Archive for November, 2006

Satellite Operation from Bonaire PJ4/K0NR

As mentioned in a previous post, I was in Bonaire on vacation, so I took along some ham radio gear and did a PJ4/K0NR Mini-DXpedition. Well, maybe it is more like a Micro-DXpedition.

Everything had to be transported via airline, so the radio gear needed to be compact, which included HF and satellite gear.

The satellite station consisted of:

The first problem I ran into was that AO-51 was configured in a rather, uh, interesting mode of SSB uplink (146 MHz) and FM downlink (435 MHz). My little HT can’t do SSB, so I was locked out of AO-51 for that week. In the second week of my trip, AO-51 was configured for 2.4 GHz uplink and 435 MHz downlink. OK, so I wouldn’t be using AO-51.

Fortunately, another VHF/UHF FM satellite, SO-50 was available. In fact, it was really available. I had not been on the satellites for quite a while and my experience was that the FM birds were usually jammed with activity. The first time SO-50 came over I didn’t hear a thing. I wondered whether I had the satellite tracking software set correctly. Daylight savings time had just changed but Bonaire does not change time, so I thought my PC might be off by an hour. I fiddled with the software until I convinced myself that I had the tracking software configured properly.

I finally figured out that the SO-50 was just not used much. Of course, Bonaire is in the southern Caribbean, near South America, so US stations were only workable for a few minutes of a pass. But still, SO-50 was very quiet. Then I realized that I normally rely on a signal on the downlink for me to adjust for doppler shift and point the antenna. Without a signal, this became more difficult. (My HT doesn’t let me tweak the downlink frequency while transmitting.)

The next thing that happened was that I transmitted on the 2M uplink and heard terrible interference on the downlink frequency. It sounded like a local broadcast station was mixing with my uplink signal and showing up on the downlink frequency. Uh, oh, this was really bad since it completely wiped out my ability to listen on the downlink. There were several broadcast stations on the island, including Radio Netherland, but I did not verify the source of the interference. Clearly, my poor little HT receiver couldn’t handle it.

The interference problem was solved by finding a good spot on the island that didn’t have the problem. Presumably, this was far enough away from the source of the interference to eliminate the problem.

I made a few skeds via email and finally got going on SO-50, using the callsign PJ4/K0NR. Bonaire falls under the CEPT licensing system, so I was able to operate without any special application or permission.

It was fun activating PJ4. Thanks to the radio amateurs that took the time to work me in Bonaire. QSL to my home call.

73, Bob K0NR

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PJ4/K0NR Mini-Dxpedition to Bonaire

PJ4/K0NR NETHERLANDS ANTILLES. Bob K0NR will be active as PJ4/K0NR from Bonaire (IOTA SA-006) from Oct 28 to Nov 9th, SSB and PSK31 on 30M through 6M. Also active on FM OSCAR satellites (Grid FK52). QSL to home call.

The AO-51 schedule has it configured for modes that I cannot work portable, so I will be focused on SO-50. Send me an email if you want to schedule a contact.

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Use MP3 Player for Portable Logging

In the past few weeks, I’ve refocused on portable satellite operations using a station consisting of a dualband handheld radio and the Arrow II antenna. One of the challenges with this kind of operation has been the logging. Sometimes I’d have someone jot down the information on paper as I worked the various stations. This can be fast and furious so it is easy to miss important information. Other times, I’ve used a small cassette tape recorder to record the audio from the contacts.

I recently came across a nice upgrade to the audio tape recorder. Creative Labs produces a very small MP3 player called the Zen Nano Plus that has a built-in microphone and recording feature. I just clip this device onto my shirt as I work the satellites, making comments about callsigns, grids, UTC, etc. into the microphone. Since I work the satellites full duplex, the downlink audio goes to my headphones and are not heard by the Nano Plus. I make it a point to repeat any important logging information. The Nano Plus does have a line input, so you could run the audio from the receiver into the MP3 player and capture the downlink audio. This has the disadvantage of shutting off the microphone, so I have not used this approach.

There are multiple versions of the Zen Nano. The “Plus” version has the built-in microphone, which is essential for logging. Of course, the Nano Plus can be used for listening to music or other audio programs. It also has a built-in FM tuner. The Nano Plus is a remarkable device, available for less than $50 on the web.

This type of audio logging may have other ham radio applications such as logging mobile operation.

For more information on working the FM birds, see the AMSAT web page. (Look for information on SO-50 and AO-51.)

73, Bob K0NR

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