Monday, June 22, 2009

1296 MHz Station

Finished building another 1296 MHz antenna last night. I have been experimenting with yagi antennas for the 23 cm band lately. Planning on doing some antenna comparisons this weekend. The new antenna was designed using the VK5DJ calculator. This particular antenna has 15 elements on a 3 foot boom. Over the winter, I built one of the WA5VJB "Cheap Yagi's", but have not been able to test it yet. I hope to be able to compare these two antennas over the weekend. This latest antenna was built on a 1/2 inch diameter round boom and is of all metal construction. The "Cheap Yagi", as with all of these antennas was built using a wood boom, in this particular example, I used a 3 foot 1/2 inch wooden dowel for the boom, and brass brazing rod for the elements. When I'm able to check the return loss on these antennas, I'll post the info here. I have a low power signal source that I can use to do relative gain measurements on these antennas. It will be interesting as to how these antennas compare to eachother.

Friday, June 19, 2009

kd0ar audio captured in a video

I found something that is WAY too cool. N0SSC captured me on video while he was making a contact on satellite AO-51. I've always been curious to see how I sounded on the satellite, and I seem to have been hitting it good that day!
The url to the YouTube video is at http://www.youtube.com/watch?v=ywECT739etI

Wednesday, June 17, 2009

More PropNET info

I spoke of PropNET in a previous post. Allow me to direct you to more information and the maps it generates to show where the propagation is happening. First, the display info can be had at http://propnet.org/index3rp.shtml . This link will allow you to set up the band and area of the country you are interested in. When you have that set up, click the "Catches" link just under the table.

Now for the software which you'll need to participate in this project. You can find the software here: http://sourceforge.net/project/showfiles.php?group_id=250959&package_id=306760&release_id=671918

leave a comment on this post if you have problems, or twitter me at http://twitter.com/kd0ar if you need more information.

Tuesday, June 16, 2009

PropNET PSK

I discovered something rather interesting a couple days ago, called propnet psk. Basically, it used psk31 to beacon, looking for propagation. The way it works is a special soundcard based program is used, you set it up for the band you want to beacon on, and input info like your grid square, power, antenna height, etc. It builds a special code to let others know your operating conditions. The beacons if heard by other beacon ops gets posted automatically to a website, showing areas of propagation. Currently there is activity on 30 meters, 10 meters, 6 meters and 2 meters. 10 meters is the most popular right now, but would like to see more of this going on 2 meters.

This could be a really good indicator of 2 meter band openings if there were more operators on this mode operating on 2 meters.

Monday, June 15, 2009

WA5VJB Cheap Satellite Yagi

Well, I was a bit bored tonite. I've been having trouble with the 2 meter portion of my satellite antenna lately. I think water got into the balun and screwed it all up. So, I've been working on replacing the VHF portion of the antenna with a 3 element version of WA5VJB's Cheap Yagi.

This antenna is an interesting design. It uses half of a folded dipole (Kinda like a 'J' shaped element) for the driven element. With the driven element alone, the SWR and feed resistance is VERY low, but when the reflector is brought real close, the SWR goes down. The spacing is strange, something like 8 inches between the driven and reflector, and the director is about 18 -19 inches in front. I'm not sure how this works, but apparently it does.

When I get the VHF portion done, I need to build the UHF one, and tune it to 432 MHz and sweep it to see how flat the SWR is between 432 and 436 MHz. The current antenna has horrid performance on AO-7, but it seems to receive well on AO-51's downlink.

Will keep you up to date as to how the antenna is coming along. My analyzer's battery is dead and is charging now, so looks like I'm done playin for tonite.

Sunday, June 14, 2009

10 GHz short range experiment

Today I took part in a shortrange experiment on 10 GHz. Because I have not made a contact in a long time, Steve, KB8VAO came over, calibrated the gear, and he ran mobile on 10 GHz. Yes, mobile, running a 10 slot alford slot antenna on a magnet mount on his car. I was able to work him over a 2 km range. Range was poor because of the trees in the path. The experiment did, however accomplish a couple things. 1. Because his rig is phase locked to a stable, calibrated source, I was able to determine that 10368.1 MHz corresponds to 144.128 MHz on my IF rig.

Second, I was able to determine that my 2 watt amplifier was working properly, as his rig runs 8 watts, and we had similar copy even over the weaker paths.

I was running the offset dish on my end, tripod mounted in my driveway, DB6NT transverter (g2 model), into a DEMI 3 watt amplifier.

I believe Steve was running a DEMI transverter with an 8 watt PA into the slot, trunk mounted.
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