So I'm going to try EME with my YL

Discussion in 'Satellite and Space Communications' started by W1GNL, Oct 19, 2021.

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  1. W1GNL

    W1GNL Ham Member QRZ Page

    Hey everyone,

    My YL is in the process of studying for her Technician Class test and knowing her she'll pass it with flying colors. One of the things that's interested her since I first mentioned ham radio/amateur radio was the notion of being able to communicate with satellites and doing EME. So I promised her that when she passes her test we'll get all the stuff together for trying to be successful with EME and so on.

    I do have a few questions with regards to this..

    Do I need an amplifier? I feel like it probably helps and looking into it people seem to be running anything up to 1kw. I was thinking that something between 300 and 600 watts would probably be a good place to start. But let me know if we should just start with 1kw. I know EME is possible with 100 watts too.

    My notion was to work EME on 2 meters and as such I was thinking of going with a quad antenna setup, as, if I'm to understand that comes with gain of up to 6db (which I'm assuming is on top of whatever gain your yagi's have to begin with). I was thinking we would use the M2 2MXP28 and connecting them with an M2 H-Frame that's made for the antenna, and of course all the a 2M4PORT divider and polarity switch and phasing lines.

    My question here is, is 4 antennas insane overkill. I mean it looks very cool in photos but can good work be accomplished with a pair of antennas rather than going quad. I'm not overly concerned with expense per se but I also don't want to over spend if two will be just as good.

    Should my antenna feed line be heliax? I have never worked with the stuff, I've seen it but have never actually done anything with it. I know it's extremely low loss so I was thinking of 7/8' heliax on transmit and LMR-600 on receive since it will be coming back from a high end pre-amp out on the H-frame so loss won't be too bad.

    My next question is the Yaesu G-5500DC up to this task or should I look into the M2 (or other) Az/El solutions? If I go with the Yaesu I would interface it to a laptop with the controller that connects to the PC also by Yaesu. I know M2 offer some solutions that look more robust but the Yaesu G-5500DC is at a good price so if it's up to the task that would be ideal.

    My last question is regarding a good 2M (with 70CM would be nice)..

    I know the Icom IC-9700 has drift issues making it lousy for digital modes, however it seems with the Leo Bodnar board and their GPS oscillator it becomes extremely stable. I don't love the idea of having to fix Icom's broken radio after the fact but I can't help it I still think it's a very slick radio. I know also the Yaesu FT-991A support 2m and 70cm as well (and HF too) and all the digital modes and (as far as I know) doesn't have the issues the IC-9700 has. Any thoughts on which one of these would be better?

    I know this will be a HUGE learning curve but we're both extremely excited to give this a go, and it's something we can do together which is also really exciting. I have to admit that this whole area of ham radio is insanely fascinating to me (and her). So any suggestions you all might have such as website and the like would also be fantastic.

    I just think it will be a hoot having this setup next to the HF setup talk about different but same, this hobby has so many interesting things!
     
    W0PV likes this.
  2. N4UFO

    N4UFO Ham Member QRZ Page

    I know nothing about EME, but I know this guy personally and he did EME with a very modest setup. When I was interested at one time, he sent me several articles on his operations... here is one article: http://www.arrl.org/files/file/QST/This Month in QST/July2016/Schaefer.pdf

    Life got in the way and I never got around to doing any ops... maybe someday. Hopefully you can glean some useful info from the article. 73 & GL, Kevin N4UFO
     
    CO8TW and W1GNL like this.
  3. K9JKM

    K9JKM Ham Member QRZ Page

  4. W1GNL

    W1GNL Ham Member QRZ Page

    Thank you for that article it was a really great read and his setup was extremely modest which makes me feel like I should just start small and enjoy getting into it. I feel like half the fun is trying things, it's about the journey not the destination all the time. I'm extremely excited to try this.

     
  5. W1GNL

    W1GNL Ham Member QRZ Page

    Thank you for the great links, I will definitely be doing a lot of reading!

     
  6. K6CLS

    K6CLS Ham Member QRZ Page

  7. KS1G

    KS1G Ham Member QRZ Page

    This write up by one of our club members may be very useful: https://history.k4lrg.org/Projects/K4MSG_EME/ You will definitely need a preamp and amp; K4MSG put the amp at the antenna in a weather protective housing (inverted cooler) to minimize signal loss. He later upgraded to a pair of larger antennas, and did same thing on 432 MHz. The WSJT software is excellent, and you can also use it for tropo, sporadic-E, and meteor scatter. (Speaking of which, see also https://history.k4lrg.org/Projects/Brick_Cooler/index.html, https://history.k4lrg.org/Projects/Brick_Cooler/Follow_Up_index.html, and https://history.k4lrg.org/Projects/Brick_Cooler/2nd_Follow_Up_index.html)
     
    W1GNL likes this.
  8. N8SAN

    N8SAN Ham Member QRZ Page

    A lot to cover here. Bear in mind I'm new to EME as well. I have a whopping 2 QSOs off the moon! One with a big gun station one with a 4x12 station. (4 beam 12 element).
    I too studied a long time while collecting parts and assembling a station.
    You've gotten good advice up there thus far.

    I love that you and the YL are getting into EME, to me it is the Grand Master Prize of this already niche hobby. And it's awesome.

    The first question though, how many stations do you want to work?
    If it's something that you want to get 1,2,5 and call it done. Then that station will look a LOT different than something more permanent and that you might work 100+ stations with.

    I'll tell you my goal. I wanted to be in the 100 initials class or so. (Initials meaning new contact to you. No repeats)
    My station is as follows.
    2 M2 2M9SSB horizontally stacked, on a non metallic boom.
    SSB SP-200 Pre amp. It can handle 750 watts of forward power as long as you sequence it. Meaning, you turn off the preamp before the forward amp comes online.
    TE-Systems 1452G Amp. About 350-400watts.
    LMR-400
    IC-9700.

    Your thinking of 300-600 is perfect to me. Hence that TE amp I have.

    You'd have a solid station here if you went that route.
    Again depending on the amount of contacts you want to make. As laid out in my opener.
    To me I stuck with 2m. For a few reasons.
    First and foremost, I believe there are more 2m moon bouncers than other bands. (I could be wrong today) more stations, more chances to work.
    #2,Amps and antennas are more readily available 2nd hand. Sometimes a bit cheaper.
    And 3, LMR-400 is plenty good at 2m. I'm running 100' of it. The higher the frequency, the more loss you'll suffer. Which means better coax. More money. Harder to work with.

    One thing I somehow missed in my researching is/are LFA (Loop Fed Array) Yagis.
    I would have gone that route if I could do it again.
    Justin G0KSC is the man with these.
    https://www.g0ksc.co.uk/
    He sells them under this company.
    https://innovantennas.com/en/
    They're not particularly cheap in comparison. But they seem very very good.
    For what it's worth... This is a comparison between two 7 ele yagis on 6m. One a traditional, one LFA.


    There are some that don't see the benefits. And it's possible they're in a quiet area. But if your QTH is noisy, these maybe something to look at.

    As far as the X polarized, I think you're right in your thinking. It does add a lot of complexity to an initial station. But you certainly add "strength" to it as well.
    Same question, how far do you want to go? (Notice a trend? ;))

    See above.
    How far from the antennas will be your receiver? If you're 20', and you run Heliax, or LMR-600 on 2m, I'd honestly argue, you probably don't need the pre amp, coupled with the added complexity.
    The preamp is to makeup for line loss. If you're running 100'+ you might see a benefit. As 1dB can be the difference of making a qso and not even seeing the trace.

    I have an old Ham IV for Azimuth and a Kenpro G550 for elevation.
    I then have an ARS-USB controller interface by EA4TX. Pablo is awesome to work with and answers questions very quickly.

    Really. Anything you want to use here will work.
    The whole system auto tracks the moon. No need to touch it. That being said. If you have any software that tells you where the moon is in relation to you, you can manually adjust the rotors every 10min or so and be fine.
    IF you go with a quad antenna. The elevation rotor might not be beefy enough. I don't know.

    Without hesitation. I would get the 9700 again.
    Especially if you're using 2m and an amp.
    The drift is caused by the cooling fan coming on and off. Nothing else.
    Yes it can be fixed by the Leo Bodnar GPS injection.
    But I drive my TE amp with 15 watts. I don't even hear the fan come on during a transmission.


    There's a lot to unpack there.
    Feel free to ask more.

    Ryan.
     
    W1GNL likes this.
  9. W1GNL

    W1GNL Ham Member QRZ Page

    Ryan,

    Thanks for such a fantastic response to my question it's exactly what I was looking for. If it's ok with you I'll PM you directly when I have more questions, unless you want to keep it public for the benefit of all. I am going to follow up with the links you provided and I'll get back to you when I have something intelligent to ask or say. Thank you again for such an amazing response!

    John
     
    N8SAN likes this.
  10. N8SAN

    N8SAN Ham Member QRZ Page

    Hey John. Not a problem at all!
    You can PM, here, or direct email.
    Sometimes email is good for referencing later. 100% up to to you.
     

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