December 2007 - AMSAT-BB - mailman.amsat.org

Ande.
by John Ronan 26 Dec '07

26 Dec '07

Has it's fate been ascertained? Regards de John EI7IG

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Questions on physically offset CP yagi feeding
by jonny 290 25 Dec '07

25 Dec '07

I've decided to rebuild my 2m antenna and have a couple of questions. I currently have vertically polarized yagis up for 2m and 70cm and they work fine; however I am becoming more interested in weak signal work and just want to rebuild my antennas in general, as they need it after a year. Due to necessity and environment, i can only have a few antennas up and have thought up a plan to meet all of my needs at a reasonable price with only one cross yagi in the air. My thinking is to build a six element wide-band 50 ohm match yagi and mount the vertically polarized elements 1/4 wavelength ahead of the horizontal ones, and feed the elements in phase. I have examined the possibility of masthead CP phasing, but am concerned about mismatching and like the arguments given for the physically offset, in-phase fed elements. My antenna to radio coax run is right around 30 feet. I am thinking of running two lengths of LMR-240, speced at 3 dB loss/100ft, so loss should be about 1 dB. If I cut the two feedlines to identical lengths, I should be able to connect them with a coax tee in the shack and use a 1/4 wave 37 ohm line to bring the system impedance back up from 25 (at the tee) to 50 ohms. I'd then have an RHCP signal for the birds. Do I _need_ to cut the feedlines to half-wave multiples, or is it just a good idea? I plan on tuning the antennas as dead on to 145.8 as I can, so mismatch will be a minimum at that frequency. When I don't need RHCP, I can simply use the horizontal feedline for SSB work and the vertical feedline for FM work, setting the coax tee nonsense aside. (as a note, the two sets of elements would be tuned identically, centered for minimum swr on 145.8, but in my experience operation across the band is no problem). A good coax relay costs about 60-80 dollars and requires associated mounting hardware and weatherproofing, this only adds another $15 for 30 more feet of LMR240. Anybody care to share thoughts on this? 73 and merry christmas matt kc4ylv

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RigExpert Tiny to Yaesu FT-847
by Stargate 25 Dec '07

25 Dec '07

Hi all, Does anyone have any experience making a RigExpert "Tiny" Model: TTL-I-1 for the Yaesu FT-100, FT-817, FT-857, FT-897 work with a Yaesu FT-847 or Kenwood TS-790. I know I will have to rewire some plugs or make adaptor wires to match the radio's but I was hoping not to re-invent the wheel if someone already figured it out. The people at RigExpert say they don't make a version for the FT-847. RoD KD0XX

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FT-847 Disaster
by k7zt＠suddenlink.net 25 Dec '07

25 Dec '07

Many Thanks for all of the responses and Merry Christmas to all! I have done some preliminary troubleshooting and have discovered the following... The fuse and the electronic cap are fine. I get good voltage to one side of the relay, the relay coil appears to be energized but the 12 VDC stops at the relay. I did jumper the 12 volts to the other side of the relay and the display lights up and I hear noise from the speaker. But no frequency displayed. This is as far as I've gotten. I did note on the schematic that the relay has two transistors (Q1118 & Q1122). Q1118 is labeled as H-V Protection on the block diagram. Both of these devices connect to the relay (FL1001). I've looked on both sides of the board and can't seem to locate these devices. Regards, - Joe K7ZT

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FT-847 Disaster
by k7zt＠suddenlink.net 25 Dec '07

25 Dec '07

All: I'm afraid that I reversed the polarity when I connected my FT-847 to its' power supply. It appears that the smoke leaked out :-/ I would like to know if anyone out there has had this unfortunate experience (names withheld), or has an idea where to begin looking for the problem. Thanks, - Joe, K7ZT

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Crossed yagis
by Andrew Rich 25 Dec '07

25 Dec '07

What is the best way to set up phased crossed yagis ? Have an electric coax switch in the middle to switch from left to right circ polar ? ---------------------------------------------------------------------------- Andrew Rich VK4TEC vk4tec(a)people.net.au http://www.tech-software.net

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Orbital classroom #2 (AMSAT Education)
by Stefan Wagener 25 Dec '07

25 Dec '07

Thanks everyone. The comments (primarily offline) to my first post on the existence of the "Orbital Classroom" just pointed to the perceived sad state of education within AMSAT. Now, we can whine and do nothing or maybe put our heads together and see what there is to do. The first thing is to gauge the level of interest. I and others will NOT engage in this without some significant feedback from the members and those that are interested in amateur radio and satellites and education. Here are a few questions and I would kindly request your thoughts on these. 1. Would you be interested in attending pre-conference courses and workshops as part of the annual meeting or at other venues? 2. Would you be willing to pay a registration fee that would cover course material, instructor cost etc.? 3. Would you be interested in receiving a certificate for ongoing education as it relates to amateur radio and satellites? 4. What topics would you like to see taught at such courses? 5. Would you be willing in helping to organize and facilitate courses (you don't have to teach for this one, just help the instructor and take care of registration, etc)? 6. Would you be willing to teach a course and if yes, on which topics? That's a start and hopefully it sparks your interest as a participant, facilitator or instructor. Please email me your responses offline (don't hit the reply all button) and I will compile the answers in a response to the board and this mailing list. FYI, I have been asked to organize and coordinate these efforts. First of all, I will NOT assist, organize and/or coordinate these efforts unless I have equal partners in assisting and helping. Secondly, AMSAT has an official "Director of Education" who needs to be involved and work on this (with our help if necessary). This person serves at the discretion of the AMSAT president and I have no intention to do his work. Hope this helps to clarify positions and responsibilities! For now, it is time for the members to voice their needs for education and define if this is relevant or not. Folks, here is your opportunity! Some of us are listening and working on this. Let us know if you want this or not by answering the questions above. As always, your opinion counts and even more your help is greatly appreciated. Have a Merry Christmas, a wonderful holiday season and an even better 2008. My best wishes to you and your families. 73, Stefan VE4NSA

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ANDE 1305z
by John Marranca, Jr 25 Dec '07

25 Dec '07

Nothing heard from FN02ox. I believe she has returned home. Merry Christmas. John KB2HSH -- _______________________________ John Marranca, Jr PBX Technician/Shop Steward CWA Local 1122 BN Systems, Inc Orchard Park, NY (716)972-2006

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Yaesu G-450A rotator
by Andrew Rich 25 Dec '07

25 Dec '07

I can see that the az el rotator from yaesu has a port for tapping into a voltage to work out where the rotator is pointed. What do the cheaper ones such as the Yaesu G-450A use ? ---------------------------------------------------------------------------- Andrew Rich VK4TEC vk4tec(a)people.net.au http://www.tech-software.net

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ANDE: December 25th not heard
by Moorby, Terry: IHAB 25 Dec '07

25 Dec '07

Nothing heard from ANDE during the 1132z, December 25th pass over eastern Canada. Terry, VE3DIJ

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