[amsat-bb] Contest - AMSAT-NA Wins!
Been around the ham radio hobby for a while? Want to use those memories to help AMSAT-NA? Be the first to correctly identify the three folks in the photograph published here ... http://tinyurl.com/K6LCS-CONTEST ... and K6LCS will donate money in your name to AMSAT-NA. Read the "fine print" on the page ... entries submitted in this message group will NOT be considered! Clint Bradford, K6LCS 909-241-7666 ___ Sent via AMSAT-BB@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
[amsat-bb] Sat32PC Question
I am using SatPC32 with WispDDE and all was working fine before an unexpected shutdown on my PC. I think some files were corrupted. When I uninstall both programs and reinstall them I notice the previous settings are still there. Can anyone tell me where the files are located? I'd like to remove them so I can install from scratch. As these programs are running now they no longer tune the radio. Any suggestions will be greatly appreciated. Paul Delaney - K6HR paul.hamra...@verizon.net http://k6hr.dyndns.org:8080 ___ Sent via AMSAT-BB@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
[amsat-bb] Arrow Antennas
Spoke with Allen Lowe the past few days. He has formally passed the baton of Arrow Antennas to fellow ham, Tim Chapman - KB7MDF, for the future of Arrow Antennas. Allen needs more time to devote to the recovery of his lovely wife from her health problem of last year. He will not disappear entirely - his "hand" will still be on the products for a few years. My personal experience began with Arrow Antennas began as a mere consumer six or seven years ago, then quickly a "devotee" (OK, "groupie"), then one who exclusively uses my Arrow for scores of satellite presentations and demonstrations the past few years ... (During my AMSAT presentations, I hold up my Arrow, and tell the audience a little story ... "This is my setup. And this antenna, faded purple as it is." (I have a six-year-old unit, but purchased a pair of new elements from Allen recently - to show what a new one looks like, versus my beloved faded purple unit) "This antenna was actually sold to a client when I worked at Ham Radio Outlet a few years ago. The gentleman who I sold it to was waiting for me to open up the shop the next day. "This cannot possibly work," he declared. "It is engineered all wrong ... " " Well, Tim, part of me wanted to pry into the guy's problem, and find out what his true problem was. BUT - the OTHER part of me thought: "I can purchase this returned item myself at a greatly reduced price ... " And I did. I cheerfully refunded the client his money. Immediately bought it myself. And use it to this day for ALL my demos and presentations. In my wanderings 'round the 'Net, detractors of Arrow Antennas' product line seem to fall into these categories - 1. Arrow doesn't give away products for us as raffle prizes at our ham fests. My reply? SHAME ON THOSE who demean a small business owner's decision to produce a high-quality product at a reasonable price, and not give 'em away to all who ask. I include this "shame" on many AMSAT members - I am an AMSAT area coordinator and benefactor myself - but have been irritated with fellow AMSAT members' attitude display towards Arrow the past few years on this point. 2. Arrow doesn't publish gain figures. I absolutely love Allen's behind-the-scenes reply to these people. It boils down to, "They work. And I can sell every one I produce." Yes, that may be interpreted as "arrogance" by some. And part of me smiles at that answer (my wife is a public relations professional ... and I have been on the 'Net for over 20 years - we bring our own online histories to the equation). But part of me DOES want to know gain figures. And I KNOW what they are. I have tested them with calibrated, quality equipment. And if people dig enough on Google, they can find the info, too. But should Arrow prominently post "gain figures" on their units? Personally, I'd leave this topic alone as the new ownership of Arrow creates its new marketing / business plan for the company. A valid study would involve hiring an outside firm to conduct independent studies (otherwise, detractors would dismiss any results). And argumentative hams would argue the merits of ay such study, anyway. Well, there you go. Un-solicited testimonial from an Arrow devotee - and one who owns most of the "alternatives" - acquired via money from my own wallet. And as you read "reviews" from others debating "Arrow versus the others" - I only ask that you make sure you determine where the "reviewers" are coming from. Make sure they actually own what they are "reviewing." And in these days of anyone being able to post anything at will, ask if the "reviewer" paid cash for the units, or had them "supplied" to them for review purposes. Sad to say, but some are not as "up front" with honesty and integrity as I would like 'em to be. Thank you, Allen, for your support of the amateur radio community. You will be missed. Clint Bradford, K6LCS 909-2410-7666 - cell http://www.work-sat.com ___ Sent via AMSAT-BB@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
[amsat-bb] Re: Arrow and ELK Comparative Antenna Tests
Patrick, I don't mean to quibble, but don't you think using a Large Capacity Filter could have biased the Arrow tests? 73, Jerry, k5OE ___ Sent via AMSAT-BB@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
[amsat-bb] Trying to find Specs
Looking for specifications on old PBS Ch 24 amplifier. Originally mfg by Comark Southwick, MA. Believe Comark was sold to Thompson. Amplifier module is model # B400698 and has 2 TRW 5030 RF transistors. If anyone has specs or source for info please reply off line. Many thanks. Farrell Winder, W8ZCF. ___ Sent via AMSAT-BB@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
[amsat-bb] Re: Arrow and ELK Comparative Antenna Tests
It is commendable to see some direct antennas comparison measurements being made. Computer modeling is one thing. Realizing it in hardware is quite another. The biggest problem in making field measurements is to reduce and try and eliminate reflections from the ground, adjacent structures and overhead wires and your antenna mount. The pattern of the antennas under test can be very significant. Two antennas can have the same direct forward gain. But one can have a narrow beam width main lobe but with relatively large side lobes, while the other has a broader main lobe beam width and low side lobes. While they both can give the same forward gain results the second antenna is obviously the better antenna. To test for ground reflections raise and lower your antenna and also move it back and forward and see if your signal strength varies. On a different day and different location repeat the measurements. Your results may well leave you wondering why you made the statements you so confidently did. To reduce ground reflections raise the antennas as far as possible above ground. Use a high gain directional antenna for the signal source so that little of the radiated power is directed at reflective surfaces. The greater the spacing between the rx and tx antennas the more likelihood of a reflection but the spacing needs to be such that a small change in spacing has little effect on the results. As a rule of thumb spacing about 10 wavelengths. In actual satellite operating a difference in forward gain of a db or less is hard to detect however the effects of the pattern can be significant in pointing a hand held antenna at a moving target. Having made hundreds of comparison measurements on 13cm helix antennas I know how much time and effort it takes. However I think it is very worthwhile to actually make real antenna comparison measurements to confirm the theoretical. Clare VE3NPC - Original Message - From: "John Kopala" To: Sent: Sunday, April 24, 2011 11:49 PM Subject: [amsat-bb] Arrow and ELK Comparative Antenna Tests > On Saturday, April 23, Pat Stoddard (WD9EWK) and I did some antenna > testing in an attempt to answer > the questions about which is the best antenna for portable satellite > operation. We only tested the > antennas in receive mode to determine their relative gain. Time > constraints prevented us from > performing additional testing to determine if the transmitted output was > consistent with the receive > gain of the antennas. For the time being we will assume (and we all know > the dangers of doing so) > that the transmit performance closely matches the receive performance. > > The antennas tested were an Arrow (3 x 7 elements), an ELK (4 elements), a > PortaFox configured for > 145/435 operation (4 elements), and a Home Brew 4 by 9 element "arrow" > antenna. The standard Arrow > antenna was the only antenna equipped with duplexer, but not the basic > duplexer which is installed > in the handle. We did not measure the insertion loss of the duplexer on > the Arrow antenna, but this > was obviously not a significant factor in the overall performance. A > duplexer could still be > required depending upon the antenna chosen and the radio(s) to be used. > > Using the Arrow antenna as the reference antenna and 145.300 MHz as our > test frequency, our > measurements indicated that the Arrow and the ELK antennas had identical > gain. The PortaFox antenna > showed 2db less gain than the Arrow and the ELK. The Home Brew 4/9 > element crossed yagi showed 2db > more gain than the Arrow and the ELK. > > On 435.300 MHz, the Arrow antenna had 2db more gain than the ELK and 8db > more gain than the > PortaFox. The Home Brew 4/9 element had 3db more gain than the Arrow. I ___ Sent via AMSAT-BB@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
[amsat-bb] Re: 2m/70cm Quadrifilar Helix antenna Antenna Kit fromAntennas.us
Zack, Any solution could have benefits, depending on your needs. These antennas would be very stealthy, if deed restrictions are an issue. Also, they are simple (as all omnidirectional antenna) and you would not have to worry about tracking (rotors, software, PC interfaces, etc.). >From a cost perspective, you could buy a brand new TV rotor, an Arrow or Elk >(user's choice, or any similar-gain pair of antennas), and a AAR/SSB/Mirage >preamp for less and have a system far superior (~6 dB) in both uplink and >downlink capability. Besides just the obvious gain benefit, directional >antennas also noticeably reduce local noise/IM exacerbated by a preamp--thus >your S/N ratio is also improved dramatically. If you do want to go with an omni solution, I concur with Mark's suggestion a pair of Tony's parasitic Lindenblad's and a separate RF-sensed preamp would be a good choice. You could build a pair in an afternoon for about $25 in parts and find a used preamp for $75 or so. UO-14 and SO-35 you could hear easily with an omni antenna. AO-27 you can't. FO-20 was easy to hear, FO-29 not quite so loud. AO-51 when at high power you can hear above 25 degrees with an omni and good preamp, but you will be frustrated by the short pass time available (and when it is set to lower output power). The bottom line is there are no truly "easy-sats" in 2011 and omni antennas are a real compromise that makes operating with them only attractive if there is a good reason you cannot use directioinal antennas. I'll give you a personal example: after moving back to Texas late last year I wanted to get back on the birds, so I "threw" up an old omin antenna (Eggbeater II from a long, long time ago) and put a Landwehr preamp in the attic (it was easy and fast). See my comment above about being frustrated--I didn't operate much. When ND9M was at sea I got really frustrated! So I swapped out the Egg II with a slightly-less old antenna, a TPM II and pointed it due ! West (fixed, no rotor) and worked Jim a few times, mostly on FO-29, when he was in the Pacific Ocean. After he went through the Panama Canal, I went back on the roof and pointed the antenna to the SE and worked him a few more times in the Carrib and GoM. I worked him in 9 grids, but was not able to work much else. Last weekend I finally made the time to run the cables through the house walls for the rotor and quickly built up a small homebrew beam for 70 cm (3x3), installed a coaxial relay for polarity switching, and moved the preamp to just below the antenna: a world of difference, as you can imagine. Solid copy on all those birds now. Sorry for the long story, but my recommendation is borne out of experience--only use the omni if you can't use a beam. 73, Jerry, K5OE --- original message --- Interesting, Zack. I would ask them about transmitting through the one with the preamp built in. Can you do it? (i.e., is it RF-sensed/switched) Or does the preamp make it a "receive only" antenna, with the accidental transmission through it smoking the device :) It's bound to happen on a dual band radio... (I think you'd be better off building a pair of AA2TX style Lindenblads...) Mark N8MH At 12:01 PM 4/25/2011 +, vtnn...@comcast.net wrote: >Antennas.us is selling a combo package of 2M and 70cm quadrifilar helix >antennas and a bias tee for $330.00. The 70cm antenna has a built-in 15db LNA >BTW. > >http://www.antennas.us/store/p/391-UC-AMSAT-KIT-2-m-70-cm-Amateur-Satellite-Antenna-Kit.html > > >The UC-AMSAT-KIT, 2 m / 70 cm Amateur Satellite Antenna Kit is a discounted >bundle combination of quantity 1 each of the following three antenna products: >UC-1464-433, VHF Amateur Satellite QFH Antenna, Passive >UC-4364-513, UHF Amateur Satellite QFH Antenna, with built-in LNA and SMA Male >connector >BIT-1500-385, UHF Bias Tee > >I was wondering though what some of you on the list think of these antennas >for FM LEO users that are looking for fixed outdoor antennas? > > >73 >Zack >N8FNR ___ Sent via AMSAT-BB@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
[amsat-bb] Re: Arrow and ELK comparative antenna tests
Hello,hi support link W1GHZ Paul website: http://www.w1ghz.org/small_proj/hna.zip 73 de iw5bsf Roberto - Original Message - From: "i8cvs" To: "John Kopala" ; "Amsat - BBs" Sent: Tuesday, April 26, 2011 2:16 AM Subject: [amsat-bb] Re: Arrow and ELK comparative antenna tests > Hi John, N7JK > > Since you are interested in accurate antenna gain measurements and > comparison I suggest you to read also the following articles: > > ANTENNA GAIN MEASUREMENTS Part 1 : Technique- the fine points > of making accurate gain measurements without access to a professional > antenna range. by Fred Brown W6HPH > published on QST November 1982 pages 35 to 37 > > ANTENNA GAIN MASUREMENTS Part 2 : Intrumentation- simple,easy > construction instruments permit a precise determination of antenna gain > by Fred Brown W6HPH > published on QST December 1982 pages 27 to 31 > > UHF ANTENNA RATIOMETRY : Inconsistent results in checking antenna > gain ? Here is a technique that can restore your faith in measurements and > speed up empirical designe by Richard T. Knadle W2RIW > published on QST February 1976 pages 22 to 25 > > 73" de > > i8CVS Domenico > > - Original Message - > From: "John Kopala" > To: > Sent: Monday, April 25, 2011 11:29 PM > Subject: [amsat-bb] Re: Arrow and ELK comparative antenna tests > > >> One supplemental note on the testing of the Arrow and ELK antennas. >> >> I indicated that having both the transmit and receive antennas in the >> same >> plane with the ELK might have some advantages. >> >> I failed to mention that having the crossed yagi design of the Arrow >> isolates the 2 antennas from each other and may help to minimize UHF >> downlink desensing when transmitting on a VHF uplink. This >> can vary greatly with the configuration and the radios used, but >> certainly >> would provide significant isolation when separate radios are used for the >> uplink and downlink. >> Recent posts on the Alinco DJ-G7 also highlight the fact that the radio >> itself my desense on one band when transmitting on the other. >> In that case, all the isolation in the world might not make any >> difference. >> >> John Kopala >> N7JK >> > > ___ > Sent via AMSAT-BB@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 ___ Sent via AMSAT-BB@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
