Steve Martinez

so ive been messing around with this for a few weeks now and i think im close but not quite there. basically i have an old Yaesu G-450A rotator and the controller still works fine but i got tired of manually turning it every time i want to hit a new bearing for satellite passes. figured i could throw an arduino in there and have it handle the positioning automatically based on output from gpredict or whatever.
what i did so far is tapped into the azimuth potentiometer on the controller, running that voltage into an analog pin on a mega 2560 and converting it to degrees. that part actually works pretty well, i can read the current heading within a few degrees which is good enough. the problem is the motor drive side. i was trying to use a relay module to switch the left/right motor lines but im getting these really ugly voltage spikes when the relay clicks and i think its causing the arduino to reset sometimes. put a snubber across the relay contacts and it helped a little but not fully.
anyone dealt with this before? wondering if i should just ditch the relays and go with an optocoupler or maybe a solid state relay setup instead. also not sure if i should be doing the serial comms to gpredict over USB or if i should wire up a proper RS-232 level shifter, the rotctld interface kind of expects real serial ports i think.

they really are different tools honestly. FT8 is optimized for making contacts — exchange callsigns and signal reports and move on, thats basically it. the decoder sensitivity is insane, something like -24dB SNR if i remember right, which is why it works so well when the band seems totally dead.
JS8Call is more like... texting over radio. you can have actual conversations, relay messages through other stations, send position reports, all that. its based on FT8's encoding so it has similar weak signal capability but the tradeoff is each transmission is longer so you need the path to hold up for more time. for pure contact making FT8 wins pretty much every time but if you want to actually say something to someone or do mesh-type messaging JS8Call is the one. i use both depending on what im trying to do.

honestly the general exam is not that bad, i was in the same boat as you, thought the math would kill me but the actual calculations they test you on are pretty straightforward once you just memorize the formulas. like you dont need to deeply understand why the formula works you just need to know it and plug numbers in. i used hamstudy.org for like 3 weeks maybe 30 minutes a day and passed with only a handful wrong. the pool of questions is finite so if you just drill the question pool you'll be fine.
as for the IC-718 dude turn that thing on. that radio is a solid HF rig and you're sitting on it doing nothing lol. once you get your upgrade just start with 40 meters in the evening, there's always people on SSB and if you find yourself on the general portion of 40m you'll hear plenty of activity. 14.225 on 20 meters is kind of a classic spot too. just listen for a while before you transmit, get a feel for how people do it. you'll figure it out fast.

dayton is absolutely worth going at least once, just be ready to walk a LOT and bring cash because the flea market out in the parking lot is where all the good deals are honestly. inside the arena is cool but its mostly vendors with new stuff. i picked up a barely used 706 for like 200 bucks out there a few years back from some old timer who was downsizing his shack. as for SARA i havent heard anything either, their website hasnt been updated since like november which is pretty typical lol

yeah the LO leakage thing is pretty much just the nature of a direct conversion design, especially if the detector isnt super well balanced. the ring detector should help versus a single diode setup but youre never going to get it to zero. a simple low pass or bandpass filter on the antenna input wont really stop it from leaking out because the problem is more about isolation between the detector and the antenna port — the LO is basically backdriving through the mixer. better shielding on the LO and making sure your si5351 output level isnt way hotter than it needs to be will probably do more good than a filter. what level are you driving the si5351 output at? those things can put out a lot more than you actually need for most detector configs and backing it off sometimes helps
the LM386 thing — yeah that chip is notoriously noisy and has a pretty weird frequency response without some help. the classic fix is the 0.047uf cap between pins 1 and 8 to set the gain and a bypass on pin 7, theres a million variations of the decoupling network online. wont make it sound like a nice audio amp but itll clean up some of the mud

the thing that got me my first real deployment was lighting. sounds so obvious but i had everything in a big pelican case and no way to see inside it at night without holding my phone in my teeth. now i keep a couple small USB LED strips and a headlamp right at the top of the kit, always accessible. also zip ties. i cannot stress this enough. you will always need more zip ties than you think and you will never regret having a hundred of them in a little bag.
the laminated cards thing is actually worth doing even if you have a tablet. batteries die, screens crack, sometimes you just want to hand someone a card so they know what frequencies the net is on without having to unlock your device. takes like 20 minutes to make and its one of those things you forget until youre grateful you did it.
your power setup sounds solid honestly. the one thing id add is some way to charge your phone independently from your radio power budget. people underestimate how much they lean on their phone during an activation even when the radio is doing the main work.