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

EQUiSat Optical Beacon CubeSat
by Trevor . 17 Oct '18

17 Oct '18

Students at the Ivy League Brown University are developing an amateur radio satellite EQUiSat that will carry a Xenon Flash Tube (XFT) subsystem to act as an Optical Beacon that should be visible to the unaided eye of observers on Earth. See http://www.uk.amsat.org/?p=10635 73 Trevor M5AKA AMSAK-UK http://www.amsat-uk.org/ ----

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LVB Tracker USB serial port driver for Windows 7 x64?
by Bill Bordy, NJ1H 22 Dec '16

22 Dec '16

Has anyone located a driver for the LVB Tracker internal USB to serial port adapter on Windows 7 x64? If not, has anyone reverted to the serial port connection on LVB Tracker and used an external USB to serial port adapter successfully with SatPC32 on Windows 7 x64? I have an Edgeport multiple USB to serial port that has drivers for Windows 7 x64 that I will use if I have to. I would prefer using the LVB Tracker with its USB to serial adapter if someone has another solution. 73, Bill NJ1H

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AO-16 telemetry 3 Oct 2010
by Mark L. Hammond 01 Jul '16

01 Jul '16

Hi All, Here is a quick AO-16 update. On Sunday I turned AO-16 long enough to get some telemetry packets. The satellite would remain on for less than one minute after being commanded on. A quick test of the "bent pipe" voice mode repeater was successful. . The "hardware watchdog timer problem" is still evident; as expected, spacecraft temperatures are insufficient to keep the transmitter ON (needs to be above 15 deg C). Orbit projections suggest that satellite illumination conditions will not result in increased temperatures for nearly 10 years. Command stations do periodically turn AO-16 "ON" to check on its condition and see if the hardware timer problem has "automagically" fixed itself (which in not anticipated, but who knows...). AO-16 telemetry 3 Oct 2010 1838 utc PACSAT MBL Telemetry Decoder Ver. 1.3 (c) Mike Rupprecht, DK3WN =============================================================================== (average values) +10V Battery Bus : 0.00 V Battery Charge Reg : 0.55 mA Base Temp : 9.07 °C PSK RF Out : 1.90 W +5V RX Bus : 4.87 V +8.5V RX Bus : 8.49 V +10V RX Bus : 11.24 V Here is another teaser :) Several months ago I commanded the AO-16 S-band transmitter ON; it too remains functional (albeit weak), and was received by me, Drew KO4MA, and Alan WA4SCA. 73, -- Mark L. Hammond [N8MH]

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Re: az-rotor
by Joe Leikhim 30 Nov '12

30 Nov '12

Al; Did you try the method in the manual first to set the rotor up? I followed the manual and it worked fine. Subject: [amsat-bb] Re: az-rotor Message-ID: <ABBEFC4E69E44BE4894A1C23DA4B0F8C@AlPC> Content-Type: text/plain; charset="iso-8859-1" Hi Erich et al., Following suggestion I did the following. Since the rotor goes beyond 180 on the right side of its travel I let it go until it stopped. I then visually noted how much beyond 180 it had gone, divided by 2 and brought the dial back to 360 plus the number just obtained. I then assumed the pot was at its halfway position. I made the following resistance measurements 1-2 was 209.7 ohms, 2-3 was 206.1 ohms, and 1-3 was 415 ohms. Considering the manual guess work I think that is a pretty good result. I then ran SatPC32 and attempted to park the rotor at 360. It was off, I had to park it at 341 for the rotor to actually be at 360. This is basically the same result as before when I was just going by the control box readings. I believe the resistance measurements would suggest that there is not a short in the pot (unless it just happened to be around the halfway point). At this point I am not sure what to try next 73 Al W8KHP -- Joe Leikhim Leikhim and Associates Communications Consultants Oviedo, Florida JLeikhim(a)Leikhim.com 407-982-0446 WWW.LEIKHIM.COM

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Re: az-rotor
by Erich Eichmann 29 Nov '12

29 Nov '12

Hello Al, you wrote: > The problem is that half way through, when it should read 360 it reads 345. > There is a nonlinearity in the readout. > I made and make the same observation with the KR-600X, the AZ rotor of my KR-5600A rotor combination. The KR-600X is completely equal with the AZ rotor of the G-5400B combination regarding control box and wire poti in the rotor (Yaesu took over the Kenpro rotor production and replaced the "KR" by "G"). When I first added rotor control to my tracking software years ago I mounted the KR-600X in the shack over a big 360° linear scale with 1 m diameter and with a pointer that moved around the scale close above it. The rotor ran exactly an 360° turn from the starting position 180° in the south to the end position 180°. In the software I entered 180 for the start positon and 179.9 for the end position. I could adjust the meter so that it also moved exactly into the start and end position, after I had adjusted the rotor interface poti and the "Out Voltage" poti at the control box. . Then I entered 360° (rsp. 0°) as target position. The rotor moved exactly to that position, the pointer pointed exactly to the opposite direction of the starting position. The meter however pointed to about 342°, so it was wrong by about 15° to 20°. The situation is the same until today. The maximum of the deviation is in the middle of the scale. So, by my experience and at least in my case the wire poti in the rotor is very linear, but the meter is not. I agree with Domenico, that the linearity of the poti is important. 73s, Erich, DK1TB ----- Original Message ----- From: <tokens(a)myranch.com> To: <APBIDDLE(a)MAILAPS.ORG>; <amsat-bb(a)amsat.org> Sent: Sunday, November 25, 2012 10:00 PM Subject: [amsat-bb] Re: G5400B Rotor Problem > Alan, > > Thanks for the answers. The rotor goes through its 360 just fine. The > problem is that half way through, when it should read 360 it reads 345. > There is a nonlinearity in the readout. > > 73, > Al W8KHP >

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NASA Cancels Nanosat Challenge
by Limaunion 29 Nov '12

29 Nov '12

fyi: http://science.slashdot.org/story/12/11/29/0459232/nasa-cancels-nanosat-cha…

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G5400B Rotor Problem
by tokens＠myranch.com 29 Nov '12

29 Nov '12

Got some unexpected time today to look at the rotor. First I set the output at pin 6 of the external control output jack to 5.0 V. Then I got readings every 45 deg from 180 at the left to 180 on the right. The readings are of course subject to parallax in reading the needle. Readings from 180 on the left to 180 on the right were 0.024, 0.606, 1.270, 1.864, 2.489, 3.074, 3.690, 4.350, and 5.000 V. The difference in voltage from reading to reading varied from 0.582 to 0.660 V. From left to right they were 0.582, 0.664, 0.594, 0.625, 0.585, 0.616, 0.660, 0.650. I then took resistance readings on the 500 ohm pot in the rotor (removing connection from control box each time). Starting at the left resistance from 1-2, 1-3, 2-3 were 415, 416, and 1.7 ohms. With the rotor halfway around (360) (dial reading 345) resistance from 1-2, 1-3, 2-3 were 241.7, 416, and 176.1 ohms. With the dial at 360 resistance from 1-2, 1-3, 2-3 were 220.4, 413, and 193.6 ohms. With the dial at the right 180 resistance from 1-2, 1-3, 2-3 were 30.4, 414, and 383 ohms. First observation is that the pot in the rotor is considerably less than 500 ohms. Next with either the rotor being halfway around or the dial reading as if it were halfway around I would expect the 1-2 and 2-3 readings of the pot to be somewhat similar but they are not. So, are these results glaringly pointing to the 500 ohm pot as the culprit? Or does someone see something else? I’d appreciate any opinions on this. Thank you once again. 73 Al W8KHP

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Microwave brick oscillators
by Lizeth Norman 29 Nov '12

29 Nov '12

Hi all! Anyone have any experience with said units made by California Microwave and Harris? I do have a general idea how they work and would like to drive them with a signal generator for lab use and testing for now. Any ideas? I have pulled the crystal and know which pads drive. how do I go from a signal generator to a crystal input? Norm

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Re: ESTCube-1 and Aalto-1
by Trevor . 28 Nov '12

28 Nov '12

--- On Wed, 28/11/12, Bob- W7LRD <w7lrd(a)comcast.net> wrote: > no transponders? Bob W7LRD No transponders on those Cubesats but Spring/Summer 2013 should see the launch of 3 CubeSats carrying 435/145 linear transponders, 1 CubeSat carrying a 145/435 linear transponder and several CubeSats carry 435/145 AO-16 style FM-DSB transponders. 73 Trevor M5AKA

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ESTCube-1 and Aalto-1
by Trevor . 28 Nov '12

28 Nov '12

2013 PSLV Launch for ESTCube-1 CubeSat http://www.uk.amsat.org/?p=11707 Finlands First CubeSat Aalto-1 - 2013? http://www.uk.amsat.org/?p=11702 73 Trevor M5AKA AMSAT-UK http://www.amsat-uk.org/ ----

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