so ive been a ham for about 12 years mostly HF stuff, some 2m weak signal, and i keep coming back to the idea of doing moonbounce. i know the basics — signal goes up, bounces off the moon, comes back down, path loss is insane, you need a big antenna and low noise everything. but i feel like every time i start reading about actual setups people are running i get overwhelmed fast.

right now i have a 4 element yagi for 2m which i know is laughably small for this but i want to understand what minimum viable looks like. ive seen people say you can work EME with a single yagi if youre using JT65 and the other station has a big dish, is that actually realistic or are those guys just being optimistic. and whats the noise figure situation — i know LNA placement matters a lot but how close to the antenna do you really need it. my preamp is currently in the shack and i suspect thats already killing me on terrestrial weak signal work let alone EME.

also curious if anyone has actually made a contact through moonbounce and what that experience was like, because from reading it sounds like you sit and stare at WSJT-X for a long time hoping something comes back

yeah the 4 element yagi is going to be rough, not gonna sugarcoat it. single yagi EME is possible on 2m but youre basically dependent on the other end having something seriously big — like a 10m dish or a 16 yagi array kind of big. and even then youre marginal. most practical starting points people talk about are 4 yagis in a cross or H-frame, something in the 12-15 dBd range with decent power behind it, 500 watts minimum really though 1kw is where it starts to feel less painful.

the LNA thing is real and you are probably hurting yourself on weak signal work if its in the shack. rule of thumb is get it right at the feedpoint, like literally mounted at the boom or in a weatherproof box at the antenna. every foot of coax before the LNA is adding noise. for EME you want something under 0.5 dB noise figure ideally, there are some nice PHEMT designs that guys build from scratch or the SSB Electronics and Kuhne units are popular. relay switching so you dont blow it on transmit is annoying to set up but necessary.

and yes JT65 changed everything for small station EME, before that you basically needed a massive array just to hear yourself. but even with digital modes the physics dont lie, path loss on 2m moonbounce is around 252 dB and youre fighting that with whatever ERP you can muster. my first actual decode was surreal, sat there for like an hour and then suddenly there was a callsign in the waterfall that wasnt local. definitely hooked me.

the sitting and staring at WSJT-X part is accurate lol. i did my first EME contact about two years ago with a 2x9el setup and maybe 400w, took forever to find a window where the geometry was right and the big gun station i was trying to work was pointed at the moon at the same time i was. timing and coordination matter a lot more than i expected, like you cant just call CQ and wait, you kinda need to know whos on and when theyre aimed your direction. the online scheduling tools and the ping jockey reflector are how people coordinate, worth getting familiar with those before you even get on the air for this.

also dont forget polarization, the Faraday rotation thing is real and annoying and sometimes you just lose the contact because the polarization shifted and theres nothing you can do about it unless you have some way to rotate your feed or you have cross pol capability which most small stations dont