so ive been licensed for about 6 years now mostly doing HF DX and some 2m meteor scatter and i keep seeing EME come up and honestly its starting to sound like something i want to try. i know its not cheap or simple but i want to understand what the real minimums are before i start spending money in the wrong direction.

right now i have a yaesu ft-991a and a decent 2m yagi i built from a k1fo design, maybe 12 elements. i know thats nowhere near enough for EME. from what ive read you basically need massive antenna gain and a low noise preamp right at the feedpoint, and a solid understanding of where the moon actually is at any given time. and digital modes, mostly JT65C from what i can tell or has that shifted to Q65 now? i keep seeing mixed info on that.

my main question is whether someone starting from scratch can realistically expect to work any contacts with like a 4-yagi array or if you really need to go 8 or 16 yagis to get anywhere. i have a decent sized yard and i could maybe do 4x 17el yagis on a small H-frame if i build it myself. power wise the ft-991a does 100w on 2m but im already looking at an HL-350VDX or maybe borrowing a 1kw amp. just wondering how realistic this is before i go full rabbit hole on this

Q65 has pretty much taken over from JT65C for most EME work these days, at least on 2m. the sensitivity is a bit better and it handles doppler spread more gracefully. make sure you're running WSJT-X 2.6 or newer and get yourself set up on the WSJT-X EME page to see whos active and when the moon is up for both stations simultaneously — that second part trips people up more than anything.

on the antenna question, 4x17el is definitely workable but youre going to be in the weaker end of things and youll need everything else to be really dialed in. preamp right at the feed is not optional, something like an SSB Electronics SP-200 or equivalent with a noise figure under 0.5dB ideally. relay switching matters too, you dont want coax between the preamp and the antenna. and yeah the ft-991a at 100w is going to hurt you, the HL-350VDX would be a step up but for EME honestly 500w or more on a 4-yagi setup is where you start having real QSOs instead of just calling and hoping. its doable though, ive seen guys work initials on smaller pistol stations with patience and good operating conditions especially around perigee when the moon is closer.

yeah what he said about the preamp placement is huge, i learned that the hard way. i had maybe 3 feet of LMR400 between my preamp and the feedpoint and my noise figure was way worse than it should have been. moved it right to the boom and it made a noticeable difference on received signals.

also dont underestimate the moon tracking software side of things. if your antenna isn't actually pointed at the moon within a degree or two you're throwing away gain for no reason. i use a green heron controller but there are cheaper options that work fine. some guys use Nova for Windows for tracking data and feed it to their rotor controller. anyway its a rabbit hole for sure but first EME initial is a pretty cool feeling, just be prepared to spend a lot of time staring at a waterfall