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Welcome to Lee Devlin's Ham Radio Page

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LongEZ satellite
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MicroDuplexer
Mir
PIC-E
PSK31
UO-14
Wired Article


APRS

APRS stands for Automatic Position Reporting System.  This system was developed by Bob Bruninga (WB4APR) for the purpose of tracking moving targets.  It utilizes packet radio and GPS to provide position information on a graphical display much like the one shown here:

APRS screen capture

 

APRS is catching on quickly thanks to small, low-cost GPS units, and a number of different software packages.

For APRS, I use several trackers with built-in transmitters called Micro-Traks that I purchased from Byonics. Over the years they have increased in capability and convenience and have become low enough in price that I have separate trackers for my car and airplane.

To learn more about APRS, visit these sites:
Get the APRS software here:   Wikipedia Article on APRS
Check out the Tucson Amateur Packet Radio site: http://www.tapr.org
Bob Bruninga's APRS site: http://www.aprs.org  
 

If I am near an I-gate (i.e. an internet link to APRS),  you can click here to find my position on the aprs.fi APRS server.  


Bicycle Mobile

I first began to think about operating bicycle mobile when I came across Steve Robert's Microship web page.  The web site has a lot of information about Steve's adventures, including riding a uniquely equipped recumbent bike across the U.S. and writing about it in a book entitled 'Computing Across America'.  It's an excellent book and I highly recommend it.  He's currently planning another nomadic adventure with a new trimaran (hence the name 'microship').  

I wanted a way to combine my ham radio interests with exercise to reduce my own case of the Ham Belly Syndrome you see so often at hamfests :-).   I have found that having a radio on the bike adds all kinds of possibilities that did not exist before.  I participate in an informal commuter's net with my ham friends at work as they commute in their cars (or, in the case of Bob, WA0EYJ, a motorcycle) and have found it makes the exercise enjoyable.   My setup is simple.  I use my FT50 or FT51 with a Yaesu headset with  boom mic and thin duck antenna.  I can hold the integral PTT in my right hand and still keep both my hands on the handgrips.  The headset fits under my helmet.  For a while I ran a whip antenna attached to the rear bike rack but have found that an MFJ 1715 14" thin duck works as well and is much more convenient.  I keep the HT is clipped to my belt.  I can't see the display, but I just usually put it on 'scan mode' until I hear a familiar voice and then stop the scan function by pushing on the PTT.  

Colorado is ideally set up for long range VHF/UHF communications with repeaters up high above the front range making QSO's of 100 miles or more possible with just a few watts.  There is even a group of more than 450 members known as the Bicycle Mobile Hams of America  founded by Hartley Alley, NA0A based in Boulder, CO.  They put out a nice quarterly newsletter filled with great information about people who like to combine these two hobbies.  There are even hams who use CW while riding along on their bicycles!

The most unusual  bicycle mobile QSO I've had so far was working a satellite (AO-27 ) from my bicycle.  I had a contact with Steve Kimber in Utah, W7VEW, in July 1999 and as far as we know, it may have been the first AO27 satellite contact from a moving bicycle.   Check out the neat QSL card  Steve made to commemorate the contact.


Amateur FM Satellite Communications (AO27,  UO14)


AO-27

I use a Yaesu FT-51 HT to communicate via satellite using an Arrow hand-held antenna.  You can talk with people thousands of miles away with only a few watts on the AO-27 satellite which orbits the earth approximately every 100 minutes. Satellite communications is a bit more challenging than talking on a local repeater but it is so rewarding to contact other hams on a satellite that's orbiting the earth at more than 17,000 mph.  In order to use satellites, you need some software to know when they will appear over your location.  Winorbit is a free program and easy to use and has a nice graphical display of various satellites and their footprints on the earth.  There are more than 18 different satellite tracking packages available and  you can find links to most of them on the Amsat download page .   These packages cost between $20-$70 and many are more capable than Winorbit, but if you're just starting out, using Winorbit is a quick way to do it.   If you just want to get a quick schedule of satellite passes, there is a web site known as Heavens Above and although it is more tailored to people looking for visible satellites, it can be used for amateur satellites as well. Just go to the website and fill out the information about your location and then look for the Radio Amateur Satellites link. You can go to that link to get a 24-hour satellite prediction list for all active amateur satellites.

Here are a few simple tips for operating AO-27 in North America:

The AO-27 satellite turns on about 12 minutes after entering into daylight and stays on for 18 minutes.  A typical pass lasts between 10-15 minutes.  Listen carefully on 436.805 initially and you will begin to hear a 'quieting' taking place.  You will have to rotate the antenna to hear this since the signal is polarized and you may not hear it if your antenna is just set vertically. You will begin to hear voices...  Keep in mind that the satellite is only transmitting with 600 mW, so the signal is pretty faint, but can be perfectly readable with the proper antenna.

You will need to periodically adjust for Doppler shift.  Since most FM radios have 5Khz step sizes, you will go from 436.805 to .800, to .795, to .790, and finally .785.  The true 'center' frequency for the downlink is closer to 436.795 than 436.8.  An approximate amount of time on each frequency would be 3, 2, 1, 2, and 3 minutes respectively.  You make these adjustments when you hear an 'improvement' in the downlink signals when making a transition to the lower frequency.  If you think you're losing the bird, go to the next frequency and see if you get it back. There is no need to adjust the uplink frequency of 145.85.

Never transmit into the satellite unless you can hear it.  Each pass seems to have some people continually transmitting 'CQ xxxx for AO-27 and standing by'.  You don't need to 'CQ' when there are at least a dozen stations all trying to get into the repeater at once.  Calling 'CQ' on AO27 is another way of saying 'I can't hear the downlink and have no idea what I'm doing.'  Don't worry if you've done it, you're in good company...now go find a gain antenna and listen first because AO27 the busiest  amateur satellite there is and with a single channel, you WILL hear others provided you are in its footprint, it is turned on, and have a good antenna and receiver.  Check here for status on AO27.

To increase your chances for a good exchange, memorize at least one or two station callsigns who are making successful exchanges and call those stations with your callsign, first name, state, and grid square.  Satellite folks have a fixation on grid squares.  If you get a reply, then you can log it as a good exchange.  If you hear someone making calls but not answering them, you can assume they can't hear the downlink so there's no need to add to the congestion by trying to contact the person yourself.

Use a tape recorder to play back the traffic on the bird after a pass.  You will notice that there are 'regulars' on AO-27 and they are always looking for new contacts and grid squares so try calling one of them on the next pass if you hear them on there.

It really helps, but is not essential, to have a radio (or pair of radios) so you can transmit on 2 meters and simultaneously listen on 440 Mhz so you'll know if your transmission got 'stepped on.'  You will need a headset to use this feature to avoid retransmitting the downlink.  

If you are using a directional antenna like the Arrow, you should print out the ephemeris of the satellite from the tracking program and have a list of times and expected paths the satellite will take to make it easier to find in the sky.  Once you have this printout, you don't need to refer to the computer program since you will listen to the downlink to keep the antenna aligned.  It really  helps to know the beginning, middle, and end azimuth and elevation of the pass.

If you are having trouble operating AO27, check out the Concise Guide to the Easy Sats from Mike Gilchrist (KF4FDJ) to improve your operating technique and maximize your chances for successful contacts.

Also, if you get an Arrow antenna, don't forget to get the  microduplexer or, if you're really adventuresome, you can build your own microduplexer.

If you really want to make yourself welcome on the birds, activate some rare gridsquares which are generally those that are relatively unpopulated.  Here's a picture of me activating grids by going portable with my LongEZ.

That's it... hope to see you on the bird.


Most of the statellites discussed below are no longer functioning.  If you want to find status of functioning satellites, visit this site.  It appears that AO-27, SO-50, and AO-51 are the only satellites operating in FM mode.


SO-35 (Sunsat) 

Unfortunately, Sunsat is no longer available.  It stopped working around the end of January, 2001.

Sunsat  was launched February, 1999 and was the second FM amateur satellite in orbit  similar to AO-27 except it  operated on a schedule and in Mode B, as opposed to mode JA like AO27 which meant the uplink was UHF and downlink was VHF.    Its uplink frequency was 436.280 and the downlink frequency was 145.825.  Doppler was a bit more challenging on SO35 since you had to adjust the uplink frequency instead of the downlink.  Thus, it was very easy to get off frequency because you had to either estimate the Doppler shift, or have a full duplex radio so you could hear when you were off frequency.  Its transmitter was much more powerful than AO27's and you  could hear it with just a whip antenna.  .  


UO-14

Unfortunately, UO-14  is no longer available.  

UO-14 was an FM voice repeater satellite available to amateurs.  This satellite spent 10 years as a store and forward digital satellite but in February, 2000, it was programmed as an FM repeater similar to AO27 and SO35.  The best part about the bird was that it was always on.  Not only did  you get 3 morning passes, but you also got 3 night passes.  The satellite operated in mode JA.  The uplink was 145.975 and the downlink was centered at 435.070.  


Russian Space Station Mir

Mir was easier to work than most other satellite particularly if you already had Packet equipment because you only needed a 2M rig and a whip antenna.  I knew nothing about packet, but that changed with I got a miniature BP2M packet modem from Tigertronics.  It uses BayCom software and turns your computer into a Terminal Node Controller (TNC).  I got interested in checking this out when I found Jeff Johns' (W4JEF) postings in the rec.radio.amateur.space newsgroup while researching AO-27 on Usenet.  Jeff had a .sig with the following text:

*--------- Jeff Johns W4JEF - AMSAT# 32615 - QRP-L# 1857 ----------*
|jeffj@scott.net w4jef@amsat.org   |Reserve Patrol Captain         |
| Satellite: Mir R0MIR-1, AO-27    |Jefferson County Sheriff's Dept|
|200LX+BayPac+FT50=Portable Packet |QTH Birmingham, AL USA         |
*------------------------------------------------------------------*

Note the last line that refers to the HP200LX Palmtop+BayPac+FT50.  I already had two of these items and so I looked into getting the third, namely the BayPac modem which is only $69.  In a short time, I had it up and running and was figuring out how to use my local  packet BBS.  A day later, I was leaving messages for the cosmonauts on Mir.  Read Jeff's story on working the Mir from his police car.

[The next instructions are for historical significance since Mir is currently at the bottom of the Pacific Ocean]

 Here's a text file from WA6LIE on How To Work Mir that was beneficial for those who wanted to work the Mir.  Here's a print out of me leaving a message for the crew of Mir amid a lot of QRM.  Once you successfully left a message for the crew, you qualified for the coveted Mir QSL card

The good news is that the International Space Station has ham radio equipment on board and as soon as I get a chance, I'll add information here about using the ISS to digipeat packets. 


RS 12/13

The Russian satellite RS-12/13 is known as one of the easier satellites to work.  It quite a bit more difficult than AO-27 or the Mir and requires SSB equipment, but if you have a satellite rig like the Yaesu FT847, chances are pretty good that you already have the other items.  Basically, you only need a 2M whip or J-pole and a 10 M dipole.  I work RS13 in Mode A using my Arrow J-Pole for the 2M uplink, and a G5RV for the 10M downlink. You have to be a lot more selective about how you adjust for doppler shift, but once you've got that figured out, making contacts on RS13 is pretty easy.  I find that using the CW key works well for finding the proper doppler shift and then I switch the uplink back to SSB and begin listening for my downlink and tuning the sub-tune knob to get my voice to sound correct.  You must constantly adjust this uplink frequency when working RS13 or the other operator will be tempted to change his downlink frequency  to make your voice sound 'correct' and you will both quickly lose each other.  Once you're in a QSO, leave the downlink frequency alone and make sure the other station does the same.  Otherwise you'll be chasing each other all over the band.


More Satellite Links:


A great starting point for anyone interested in satellites:  AMSAT Home Page
Great link to satellite descriptions, equipment vendors, etc:  The K7XQ 50 Mhz and Above Weak Signal Page
Tony Langdon's site on working the satellites from trains in Australia: Tony Langdon, VK3JED satellite site

PSK31

PSK31 is a new mode of keyboard-to-keyboard digital communications.  It's an exciting new development which is really catching on quickly.   It's extremely efficient with a bandwidth of only 31 Hz which is actually less than CW.  You can build the interface for about $10 and it uses your PC's sound card to modulate and demodulate the signal.  If you're interested in monitoring some PSK31 QSOs, visit the WM2Y web site to get the free software and just connect the radio to your soundcard's input in the manner shown on the simple interface.  My first interface was a stereo patch cord  and potentiometer from Radio Shack.  The web site has an audio clip so you'll know what the signal sounds like which is a sort of pleasant warble, not at all like the scratchy cricket sounds you hear on the bands coming from some of the PACTOR stations.   If you want to just see what PSK31 is like, monitor 20 meters around 14.070 Mhz and use a microphone for your PC  (you can use one from a computer headset) to demodulate the text using the G3PLX software and your soundcard.  It will give you some good experience on how to tune the signals so that when you're  ready to get on the air, it will be much easier for you.

There are several more capable programs available for PSK.  The free ones include a 'front end' for the G3PLX software from  WD5GNR and another more capable (and complicated) program called Logger.  

Here's something else which I found absolutely stunning after hooking up the PSK31 interface.  You can use your soundcard as a very capable bandscope using free Spectrogram software.    It's also very instructional to view the band  to see how your filtering and IF shift really work.  Try it with CW and you'll see how many stations are good at zero beating the calling stations.

Once you have the interface, you'll also be able to send and receive SSTV pictures just by installing some simple software on your computer.  You'll finally be able to figure out what all that funny noise is around 14.230 Mhz!  Check out this ham software from Silicon Pixels SSTV for starters.

Check out Oliver Welp's ham radio/soundcard web site for a complete list of ham radio related software that is available for the soundcard.


Ham Links:

Callsign Lookups QRZ Call Lookup Buckmaster Lookup WM7D.net call Lookup FCC ULS
Equipment links Ham Radio Outlet Amateur Radio Supply   QTH.COM Virtual Hamfest  
Testing Links Ham Question Pools AA9PW Test Practice  
Ham Reference sites Wikipedia entry for Amateur Radio AC6V's Ham Links    
Colorado Clubs N. Colorado ARC Colorado Amateur Radio Loveland ARA

Here's some Ham humor from Nick Sues about operating on My Frequency :-)

Classic Dilbert strip about getting a ham license to improve one's sex appeal.


Send me email at: lee810@yahoo.com

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