AMSAT-BB March 2008

188 participants
333 discussions

Call for Papers--2007 ARRL/TAPR Digital Communications Conference

by Ford, Steve, WB8IMY

Technical papers are solicited for presentation at the 26th Annual ARRL and TAPR Digital Communications Conference to be held September 28-30, 2007 in Hartford, Connecticut. These papers will also be published in the Conference Proceedings (you do NOT need to attend the conference to have your paper included in the Proceedings). The submission deadline is July 31, 2007. Please send papers to: Maty Weinberg ARRL 225 Main St Newington, CT 06111 or you can make your submission via e-mail to: maty(a)arrl.org Papers will be published exactly as submitted and authors will retain all rights. 73 . . . Steve, WB8IMY ARRL

10 years, 2 months

AO-16 Update and brief mode change

by Mark L. Hammond

Hello All, AO-16 has been in its "voice mode" continuously for nearly a month now. Many thanks to all the users of this "new" bird! It is time to pause voice operations long to receive some MBL telemetry (limited as it is, it's all we have). Around 0920 UTC on 17FEB08 I plan to return AO-16 to digital mode in order to receive some telemetry. If all goes as planned, it should be back to "voice mode" during the same pass. If not, I'll try to catch it on the 1056 UTC pass. Most of you will be asleep, so I don't think it will interfere with too many contacts. Looking to the future, we can see that after several months of continuous illumination, AO-16 will begin to experience eclipse periods at the end of March. The eclipse periods will increase and extend through the summer. This may impact AO-16's power budget such that the transmitter output will have to be reduced in order to protect its 18 year old batteries. We'll know more after the eclipse periods begin in late March and early April. In the meanwhile, enjoy AO-16 and her strong signals! 73 on behalf of the command team, Mark L. Hammond [N8MH]

14 years

Santa docks at the ISS

by Ed Tump

Happy holidays! I got a kick out of this video: http://youtube.com/watch?v=_Di8mZLu0VE <http://youtube.com/watch?v=_Di8mZLu0VE&feature=PlayList&p=26B9B2ACB4AAC849& index=7> &feature=PlayList&p=26B9B2ACB4AAC849&index=7 Maybe he dropped off some more amateur radio gifts. 73, Ed KC9GWK Grid EN52 AmSat Member

14 years, 1 month

Yaesu G500 bearings, KLM antennas

by KYLE YOKSH

Hello, I've got a KR-500 and G500a rotor that need a good servicing. I've found a lot of great info in the archives that will help me, but still have a few questions.. I've read that the original bearings were steel, and begin to rust almost immediately after installation. Can anyone suggest a better quality bearing, and perhaps a source and part number? I've also read that the bearing cages are subject to failure, and some folks prefer to ditch them altogether. I'm also curious if anyone has any suggestions to optimize my old KLM crossed yagis? I use a KLM 2m14c and 43518c, and they seem to work fairly well, but are not exactly top performers. I've never opened the polarization switcher units on either antenna, but suppose I might want to clean the relay contacts? Since my tower must be tilted over to service the rotator and antennas, I'd like to get several years of service out of this gear. Thank you for any help. 73, Kyle K0KN

14 years, 4 months

Re: OLPC ... Neat!

by Bob Bruninga

> I think the XO is a... ground breaking device. > Did I get one? No, I realized that it is does > not meet my needs and would end up in the > closet or given away to a child... Mine have done just that since Xmas, until today. ... I couldn't find my shoulder bag big laptop and so on my way out the door, I grabbed one of the kids XO's so I could try it out for the 5 hours I would be sitting at the kids swim meet. Sitting in the stands, I fired it up, and to my amazement wireless! bingo up came my favorite web pages, and then email. After reading email I went to edit some of my web pages. Flipped the screen around to tablet/book style so that the pages were long and I could read like a book. Holding the device in one hand with the nice finger holes provided. Wow, what a neat way to access wireless, email, web pages, and live mobile APRS. Less than 1/2 the bulk of my big laptop, and only $200 at risk instead of the $1200 labtop. I can't wait for the ham software to start working with it. Talk about portability... The ease of use, will assure that I will now probbly have the ham radio laptop apps with me more often than before since I will be more apt to carry the small XO at low risk then lug the big laptop. I'm sold! And now that my kids see how easy the itnernet access was, I now have to buy my own XO, since now their inteerest has been re kindled and they do want to take them both back to school... Bob, WB4APR

14 years, 5 months

Yuri UT1FG/mm travel plans

by Robert Turlington

Hi All here is a list of Yuri UT1FG/mm destinations over the next month EXPECTED DEPARTURE FROM ANNABA 31-MARCH.1ST APRIL PORT EL KALA/ALGERIA " JM47FA ". 2ND/3RD OF APRIL PORT EL KALA " JM46FW " .FROM 3TH UPTO 5TH APRIL BOUND TOGIBRALTAR STRAIT THROUGH JM47,JM37,JM27,JM17,JM07,IM96,IM86, IM76 AND IM75 THEN ALONG COAST OF EA/CT-LAND THROUGHBISCAY BAY,ENGLISH CHANNEL,NORTH SEA,BALTIC SEA. 13TH APRIL GDYNIA/POLAND/SP2 LEAVE ST.PETERSBURG/RUSSIA/UA1 ON 25TH APRILUA1 OF APRIL ) FOR LOADING CARGO AND THEN WE WILL BE BACK AGAIN THROUGH NORTH SEA,ENGLISH CHANNEL BOUND TO WEST COASTOF SOUTH AMERICA PERU AND CHILE. Regards Robert G8ATE _________________________________________________________________ Win 100’s of Virgin Experience days with BigSnapSearch.com http://www.bigsnapsearch.com

14 years, 5 months

Preamp for a Mobile Application

by Kent R. Frazier

Hi all, I am really enjoying the satellite aspect of the hobby and have enjoyed the contacts I have made with my Icom IC-2720H with a 19" whip antenna from my vehicle. I have seen talk recently of using a preamp to improve the reception. From what I've read and understand, it appears that a "switching" preamp is needed for a setup using only one antenna for Tx and Rx such as mine. Is this correct? It also appears that most of the preamps are mast mounted. Since this would not be an option for me can the preamp be put near the transceiver? Are there any issues that result of doing so? Lastly, what preamp(s) would you recommend for an application such as mine? Thanks, Kent -- Kent R. Frazier, K5KNT

14 years, 5 months

Easy to make, low cost omni-directional antennae

by Graeme Nelson

Hi all, I'm wanting to make an antenna for "talking with the birds", mainly ISS and LEOs. Thank you to Don ZL1THO and John KB2HSH for the suggestions and encouragement they have already e-mailed me. I have done some more thinking since then and come up with the following list of criteria for the first antenna I make for satellite work: * easy to make * lost cost * omni-directional * good performance, especially for satellite work, without moving it * portable enough that I can pack it into the van when I go on holiday and it won't take up much space (it needs to share the space with all the stuff for my wife and 3 children, as well as me). It would also be nice to be able to store it in the corner of my office at work if I so desire. When I started looking in earnest last Friday, a ham colleague of mine did a Google search an came across a turnstile antenna that looked promising (http://www.wb8erj.com/turnstile_antenna.htm). That evening, I noticed the eggbeater on the web site of John KB2HSH (http://kb2hsh.blogspot.com/), which looks nice and easy to build. I then did some searching and came upon the Eggbeater II by Jerry K5OE (http://members.aol.com/k5oejerry/eggbeater2.htm), arguably a better fixed antenna for satellite use than the original eggbeater. A while later, I also found the EZ-Lindenblad by Tony AA2TX (http://www.arrl.org/qst/2007/08/monteiro.pdf). I am currently leaning towards the EZ-Lindenblad (for 2m) and a parasitic Lindenblad (for 70cm ... when I get hold of the design; I intend to e-mail Tony about it if/when I go ahead with the EZ-Lindenblad). How do these antennae compare performance-wise? Am I leaning in the right direction (EZ-Lindenblad), or should I be looking at something else? Your input would be much appreciated. TTFN., Graeme ZL2GDN

14 years, 5 months

Re: ARR pre amp Query

by John W Lee

I have an FT-847 with the good internal preamps. The ARR SP432VDG even makes this setup BETTER! I use both the internal and SP-432VDG. Signals are mostly VERY good. Also use a 20 element beam on the downlink. When I say VERY good, I mean over S9 a lot of the time and all over the place between zero and 60 over 9. That way, you don't have to be so careful in aiming the antenna, and you can hear the birds basically 100% of the time. If the signal goes down a few S-units you can move the antenna and get it back up again. Without all that, when it goes down a few S-units, it's GONE! Regarding the power cable, I have been using two of these preamps for years and years with a small cable attached and no problems. 73 John K6YK On Mon, 31 Mar 2008 14:03:10 -0500 "Alan" <ve4yz(a)mts.net> writes: > Very timely discussion for me as the snow sloooowwly disappears and > the > return of the Canada geese and robins signals the time for tower > work :-) > > Some previous comments suggest that a preamp near the rig is not > significant, but, I suggest otherwise as my Ft-847 internal preamps > can make > a significant difference in RX. Anecdotal, not empirical, but I can > hear > the diff at the push of a button. > > Now, I am consider mast mounted preamps as an alternative to my > FT-847 > internal preamps for one of my sites. I run Landwehr VHF and UHF > preamps at > 2 other locations and they are terrific! They are also almost 20 > years old > and no longer available :-( > > The preamps on the AR2 site look like what I could use. > > My questions are... Is the sequencer > > http://www.advancedreceiver.com/page20.html > > really necessary or recommended when using the MSP432VD-25 or > MSP144VDG-25 > preamps? My first thought is NO. 15-20 years of use of 4 Landwehr > preamps > without a sequencer is my rational. > > Finally, does anyone have a nice "warranty voiding" hack to get > around the > these different power connectors we see on indoor preamps and down > converters such as my KEPS http://www.keps.it/images/13lnc72db_m.jpg > ? > Instead of soldering to the pin and a ground lug > > http://picasaweb.google.com/ve4yz.alan/24Ghz/photo#5172119570416133618 > > Something as simple as removing the connector from the case and > running a > cable through the remaining hole, soldered internally with something > like > Anderson Power Poles at the other end for 12VDC????? I'm going to > do it one > day, but would rather have someone else confirm that it would work > without > adversely effecting performance characteristics. No guts; no glory > here. > > > Thanks for any feedback > > 73, Alan VE4YZ > EN19kw > AMSAT LM 2352 > http://www.mts.net/~ve4wsc/ > AMSAT A-485 > > > > _______________________________________________ > Sent via AMSAT-BB(a)amsat.org. Opinions expressed are those of the > author. > Not an AMSAT-NA member? Join now to support the amateur satellite > program! > Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb > >

14 years, 5 months

Re: Preamp for a Mobile Application

by Bill Dzurilla

Kent, Never tried it, but I doubt a preamp would be worth the expense if mounted at the rig in a mobil set-up. I assume the feedline is only 10' or so. The preamp helps most when the feedline is lengthy, especially if cheap coax is used. If you want to try a switching preamp, the ARR SP432VDG is a good one, see http://www.advancedreceiver.com/page7.html For about the same price, you could buy an Arrow handheld yagi antenna, which would substantially improve both reception and transmission. See http://www.arrowantennas.com/146-437.html , although if the rig is fixed inside your car if might not be convenient to hold the Arrow, unless your mike cord is long enough so you can stand outside the car. If you are limited to operating from the car, try driving to a hilltop or somewhere with a clear view from horizon to horizon. 73, Bill NZ5N ____________________________________________________________________________________ Like movies? Here's a limited-time offer: Blockbuster Total Access for one month at no cost. http://tc.deals.yahoo.com/tc/blockbuster/text4.com

14 years, 5 months

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AMSAT-BB March 2008