Back when I used to get on the ISS APRS all I used was a j-pole antenna. It might not be the best but I never had a problem getting in.

73 Matt W5LL

On 5/5/2011 7:06 AM, Bob Bruninga wrote:

...

The issue is an antenna. I live in an antenna restricted area so I am not sure what to do. My goal is to work minimally the ISS! :-) I own a Kenwood TH-D72A

Walk outside during a pass. Have the radio configured and working for normal APRS. Then just change from 144.39 (APRS) to 145.825 and you should see everything from the ISS. No need for anything other than the rubber duck antenna.

You can confirm the ISS is in APRS mode by checking the age of packets on this site: www.ariss.net. As of right now, it appears the packets are less than an hour old, so clearly the ISS APRS downlink is on and working.

You can try to send a few packets, but with the rubber-duck you won't make it in. With a full sized 19" whip you can make it (but only if you have the uplink all to yourself). Of course, the arrow antenna should do it fine. But there are two other approaches.

1. A simple dipole held horizontal 18" above a ground plane of some kind.

Chicken wire, rabbit fencing, should be about 4' square or so. This should give you about 5 dBi gain. Then you should be able to get in during the center 2 minutes of the overhead pass each day.

2. Use the same ground plane above, and install a 58" vertical whip antenna

on it. That antenna will give almost 7 dBi gain when the ISS is above 30 degrees (center 2 minutes of an overhead pass).

When you TX and see the radio flash "MY POSITION", then you know you got in and everyone else saw you too. Or send an email to yourself using the APRS message feature.

Good luck! Bob, WB4aPR

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On Thu, May 5, 2011 at 8:06 AM, Bob Bruninga bruninga@usna.edu wrote:

...

The issue is an antenna.  I live in an antenna restricted area so I am not sure what to do. My goal is to work minimally the ISS! :-) I own a Kenwood TH-D72A

Walk outside during a pass.  Have the radio configured and working for normal APRS.  Then just change from 144.39 (APRS) to 145.825 and you should see everything from the ISS.  No need for anything other than the rubber duck antenna.

You can confirm the ISS is in APRS mode by checking the age of packets on this site: www.ariss.net.  As of right now, it appears the packets are less than an hour old, so clearly the ISS APRS downlink is on and working.

You can try to send a few packets, but with the rubber-duck you won't make it in.  With a full sized 19" whip you can make it (but only if you have the uplink all to yourself).  Of course, the arrow antenna should do it fine. But there are two other approaches.

1. A simple dipole held horizontal 18" above a ground plane of some kind.

Chicken wire, rabbit fencing, should be about 4' square or so.  This should give you about 5 dBi gain. Then you should be able to get in during the center 2 minutes of the overhead pass each day.

2. Use the same ground plane above, and install a 58" vertical whip antenna

on it.  That antenna will give almost 7 dBi gain when the ISS is above 30 degrees (center 2 minutes of an overhead pass).

When you TX and see the radio flash "MY POSITION", then you know you got in and everyone else saw you too.  Or send an email to yourself using the APRS message feature.

Good luck! Bob, WB4aPR

Bob, Everyone:

Thanks for the advice. I think I am going to try exactly what you describe with respect to receiving APRS packets from the ISS. Then if that goes well I will most likely get a portable Arrow.

I do use for HF a Buddipole - I am pretty sure I could make a vertical with enough gain to accomplish bullet item #2 above. However, its less maneuverable for manually tracking a satellite.

73

-aps