AMSAT-BB January 2019

158 participants
170 discussions

... Will Launch 20,000 Satellites!!! [read SEVENEVES]
by Robert Bruninga 09 Jan '19

09 Jan '19

SEVENEVES: A fantastic book. Bill Gates' favorite SciFi because it is all grounded in true engineering more or less. All based on expanding the space station to thousands of inhabitants to escape the natural calamity on Earth. -----Original Message----- From: AMSAT On Behalf Of Don KB2YSI > Read some fiction: Neal Stephenson "Seveneves", > https://www.goodreads.com/book/show/22816087-seveneves On Tue, Jan 8, 2019, 18:12 Zach Metzinger <zmetzing(a)pobox.com wrote: > >> Has anyone written a science fiction story about a planet so > >> surrounded by satellites and other orbital trash > >> that it could not be reached from outer space? > >> K5HV

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Cellular 5G Will Launch 20,000 Satellites!!!
by R.T.Liddy 08 Jan '19

08 Jan '19

Imagine 20,000 MORE satellites! Cellular 5G will make use of them in the coming years!! http://healthimpactnews.com/2019/20000-satellites-for-5g-to-be-launched-sen…

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Re: [amsat-bb] CAT Cable and Rotor Controller for FT-736R
by ok2gz 08 Jan '19

08 Jan '19

Hi Laird Taylor N7RSR, with FT736R there is one more problem, not just how to gain suitable cable. CAT system in FT736R allows us to set Freq for RX and TX only. But no possibility how to read RX freq! And this causes us difficulty. Frequency setting algorithm works with feedback. First set the frequency and then read it back. Verify that both frequencies are the same.If the verification fails, the control loop will stop working. There exists some solutions to this problem. For example, insert a small 8bit microcontroller between the PC and the TRX. Microcontrollerdecodes the command to set the RX frequency and remembers it.The read command returns the stored frequency from memory without reading it in the RX. When working through satellites, it is necessary to tune the RX using the mouse wheel. I do not know if the MacBook works as I have described. But GPredict sat software works as described and stops the control loop after 5 errors in the read command. Mr. Google help us to find concrete solution. 73 jarda ok2gz //================================= I have an FT-736R and have just purchased MacDoppler from AMSAT. It will be installed in a MacBook running OS 10.13.6. I’m shopping for a CAT cable to go between the two units. The guy at HRO said the original Yaesu cable to go with Macs has part# FIF-65A but I don’t see anything yet on Google by that moniker. He also said the Yaesu CAT cable for PCs is FIF-232C - which I DO see around. Then I see a caution that there are lots of cheap cables around that use terrible chips that are a nightmare to keep running. The only cable I’ve found so far (on eBay) is $35 and the vendor doesn’t seem to admit which chip set is used. Amazon in the UK has a cable for sale for 16 GBP, which could be one of the cheaper ones. Immediate questions: 1. What subset of the alleged plethora of available cables is MacDoppler compatible with CAT on the FT-736R? 2. Who sells such cables nowadays? So far I’ve found only eBay and Amazon; it’s not even clear they’re selling the same cable - never mind the one I must use... 73 Laird Taylor N7RSR --- This email has been checked for viruses by AVG. https://www.avg.com

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HS_Soundmodem & MinXSS 2
by Gustavo Carpignano 07 Jan '19

07 Jan '19

I'm using the HS_soundmodem from UZ7HO, to receive at 9600 baud theMinXSS 2 packets. I also use the frame decoder of the MinXSS provided bythe satellite's team. For that I use the AGW port 8000 and the host local address 127.0.0.1 For some reason the packets do not arrive from the HS_modem to the decoder. Any help is welcome. 73 Gustavo, LW2DTZ

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UPDATE
by James McIrvin 07 Jan '19

07 Jan '19

Good evening all. I would like to thank all of those that have helped with information that they have sent to me and also Erich Eichmann for him pointing me in the right direction to finding my error in trying to get the software working with the radio. He forced me to look at things deeper than I had and once I did what he said things came together nicely. Now that I have been able to make a small handful of contacts on the XW-2 sats, I can start to work on some of the other things to make it much more enjoyable and be able to see about doing a couple other sats where there is digital stuff going on. Have to take some of this in small steps to get it working and that is what is going on. I also have to figure out the settings to tweak the doppler file for the radio so that I may not have to fiddle with too many adjustments. I know that there will be some, but that is the way things work. I also have to work on making up some cheat sheets for myself, now that I am able to get on some I look forward in working some of you folks when the sats permit me to have those qso's. However, the next venture I need to deal with here is getting mast mounted preamps setup so that I will have a better chance of hearing things and working more stuff when it is there. The ones that I have made have been with just the eggbeater antenna's that I have set up on a temp tripod and the radio preamp. I know once I get it out at the base of the antenna it will enhance things due to feedline loss that I have now. Once I figure out what I want to do with some of this stuff as to placement of the antennas to a more permanent location in the yard I can tweak feedline and alike. However, here in the northeast with the ice and snow at this time can't do much in trying to dig up the ground and lay a conduit to the site for working with this stuff. It all comes in time. THANK YOU AGAIN TO ALL THOSE THAT HAVE HELPED ME. Have a great evening. 73 de Jim N1IPA <http://www.avg.com/email-signature?utm_medium=email&utm_source=link&utm_cam…> Virus-free. www.avg.com <http://www.avg.com/email-signature?utm_medium=email&utm_source=link&utm_cam…> <#DAB4FAD8-2DD7-40BB-A1B8-4E2AA1F9FDF2>

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Experiences on Yaesu FT-712 for 70cm & Satellite?
by Pavel Milanes Costa 07 Jan '19

07 Jan '19

I know, this is a pretty old rig. But in Cuba we can't just buy a radio from a shelf, and one of these (FT-712L) appeared on the local swap market, having problems with my Baofengs for Satellite I was wondering if any of you have some experience with one of this units? Pros, cons? 73 Pavel CO7WT.

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FT-837 port config question
by Mark Coulthurst 07 Jan '19

07 Jan '19

Hi Im new to the BB list so i hope this has been done correctly.... I have a Yaesu FT847. I have satpc32 that will connect happily to the radio and control everything as required but this only works if i set the radio CAT menu to 9600. Everything esle i run works at the 57600 CAT Rate and i have to change the radio every time to 9600 CAT rate to use satpc32. My question is this: i presume there is a file that has the radio CAT configurations within the sodtware. I would like to know if this is accessable and if i can overide the 9600 current setting within satpc32 to change it to 57600? Thanks in advance M1AEC

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Re: [amsat-bb] Antenna and Doppler Question
by jim＠k6ccc.org 07 Jan '19

07 Jan '19

For your first part, if they are fixed polarity, I would recommend crossed polarization as it helps prevent killing your downlink with your own uplink. This is particularly true for Mode V/U operation where that third harmonic can be particularly troublesome. For your second question, that one can be debated forever. The official "One True Rule" is to adjust both uplink and downlink to maintain the same frequency at the satellite. That is fine IF everyone in the conversation is using computer frequency control. If you are manually correcting for doppler, it's almost impossible. Therefore, the alternative rule is to tune the higher frequency. In reality, it will somewhat depend on what the other person is doling or is capable of. Personally I never used computerized frequency control - mainly as a limitation of my Yaesu FT-736 which only has one way CAT control. I found it to be an absolute pain in the backsides to attempt to dial around looking for conversations from the computer Jim Walls K6CCC -----Original Message----- From: "NA1SA Loon" <na1saloon(a)outlook.com> Sent: Monday, January 7, 2019 06:34 To: "AMSAT-BB" <amsat-bb(a)amsat.org> Subject: [amsat-bb] Antenna and Doppler Question Greetings, I recently purchased an FT-857D with hopes of working some linear birds. I know it's not the prime radio for the task, but I'm on a budget and would like to remain happily married, although she understands and supports my love for this hobby. The antennas are a rotatable array, each fixed 20 degree elevation, consisting of a Diamond A144S5 for 145mhz and a Diamond A144S10 for 435mhz. The antennas are currently mounted 2 meter horizontal, 70cm vertical. I have had success using this configuration, knowing full well I will not have the coverage I would as if I had circularly polarized antennas for each band (again, budget and marital status come to mind). My thought behind this was if I'm using my Arrow, the 2 meter and 70cm elements are 90 deg to each other and it works, for both FM and SSB birds (seen it on YouTube). Question is, would it be beneficial to put them (a) both horizontal, (b) both vertical, or leave it like I currently have them? Again, I know there is no correct answer due to a tumbling satellite and changing polarity, I just haven't had time to experiment with different configurations, and thought maybe someone has and found that one configuration may have been more consistent than the other. Now for the linear bird question... I have an Icom IC-746PRO that I use to listen to, or for, the downlink frequency. I was told to set the uplink frequency and DO NOT touch it, just tune the downlink frequency. Running CAT control (OmniRig with PstRotator), it is constantly updating both uplink and downlink frequencies for doppler. I thought that was the whole purpose of running CAT control with a doppler updating program, to keep you on frequency, or close anyways. This area of the satellite world is all new to me. I never had the chance to observe some work a linear bird to get an idea on how to do it properly. I certainly do not expect to carry a QSO throughout pass, I'm just seeking to explore another avenue of this hobby and to have fun making a contact or two on a good pass. Like I said this all new to me and I'm just seeking good advice and some positive guidance to be successful. Thanks, NA1SA _______________________________________________ Sent via AMSAT-BB(a)amsat.org. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed are solely those of the author, and do not reflect the official views of AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb

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Trade, Elecraft K2 for TH-D72A
by Doug Faunt N6TQS +1-510-717-1197 07 Jan '19

07 Jan '19

I have a K2-100, last used for the T33C DXpedition IIRC. It's got a couple of mods for audio out on the mic connector and an IF output for a band display. I'd like to get a D72 for portable sat work. 73, Doug

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Re: [amsat-bb] KR400 controller question
by Paul 07 Jan '19

07 Jan '19

Thanks George, I tried it with and without the resistor and couldn't see any difference with the LEDs so wondered if it was just put in to increase the life of the bulb. I'll leave them in and see how we go. The controllers now look like this adding a splash of colour to the shack. http://www.ukdx.org.uk/tv/rotator/400s.jpg Paul Sussex Coast. JO00 On 06/01/2019 22:33, W3AB/GEO wrote: > Paul, > > It appears that one unit uses 28V to light the bulb & the other uses > 14V. If the mod is for the unit that is 14V, leave the resistor in the > circuit. > > ___ > Sent from my two way wrist watch > 73 de W3AB/GEO > On Jan 6, 2019, at 03:26, Paul <paul(a)ukdx.org.uk > <mailto:[email protected]>> wrote: > > As both my KR400 controllers have blown bulbs I've modified them to use > LEDs as per https://bit.ly/2TzeHud There is however a small difference > that I'd like an opinion on as I'm not very electronically minded. > > Eddie modified his KR-400RC however on my KR-400 controllers there is an > additional 100R between the transformer and bulb. What is its purpose > and should I leave it in or remove it when adding the diode, limiting > resistor and LEDs shown in the mod? > > CCT grabs showing the difference https://bit.ly/2FbKIo5 > > Paul > Sussex Coast. JO00

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AMSAT-BB January 2019