October 2006 - AMSAT-BB - mailman.amsat.org

Melbourne Hamfest demos
by Andrew Glasbrenner 14 Oct '06

14 Oct '06

Just a quick note to keep an ear out for KO4MA and KI4HXT on Saturday and Sundays AO-51 and VO-52 passes. For AO-51 we plan to be on the 1343Z and 1523Z passes on Saturday, and the 1443Z pass on Sunday. VO-52 demos will be at 1539Z Saturday and 1558Z Sunday. We'll be portable at the Melbourne Hamfest and would appreciate a contact or two. 73, Drew KO4MA AMSAT LM 2332

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SO-50 under-utilized again
by John Mock KD6PAG 14 Oct '06

14 Oct '06

I've only heard one station in two of the past three SO-50 passes i've worked and most of them covered the East Coast. The last pass had no one else on at all and was 15 degrees elevation in New York City (8 degrees in California). I sent out a dozen QSL cards from my trip to CM99, and the majority were on SO-50, so there are usually people there to work (just not much in the past two days). On the other hand, AO-51 has been quite busy on the transcontinental passes and has been hard to get into. SO-50 isn't hard to work if you have an AZ- EL mount and works well hand-held with an Arrow (or equivalent), albeit a bit hard to find when it's so quiet. Both use a 67 Hz PL and there's often someone to turn it on if you don't know how (and it's not hard). 73's and catch you on the birds. -- KD6PAG (Networking Old-Timer, Satellite QRPer) [Note: I never send unsolicited binary attachments and if you receive anything purportedly from <kd6pag(a)qsl.net> or <kd6pag(a)amsat.org> that isn't signed with my callsign, then it probably isn't from me. There seems to be a new virus or worm around, so beware.]

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Re: 10' Dish available
by Steve kb9ups 13 Oct '06

13 Oct '06

Hello All, I also have "several" 8 and 10 foot dishes that anyone can "have"..All wire type and most in great condition. I have been collecting them as they are getting harder to find. Robert/w0lmd has many types of drive systems shown on his web pages and they helped me put my 12' dish up and it works great..Anyone wanting a 10' dish can contact me as well..I'm in the Toledo, OH. area just off the turnpike. Steve/kb9ups AMSAT area coordinator, Toledo, OH. AMSAT area coordinator, Streator, IL. www.qsl.net/kb9ups --- On Fri 10/13, Gunther Meisse < gogm(a)wmfd.com > wrote: From: Gunther Meisse [mailto: gogm(a)wmfd.com] To: amsat-bb(a)amsat.org Date: Fri, 13 Oct 2006 11:02:24 -0400 Subject: [amsat-bb] 10' Dish available With the coming of the next group of HEO satellites I am checking if thereis any interest in a 10' Weingard mesh dish. It has been taken out ofservice by a local manufacturing company here in central Ohio and has beentaken apart and will be created, ready to be shipped. If you have aninterest, please contact me at gmouse(a)neo.rr.comRegards,Gunther MeisseW8GSM Gunther (Gog) MeisseWVNO / WRGM / WMFD2900 Park Avenue WestMansfield, OH 44906Ph: 419-529-5900Cell: 419-544-8622Fax: 419-529-2319www.NorthcentralOhio.com _______________________________________________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 _______________________________________________ Join Excite! - http://www.excite.com The most personalized portal on the Web!

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FW: AO-51
by willmarbrowns＠peoplepc.com 13 Oct '06

13 Oct '06

_____ From: Thomas Lubbers [mailto:k8tl@earthlink.net] Sent: Friday, October 13, 2006 9:18 AM To: willmarbrowns(a)peoplepc.com Subject: AO-51 OM I have been trying to use the data mode on AO-51. I am using WISP3212 IC 910 Kantronics 9612+. The down link works fine. When it should be transmitting for a fill I see the STA light flicker but no PTT! The TNC will talk to another TNC at 9600 using HyperTerminal. I assume there is one more parameter that needs to be changed but I sure don't know what it is any hints? Is there something newer than WISP3212 out? Is there anything that will work with sound card packet? Know of any one who is using the 9612+ sucessfully? Saw Your call in the cue last night. 73 Tom K8TL Thomas Lubbers k8tl(a)earthlink.net EarthLink Revolves Around You.

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Re: 10' Dish available
by Jason White 13 Oct '06

13 Oct '06

My first AO-40 downlink antenna (or attempt at one) was a 16' foot TVRO dish I found on the side of the road in rural FL (couldn't beat the price, they were happy to see it go). Making a mount for it was no small accomplishment.With a small helix feed, an AIDC downconverter, and my TS-700A, I could hear the images from the IF in the sat! Well, for about 10 seconds, then I had to repoint the dish.. I had intended to mount the down converter at the feed point but it eventually occured to me that I had enough gain that my converter's LO might make a great transmitter, so fortunately I avoided that problem ahead of time. I eventually concluded the dish was much better for watching C-Band satellite TV and used a 90cm Primestar dish for AO-40 after that :) I used to have a picture of myself napping in the dish like it was a hammock on qrz.com.. It did lend a sort of "Green Bank" atmosphere to my yard as well. 73, Jason N1XBP P.S. - Gunther, you might consider that you've got 4 antenna's available as Bob suggested in an earlier post.. smaller, lighter, and easier to ship. John Champa wrote: > Wow, Gunther! That is a lot of antenna. How are you going point that > monster? Auto-tracking will be required, and when you do that, it had > better be right on the money, and update about every minute or so. > Well, whatever floats your boat. Enjoy! > > Remember, once you can hear the noise floor of the transponder, then > additional gain is, well, not needed very much, let's say (HI). > > I, on the other hand, plan to use the smallest antenna pair I can get > away with. I thought that was the advantage of satellite operating: > 140 foot towers with a stack of monobanders not needed? (HI). > > 73, > John - K8OCL > > > >> From: "Gunther Meisse" <gogm(a)wmfd.com> >> To: <amsat-bb(a)amsat.org> >> Subject: [amsat-bb] 10' Dish available >> Date: Fri, 13 Oct 2006 11:02:24 -0400 >> >> With the coming of the next group of HEO satellites I am checking if >> there >> is any interest in a 10' Weingard mesh dish. It has been taken out of >> service by a local manufacturing company here in central Ohio and has >> been >> taken apart and will be created, ready to be shipped. If you have an >> interest, please contact me at gmouse(a)neo.rr.com >> >> Regards, >> >> Gunther Meisse >> >> W8GSM >> >> >> >> >> >> Gunther (Gog) Meisse >> >> WVNO / WRGM / WMFD >> >> 2900 Park Avenue West >> >> Mansfield, OH 44906 >> >> Ph: 419-529-5900 >> >> Cell: 419-544-8622 >> >> Fax: 419-529-2319 >> >> www.NorthcentralOhio.com >> >> >> >> _______________________________________________ >> 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 > > > >

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test,
by Mr Jeffrey L.Ross 13 Oct '06

13 Oct '06

test

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Matt Ettus
by Robert McGwier 13 Oct '06

13 Oct '06

http://www.spectrum.ieee.org/oct06/4654 -- AMSAT Director and VP Engineering. Member: ARRL, AMSAT-DL, TAPR, Packrats, NJQRP, QRP ARCI, QCWA, FRC. ARRL SDR WG Chair "You see, wire telegraph is a kind of a very, very long cat. You pull his tail in New York and his head is meowing in Los Angeles. Do you understand this? And radio operates exactly the same way: you send signals here, they receive them there. The only difference is that there is no cat." - Einstein

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Matt Ettus N2MJI, IEEE Spectrum
by Robert McGwier 13 Oct '06

13 Oct '06

In the October issue of the IEEE Spectrum is a review of GnuRadio and the USRP and in the contents is a picture of Matt with his USRP and some attachments. The article by Stephen Cass is in the "Tools and Toys" section. It is quite favorable and points out what we all know. The software needs to be easier to install and maintain and as always, there needs to be better documentation. The one software module they mention as working is the FM Stereo demodulator I wrote so I am awfully glad we did it. He mentions that he got the TV demodulator going but that its rasterization was as yet, incomplete. We in the process of getting the digital subcarrier demodulated and decoded (RDS) at this moment. This is being done by someone else. This was a thoroughly written, and very positive review for Matt and GnuRadio, both important contributors to Eagle. Matt is the designer of the Advanced Communications Package and, with me, the co-proposer of the current Eagle mechanical concept. Congratulations to Matt of USRP and Eric Blossom of GnuRadio and part of the growing cadre of truly exceptional people working on our spacecraft. Bob N4HY -- AMSAT Director and VP Engineering. Member: ARRL, AMSAT-DL, TAPR, Packrats, NJQRP, QRP ARCI, QCWA, FRC. ARRL SDR WG Chair "You see, wire telegraph is a kind of a very, very long cat. You pull his tail in New York and his head is meowing in Los Angeles. Do you understand this? And radio operates exactly the same way: you send signals here, they receive them there. The only difference is that there is no cat." - Einstein

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2MCP22
by Steve kb9ups 13 Oct '06

13 Oct '06

Hello All, I have two used 2MCP22 beams and have found that the element lenghts on one are 1" shorter than on the other..Does anyone know if this is a problem or not? Some difference in boom but the same length over all. The elements do not look like they have been cut off..anyone have any clues to the difference? Steve/kb9ups AMSAT area coordinator, Toledo, OH. AMSAT area coordinator, Streator, IL. www.qsl.net/kb9ups _______________________________________________ Join Excite! - http://www.excite.com The most personalized portal on the Web!

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Retuning surplus 400 MHz Tubular Bandpass Filters in to 435 MHz
by i8cvs 13 Oct '06

13 Oct '06

Hi, All I got a surplus K&L MICROWAVE ,INC Tubular Bandpass Filters model 3B340-400/16-N75-SMA50 D.C.-8040 of the type described in the following URL http://www.klmicrowave.com/ecommerce/files/Tubular%20Bandpass.pdf The above filter was originally integrated in to a vertical dipole with a low noise preamplifier at 400 MHz and used for the Maritime Satellite MARISAT system between shore and shipboard terminals and the satellite. Many of this filters are still available in the surplus market Code Description 3 numbar of sections B bandpass filter 340 outside diameter 0.75" - 19.05 mm 400 center frequency (MHz) 16 3 dB bandwidth (16 MHz) N75 input connector (see note) SMA50 output connector D.C.8117 D.C. block Note:The input of the filter is fitted with a 75 ohm N female connector to be screwed directly at the dipole ( 75 ohm impedance) Just for curiosity I decided to unscrew both caps with connectors and pull off the filter from the tube in the hope to understand how a Tubular Filter works and I realized that this 3 sections Chebychev response filter is made by a teflon flexible rod in wich are slipped on in sequence coil-capacitor-coil-capacitor-coil The end coils are 2 turns of enameled nr 18 copper wire while the center coil is 3 turns Each concentric capacitor between coils is made with two brass disc as amature with inside a numbar of disc of low loss teflon foils for dielectric. The above filter is wrapped in to a single layer of low loss teflon foil and than it is pushed inside the aluminum pipe. The function of the teflon foil is not trivial because it represent the dielectric to form many small capacitors between each coil and each series capacitor with respect to ground as required by a bandpass Chebychev filter. The aluminum pipe has 3 longitudinal holes each 5.5 mm in diameter and the holes are drilled just in correspondence to the middle of each coil so that the turns are visible from the outside allowing the spacing adjustement possible during tuning at the factory. Since the difference between the original 400 MHz center frequency and our 435 MHz frequency band is very small i.e. between 1/12 and 2/12 of an octave higher i decided to see if spacing the turns a little bit it would be possible to shift the center frequency 35 MHz higher in frequency keeping as well the flatness of the bandpass as in the original filter. The N75 female connector was then removed and replaced with an SMA female connector and the filter was connected via 6 dB 50 ohm attenuators between a HP8444A Tracking Generator and a HP8555A Spectrum Analyzer A small tool made of insulating epoxy G10 for PCBs was shaped in the form and size of a hard and sharp-pointed toothpick with the copper removed from it and it was found to be OK to fine adjust the spacing of the coils. During retuning step by step it was observed that changing the spacing of the central coil it mainly shift up and down the whole band while adjusting the end coils mainly changes the flatness and the shape of the bandpass. In addition it was observed that introducing or removing the insulated tool in to the holes of the filter while spacing the coils it do not change at all the previously made adjustement. If the adjustement of the spacing in the coils is carefully made it will converge with easy to translate the original 400 MHz bandpass center in to the new 435 MHz center frequency with the same flatness in to the same 16 MHz bandwidth as in the original filter. Here are the results after retuning. Center frequency 435 MHz 3 dB bandwidth 16 MHz from 427 to 443 MHz Response 0.05 dB flat from 430 to 441 MHz Insertion loss center frequency 1.5 dB VSWR center frequency 1.5:1 Measured attenuations: MHz dB 270 -60 340 -50 380 -40 400 -30 415 -20 420 -10 427 -3 435 -1.5 (0.05 dB flat from 427 to 443 MHz) 443 -3 450 -10 460 -25 470 -30 480 -40 500 -50 535 -60 560 -70 580 -75 This low loss bandpass filter is very small can handle 40 watt CW continuously and can find many applications where low loss at 435 MHz and high rejection outside the 70 cm band is required. If you find one of this filter in your junk box do not throw this piece of cake out of the window. 73" de i8CVS Domenico

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