Category Archives: Amateur Radio

AO-51 from inside…

Well, the weather today sucks. We have 40mph gusts, and are expecting a full 2 inches of rain. That being said, I decided to try to work AO-51 as it came overhead by standing in my living room with my handheld yagi. It wasn’t stellar, but I did manage to get W8SME (you can hear him tease me that it isn’t “shorts weather” since I usually have been operating in shorts and a T-shirt from my front yard). The interference from the roof made it pretty difficult to receive and even harder to receive, but you can hear a bit of the traffic.

Pass recorded from my living room, pretty marginal.

Another weather satellite pass…

Well, during a road trip with my wife to San Diego and back, I managed to begin to type up my notes for an upcoming tutorial article (cross fingers) on reception and decoding of weather satellite imagery. I basically reimplemented what I had, stripping it down to its barest essence, and trying to make it easy to understand, yet still capable of creating good imagery. Oddly enough though, in the process, I inadvertently seemed to introduce some aliasing artifacts which I must admit, are puzzling me mightily. Oh well.

This morning I decided to try to record a low 25 degree maximum pass of NOAA17 that occurred to the east. It starts out fairly noisy because I have a pretty high horizon to the northeast. The first is my “advanced” decoder, which is about six times longer than the simpler decoder I wrote.

My “advanced” decode…

The second is the same data file, processed with my “simple”, easy-to-follow decoder. The only serious feature it is lacking is the sync detection and rectification, which as soon as I can figure the simplest way to add, I’ll try to get in. The simple version is two pages of code, not including the data for the filter tables.

My “simple” decode

You can hear Genesat telemetry too…

Okay, I was bored waiting for potential Ande passes, so I tuned into Genesat. I got a few telemetry packets, although the frequency seemed to be 5khz low from the published frequency of 437.075Mhz.

KE7EGC>UNDEF,TELEM:GeneSat1.orgB4511B0A00000000000000260069009F7113722166CC790B02F0
KE7EGC>UNDEF,TELEM:GeneSat1.orgFA511B06000000000001002600690001EA02BA27081CBF026621
KE7EGC>UNDEF,TELEM:GeneSat1.org04521B8A010E018901DD010100A4015F2DCB1C226D951D1C023A
KE7EGC>UNDEF,TELEM:GeneSat1.org36521B73010F017101DE010000A4019F992216023D996D22E207
KE7EGC>UNDEF,TELEM:GeneSat1.org3B521B72010F016E01DE010000A4015F2DCB1C226D951D1C023A
KE7EGC>UNDEF,TELEM:GeneSat1.org40521B0100000001000100250069005F2299221C02202274231C
KE7EGC>UNDEF,TELEM:GeneSat1.org45521B0200000002000000260069009F07BC13A0230013281C02

Not sure what any of it means, but there it goes.

Ande Still Lives at 21:53Z

Around 21:53Z, I got two packets for the NO-61, otherwise known as ANDE

ANDE-1>BEACON:T#002,002,010,009,004,003,01000000,000
ANDE-1>APRS2,SGATE::BLN2ANDE :ANDE stays  awake for 30 secs after last pkt heard.

Ande is due to deorbit very soon, probably within the next 24 hours, maybe even sooner. My orbital elements indicated its altitude was only about 107 miles, and it’s dropping fast. I won’t likely get another good chance to here it. Merry Christmas Ande, and thanks from all the radio amateurs whom you have helped entertain and educate.

Addendum: The software I use for satellite predictions no longer predicts any passes for Ande. Sayonara.

NO-61 has decayed, at least according to “predict”
Addendum2: Predict is no longer guessing where ANDE is: it merely marks the position as “decayed”.

SO-50 pass this morning…

During the SO-50 pass this morning, WA8SME was asking if I was using a preamp, and whether I had any difficulty with receive sensitivity. On the Amsat mailing list, I’m amazed by reports of people who get weak signal strength using 14 element antennsas and the like, my handheld Arrow antenna, while not perfect, is remarkably good, and I normally hear just about everything on the satellite.

Here’s a link to the mp3 as recorded on my Sony voice recorder:

SO-50 pass, with QSOs from WA8SME, N6KTH and W6HF (with a brief appearance from AB9LA)

Tonight’s AO-51 pass…

I managed to work WD9EWK from my car using only my Kenwood HT and the omnidirectional whip mounted on the roof of my SUV. I didn’t have my voice recorder with me, so I didn’t get a recording though. Obviously using an omni antenna picks up a lot of signals and intermodulation distortion: there were all sorts of carriers and pager noise from all directions. Still, it was doable. QRP into an omni!

Chatting on AO-51

It was positively chatty on the westward pass of AO-51 this morning. For fun, I reduced power to just 1w on my HT, and nobody seemed to notice, although it did get scratchy at the end of the pass.

Dec 16 pass of AO-51, 8:57 Local Time

The beginning of the pass is a little noisy, because for some reason I thought the pass was going to the east, when it was in fact a western pass. I was fishing around with the antenna, trying to track it to the east. Once I realize how stupid I was, it settles in to a fairly strong signal.

Wow… RFI overload on the AO-51 downlink

I tried to work AO-51 from the parking lot at work tonight. It was a low pass, and just about every noise source in the universe seems to be on the recording. I tried feebly to send at the end, but the nose was horrible, with tons of intermod coming back through the earphones. Yuck! I won’t even bother trying this with my HT again. It’s a pity, because I heard lots of eastern stations, but it was just pointless with all this racket.

I’ll try again from the peace of home sometime soon.

Yucky noise while working AO-51.

Packets from ANDE

Well, didn’t get any packets relayed through ANDE, but I did receive some W6SMU during its pass just before lunch. I have sworn that I will get something echoed through it before it deorbits, now best guess to occur on Christmas Eve.

W6MSU>APRS,ANDE-1*:=3803.21NS12121.62W&
W6MSU>APRS,ANDE-1*:=3803.21NS12121.62W&

NH7WN and WA7SDI on AO-51

Robert (NH7WN) was my first QSL card for a contact via AO-51. I still owe him a QSL card, but to be fair, I haven’t designed one yet. Still, on a low pass to the west, I managed to work him again. He was recording the contact, here’s my recording. Paul (WA7SDI) comes in from Eugene, OR at the end. Had some trouble with the signals in spots, there’s quite a static burst in the middle, where I just couldn’t seem to hit the satellite (my aiming might not have been that good). Still, worked out pretty well.

Here’s the MP3 of this Dec 13, 2007 QSO.

Bouncing Packets off the ISS

Using information from the post I mentioned earlier about operating via packet on the ISS, I decided to give it a try. It was a nominal success, although the pass was short and I was operating with just 5w into the omni on the top of my car. Sorry KD7ZLF, I’ll be better prepared next time and we’ll have a real QSO.

cmd:k
howdy from mark in cm87
W6MSU>APRS,RS0ISS-4*:=3803.21NS12121.62W&

KD7ZLF>CQ,RS0ISS-4*,CN85::W6MSU    :ge de CN85 QSL?

K7SAO>CQ,RS0ISS-4*::W6MSU    :Hi Guy de Stephen
K7SAO>CQ,RS0ISS-4*::W6MSU    :Hi Guy de Stephen
W6MSU>APRS,RS0ISS-4*:=3803.21NS12121.62W& GE KD7

kd7zlf howdy!
KF6KYI-1>CQ,RS0ISS-4*:kd7zlf howdy!

RS0ISS-4>CQ,SGATE:>ARISS - International Space Station (BBS/APRS on)

this is my first attempt a iss keyboard packet
KB0VBZ>SYSWUS,WIDE2-1:`r[Rl `/>=KB0VBZ@GMAIL.COM

K7SAO>CQ,RS0ISS-4*::W7XZ     :Hi Jim de Stephen
operating with just 5w into an omni.
KF6KYI-1>CQ,RS0ISS-4*:operating with just 5w into an omni.

W7XZ>APRS,RS0ISS-4*::K7SAO    :Hi, Stephen.  Nice pass tonight.
WA0D-11>WA0D,RS0ISS-4*,EM12KW,RANDY:Happy New Year

w7xz howdy from cm87
KB0VBZ>SYSWUS,WIDE2-1:`r[Rl `/>=KB0VBZ@GMAIL.COM

N0AN-6>APRS,RS0ISS-4*:=4205.00N/09400.00WS73' Via Sat {UISS50}
WA0D-11>WA0D,RS0ISS-4*,EM12KW,RANDY:/EX

W7XZ>APRS,RS0ISS-4*:=/:Pu#/hL'-  B/Jim
RS0ISS-4>CQ,SGATE:>ARISS - International Space Station (BBS/APRS on)

WA0D-11>WA0D,RS0ISS-4*,EM12KW,RANDY:Happy New Year

WA6YET>WAYNE,RS0ISS-4*,EM36:

WA0D-11>WA0D,RS0ISS-4*,EM12KW,RANDY:>Happy Holidays to all and New Years from Randy in Dallas Fort Worth Texas USA... EM-12kw

KD7ZLF>CQ,RS0ISS-4*,CN85::KF6KYI-1 :ge QSL

WA0D-11>WA0D,RS0ISS-4*,EM12KW,RANDY:=3256.46N/09706.00W'PHG6230

kd7zlf :qsl!  thanks for the qsl card on no-44
pass is down to 6 degrees.  later all.

cmd:

43 Days to Delfi-C3 launch

This was mentioned on the AMSAT mailing list. In 43 days, the Delfi-C3 cubesat will be launched. After a 90 day mission, it will have a 400mw linear transponder enabled for amateur radio use in mode U/V. Awesome. Unfortunately, it’s another one of these satellites that is in low earth orbit, and is likely to have a significantly limited lifetime, perhaps a year.

Delfi-C3 – Home