site. From my earlier AO-27 page, here are some brief notes TEPR states, (or in plainer language, when AO-27 is operating) and archived news about of AO-27. Since the question comes up from time to time, here's an article about packet on AO-27. Also, if you want to work me on AO-27, here's how to arrange a sked with me, and here's a list of states and grid squares I have confirmed. (I've worked quite a few more than that, and yes, i am way behind in sending out cards.)