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

Re: GO32 APRS test successful
by Mineo Wakita 14 Aug '07

14 Aug '07

UNPROTO 4APRS VIA 4XTECH 4XTECH-12>STATUS [08/14/07 10:44:41z] <UI R>:UTC: Tue Aug 14 10:44:57 2007 | Gurwin Techsat1B (V9.87) 4XTECH-12>STATUS [08/14/07 10:44:42z] <UI R>:Gurwin Techsat1B's BBS is active again,(version 9.87 beta) . 4XTECH-12>STATUS [08/14/07 10:44:42z] <UI R>:u wellcome! 4XTECH-12>STATUS [08/14/07 10:44:42z] <UI R>:2 Users/8 Broadcasts , Uplink freq:145.890,145.850,145.930, 1269.800, 1269.900 JE9PEL>4APRS,4XTECH [08/14/07 10:44:43z] <UI R>:Hello de JE9PEL via GO-32 JE9PEL>4APRS,4XTECH [08/14/07 10:45:20z] <UI R>:Hello de JE9PEL via GO-32 4XTECH-11>PBLIST [08/14/07 10:45:38z] <UI R>:PB: Empty. 4XTECH-12>BBSTAT [08/14/07 10:45:40z] <UI R>:Open:AB1C23: 4XTECH-12>STATUS [08/14/07 10:45:40z] <UI R>:B:23091370 JE9PEL>4APRS,4XTECH [08/14/07 10:45:50z] <UI R>:Hello de JE9PEL via GO-32 de JE9PEL, Mineo Wakita

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Re: AMSAT-BB Digest, Vol 2, Issue 504
by richard＠g3rwl.demon.co.uk 14 Aug '07

14 Aug '07

Scott > The other downside is that even with two transceivers, I'm unable to work > full-duplex. The two bands on the antenna use seperate elements and feed > points, but share a boom. Transmitting on 2m completely overloads the > front-end of the IC-7000. While full duplex would be useful, it's not > absolutely necessary. Theres also the old fashioned stub, you put a 2m quarter-wave open-circuit stub on the 70cm feeder close to the input of the preamp (maybe another close to the input of the rig). A little bit tricky to tune (fabricate it long and snip tiny bits of it off until you get maximum attenuation). 73 Richard G3RWL

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Help with WiSP software, IC-821H and KAM-XL
by Hamradio .9m 14 Aug '07

14 Aug '07

I've been struggling with WiSP since day one. I have a IC-821H and TNC model KAM-XL and have not been able to get it to communicate with any satellite although I heard the bird CW. Is there any setting required on my radio and TNC to using WiSP? Part of my problem might also be that I am VERY new to satellite and still struggling with them in general. Thanks -- 73 Nuril 9W2NRL

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Mode-J Desense Cure
by John Beanland 14 Aug '07

14 Aug '07

13 August 2007 NW2S de S.I. Scott, Charlie, N5TD, offers you good advise with his recommendations for eliminating your "Mode-J" desense problem. There are several possible sources of the overload trouble, viz: - 1. Third harmonic output from your 2M Tx. 2. Brute force (2M) overload of your 70cm Rx system, particularly a low noise pre-amplifier. This will generate 70cm energy even from a 100% clean 2M signal. 3. Third harmonic generation (of the 2M signal) by a "dirty" joint, which acts like a diode, in the antenna system. The solutions that we offer are: - 1. Our 2M Lowpass filter, model MMf200-7. This is a 7-section, lumped constant, lowpass LC filter. We guarantee at least 40dB suppression at 435MHz, reference the 2M response. Typically you will get over 50dB suppression. The insertion loss (actually reflection loss) at 2m is typically 0.5dB. You install this to the 2M transmitter's output coax connector. 2. Our 70cm, low loss, Bandpass filter, model PSf432. This is a 3-section, 0.1db ripple, Interdigital, bandpass filter. The insertion loss at 435MHz is typically 0.1dB The attenuation at 335MHz is typically 80dB, and continuing down at lower frequencies. Install this, on the tower, at the input of your 70cm pre-amplifier. Water will not harm it or change its characteristics (provide a drain hole). 3. Careful attention to all mechanical joints on your antennae and the tower (make sure all joints are clean and tight) is the solution to this possible cause. A "dirty" joint acts like a diode. It rectifies the Tx 2M signal generating and radiating harmonic energy, which enters the 70cm system with negligible attenuation. See our advertisement in CQ-VHF for other details. PS: Don't use a 2M interdigital bandpass filter (our PSf144) on the output of your 2M transmitter. Being a transmission line style filter, it has multiple low loss passbands at odd harmonic frequencies. Its attenuation at 435MHz is negligible! 73s, de John G3BVU/W1. Yours truly, C.J.Beanland, MSEE, C.Eng., MIEE, MRAeS. Sales Manager, Spectrum International,Inc. spectrum.ma.ultranet(a)rcn.com P.O. Box 1084, Tel: (978) 263-2145 Concord, Mass. 01742. Fax: (978) 263-7008

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Re: FO-29 sked 14-19 Aug
by TOFFY 14 Aug '07

14 Aug '07

Thank very much. 73s de Toff HS0NNU ----- Original Message ---- From: Masahiro Arai <m-arai(a)a.email.ne.jp> To: amsat-bb(a)amsat.org Sent: Monday, August 13, 2007 12:50:08 PM Subject: [amsat-bb] FO-29 sked 14-19 Aug Here is tentative FO-29 operation sked from JARL command station. from to 14 Aug 0245z eclipse (0322z +??) 0426z eclipse (0509z +??) 0615z eclipse (0655z +??) 15 Aug 0335z eclipse (0413z +??) 0520z eclipse (0559z +??) 16 Aug 0240z eclipse (0317z +??) 0425z eclipse (0504z +??) 0610z eclipse (0650z +??) 17 Aug 0330z eclipse (0408z +??) 0515z eclipse (0554z +??) 18 Aug 0235z eclipse (0312z +??) 0420z eclipse (0459z +??) 0605z eclipse (0645z +??) 19 Aug 0323z eclipse (0403z +??) 0510z eclipse (0549z +??) Telemetry reception report is welcome. Please send report to lab_at-sign_jarl.or.jp (_at-sign_ is @) 73 Masa JN1GKZ Tokyo Japan _______________________________________________ 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 ____________________________________________________________________________________ Fussy? Opinionated? Impossible to please? Perfect. Join Yahoo!'s user panel and lay it on us. http://surveylink.yahoo.com/gmrs/yahoo_panel_invite.asp?a=7

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Re: keps for earthbound objects
by Wayne Estes 14 Aug '07

14 Aug '07

Eric Fort wrote: At certain times I would like an automated az-el rotor run by predict to "track" a fixed point on earth, say for instance a local mountain top. could a set of keps be derived such that this just looks like yet another satellite? How would this be done? Is there an easier way? Wayne W9AE replies: SatPC32 (sorry, not a LINUX application) has a function similar to this, intended for terrestrial use. It's the "standard directions" function in the "Rotor" menu. It allows you to create a list of names and their associated azimuths. After the list is created, go into the "Rotor" menu and click on the name to steer the antennas to that azimuth. It doesn't support an elevation, but Erich DK1TB might be willing to make a custom version that stores elevations as well. Unless your antennas have extremely narrow beamwidth, or unless you are extremely close to a very large mountain, you should be fine with the elevation fixed at the horizon. The summit of a big mountain a few miles away is likely to be only 5 degrees elevation. Wayne Estes W9AE Oakland, Oregon, USA, CN83ik

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keps for earthbound objects
by Eric Fort 14 Aug '07

14 Aug '07

at certain times I would like an automated az-el rotor run by predict to "track" a fixed point on earth, say for instance a local mountain top. could a set of keps be derived such that this just looks like yet another satellite? How would this be done? Is there an easier way? KG6KQT

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Re: keps for earthbound objects
by Glenn Little WB4UIV 13 Aug '07

13 Aug '07

I guess that you have the rotor on a moveable platform such as a truck, spacecraft. watercraft, etc. The look angle to the fixed object is the reciprocal of the angle generated by the tracking program. It should work if the antennas are mounted 180 degrees from where they would normally be mounted. 73 Glenn WB4UIV At 05:13 AM 08/13/07, Eric Fort wrote: >at certain times I would like an automated az-el rotor run by predict to >"track" a fixed point on earth, say for instance a local mountain top. >could a set of keps be derived such that this just looks like yet another >satellite? How would this be done? Is there an easier way? > > >KG6KQT >_______________________________________________ >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

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Success - and thanks!
by Scott Wilson 13 Aug '07

13 Aug '07

I can finally report a successful satellite QSO! Many thanks to all of you for your very useful feedback. I ended up using my existing 2m/70cm 3el beam on the TV rotator with the addition of an SSB preamp for 70cm. There are still a couple of limitations with my system. The first being that the antenna is fixed at a 0 degree elevation. I was able to work AO-51 from 7 degrees above the horizon, but lose it around 20 or so degrees elevation. While it's great that I can work it that far out, I'm losing out on the better passes with less path-loss. The other downside is that even with two transceivers, I'm unable to work full-duplex. The two bands on the antenna use seperate elements and feed points, but share a boom. Transmitting on 2m completely overloads the front-end of the IC-7000. While full duplex would be useful, it's not absolutely necessary. My primary goal is achieving reliable, repeatable communications (i.e. removing the luck from the equation as much as possible!). Hopefully I'll be able to reproduce yesterday's performance with my exising kit for a little while longer and consider how to add a permanent elevation and slightly longer booms. Regards, Scott NW2S

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Alaska on the Satellites
by Ken Farr 13 Aug '07

13 Aug '07

I am currently looking for easterly FM contacts on AO-51, AO-27 and SO-50 from here in Anderson, Alaska, BP54kh. I currently am active from 1600 to 0200 the following day GMT seven days a week until I return to Norther California. I am willing to arrange schedules. Please contact me at KL1WE(a)arrl.net. 73, Luci

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