September 2006 - AMSAT-BB - mailman.amsat.org

Re: Primestar L Band
by Edward R. Cole 28 Sep '06

28 Sep '06

At 02:25 AM 9/28/2006 +0000, w7lrd(a)comcast.net wrote: > >Hello >How much gain can I expect to get from a 36x30 inch primestar dish. Also a 54X48 ps dish? I plan to use a 5-6 turn helix feed. I've been googleling around and I can't find out. I have some 7/8 hardline I'll use from my IC-1271A running 10 watts. >73 Bob W7LRD >Seattle Since the dishes are elliptical standard formula for a circular parabolic dish will not properly calculate gain. But if you use the smaller dimension as a diameter in those formula you should come up with the minimum gain. Using 30-in, gain = 24.1 dBi at 2401 MHz Using 48-in, gain = 29.2 dBi at 2401 MHz, gain = 23.7* dBi at 1268 MHz * Note: The smaller dish is too small at 1268 MHz and the larger dish may not produce this gain since it < 10 wavelength in diam. 73's, Ed - KL7UW ========================================= http://www.qsl.net/al7eb - BP40iq 144-EME: FT-847, mgf-1801/1402, 4xM2-xpol-20, 170w 432-EME: FT-847, mgf-1402, 1x21-ele (18.6 dBi), 60w =========================================

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YES !! RS-15 is alive !
by lu7abf 28 Sep '06

28 Sep '06

YES !! RS-15 is alive ! Reading a recent report on AMSAT-BB from Gary deMunbrun WA4RKS about RS-15, move me to try. Tks Gary! I tried on several passes, I always heard the intermitent carrier at 29.352, but no repeat of my uplink, trying either on official 145.858-98 or on suggested 145.958-98. All of tries were made with RS-15 on her night. But today I gave her another try. This time RS-15 was sunlight on a pass that lasted 20 minutes on Sept-28 00:24 to 00:43 LU Time. I could uplink first CW and after SSB and hear it back !!!!, despicte the fact that I'm only using 25 W from FT-736 on 2mts and a 2m turnstile !! Frequencies I operate where: Uplink 145.875 , downlink 29.374 with good signal return about s3. Unfortunately no one to try a QSO. RS-15 is amazing, with 2000 Km height, passes can last up to half an hour ! even earth coverage is quite broad ! So, looks that we have had a new child reborn, coming back to life from over ten years ago. You can find on http://www.amsat.org.ar RS-15 passes precalculated for your location and on your time, for a quick RS-15 . 73, Pedro LU7ABF lu7abf(a)amsat.org.ar

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HITSAT 1517 UTC
by Mike Rupprecht 28 Sep '06

28 Sep '06

AOS 1517 UTC Sep 28 (JN49lr) Hit2 9290015373f Hit3 414a4e494c494949 Hit4 8bd6d1e2 Hit1 jr8yjt Hit2 9290019442a LOS 1523 UTC 73, Mike DK3WN

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70cm preamp
by Alan P. Biddle 28 Sep '06

28 Sep '06

Bill, Something is very wrong. Setting aside the inaccuracy of S-meters, there should be negligible loss. I would expect something like that if the 2 meter output were used by mistake, since they are rated at about a 60 db isolation. However, your description seems to preclude that. "I also reversed it with the same results." Does this mean you swapped direction, or tried the 2 meter lead? What did you see for an SWR when you transmitted on 70 cm with the duplexer(s) in place? If you really have that high a loss, it will show up. Did you try and receive the satellite, or a local repeater, with the duplexer? Perhaps someone else will have an idea. Alan WA4SCA

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Arrow Antennas
by Fabio Roccatagliata 28 Sep '06

28 Sep '06

Dear OMs, I was wondering if arrow antennas are the only portable antennas available on ham shops or other similar products are/were available. Any other suggestion for a simple V/U portable antenna to use for handheld or portable operations ? Thanks Fabio IZ1EGT / F5VKV

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HITSAT FM recorded
by Mineo Wakita 28 Sep '06

28 Sep '06

Today, 09:00 UTC, 28 Sep 2006, I recorded the HITSAT FM sounds on 437.425 MHz. These signals were switched on ONLY in the range of Japan. And these 1k2 AFSK (FM 437.425 MHz) be able to decode by modem of IC FX614, becauce NOT AX.25 (not NRZ-NRZI). http://www.ne.jp/asahi/hamradio/je9pel/60928hit.wav --------------------------------------------- Name: Mineo Wakita / JE9PEL, JAMSAT member Mail: ei7m-wkt(a)asahi-net.or.jp URL : http://www.ne.jp/asahi/hamradio/je9pel/ QTH : Yokohama Japan, GL:pm95tj Date: Sep 28, 2006 ---------------------------------------------

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Antennas IOio and CJU for VHF/UHF Satellite Mobile Operation
by i8cvs 28 Sep '06

28 Sep '06

Hi Rick, N1HID I have sent to you the requested drawings and information about the antennas IOio and CJU Unfortunately my message sent to n1hid(a)comcast.net failed and bounced back Do you have another email address to try again ? 73" de i8CVS Domenico

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Fw: 23 cm Loop feed
by kc6uqh 28 Sep '06

28 Sep '06

Here is a modification to a standard conifer type 2.4 GHz grill antenna. The loop gives it a feed for L Band used here to receive ATV 1.253 GHz while transmitting on 2.441 GHz. Filters are required on both bands to reduce white noise from the Xmit PA and leep power out of the receive preamp. Those interested in Pictures request via E-Mail and I will forward them. Art, KC6UQH Subject: 23 cm Loop feed Dave, Ted and Gary, Here are some pictures. #1, & #2 show the feed mounted on the dish from both sides, #3 shows the Split Feed balun. Clamp tight one end 12" length of # 12Ga house wire in shop vise, pull hard until straight, then strip off insulation with a box cutter. The loop is 2.64 " square center to center, formed from the # 12 hard drawn house wire with the insulation removed. Using a 3" length of 1/8 " copper hobbie tubing, cut two .025" wide slots one on each side for 2.4 " long. Trim back the braid 2.9 " on a piece of R/G 142, Strip 0.2" of the center dielectric from the end of the cable. Slide the copper tube on to the coax unsplit end first, fan out the braid, and bend over the center conductor and solder to one of the split ends, Each side of the loop connects to a split end of the tubbing. Silde a piece of 1/4" heat shrink tubbing over the copper tubbing and solder the braid to the unsplit end You can also solder a bracket to this end to support the cable, and in the center of the opposite side use a piece of acrylic plastic 1/16 thick, heated and bent to support the other side of the loop. After connecting the loop, shrink the tubbing and coat the matching section and connections with liquid electrical tape or yellow weatherstrip adhesive. Cable is then wire tied to the boom. The loop is 2.75 " from the center of the reflector where it is screwed to the 2.4 GHz antenna cover. This is a living document and comments about omissions, changes etc are welcome in the intrerest of maintaining an accurate documentation. Art, KC6UQH

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L Band Uplink Ant
by sco＠sco-inc.com 28 Sep '06

28 Sep '06

What do most folks use for a L Band uplink antenna? Les W4SCO

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Re: L Band Uplink Ant
by Wayne Estes 28 Sep '06

28 Sep '06

Ed Cole wrote: That being said, there is the benefit of using it [4-foot dish] as a dual-band antenna on 1268/2401. Wayne replies: AND it has right hand circular polarization to minimize fading. Wayne Estes W9AE Oakland, Oregon, USA, CN83ik

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