January 2008 - Eagle (INACTIVE)

Florida AMSAT Net Will Host W2GPS This Thursday
by JoAnne Maenpaa 13 Jan '08

13 Jan '08

AMSAT President, Rick Hambly, W2GPS will join the Florida AMSAT Net, Thursday Jan 17, 2008 from 7:30 - 8:30 pm EST to give a short status report and field questions. This net links repeaters all over Florida and via EchoLink so there is ample opportunity for those that want to listen or ask questions. The EchoLink nodes to connect through are: KG4YZY-R or N4HHA-R. The net's purpose is to provide a platform for hams with amateur satellite interest to meet and discuss topics of interest. All amateurs are invited to check in. Expect other AMSAT Officers and Board members to participate over the next few months. -- 73 de JoAnne K9JKM k9jkm(a)amsat.org

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AMSAT Web Page Updated
by JoAnne Maenpaa 12 Jan '08

12 Jan '08

Hello everyone, The http://www.amsat.org web page has been updated with an executive summary of the EAGLE engineering team meeting we held on Tuesday, January 8. Goal is to provide general information via the web and mail lists to the amateur radio community. We plan to publish complete details in the Journal so paid members receive this as a benefit of signing up. -- 73 de JoAnne K9JKM k9jkm(a)amsat.org

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Mumble
by Bob McGwier 10 Jan '08

10 Jan '08

FYI, there is absolutely NO comparison between Mumble and Team Speak. Mumble is awesome and Team Speak SUCKS. It allows you to adjust for the lowest latency your computer can tolerate. It is so good you can carry on two way casual conversations as if you were on the telephone. There is latency, but it is in no way as bad as TeamSpeak. If we do the Ham Radio server change over with Eric Ellison, Eric will need to set it up as multiple servers on separate ports, one for each room. But it is very very light weight. The speex speech quality is just fantastic. I am going to run some Flex Radio developer tests, where we get all of the developers on to see how it scales. I would not want to have all of AMSAT Engineering change over and it fail when we have the kind of great turn out we had last week. Bob

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Teamspeak isn't working for me
by Matt Ettus 08 Jan '08

08 Jan '08

If somebody could help me figure out why I am muted in teamspeak and can't send or receive, that would be helpful. There is no unmute option in the menus, but clicking Self/Mute Microphone and Self/Mute Speakers don't unmute me. Otherwise, you're not getting an ACP report... Matt

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Team Speak
by Robert McGwier 08 Jan '08

08 Jan '08

Tonight at 9 P.M. Eastern time engineering will meet on the Amateur Radio Developer's Team Speak server. I didn't realize why Matt hated it so much until I realized the default password for access to the main system is Flex4U. ;-). It was originally started up by owners and users of the SDR-1000 by Flex Radio but it is now the default meeting place for Here are your instructions copied from the password protected EaglePedia page. I am happy to announce that Dave Hartzell has volunteered to take on the reorganization of the EaglePedia content. I am very hopeful that with his leadership and contributions from the individuals involved, it can meet the clear promise it holds. I am sitting in the AMSAT Engineering room with away selected. 73's Bob N4HY Getting Started 1. Download and install the TeamSpeak client. 2. Bring up TeamSpeak client. 3. Click Connection 4. Click Connect 5. Right Click Servers 6. Click Add Server 7. In the Label field, enter AMSAT (could be anything you want.) 8. In the Server Address field, enter "70.84.228.202:9274". Include the colon and port number, but do not include the qoute marks ("). 9. In the Nickname field, put whatever you want. Suggest at a minimum, name and callsign 10. Select Anonymous 11. In the Server Password field, put "Flex4U" as password without the quotes. 12. In default channel, enter "AMSAT Engineering" without the quotes. 13. In channel password, enter "Eagle" as password, again without the quotes. [edit] Connecting to TeamSpeak 1. Click connect. 2. In Settings, select Sound input/output settings. 3. Leave everything at the default, except select Push to talk mode. You'll then be asked to select a key for your PTT switch. I use the right <CTRL> key (the left one on my laptop); some use the spacebar. Whatever you like, but you probably want a key which does NOT go into the keyboard buffer. Note that this is like a PTT switch on a radio, you must _hold it down_ to transmit. 4. Leave everything else at default; select CLOSE. [edit] Once You Connect This should work; I'll be listening. Amazing how WELL it works on my dialup! If by chance, I'm not hearing you but you're hearing me: 1. Open your sound card mixer application (varies with windows version and sound card.) Make sure the microphone is enabled on the INPUT (may be called RECORDING) side. Probably should be disabled on the Playback side. If you have any questions about TeamSpeak please post them to the Eagle Mailing list.

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Proposed agenda for Jan. 8 TS meeting
by Robert McGwier 07 Jan '08

07 Jan '08

This is a proposed agenda for next week's meeting. Poor Howard! If he cannot make it for that meeting, we will get the report from him earlier and deliver it. Please send me your modifications. I will contact each of the proposed presenters directly. http://n4hy.org/AMSAT_Engineering_Meeting_2008_i.pdf Barry Baines is the leader of the meeting and the time enforcer. Bob -- AMSAT Director and VP Engineering. Member: ARRL, AMSAT-DL, TAPR, Packrats, NJQRP, QRP ARCI, QCWA, FRC. ARRL SDR WG Chair “An optimist may see a light where there is none, but why must the pessimist always run to blow it out?” Descartes

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SBD Varactor Help
by Tom Clark, K3IO 07 Jan '08

07 Jan '08

Many of you have seen my idea of a voltage tunable phase shifter for Eagle's S2 & C-band arrays. If you haven't, a copy of my paper from the 2007 AMSAT Space Symposium is available for download at http://mysite.verizon.net/w3iwi/electronic_scanning_antennas.pdf. I haven't had time to do much on the project the past few months, but in the initial breadboard I found that conventional varactor diodes simply create to be a discontinuity at the tap. I've done a little testing with a resistor in series with the varactors, but I have no progress to report. Matt Ettus and others have been providing me with a lot of reprints on NLTL (non-linear transmission lines) used to generate picosecond risetime pulses, and it is very interesting. The web has a lot of relevant publications, including the voltage-steerable array described at http://tempest.das.ucdavis.edu/mmwave/NLTL/NLTL.html. At least these publications show me that my idea is not totally screwy. After researching the topic, I have come to realize that what we need are not varactors used for tuning VHF radios, but rather some diodes with MUCH smaller junction capacity. This seems to dictate the use of Schottky Barrier Diodes (SBD) as varactors. Microwave SBDs are used as parametric frequency multipliers and mixers up into sub-mm wavelengths. In doing literature searches, I came across the MACOM 44700 series of diodes (PDF attached) that look pretty good. I wonder if we have some talent here in the EAGLE group who have experience with low-capacity (range 0.1-2 pf or so) varactors who can point the way to some suitable parts we might try. 73 & Happy New Year -- Tom

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[Fwd: Maxwell 3D Training, Burlington MA, January 17-18]
by Tom Clark, K3IO 04 Jan '08

04 Jan '08

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Hello - D. Goncalves
by David Goncalves 04 Jan '08

04 Jan '08

Hello All, I think I was invited here by Robert McGwier. I would like to say hello to all of you, and Happy New Year. I am David Goncalves (W1EUJ), I live in Lexington, MA, have had some experience in working on a satellite project (RAFT), and work by day as an electrical engineer designing hardware for heart support/replacement devices. I work currently with FPGAs (using VHDL) for backup control of pneumatically driven blood pumps. I think my skills might be of use here. In particular, I offered to help with the PWM control, and possibly other tasks. I did get an education in LTI systems, DSP and digital design from Northeastern University, from which I graduated in 2004, so the topics here are not new to me. I understand that the Xilinx Spartan (I hope I have that right) is being used here, and I can start by getting familair with that hardware. Robert, as I came on to help you, I await your 'command'. To anybody and everybody else, if there is documentation that I should go read, point the way, and also good luck in your endeavors. -- David Goncalves

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Re: [Bod] Re: Proposed agenda for Jan. 8 TS meeting
by Robert McGwier 02 Jan '08

02 Jan '08

We will investigate having Eric set up a server. There is no mac distributable but there is source and details on how to make it. For the time being, we are sticking with what works. We have to conduct business and not fight a new system. When we know it works, is stable, doesn't cause us to lose anyone because it doesn't work on their computer (which is what TS did for us), we will give it a test drive. For me, this is off topic as of now. Bob Lou McFadin wrote: > TS seems to work fairly well. I wouldn't wan to switch to anything that > didn't include a Mac OSX version. > > Louis McFadin > 701 Deerwood Ave. Orlando Fl 32825 > 407 658 8179 > w5did(a)amsat.org > -- AMSAT Director and VP Engineering. Member: ARRL, AMSAT-DL, TAPR, Packrats, NJQRP, QRP ARCI, QCWA, FRC. ARRL SDR WG Chair “An optimist may see a light where there is none, but why must the pessimist always run to blow it out?” Descartes

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