October 2008 - AMSAT-BB - mailman.amsat.org

Re: AOP-1 Polarity Switch
by Henk, PA3GUO 25 Oct '08

25 Oct '08

> I realize this is a long shot, but...am looking for a PS-4 > polarity switch that was used with the 416-TB, 70CM, > antenna. Any information about this switch would really be appreciated. Tks > Bruce KEØLX Hi Bruce ! Can't help you with the original PS-4 unfortunately, but .. I just finished documenting what I did in the past 3 weeks with my 416TB. See http://www.pa3guo.com (click on ANTENNAS, click on Cuchcraft 416TB). Henk "Modification of the Cushcraft 416TB (2x8 elements) 70cm antenna" (add switchable circular polarization) Introduction Cushcraft provided with the 416TB antenna a polarization 'phasing harnesss' that allows either fixed LHCP or RHCP. For years I used RHCP and was fully satified with the performance (AO51, VO52, FO29, Cute-II, ...) Click here for the original Cushcraft 416TB Manual (pdf): http://www.pa3guo.com/cushcraft_416tb_manual.pdf Below a picture of the harness as I had it mounted (fixed RHCP) for years: http://www.pa3guo.com/cushcraft_416tb_original.jpg With AO51's 435.150 MHz downlink I had an issue as that applies LHCP. I could clearly notice the signal strength difference between 435.300 (RHCP, strong) and 435.150 (LHCP, hardly audible). Then when AO51 started to apply repeater modes on 435.150 as well, which I now was starting to miss out on, I wanted to be able to switch between LHCP and RHCP. Design As I had only one relay available (these projects alway start on Sundays when shops are closed), the option of HOR/VER/LHCP/RHCP was dropped and only switching between LHCP/RHCP remained. >From various sources on the internet and an article of Domenico Marini, I8CVS, ("Switching four Polarizations on a 70cm Crossed Yagi", AMSAT Journal May/June 2007) I derived the set-up needed for the Cushcraft 416TB, which has both antennas at 1/4 lambda distance separated from eachother (A - B in the diagram below): http://www.pa3guo.com/cushcraft_416tb_pol_system.jpg The original Cushcraft harness basically consisted of Z1 and Z2 only, and RCHP vs LHCP was selected by swapping the conductor & shielding at the feedpoint of the front dipole. In the new above set-up, LHCP is obtained when the relay is excited (signal travels through Y2), else the resulting polarization is RHCP. Z1 and Z2 form the impedance transformers, which transform the 50 ohm of each dipol into 100 ohm, which are then connected in parallel resulting in 50 ohm. Y2 is the phase shifter: if enabled the signal from/to the front dipol is shifted 180 degrees (1.2 wave). Implementation For Z1 and Z2 I used RG59B/U (75 ohm): V=0.66: ((300/435)*0.66)/4= 11.4cm. X1 and X2 just need to be identical in length, I have used 40 cm Aircell (50 ohm). u1 and u2 need to be identical in length, u2 is a small piece of copperwire between the relay pins (~4mm). Y1 needs to be 1/2 wave longer as u2, I used Aircell (50ohm): V=0.83: (((300/435)*0.83)/2)+4mm= 29.0cm U1 is created by soldering the conductors of the two coax cables directly together and putting a closed copper shielding around that (by soldering the shieldings/braids of the two coax cables together and around the conductor) to form again a shielding. Refer to point 'u1' in the picture of the box below. Domenico Marini advices in his article to use proper coax relay and in general describes a more perfect system, including HOR/VER/LHCP/RHCP options. I have chosen a much cheaper and simpler implementation, which is most likely also less accurate. So for those that want to built this system as well, I recomment them to read the article of Domenico first and decide themselves how to built. Do not only refer to my implementation described here. I have used a simple SDS S2-12V relay, which is expected to work up to 450 MHz. Key is to keep all wires as short as possible. All coax braids (shieldings) have to be soldered together via the shortest possible way. See the yellow circle in the picture of the box. Parallel to the relay I have mounted an LED, which makes it easy to be able to see without a voltage meter (eg outside standing at the roof) if the 12V is present in the box or not: http://www.pa3guo.com/pol_switch.jpg Again: using a real coax relay would have been much better. Using a waterproof metal box instead of my plastic one would have been better as well, but I didn't have one and it would have made the construction much heavier. But as I am not aiming for an EME station I decided to give this implementation a try. First I stripped the antenna and removed the original phasing harness: http://www.pa3guo.com/cushcraft_416tb_stripped.jpg The baluns are carefully removed and cleaned as I needed them also in the new set-up: http://www.pa3guo.com/cushcraft_416tb_balun.jpg Next the actual switch was made and placed in a 220V outdoor box (waterproof) and mounted in the tower: http://www.pa3guo.com/cushcraft_416tb_switch_a.jpg http://www.pa3guo.com/cushcraft_416tb_finished.jpg Results Just comparing the 435.150 and 435.300 downlinks of AO51 I concluded the system works: - In the past I could not hear the 435.150 downlink. Now I can; by selecting the correct polarization. - Signal strength of the 435.300 downlink has not decreased compared to the past (the fixed Cushcraft harness). Conclusions With a few pieces of coax, a waterproof housing and a relay a Cushcraft 416TB can be upgraded from fixed Circular Polarization (CP) to (remote) switchable Left or Right Hand Circular Polarization (LHCP or RHCP). Implementation has been done using spare parts as I needed LHCP/RHCP to become available quickly. However, a next time, instead of a normal relay, I will use a coax relay as it is expected to give better mechanical stability and improved RF performance. Henk, PA3GUO http://www.pa3guo.com October 2008

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Re: ISS late pass at 1817utc
by James - KB7TBT 24 Oct '08

24 Oct '08

Is there a recording of this last pass? Sherry KJ4DUN (my better half and a new ham) made what I am to believe the last NA contact. James KB7TBT NEGARC Activities Manager www.kb7tbt.com www.ne4ga.org www.myspace.com/kb7tbt >> Congratulations to the following stations I could pull out of Richard's >> (reported) last transmission. >> >> VE3ECO, VE3KHQ, KA9ERV, KC9EIZ, W?KWQ, N0UOE, W4CMB, KS4RX, W5KSI, >> VE3IJD, >> KN4F, WA1QDP, W4NTF AND KJ4DUN. >> > >

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A little bit of history could be yours
by James R Miller 24 Oct '08

24 Oct '08

Dear All, A little bit of ham radio history could be yours; I am having a tidy up, and have put this up for auction on ePay: http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=330280516648 Among other things it was used to make the first transatlantic 1200 bps PSK packet contact (via FO-12 in late 1986) with Tom Clark W3IWI, now K3IO. Somewhere I still have the cassette tape ... The TNC2 (serial #1587) was also used to develop my 9600 baud Packet Radio modem, which happily went on to become a de-facto standard. Older readers probably know what that is/was, but anyway you can read about it at: http://tinyurl.com/5jxhlf and at http://tinyurl.com/6dn5r3 --------- Kind friends occasionally ask after me. Well, whilst waiting for the next HEO, this project http://tinyurl.com/6yfqp4 and P5A keeps me alert, as does this product http://tinyurl.com/unva6 And a teenage daughter keeps me young/old/poor. Best wishes to friends at Atlanta this weekend! 73 de James G3RUH (former AO-13 and AO-40 Command Station) -- ========================================================================== James R Miller WWW/PGP: http://www.jrmiller.demon.co.uk/ Cambridge, England Stardate: 2008 Oct 24 [Fri] 1544 utc ==========================================================================

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AOP-1 Polarity Switch
by charter 24 Oct '08

24 Oct '08

I realize this is a long shot, but...am looking for a PS-4 polarity switch that was used with the 416-TB, 70CM, antenna. Any information about this switch would really be appreciated. Tks Bruce KEØLX #30873

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[sarex] ISS 1820UTC pass
by Luc Leblanc 24 Oct '08

24 Oct '08

On the 1820Z October 23 2008 Richard confirm that this pass will be his last one as he will dismantle his radio setup as he will be in the process of preparing for his return to earth. He say "goodbye and see you the 12" "-" Luc Leblanc VE2DWE Skype VE2DWE www.qsl.net/ve2dwe WAC BASIC CW PHONE SATELLITE

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SO-50 Demo / Presentation San Diego 09/25/08
by Clint Bradford 24 Oct '08

24 Oct '08

I'll be presenting my "How to Work Amateur Satellites with your HT" multimedia extravaganza tomorrow in the San Diego area. We'll attempt to work SO-50 as it passes at 10:31AM Pacific time (1731 GMT). All are welcome to attend. Lunch at Filippi’s Pizza Grotto, 5353 Kearny Villa Rd., San Diego - right across from the San Diego Ham Radio Outlet store. We'll work SO-50 from HRO, then migrate to the restaurant for the presentation and lunch. Clint Bradford, K6LCS http://www.clintbradford.com 909-241-7666

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ISS Recording For 22/10.2008
by Callum Graham 24 Oct '08

24 Oct '08

Hello everyone. Does anyone have a recording of the ISS pass over the UK for the 22 October around 11:30 AM when he was calling some scottsh stations ? If so coould you please email it to me at mm3ycg(a)btinternet.com as two of my friends were lucky enough to catch richard and would like to hear the recording if anyone has it. 73.

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Re: Web streaming ARISS School Contact?
by AJ9N＠aol.com 24 Oct '08

24 Oct '08

Hi all, The text file (_http://www.amsat.org/amsat/ariss/news/arissnews.txt_ (http://www.amsat.org/amsat/ariss/news/arissnews.txt) ) indicates whether an ARISS contact is expected to be retransmitted via Echolink, IRLP (there are 2 ways to listen if using IRLP, more down below), or any other media. This is purely at the discretion of the ham crew and the school where the contact is to take place if the contact is to be a direct one. We at ARISS encourage this to happen but we are not in control; the local hams and the school are. So when I say should be on Echolink and IRLP; it means exactly that. We have been told that the Armada contact will have audio provided to both Echolink and IRLP; but there can always be a last minute problem that will prevent that from happening. If the contact is a telebridge, then just about all of the contacts are retransmitted via Echolink and IRLP. For some schools, the use of Echolink or IRLP is a last minute thing; so sometimes we don't know until very late. When I post my announcements to the various bulletin boards, I try to indicate whether Echolink and IRLP is a possibility. Sometimes Kenneth gets later last minute news and he posts that info. Not all schools have the ability to even do one or the other. Many of the schools do not have an IRLP or Echolink repeater nearby. With Echolink you could go directly to a computer and then to the Echolink system; unfortunately, many schools have firewalls that prevent that from happening. I think for the Armada contact the audio will be going out via Skype and then our IRLP and Echolink ham interfaces will pick up the audio and retransmit it to the 2 systems. As Kenneth pointed out, you can listen to the contact via the IRLP website at the Discovery Reflector. Or if you have an IRLP repeater nearby, go to 9010 . Everyone should be aware that there is a delay between real time and when the audio comes out of IRLP. Sometimes it is about 2 minutes; it could be more or less. The best place to find information of any contact is to wait for the announcements that are sent out by Kenneth or me (usually I have the first posting). We are as close as one can get to the latest news. So once again, here is the link to latest news and instructions for all of the contacts. _http://www.amsat.org/amsat/ariss/news/arissnews.txt_ (http://www.amsat.org/amsat/ariss/news/arissnews.txt) Here is the link if you want to listen via the web to the IRLP feed (you do not have to have an IRLP license or anything, just a computer that get to the world wide web): _http://www.discoveryreflector.ca/events.htm_ (http://www.discoveryreflector.ca/events.htm) If you want to use Echolink: Please give the EchoLInk EDU_NET server your preference over the EchoLink AMSAT server for your connection. This will keep the load light on the AMSAT server, assuring us of better audio quality all around. You can connect to the AMSAT Conference Room server at node 101377. Audio is also available at times on the JK1ZRW server at node 277208. Please connect to the *JK1ZRW* server to keep the load light on the *AMSAT* server. This will ensure good audio quality for all listeners. Of course if you are in the ISS footprint, then listen directly to the downlink at 145.80 MHz. Hope this helps. By the way, hope you all made contact with Richard over the last few days. If you had a blast following him, ARISS suggests that you help out a local school, fill out the application and get on the waiting list for school contact. It is well worth the effort. 73, Charlie Sufana AJ9N One of the ARISS mentors In a message dated 10/23/2008 3:27:55 P.M. Central Daylight Time, Kenneth.G.Ransom(a)nasa.gov writes: IRLP streaming of ARISS school contacts is often available via the IRLP discovery reflector. Try this link http://www.discoveryreflector.ca/events.htm Kenneth - N5VHO -----Original Message----- From: amsat-bb-bounces(a)amsat.org [mailto:[email protected]] On Behalf Of Curt Nixon Sent: Thursday, October 23, 2008 3:18 PM To: AJ9N(a)aol.com Cc: amsat-bb(a)amsat.org Subject: [amsat-bb] Re: Web streaming ARISS School Contact? SO...based upon the info in that text doc, the contact SHOULD be on IRLP and Echolink? I can find no information in support of that...but it makes no difference..the whole question is whether it will be available via a website so civilians can get it? No access to IRLP or Echolink. It would be a shame for any of these contacts to go without some kind of open access.\ Am I missing something? Thanks Curt AJ9N(a)aol.com wrote: > Hi all, > > Every time I post the ARISS announcements, you will see a file to grab > that has the complete schedule and any instructions for Echolink and IRLP. > > Here is a part of the announcement I sent last night: > > > The complete schedule page has been updated as of 2008-10-23 04:00 > UTC. (***) > > > > Here you will find a listing of all scheduled school contacts, and > questions, other ISS related websites, IRLP and Echolink websites, and > instructions for any contact that may be streamed live. > http://www.amsat.org/amsat/ariss/news/arissnews.txt > > > > Hope this helps. > > > > 73, > > Charlie Sufana AJ9N > > One of the ARISS mentors > > > In a message dated 10/23/2008 9:43:09 A.M. Central Daylight Time, > cptcurt(a)flash.net writes: > > I had found information on listening to the ARISS School contact last > week at the Challenger Center but can not find anything referencing a > site to listen in on the Armada Michigan contact tomorrow at 17:13 > UTC. > > I have a classroom with web access but no Echolink that would like to > listen to the contact. > > Someone point me to the information?? > > Thanks, > > Curt > KU8L > _______________________________________________ > 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 > > > > > ------------------------------------------------------------------------ > Play online games for FREE at Games.com! All of your favorites, no > registration required and great graphics - check it out! > <http://pr.atwola.com/promoclk/100000075x1211202682x1200689022/aol?redir =%0Ahttp://www.games.com?ncid=emlcntusgame00000001> _______________________________________________ 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 _______________________________________________ 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 **************Play online games for FREE at Games.com! All of your favorites, no registration required and great graphics – check it out! 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QSL
by Arlon Nelson 24 Oct '08

24 Oct '08

Lucky enough to get a contact at 16:42 UTC 10/23/08. What is the QSL address for a contact with Richard Garriott (NA1SS) Thanks 73, Nels, WØTUP Minot, North Dakota anelson(a)min.midco.net - w0tup(a)arrl.net http://min.midco.net/ws Ward County - Grid Locator DN98if SKCC 31T - Flying Pigs 590 - QRPp-I #760 ARRL - FISTS #8610 - CC #1310 - FISTS WAS #143 FISTS PLATINUM #365 - FISTS SILVER #367 ARRL SSTV WAS #33 - IVCA MIXED BAND SSTV #1 40 MTR CW WAS - DXCC # 39623 RTTY WAS # 585 - A1 OPERATOR CLUB COMMERCIAL RADIO OPERATORS LICENSE *-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-* CLUB CALL - WØJER (MAGIC CITY QRP CLUB) FISTS #11975 SKCC #1000 *-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-* Two antennas met on a tower, fell in love and got married. The ceremony wasn't much, but the reception was excellent. *-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*

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Garriotts Safe Return - BBC Web News Item
by David Barber 24 Oct '08

24 Oct '08

Link to BBC Web news item on the safe return of Richard Garriott and his colleagues. http://news.bbc.co.uk/1/hi/sci/tech/7688021.stm

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