Need your satellite antenna suggestions/secrets

Discussion in 'Satellite and Space Communications' started by W9YW, Oct 14, 2021.

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  1. W9YW

    W9YW Premium Subscriber Volunteer Moderator QRZ Page

    I have a dual need.

    First, I'm trying to perfect the hardware list for my own ground station. I recently acquired an AZ/EL rotator, and will choose a more fixed antenna for it, and I'm writing a recipe book for others.

    The second need is that I'd like to do a How-To guide (probably PDF) that is a compendium of wisdom about satellite communications steps, from your Ez First Try to the tough ones, in graduated steps.

    Help, URLs, tried-and-true, tried-and-burned, all of these are helpful.

    Thanks in advance,

    73 Tom W9YW
     
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  2. KO4MA

    KO4MA Ham Member QRZ Page

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  3. N4UFO

    N4UFO Ham Member QRZ Page

    Drew... he wants to DO a manual. Meaning, tell your stories so he can do a compendium and share it. I don't know if he wants to 're-invent the wheel' compared to the AMSAT manual, but something extra possibly couldn't hurt. Might be a little too groggy to type that much right now, but perhaps a couple pictures...


    Tom, what you will find about info on satellites is that it is all over the place by the nature of the fact that satellites & satellite operating practices are constantly changing. Broad example, in the 'old days' most had very long boom yagis and CP antennas. Now it is often better to NOT have the big long yagis as they need to be relatively pinpoint on LEO birds that are constantly in motion. And the later birds tend to have 1/4 wave verticals for antennas and CP is more luxury than necessity.

    My general recommendations/experiences are:

    1. typical base antenna - okay for transmit, but heard better with a small directional antenna mounted on an HT. Was sufficient to jerk the hook firmly into mouth to get back into satellites. My previous experience with was RS-12/13 satellite on 15/10m, but none with FM birds.
    2m squalo closeup.JPG Sat HT.JPG

    2. handheld antenna - short coax means less loss, handheld means easier accuracy to find bird. Optional: go overboard with Alaskan arrow (an attempt to work HI)
    Gridiot station.JPG 6 - western SO-50 pass.JPG attempting HI.JPG


    2a. tripod mounted - same as above but requires some doing to get proper three axis moveablity; I am embarking on such an adventure soon as I no longer own AZ/EL rotors and have an enclosed porch (that belongs to the cats) to operate from. Not as comfortable as the shack... much more comfortable than 'outside'.


    3. no AZ/EL - tilt a reasonable size yagi (3 el on 2m, 5-7 on UHF OR an Elk) 15-25 degrees up and turn with a cheap azimuth only rotor. In the above pic, I learned to not put the 2m behind the uhf as I blasted the 2m third harmonic into the uhf receive and had some problems with V/u birds. Also learned not to attempt to use cheap kit preamps as they caused more harm than good. Preamps are almost a must with some antenna setups/birds, not so much with others... depends on coax type/length and the bird itself. - Reasoning? Birds will spend the vast majority of there time below 45 degrees relative to you. When they 'pass directly over', they are moving at their fastest relative to you, so you literally just need to 'wait a minute'... as in, not much longer than it takes to rotate your antenna 180 degrees anyway.
    sat antenna.JPG


    4. Full on AZ/EL, single polarity - speaks for itself. Horizontal orientation can mean less noise, but may require a much longer 'non-conductive' cross boom. Tilting each at 45 degrees off center (one way for one antenna, other way for the other) is also an option, but can require complicated mounting. I found vertical orientation worked for me. Preamps with diplexers (to act as bandpass filters) in front. Found I rarely needed the 2m preamp, but the first time I turned on the UHF preamp, it was like 'WHOA!'... didn't know what I wasn't hearing.
    sat antennas 2.JPG wired box 2.JPG

    5a. AZ/EL Switched dual polarity - put up dual polarity yagis and install switching to vary between polarities. This allow one to avoid many 'fades' due to the single polarity antennas on the bird at times being 90 degrees off polarity from you as it spins. Signal fades? Switch polarities. Some fades where antenna is 'behind' the bird, still going to happen. I opted for single polarity and just wait out any fades.

    5b. AZ/EL CP antennas - suggest RHCP or get elaborate and install switching between RHCP & LHCP. The Leopack antennas are a good choice for this.

    Have done 1, 2, working on 2a, 3 and 4. (Atypically, not in that order... 3, possibly even 4 came before 2, just to be honest.) More on 2 here: N4UFO/P. I never saw a need to go all the way to 5 and while I started to install automated everything, as soon as I hooked up the serial cables, a lightning storm convinced me to try things another way. Took out the serial chips in the radio, PC and controller box; nothing else was damaged. So... I opted for manual control of everything. Challenging at times, but also much more fun to me... reminded me of my days as a radio disc jockey, spinning records and running a control board all by hand. :):cool:

    Okay, I wasn't so groggy... well, I assume that now, but wait until I read this tomorrow. Is this what you were looking for Tom? If so, let the stories begin!!! And if you have any questions, fire away... in thread or in private, either way. Good luck with the effort, I applaud it. Just keep your text editor handy. ;):rolleyes:

    73, Kevin N4UFO
     
    Last edited: Oct 14, 2021
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  4. W9YW

    W9YW Premium Subscriber Volunteer Moderator QRZ Page

    This is closer to what I'm looking for. I'm trying to solve the problem(s) progressively, so that neophytes will have joy, and if you really want to go down the rabbit hole, think about X Y and Z.

    My own will be your 5a, modified for 5b. I've done the short 4-6el yagis and had joy. I'm making recipes so that others can be motivated by successful initial tries, then get deeper as their interest parallels discovery.

    I'm an AMSAT member, and have gleaned a few things from their very nice series. I want to do this in an open way, and get people OnTheAir in a realistic way.

    Recipes that are easy to follow and produce results are my goal for the final product. I'm a semi-retired researcher and do tech writing for pocket money; this is not for money. I want something that appeals to a wide audience, and has some graphics to help people understand the theory and applications.

    Thanks!

    73 Tom W9YW
     
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  5. K7WDO

    K7WDO Ham Member QRZ Page

    I’ll give another +1 vote to the M2 LEO pack. Those are some very nice compact CP antennas that really work great on the current satellites. I also appreciate N4UFO’s writeup above as sometimes reading this forum, it’s either a Baofeng and an arrow or full computer control on an IC-9700 & G-5500. I never see much mention about options in between.

    I’ll go with a quick recap of my own history with the amateur satellites since most of the advice I’d give is based on that experience and it gives context on why I did it that way.

    It really started around the time I was debating a full plunge into amateur radio and getting licensed. I’d recently finished building a HF receiver kit, picked up a cheap (used) 2m FM radio & a mobile whip antenna and was listening to the repeaters to figure out what to do next. It was about this time that I heard about an upcoming satellite called ARISSat-1. Years earlier, I’d been introduced to AO-21/RS-14 and the memory that stuck with me from that satellite was where it would send recorded voice messages. For some reason, that captured my attention more than the usual transponder activity. So flash forward to ARISSat-1, and one of it’s goals was education outreach with voice greetings being one of its features. It peaked my interest, so I decided to see if I could give it a listen. I was lucky enough to have a Ham Radio Outlet in town so I picked up a 4-element 2m yagi and a piece of coax on my way home from work and started putting together the beginnings of a satellite station. I found some satellite tracking software online to tell me when the pass would be and strapped the newly assembled antenna to my camera tripod with a shoelace so my arm wouldn’t get tired. The original attempt was a bust, but that was my start.
    I didn’t let my initial setback get me discouraged as I was more curious as to if my satellite setup could hear anything than frustrated. I discovered that my initial ARISSat-1 failure wasn’t my fault (flat batteries on a pre-deployment test activation), so I did some research on what was currently active in orbit and was transmitting in 2m FM. I found my next target in UO-11. It was just digital telemetry, but it was a constant signal to listen for and on this attempt, I was successful in hearing something transmitting from orbit. ARISSat-1 was deployed from the ISS and I had an absolute ball listening to that satellite during its brief life. The satellite bug had struck.
    By this time, I was finally licensed so it was time to look at expansion. The next addition was 70cm so I hunted down an all-mode radio so I had more options to work with. With that came a 70cm antenna and the 2m FM rig was replaced with a 2m all-mode radio. I was operating on a budget so I was sticking with older pre-owned radios to keep my costs down. This opened up learning how to work the linear satellites like FO-29, VO-52, and AO-7. The FM birds never grabbed my interest. I never could hear SO-50 with my setup and AO-51 was so busy, I always found it more interesting as a reception test than something I wanted to transmit to. A 70cm preamp quickly joined the shack to improve my FO-29 reception and that was my basic setup until I moved to a new location a few years later.
    At the new house, I decided to go big and put up a tower, rotors, and some nice CP antennas. It took about a year to do - design, acquiring the parts, construction permit, finding a concrete contractor to pour the base, passing inspection, installing the antennas, but with it finally done, that’s what I’ve been running ever since. I still operate everything manually. (it’s more fun)

    How it started:
    shoestring_antenna.jpg
    And how it's going:
    K7WDO_antennas.jpg

    So lessons learned:
    Follow what grabs your interest. It might be FM, linear, telemetry, SSTV, weather images, or something else entirely.

    You can grow your station over time. It might be to add new capabilities, improve reception, listen for a new satellite, or just get in out of the rain. It’s easier to justify bigger antennas or a new radio when you’ve been at it a while vs just starting out and not being sure how long it will hold your attention.

    It’s not too hard to do on a budget. I started with pre-owned gear to keep my initial costs down and raided various sources (HRO, eBay, hamfests, etc.) to find what I needed. I managed to build a working linear-capable station for about $1000.

    Read up on the current satellites. Old satellites die or deorbit, new ones go up with different capabilities. It’s a changing scene up there and what might of worked for one satellite might not do as well on another.

    Telemetry signals are great for troubleshooting. If you’re debugging your antenna setup or testing your radio, a nice, steady, telemetry beacon can be a great help compared to the unpredictable nature of transponder activity.

    And of course, have fun with what you’re doing.
     
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  6. N8NMG

    N8NMG Premium Subscriber QRZ Page

    Tom I like your concept. I read the AMSAT articles and a realistic open way of sharing is a great idea! I just posted questions about AZ / EL Alignment. Feel free to grab any useful clues that get posted to my thread. 73 John N8NMG
     
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  7. W9YW

    W9YW Premium Subscriber Volunteer Moderator QRZ Page

    Thanks, John. This is starting to go where I'd like it to go, and may add a section for how to listen to sats before you work (or attempt to work) them.

    I don't have the ideal QTH for satellite work, but it's not in a 4th-story basement.

    73 Tom W9YW
     
  8. SWL37632

    SWL37632 QRZ Member

    My two cents...

    Started into sats a couple years ago after thinking about it for decades.

    I'm glad you're doing this.....it was a real hassle getting all the basic info to get up and running. This despite the AMSAT resources and Facebook website.

    My interest: 450 uplink (TX) and 144 downlink (RX) SSB.

    Biggest challenge: 2m receive of the RX downlinks.
    Icom IC-7000, and then a homebrew downconverted module to a direct high performance SDR and then IC-735.

    Used Simon Brown's doppler tracking software 'SDR console'.
    All the others were a PITA to get to work or use.
    Although Simon's software took fortitude to learn and set-up, it was more easy to get it up and running.

    Besides a pre-existing 30 MHz thru 1 GHz Rad Shack discone, I progressively built all my antennas using 12 gauge solid copper wire or aluminum tubing on closet pole scrap I had on hand.

    First a home brew 2m egg beater, modified to a 'Texas Potato Masher', 2 element cross-polarized yagi and then a 4 element cross-polarized yagi.

    As expected, the 4 element yagi gave the biggest gain and as we all know, the need to have an old Rad Shack azimuth rotator to control it....in my case no software tracking control but good enough for QSO's commanded manually by 'riding' the control box in the shack....and a Heinekin on the desk.

    Biggest surprise was the significant RX performance that was gained by the addition of a homebrew 3 stage helical filter on the front end of the RX.

    In the LA metro area, the addition of the filter showed a significant reduction of apparent broadband 'noise', which was due to the high level and number of FM broadcasters (88-108 MHz) and public services, TV, etc.

    Besides the antenna, the helical filter was the most significant improvement to add to the system.

    Hope these are good inputs to your efforts.

    Bill

    20+ WPM 1970's EXTRA
     
  9. W9YW

    W9YW Premium Subscriber Volunteer Moderator QRZ Page

    What kind of helical filter are you speaking of? I have (sub)urban noise sources that I'm trying to quench/stanch/stomp/stop.

    I'm also thinking of making my own bandpass filters (simple Butterworth networks) to shunt 130MHz/south on a 12db slope. Should be fairly easy to do, as this is low power.

    The QRM from local TV/FM/AM broadcast isn't too bad, rather, it's consumer gear and random noise shelf increases that are rough. Add that to my tinnitus, and yikes it can be noisy!

    73 Tom W9YW
     
  10. N4UFO

    N4UFO Ham Member QRZ Page

    Would they be much different than a duplexer? MFJ-916s can be had pretty cheap. I used them in front of my preamps to filter out the transmit from the other band.
     

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