[amsat-bb] Polarity switching question
I recently obtained a pair of KLM yagi's for satellite work. They both have the KLM polarity switching box mounted and wired up. Since I havent put them up yet, and not well versed in the subject, I got out my ohm meter just to see what was what on this item. I noticed that both driven elements have continuty to the center pin of the coax at the same time. I was under the impression that the relay switched back and forth the driven elements to give either RH or LH polarity. I havent applied the 12 volts to the box yet to check that out, but was just curious. One thing I have noticed while using the downlink yagi is that I get very little fade due to polarity when I turn the antenna. I hope that is a good thing?? I havent checked the uplink yagi to see if it has the same results. I hope someone can enlighten me abit. 73 de John W6ZKH ___ Sent via amsat...@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
[amsat-bb] Re: LVB
Hi Myles > Just wondering if anyone out there using the LVB, could drop me a > line and let me know their opinions and experience with it I can only say good things about the LVB Tracker ;-) 73, Howard G6LVB ___ Sent via amsat...@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
[amsat-bb] Re: Polarity switching question
On Mon, 2009-07-13 at 14:51 +, w6...@comcast.net wrote: > I recently obtained a pair of KLM yagi's for satellite work. They both > have the KLM polarity switching box mounted and wired up. Since I > havent put them up yet, and not well versed in the subject, I got out > my ohm meter just to see what was what on this item. I noticed that > both driven elements have continuty to the center pin of the coax at > the same time. I was under the impression that the relay switched back > and forth the driven elements to give either RH or LH polarity. I > havent applied the 12 volts to the box yet to check that out, but was > just curious. One thing I have noticed while using the downlink yagi > is that I get very little fade due to polarity when I turn the > antenna. I hope that is a good thing?? I havent checked the uplink > yagi to see if it has the same results. > > I hope someone can enlighten me abit. If it's circular-polarised then both elements should be wired, with one going through a 1/4-wavelength loop of wire. That way, the 90-degree rotation of the circular polarised signal translates into a 90-degree phase shift between the horizontal and vertical elements. Imagine trying to thread a corkscrew through the elements along the length of the boom, and you'll get it. Gordon 2M0YEQ ___ Sent via amsat...@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
[amsat-bb] Re: Polarity switching question
The relay switches the coax between either end of the phasing line. w6...@comcast.net wrote: > I recently obtained a pair of KLM yagi's for satellite work. They both have > the KLM polarity switching box mounted and wired up. Since I havent put them > up yet, and not well versed in the subject, I got out my ohm meter just to > see what was what on this item. I noticed that both driven elements have > continuty to the center pin of the coax at the same time. I was under the > impression that the relay switched back and forth the driven elements to give > either RH or LH polarity. I havent applied the 12 volts to the box yet to > check that out, but was just curious. One thing I have noticed while using > the downlink yagi is that I get very little fade due to polarity when I turn > the antenna. I hope that is a good thing?? I havent checked the uplink yagi > to see if it has the same results. > > I hope someone can enlighten me abit. > ___ Sent via amsat...@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
[amsat-bb] Re: Paccomm information
Hi John > Hi I was wondering if some one has any manuals for the DFM TNC and the PSK-1 or the the PSK-1+? Sorry for the delay in replying. Many lunar cycles ago I scanned in the PSK1 manual for someone else on the reflector. It's not the best quality, but hopefully it will be of some use. http://www.g6lvb.com/images/psk1.pdf 73, Howard G6LVB ___ Sent via amsat...@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
[amsat-bb] Delaware Operation FM29ft
Our mini WAS-pedition to Wilmington Delaware FM29 ended with the 7/12/2009 1305-1316z AO51 pass which was only 11 degrees in Delaware. In just two days approximately 85 different callsigns were logged (including 4 with KD4ZGW who operated from his 18 wheeler in DN90, EM38, EM29 and EM65). If you were thinking that there are only a few regulars operating the FM birds, this should make you rethink that notion. For those that are chasing grids, there are plenty of new people showing up in grids that have not been very active. Many of the "regulars" were not on during this period, but if they were the total could have easily gone over 100 different callsigns worked. My operation took place from the Days Inn tree lawn on Concord Pike just south of Naamans Rd for western passes and the Concord Mall parking lot, about 1000' south for eastern passes. I was able to make qso's to the west down to about 5 degrees or less. The AO27 pass on 7/11 at 2041-2051z was only 7 degrees but it did net 4 stations. The QRM was heavy and my signal was not strong enough to get through the many stations that were operating. KI6YAA was heard but could not be worked. But on Sunday morning, Larry was up at 6am for the AO51 pass (11 degrees for me) and a qso was easily completed. The early bird still does get the worm. Several stations including K7WIN and VE6AB mentioned that Delaware was the last state they needed. It was great to be able to give them Delaware. Between Jim's (ND9M) operation and this one, Delaware should be very low on the most wanted State list. There will be a special QSL card for this operation. Cards will be sent to every station that was worked. There is no need to send a card or an SASE to me although you can if you want to. I'll put an announcement on the BB and my QRZ.com page when the cards are mailed. If you don't get one and think you worked me, please email me. All passes have been recorded and can be checked. Thanks to everyone who worked me. If you want to have some fun on the birds, try operating from a grid away from home. And thanks to all of you who do activate these grids and help us with our VUCC! 73, John K8YSE ___ Sent via amsat...@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
[amsat-bb] Pass predictions and differences in software
Good afternoon I am running gpredict on an ubuntu linux box - I am looking at the SO50 satellite - It is currently 1412 (1812utc) - I advanced the clock of the software forward by about 3 hrs (1712 local) and see what looks like a great pass on screen I went to verify using the webbased prediction on the amsat website, and. Don't see anything in the list of passes even close to what gpredict says will happen in the future I updated the keps thinking maybe they were out day, and got the same results I then fired up my winXP machine and SatPC32 - and got results that are closer to what the amsat site says. When looking at real time, all three show the SO50 in just about the same spot I think I believe the amsat site and satPC32 software. Not sure of the question to this post - wondering more or less what factors effect how the pass predictions work. When they (or at least the two I have control over) have updated keps shouldn't they give the same information or realitivly close - as I look at the two programs running side by side I do see slight differences in where SO50 is located on the map currently. But it is only slight and may have more to do with the scale of the display maps and not the software. If I advance the time thou I don't get the same results. And this confuses me Thanks, LeRoy, KD8BXP http://www.HamOhio.com Sent on the Now Network� from my Sprint® BlackBerry ___ Sent via amsat...@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
[amsat-bb] G5500 Rotor Drift Issue
There have been a couple of recent posts about a G5500 voltage drift issue and some solutions. I'd like to thank those gentlemen for the posts and the solutions. I am in a unique position to be able to work with nine G5500 rotors side-by-side in preparation for the Teachers Institute II that I will hold at the end of the week. I noticed the same warm-up/calibration issue mentioned in the posts. I discovered that it took on average 10 minutes of warm up time for the voltage to stabilize, and this voltage is the reference on which the antenna position indications are based. The difference between the cold start and warm up position was around 10 degrees for AZ and 4 degrees for EL. Minor but irritating. I thought I'd try the easiest solution suggested first (changing the output cap on the regulator to .1uF) before I tried the more dramatic solution of changing out the voltage regulator. I simply tack soldered the .1uF cap on the exposed leads of the existing .01uF cap, and it worked like a charm. All nine rotor controllers fire up at 6.12 volts and hold that voltage throughout the operation of the rotor. This sure will make instruction of rotor setup and calibration a heck of a lot easier. Thanks for the suggests. Mark Spencer, WA8SME ARRL-The national association for Amateur Radio Education and Technology Program Coordinator mspen...@arrl.org http://www.arrl.org/FandES/tbp/ 530-495-9150 ___ Sent via amsat...@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
[amsat-bb] Amsat-UK Oscar News
My copy of O.N. 186 arrived today, Thanks to Dave Johnson G4DPZ, Graham Shirville G3VZV and all contributors for a much improved ON. I well remember how Ron Broadbent used to hustle everyone for contribution articles, on the basis that as the editor he couldn't produce a good magazine with out material to work with. Lets see what we can do to support Dave and Graham in keeping O.N full and interesting 73 John G7HIA ___ Sent via amsat...@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
[amsat-bb] Re: Pass predictions and differences in software
Hi LeRoy, Which version of gpredict are you using? The one that is included with Ubuntu? That version is very much out of date and did have several bugs that could affect pass predictions. In particular the "time controller" function was very immature back then. Did you try the predict pass functions instead of advancing the clock (i.e. right click on a satellite)? 73 Alex OZ9AEC On Mon, 13 Jul 2009 18:27:42 + kd8...@aol.com wrote: > Good afternoon > > I am running gpredict on an ubuntu linux box - I am looking at the > SO50 satellite - > > It is currently 1412 (1812utc) - I advanced the clock of the software > forward by about 3 hrs (1712 local) and see what looks like a great > pass on screen > > I went to verify using the webbased prediction on the amsat website, > and. Don't see anything in the list of passes even close to what > gpredict says will happen in the future > > I updated the keps thinking maybe they were out day, and got the same > results > > I then fired up my winXP machine and SatPC32 - and got results that > are closer to what the amsat site says. > > When looking at real time, all three show the SO50 in just about the > same spot > > I think I believe the amsat site and satPC32 software. > > Not sure of the question to this post - wondering more or less what > factors effect how the pass predictions work. When they (or at least > the two I have control over) have updated keps shouldn't they give > the same information or realitivly close - as I look at the two > programs running side by side I do see slight differences in where > SO50 is located on the map currently. But it is only slight and may > have more to do with the scale of the display maps and not the > software. > > If I advance the time thou I don't get the same results. And this > confuses me > > Thanks, > LeRoy, KD8BXP > http://www.HamOhio.com > Sent on the Now Network from my Sprint® BlackBerry > ___ Sent via amsat...@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
[amsat-bb] Oscar 5 in SatMagazine
The Oscar 5 satellite built by Australian Radio Amateurs at the end of the 60's is mentioned in the latest issue of SatMagazine The July/August issue of SatMagazine covers the Australian space program and mentions the work of Australian Radio Amateurs who built Oscar 5. The article on page 59 includes a picture of Oscar 5 which carried transmitters on 29.450 MHz and 144.050 MHz and was launched on January 23, 1970, into an orbit of 1435 x 1481 km with an inclination of 102.0 degrees. Ther July/Aug 2009 issue of SatMagazine is at http://www.satmagazine.com/2009/SatMag_JulAug09.pdf SatMagazine http://www.satmagazine.com/ 73 Trevor M5AKA RSS Daily Radio News: http://www.southgatearc.org/ Daily News via Email: http://www.feedburner.com/fb/a/emailverifySubmit?feedId=2783644&loc=en_US Submit your news: http://www.southgatearc.org/news/your_news_1.htm or email editor at southgatearc.org ___ Sent via amsat...@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
[amsat-bb] Re: G5500 Rotor Drift Issue
Hi Mark, WA8SME Sometime the voltage regulators tends to self-oscillate in a very low but very wide frequency band. In this condition the regulated voltage is unstable not clean and dirty as can be seen using an oscilloscope. This problem is well know by the microwave people when they try to get a local oscillator clean and stable. To eliminate the self-oscillation an effective cure is to put a ceramic capacitor of 0.1 uF in parallel to an electrolitic capacitor ranging from 1 to 10 uF both at the input and the output of the regulator and check again with the oscilloscope any trace of oscillations at the regulator output. 73" de i8CVS Domenico - Original Message - From: "Mark Spencer" To: Sent: Monday, July 13, 2009 8:42 PM Subject: [amsat-bb] G5500 Rotor Drift Issue > There have been a couple of recent posts about a G5500 voltage drift issue > and some solutions. I'd like to thank those gentlemen for the posts and the > solutions. I am in a unique position to be able to work with nine G5500 > rotors side-by-side in preparation for the Teachers Institute II that I will > hold at the end of the week. I noticed the same warm-up/calibration issue > mentioned in the posts. I discovered that it took on average 10 minutes of > warm up time for the voltage to stabilize, and this voltage is the reference > on which the antenna position indications are based. The difference between > the cold start and warm up position was around 10 degrees for AZ and 4 > degrees for EL. Minor but irritating. I thought I'd try the easiest > solution suggested first (changing the output cap on the regulator to .1uF) > before I tried the more dramatic solution of changing out the voltage > regulator. I simply tack soldered the .1uF cap on the exposed leads of the > existing .01uF cap, and it worked like a charm. All nine rotor controllers > fire up at 6.12 volts and hold that voltage throughout the operation of the > rotor. This sure will make instruction of rotor setup and calibration a > heck of a lot easier. Thanks for the suggests. > > > > Mark Spencer, WA8SME > > ARRL-The national association for Amateur Radio > > Education and Technology Program Coordinator > > mspen...@arrl.org > > http://www.arrl.org/FandES/tbp/ > > 530-495-9150 > > > > ___ > Sent via amsat...@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...@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
[amsat-bb] Re: Polarity switching question
Hi John, W6ZKH The 2 meters KLM antenna uses two crossed folded dipoles wich are spaced 1/4 wavelength in air over the boom so that to get circular polarization no coax delay lines are necessary. Each folded dipole has a wounded coax balun with ratio 4/1 wich is made with 1/2 electrical wavelength of 50 ohm coax cable RG 303 to transform the balanced impedance of 200 ohm of the folded dipole into a 50 ohm unbalanced impedance at the output of balun. The phasing harness coming out from the plastic barrel is made with two maching lines of 75 ohm coax cable type RG 302 and they are both 1/4 electrical wavelenght long. Each maching line of 75 ohm transforms the 50 ohm impedance of the dipole to about 100 ohm into the barrel but two 100 ohm in parallel becomes 50 ohm as seen from the coax line connected to the barrel PL connector and going down to the shack. The 75 ohm line connected to the polarization switching relay is also 1/4 electrical wavelenght long but including the electrical lenght of the relay itself. To switch polarization from RHCP to LHCP the relay only switches the inner conductor of it's 75 ohm coax cable from one to the other stud i.e. from one to the other screw of the same folded dipole. The 70 cm KLM antenna uses the same basic criteria but to switch polarization from RHCP to LHCP the relay add to one folded dipole a 1/2 wavelenght delay line wich is included into the aluminum box and is made with a 50 ohm strip line over a fiberglass printed circuit. I hope this helps. 73" de i8CVS Domenico - Original Message - From: To: "amsat-bb" Sent: Monday, July 13, 2009 4:51 PM Subject: [amsat-bb] Polarity switching question > I recently obtained a pair of KLM yagi's for satellite work. They both have the KLM polarity switching box mounted and wired up. Since I havent put them up yet, and not well versed in the subject, I got out my ohm meter just to see what was what on this item. I noticed that both driven elements have continuty to the center pin of the coax at the same time. I was under the impression that the relay switched back and forth the driven elements to give either RH or LH polarity. I havent applied the 12 volts to the box yet to check that out, but was just curious. One thing I have noticed while using the downlink yagi is that I get very little fade due to polarity when I turn the antenna. I hope that is a good thing?? I havent checked the uplink yagi to see if it has the same results. > > I hope someone can enlighten me abit. > > 73 de John W6ZKH > > > ___ > Sent via amsat...@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...@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
[amsat-bb] Re: Polarity switching question
Hello to all You might want to check out this site for the info you may need http://sv1bsx.50webs.com/antenna-pol/polarization.html some good info there thanks all Howard VE4ISP - Original Message - From: "i8cvs" To: ; "amsat-bb" Sent: Monday, July 13, 2009 8:23 PM Subject: [amsat-bb] Re: Polarity switching question > Hi John, W6ZKH > > The 2 meters KLM antenna uses two crossed folded dipoles wich are spaced > 1/4 > wavelength in air over the boom so that to get circular polarization no > coax > delay lines are necessary. > Each folded dipole has a wounded coax balun with ratio 4/1 wich is made > with > 1/2 electrical wavelength of 50 ohm coax cable RG 303 to transform the > balanced impedance of 200 ohm of the folded dipole into a 50 ohm > unbalanced > impedance at the output of balun. > The phasing harness coming out from the plastic barrel is made with two > maching lines of 75 ohm coax cable type RG 302 and they are both 1/4 > electrical wavelenght long. > Each maching line of 75 ohm transforms the 50 ohm impedance of the dipole > to > about 100 ohm into the barrel but two 100 ohm in parallel becomes 50 ohm > as > seen from the coax line connected to the barrel PL connector and going > down > to the shack. > The 75 ohm line connected to the polarization switching relay is also 1/4 > electrical wavelenght long but including the electrical lenght of the > relay > itself. > To switch polarization from RHCP to LHCP the relay only switches the inner > conductor of it's 75 ohm coax cable from one to the other stud i.e. from > one to the other screw of the same folded dipole. > > The 70 cm KLM antenna uses the same basic criteria but to switch > polarization from RHCP to LHCP the relay add to one folded dipole a 1/2 > wavelenght delay line wich is included into the aluminum box and is made > with a 50 ohm strip line over a fiberglass printed circuit. > > I hope this helps. > > 73" de > > i8CVS Domenico > > - Original Message - > From: > To: "amsat-bb" > Sent: Monday, July 13, 2009 4:51 PM > Subject: [amsat-bb] Polarity switching question > > >> I recently obtained a pair of KLM yagi's for satellite work. They both > have the KLM polarity switching box mounted and wired up. Since I havent > put > them up yet, and not well versed in the subject, I got out my ohm meter > just > to see what was what on this item. I noticed that both driven elements > have > continuty to the center pin of the coax at the same time. I was under the > impression that the relay switched back and forth the driven elements to > give either RH or LH polarity. I havent applied the 12 volts to the box > yet > to check that out, but was just curious. One thing I have noticed while > using the downlink yagi is that I get very little fade due to polarity > when > I turn the antenna. I hope that is a good thing?? I havent checked the > uplink yagi to see if it has the same results. >> >> I hope someone can enlighten me abit. >> >> 73 de John W6ZKH >> >> >> ___ >> Sent via amsat...@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...@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...@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
