August 2012 - AMSAT-BB - mailman.amsat.org

AO-7B Performance 1005utc 3Aug2012
by John Papay 03 Aug '12

03 Aug '12

AO-7B continues to struggle along. This mornings 1005utc pass was no exception. No signals were heard from Europe and I could not hear my downlink until the satellite was over 15 degrees. Low power up on cw produced key clicks in the downlink. Surprisingly, higher power started to produce a tone along with the key clicks. On voice the downlink was distorted with low power. Again, higher power produced more audio and less distortion. I only heard one station sending dah's but very weak. AO-7 seems to have good passes and not so good passes. You just have to keep trying and hope to find a good one. 73, John K8YSE

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EM46 this weekend
by Rick - WA4NVM 03 Aug '12

03 Aug '12

Anyone that needs to confirm grid square EM46, I will be there until Monday, Aug 6th. FM birds only. I will leave Memphis mid morning today. 73, Rick WA4NVM

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Health of Oscar 7
by VK2MAL Yahoo 03 Aug '12

03 Aug '12

Oscar 7 has been sounding rather rough on the edges the last few passes in mode B. Signals were more distorted then sounding FM. All stations here in VK were using low power and there was only one QSO at a time going through the transponder with our usual round table discussion. Don't know if anyone can comment on there experience with her lately and on how she is going? 73's Mal - VK2MAL

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Re: G-5500 alignment
by Tom Gentry 03 Aug '12

03 Aug '12

On 8/2/2012 2:00 PM, amsat-bb-request(a)amsat.org wrote: > I had a 5500 azmith rotator lockup over winter. I finally had time to > take it down and find the problem. Now a different problem. I forgot to > mark the housing position before separating the upper/lower azmith > assemblies. I think I know where it was pointed, but how can I tell > where it should be aligned? Is this really a non issue? It really is an issue as to how it goes back together because of the way the AZ and EL motors are mounted on the L-bracket. You can tell which way the top should go on by connecting the motor and the pot to the controller box and stopping it at zero (N). Then install the case so that the limit dog is exactly halfway between the limit switches. That should have the cross boom pointing east and west and the antennas pointing north. 73, Tom

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Hudson Valley Satcom Group Net Tonight Aug02@8PM Eastern On N2EYH-L Echolink
by cotejaune2＠aol.com 02 Aug '12

02 Aug '12

Hope to hear you all on the net tonight Aug02 @ 8PM Eastern on Echolink N2EY-L or the MtBeacon Repeater 146.970 pl 100. Please join us and share your satellite knowledge with the net. 73 Gary wa2aqh and Tom kc2dtq.

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Re: [aprssig] MATLAB serial comms? (solved!)
by Bob Bruninga 02 Aug '12

02 Aug '12

Matt Willis answered it! Use fwrite instead of fprint. Done! End of drill. Bob, WB4APR -----Original Message----- From: Matthew Willis [mailto:mattwillis@gmail.com] Sent: Thursday, August 02, 2012 10:28 AM To: bruninga(a)usna.edu Subject: Re: [aprssig] MATLAB serial comms? I assume you've tried fwrite as documented here? http://www.mathworks.com/help/techdoc/matlab_external/f62852.html On Thu, Aug 2, 2012 at 10:18 AM, Bob Bruninga <bruninga(a)usna.edu> wrote: > Does anyone know how to send SERIAL Characters from MATLAB? > > The catch is, we are trying to send BYTES above 127 (Extended ASCII) and the > usual %c formatter while using CHAR(133) for example, does not actually send > the byte "133". > > Relevance is: Students working on an APRS satellite project. > I can do it EASILY from all kinds of other devices, but the professor > insists on using MATLAB syntax. > > Thanks > > Bob, WB4APR > > > _______________________________________________ > aprssig mailing list > aprssig(a)tapr.org > https://www.tapr.org/cgi-bin/mailman/listinfo/aprssig

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Fw: Appreciate Assistance in Tuning MBM88/70cmAntenna
by Farrell Winder 02 Aug '12

02 Aug '12

I forgot to mention that the MBM88 was also referenced as a Jaybeam. It was manufactured by Jaybeam Limited, ,Northampton, England and was recognized for its excellent performance. From: Farrell Winder Sent: Thursday, August 02, 2012 10:23 AM To: AMSAT Subject: Appreciate Assistance in Tuning MBM88/70cmAntenna I have an MBM88/70cm antenna that was very popular several years ago. Is anyone currently using it on satellite reception? I want to tune it for 439.25 MHz. Does anyone have a procedure for tuning to reduce SWR ? Specifically can the wing nuts on the reflector and director be loosened to slightly move the element position to optimize SWR? Anyone with experience of coax length that might effect SWR? Any references or suggestions would be most appreciated. Pleases reply off line. Thanks, Farrell Winder, W8ZCF Cincinnati, Ohio, USA

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Appreciate Assistance in Tuning MBM88/70cmAntenna
by Farrell Winder 02 Aug '12

02 Aug '12

I have an MBM88/70cm antenna that was very popular several years ago. Is anyone currently using it on satellite reception? I want to tune it for 439.25 MHz. Does anyone have a procedure for tuning to reduce SWR ? Specifically can the wing nuts on the reflector and director be loosened to slightly move the element position to optimize SWR? Anyone with experience of coax length that might effect SWR? Any references or suggestions would be most appreciated. Pleases reply off line. Thanks, Farrell Winder, W8ZCF Cincinnati, Ohio, USA

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MATLAB serial comms?
by Bob Bruninga 02 Aug '12

02 Aug '12

Does anyone know how to send SERIAL Characters from MATLAB? The catch is, we are trying to send BYTES above 127 (Extended ASCII) and the usual %c formatter while using CHAR(133) for example, does not actually send the byte "133". Relevance is: Students working on an APRS satellite project. I can do it EASILY from all kinds of other devices, but the professor insists on using MATLAB syntax. Thanks Bob, WB4APR

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ISS Packet with FT-817ND and SignaLink
by Luciano Gasparini 02 Aug '12

02 Aug '12

Hello folks! Has anyone on this BB ever tried digipeating via ISS with a Yaesu FT-817ND and Tigertronics Signalink? I'm a newbie to packet and digital modes and will appreciate any comments/advices. 73, Luciano Gasparini PT9KK

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