David Davis41

so ive been sitting on doing the mars/cap mod on my ft-857d for probably two years now, kept putting it off because i was worried about voiding warranty which is kind of a joke since the thing is like 8 years old at this point. anyway finally cracked it open last weekend, it's literally just moving one jumper on the main board, took maybe 20 minutes including the time i spent double checking the diagram because i was paranoid. but thats not actually the main thing i wanted to talk about. while i had it open i went ahead and did the collins filter mod too, swapped in a 500hz CW filter in the IF and the difference on 40m at night is pretty substantial. crowded band conditions are just way more manageable now, i can actually pull out signals that were getting buried before. the filter itself was like 45 bucks from universal radio i think, installation wasnt bad if you're comfortable with a fine tip soldering iron. anyone else done any mods to theirs? curious if the audio filtering mods are worth it, ive seen some stuff about modifying the TX audio chain for better voice quality on SSB but i cant find a good writeup that isnt from 2009 and half the links are dead.

yeah the swr sounds fine to me, my first dipole was way worse than that lol. one thing i learned the hard way is that stranded wire from extension cords can stretch a little over time especially if its holding any tension, so just keep an eye on your connections at the feedpoint after a few weeks of weather. my center connector pulled apart once during a rainstorm and i didnt notice for like a month wondering why the band seemed dead

I went through this same rabbit hole last winter. ended up spending way too many hours on the VHF reflectors reading old posts from the pre-digital era trying to figure out what was still relevant and what wasnt. short version from what i gathered: system noise temperature is basically everything. like you can have a huge antenna and if your feedline loss before the preamp is bad youre throwing signal away. i picked up a Kuhne preamp for 2m, NF something like 0.4dB, and mounted it right on the boom and that alone made a noticeable difference on tropo before i even pointed at the moon. havent made an actual EME contact yet but ive decoded a few of the big EU stations on 144.174 which was kind of exciting just to see that working. my setup is two 9el in H polarization so still small by any measure. i think the honest answer to your question is get your noise floor as low as possible first, then worry about adding more antenna later. also make sure your Az/El rotators can do at least a few degrees per second or you'll spend half the moon window waiting for the antenna to catch up

honestly the extra exam is more about pattern recognition than actually doing math in your head. yeah there are some formula questions but if you use something like hamstudy or the arrl extra book and just grind through the pool for a few weeks most of it starts to click. i was terrified of the filter Q stuff and the smith chart questions but once you see the same question phrased four different ways you kind of just know the answer. the theory does actually help though, i wont lie. understanding why certain filter topologies behave the way they do made me way better at troubleshooting RF issues in my shack. like i actually understood what was happening when i had a feedline mismatch instead of just wiggling cables and hoping. the extra band segments on 40 and 75 are surprisingly less crowded too, at least in my experience. whether its worth it depends on if you want to actually dig deeper into the hobby or if youre happy where you are, both are totally fine answers

yeah post the schematic, hard to say much without it. but a few things come to mind -- 200mW from a single BS170 at 12V isnt actually that far off depending on how the drive level looks. those little mosfets are pretty sensitive to gate drive, too much and you saturate early and waste power as heat, too little and youre just not turning them on properly. what does the drain waveform look like if you have a scope? even a cheap one will tell you a lot. if you dont have a scope then youre kind of flying blind on RF stuff like this unfortunately. also your toroid winding counts matter a lot on 40m, even being one turn off can shift the filter response enough to cause some loss. did you verify the filter with anything or just wind it to the design values and hope for the best? i've done that plenty of times and usually it works out close enough but sometimes it doesnt

yeah ive done almost exactly this, used a nano for mine. the voltage mapping isnt too bad once you just do a big if/else if block with some tolerance on each side of the expected voltage — like if the voltage reading is between 180 and 220 (in raw ADC counts) treat it as 40m, that kind of thing. works fine in practice even if its not elegant. the hot-switching thing is a real concern though. what i did was add a small delay after detecting a band change before actually firing the relay, like 200ms or so, and also read the PTT line from the radio so the arduino knows not to switch if youre transmitting. you can usually grab PTT from the same accessory connector. took me an afternoon of fiddling but its been solid for like 8 months now. never fried anything. arduino is totally the right call for this over a pi honestly. the pi boot time alone would annoy you every time you powered up the shack. for something that just needs to read a voltage and flip a relay an arduino is perfect, simpler is better.

so ive been messing with an RTL-SDR v3 dongle for about six months now and honestly its been pretty great for just learning the landscape, been doing ADSB, some ACARS, poked around the aircraft band a bit, even decoded some NOAA APT passes which was genuinely cool. but im starting to feel the limits of it especially on HF where i have to use the direct sampling mode and it just feels... not quite right? like the noise floor is all over the place and im pretty sure my cheap laptop is not helping things either. anyway ive been looking at either stepping up to the SDRplay RSP1A which i can get for around $120 or just biting the bullet and getting a HackRF One for like $300-ish. the thing is i dont really have a transmit need right now, im mostly receive only and just want better dynamic range and actually usable HF coverage. the RSP1A seems like the obvious choice for that but then ive read some stuff about the SDRuno software being a bit clunky and im already pretty comfortable with SDR# and CubicSDR. does the RSP1A actually work with SDR# still? i thought i saw something about a plugin but wasnt sure if it was still maintained. and is the HackRF receive quality actually as mediocre as people say for a $300 device, because that seems like a lot to spend for worse RX than a $120 dedicated receiver

the RSP1C is solid but just wanted to throw in — if you think theres any chance you'll want to transmit eventually or get into more advanced stuff, a HackRF might be worth considering instead. yeah its more expensive and the receive performance isnt quite as clean as the SDRplay for straight listening, but having TX capability opens up a ton of stuff. i use mine for everything from playing with WSPR beacons to testing antenna patterns. just depends what direction you see yourself going i guess.

ok so i just got my technician a few months ago and ive been on 2m mostly doing local repeater stuff. my question is about phonetics, like when do you actually use them vs just saying the letter normally. i hear some guys on the repeater just say their callsign normally like they would say a word, and then some guys go full NATO phonetic for every single letter every single time. is there like a rule about this or is it just whatever feels right also i noticed some older guys use different words sometimes, not the standard NATO ones. one guy said "baker" instead of "bravo" the other day and i wasnt sure if i heard him wrong or if thats a real thing. just trying to figure out the etiquette i guess

the 100ah lifepo4 should be fine honestly, especially on digital. i ran a similar setup at a simulated emergency test last spring, IC-705 instead of the 7300 so bit different draw, but i had a 50ah battery and was doing winlink and js8call for about 6 hours before i even thought about recharging. the 7300 pulls more on transmit obviously, maybe 20-22 amps at 100w, but if you're running 50w which is usually plenty for js8 it's a lot more reasonable. in receive you're looking at maybe 2-3 amps. rough math puts you well over 8 hours at moderate duty cycle so you should be in good shape without a genny at all depending on how often you're actually keying up. as for the generator question — i get the sticker shock on the honda but those eu2200i units are genuinely a different class of machine for this stuff. the inverter output is clean enough that i run it direct to my radio without a UPS in between, and the noise level matters a lot when you're trying to copy weak signals in a field environment. i tried a cheaper inverter genny once and the RF hash was a real problem, had to move it way further away and run a long extension. that said i've heard some guys have good luck with the westinghouse igen2500 so it might be worth looking at that one specifically if budget is an issue.

headlamp. seriously. i know it sounds dumb but i showed up to a deployment after a tornado came through, pitch black, fumbling around trying to set up with my phone flashlight while holding coax with my teeth. now i have two headlamps in the kit plus extra batteries and i will fight anyone who tells me thats overkill. also a laminated card with your frequencies, your net info, any local repeater stuff. when things get chaotic your brain goes sideways and having that right there saves you from blanking at the worst moment. i also started keeping a small notebook with my radio's menu shortcuts written out because i always forget how to get into the weird sub-menus on the 857 when im stressed.

so i finally finished putting together a MTR-3B kit over the past few weekends and honestly i was not expecting it to actually work on the first power up but it did, made a contact into ohio from pennsylvania on 40m running maybe 3 watts and i was pretty stoked about that. the whole thing just amazes me that you can do that with basically nothing. anyway i do have some questions. im getting what sounds like a little bit of receiver hiss or maybe background noise that i didnt expect, not sure if thats just the nature of the radio or if i did something wrong in the build. also the battery situation is confusing me a little — right now im using a 3s lipo i had sitting around from an RC hobby thing and it seems to work but i dont know if thats the right call long term. anyone run these on lipo and had issues? and one more thing, whats a good way to get spotted without a phone or internet out in the field, i know SOTA activators manage it somehow but i havent figured that out yet.

yeah you pretty much had QRM and QRN right, QRM is interference from other man-made signals like another station bleeding over or someone keying up nearby, and QRN is natural stuff, lightning crashes, static from weather that kind of thing. QSY is definitely change frequency, you'll hear that one a lot especially when someone wants to move a contact to a less busy part of the band. the ARRL publishes a Q code list and its in the back of the handbook if you have one, also just searching "Q codes list" will get you a dozen decent pages. honestly though most of the common ones you'll just absorb after a while. QTH is your location, QSL is confirm/acknowledge, QRZ means whos calling me or sometimes people use it wrong to mean who is that. QRP means low power which a lot of guys run intentionally. 73 is best regards basically, old telegraph thing, and 88 is love and kisses which you mostly hear used between operators who know each other or sometimes a husband and wife team. de just means from, so like W1ABC de K4XYZ means K4XYZ is calling W1ABC. dont stress too much about sounding clueless, everyone was there once and most hams are pretty patient with new folks

the UDP thing for WSJT-X does work but heads up that if you have both Log4OM and something like JTAlert running you have to daisy chain them, WSJT-X can only send UDP to one address at a time so JTAlert has to forward to Log4OM or vice versa. tripped me up for a bit when i first set it up because i was getting duplicate logs or missing QSOs entirely also worth mentioning the adif import from your old logs is usually pretty clean, i brought in like 8 years of logs from various sources and only had a handful of weirdly formatted entries that needed fixing

haha i did almost the exact same thing, said 73 like halfway through my first contact because i panicked. been licensed about 8 months now and i still get a little nervous calling CQ on HF but repeater stuff feels totally normal now. congrats on passing btw