David Chen

so i finally got around to building a center-fed dipole for 40m, been putting it off for months because i kept second guessing myself on the math. used the 468/f formula and cut my wire to around 66 feet total, split in the middle with a SO-239 chassis connector i had in the junk box. wire is just 14 gauge stranded from the hardware store, nothing fancy. hung it up in an inverted-V configuration with the apex at about 35 feet off a fiberglass push-up mast and the ends drooping down tied off to fence posts maybe 8 feet up. fed it with about 50 feet of RG-8X into my 7300. problem is my SWR at 7.200 is reading like 2.8:1 which i wasnt expecting. i trimmed a little off each side and got it down to about 2.3 but that still seems high. the radio is tuning it fine with the internal tuner but i kinda want to understand whats going on rather than just let the tuner handle it. is the inverted-V shape throwing off the resonant frequency or did i just cut it wrong? ive read that the angle of the legs affects things but i dont really know how much

yeah the Q codes go way back to telegraphs, like before voice radio was even a thing, so thats why they seem kind of cryptic if you dont know the history. QTH is indeed your location, QRZ means "who is calling me" which you hear a lot when someone is starting a contact or didnt catch who called them. QSL is basically confirmation, like "I acknowledge" or "I got your message" -- you'll also hear it used when people are confirming a contact happened for logging purposes. QRM is interference from other stations, man-made stuff, and QRN is natural static, like from thunderstorms or whatever. so yeah your instinct was right that someone was complaining about noise. honestly the best way i found was just to look up the ITU Q code list and bookmark it, and after a while you stop needing it because you just hear them so much they stick. QSB is fading signals, QSY means change frequency, those come up all the time on HF. it does just kind of sink in after enough listening.

so ive been chasing DX pretty seriously for the last couple years and i keep seeing the same debates come up on clusters and in local club meetings about how to actually break a pileup. figured id share what ive found and see what other people think. the thing that changed my game more than anything was learning to listen before transmitting. sounds obvious but most people in a pileup are just firing away constantly and not actually hearing where the DX is coming back. if youre on split and hes working 5 up, everybody piles onto 5 up, so i started experimenting with going 6 or 7 up when the pile seems really dense there. doesnt always work but ive had a few cases where the DX op picked me out almost immediately just because i wasnt buried in the same 500hz as everyone else. timing is the other big one. right after the DX op finishes a QSO theres this half second window where everyone keys up at once and its just a wall of noise. if you can time your transmission to start just slightly after that initial burst you can sometimes sit in a cleaner part of the chaos. i cant really explain why this works as well as it does but it does. also — and this is controversial — running more power isnt always the answer. ive broken pileups with 100w when guys running amps couldnt get through, just because of timing and frequency placement. the DX op isnt necessarily hearing the loudest signal, theyre hearing whichever signal they can decode out of the mess. antenna efficiency matters way more than an extra 6db from an amp if your antenna is mediocre to begin with. curious what other peoples experiences are, especially anyone whos actually operated a DXpedition and can say what they hear from the other side

so ive been chasing DX seriously for about three years now and i feel like i finally have some things figured out but also still get my face kicked in regularly so maybe i dont. wanted to write up some thoughts and see what others are doing differently. the biggest thing i had to unlearn was calling on frequency. for years i just tuned to the DX station and called right there like an idiot, wondering why i never got through. once i actually started listening for where the DX was coming back and spreading my calls up 2-3 khz from where most of the pileup was sitting, my rate went up noticeably. not revolutionary advice but it took me embarrassingly long to really internalize it. the other thing — and i feel like this is controversial — is power. ive worked plenty of rare ones running 100w but there's definitely a real difference when i can run the amp. the problem is when everyone in the pileup is running legal limit it just turns into noise. i've had better luck sometimes deliberately running less power and focusing on timing, catching the DX operator right as they finish a QSO before the pileup builds back up. the timing thing is hard to explain but you start to get a feel for the rhythm of how a particular op works. some guys are very mechanical about it, come back exactly every X seconds, some are chaotic. anyway curious what techniques people here actually use, not the textbook stuff, the stuff that actually gets you in the log.

hamstudy.org is honestly all you need to pass the exam, dont overthink it. i used it for maybe a week and a half, maybe two weeks, doing like 20-30 questions a night after work and passed with only a couple wrong. the way it tracks which questions you're weak on is pretty useful. your friend isnt totally wrong either — for some of the more obscure regulatory stuff its basically just memorization anyway because you're not going to intuitively figure out what the FCC says about third party traffic or whatever. that said for the electrical stuff i actually think understanding it helps you remember it better. ohms law is just V equals IR and once that clicks you can derive the other forms instead of memorizing three separate formulas. there's a guy on youtube, i forget his name, who does a whole series walking through the tech pool and he explains the why behind things which helped me more than just flashcards. the antenna questions are mostly just knowing some basic rules of thumb, half wave dipoles and stuff like that, nothing too crazy at the tech level.

ok so I just got my technician license about three weeks ago and I've been trying to get on some of the local FM repeaters in my area. I have a baofeng uv-5r (yeah I know, everyone has one) and I can hear people talking fine but when I key up nobody seems to hear me, or a couple times someone came back and said something about a tone I wasn't transmitting. I honestly had no idea what they meant at the time and kind of just said sorry and went quiet. so I looked it up and I think it has something to do with CTCSS? like the repeater needs a specific sub-audible tone before it'll open up? I programmed what I thought was the right one from a repeaterbook listing but I'm still not sure I did it right because the menu on the baofeng is honestly a nightmare. is there a way to test if the tone is actually going out or do I just have to hope for the best and try to make a contact

so i finally did my first activation last weekend at a state park about 45 mins from my house, K-4892 if anyone knows it. I was honestly pretty nervous going in because ive read so many posts about people struggling to get their 10 contacts and all that. brought my KX3 and a 40m EFHW strung up between two trees, nothing fancy. ended up with 23 QSOs in about an hour and a half which i was pretty happy with for a first time out. mostly 40m SSB but i did manage a few on 20m toward the end when 40 started getting a little long for stateside stuff. a couple of guys actually spotted me on the POTA app which helped a ton, suddenly had a small pileup which was fun to deal with. anyway my questions are kind of basic. first, do i need to log the park reference in every single log entry or just note it somewhere on the submission? and second, is there a good way to know ahead of time if a park is actually accessible and has decent tree cover for a wire antenna? i looked at the park page on the POTA website but it didnt have much info beyond the basic stuff. also wondering if SSB is still the most common mode out there for activators or if FT8 has kind of taken over for hunters trying to rack up park counts

so i finally worked up the nerve to check into the local tuesday night net, ive been licensed for about 4 months now and mostly just been listening but figured it was time to actually participate. anyway the net control called for check-ins and i keyed up and gave my call but i guess i was talking way too long because when i unkeyed there was this awkward silence and then the NCS just kind of moved on and i dont think my check-in actually went through properly. or maybe it did and i missed it, i honestly couldnt tell. then later when they opened it up for comments i tried to reply to something someone said and i think i stepped on another station because i didnt wait long enough after the previous person finished. nobody said anything but i felt bad about it. is there like a standard amount of time you're supposed to wait before keying up? i feel like everyone else just knows this stuff instinctively and i'm still fumbling around. also does net control usually acknowledge every single check-in individually or do they sometimes just log you and move on?

haha yeah my first one i forgot the coax. like the actual coax to connect the radio to the antenna. stood up there for a minute just staring at my bag wondering what felt wrong and then it hit me. had to use a random bit of RG-174 i found at the bottom of my kit bag that was probably 3 feet long, not ideal but it worked enough to get the 4 contacts. now i have a laminated checklist that lives in the top of my go bag permanently.

so i finally got around to building a proper 40m dipole instead of using that random wire i had strung up for the past two years. cut it to the standard 468/f formula which came out to about 66 feet total, used some 14awg stranded wire i had laying around from an old project and a SO-239 chassis connector in a little weatherproof project box for the center insulator. got it up in an inverted-v configuration with the apex at about 30 feet off the ground using my push-up mast. the legs are drooping down to about 8 feet at each end tied off to some trees. SWR at resonance is sitting around 1.4:1 which honestly isnt bad but i trimmed the ends and now its resonant at like 7.150 which is fine for my purposes. my question is about height though. everything i read says you want a half wavelength up for a dipole at 40m which is like 66 feet, which obviously i dont have. am i losing a lot by being at 30 feet? like is it worth trying to get a taller center support somehow or is the inverted-v at 30 feet still reasonably usable for making contacts and not embarassing myself on the band

so i dont know if anyone else has been paying attention but 6 meters has been absolutely wild the last few days. been working stations i have no business working from my little attic dipole setup. got a QSO with a station in the caribbean yesterday afternoon which honestly blew my mind because i usually cant hear anything past like 500 miles on 6m. also saw some chatter that the new Icom IC-905 is finally showing up at some dealers, havent seen hands-on reviews yet but the specs on that thing look pretty serious for the bands it covers. curious if anyone here has actually touched one. anyway just wanted to throw this out there in case people werent watching 50.313 — worth firing up the radio if you havent. propagation feels very Es-ish but its been going on longer than typical sporadic-E usually does for me. maybe something else is going on, not sure.

so ive been a general for about two years now and lately ive been thinking about just going for the extra. mostly because i want to get into some of the cw segments and also just to say i did it i guess. but everyone i talk to at the club keeps telling me the theory on the extra exam is a massive jump from general and i honestly cant tell if theyre exaggerating or not. like i understand basic electronics reasonably well, i can follow along when people talk about impedance matching and i built a few kits so its not like im starting from zero. but some of the sample questions ive looked at, the ones about filter design and transmission line stuff and the math behind oscillators, that stuff looks pretty rough. is it actually something you can self study for in a reasonable amount of time or do i need to like take a formal class or something. also is the full privileges thing actually worth it in day to day operating or does it not come up much

hand holding the arrow for a full pass is honestly a workout especially if its a high elevation one. i did it for about 6 months before i caved and built a cheap az-el mount out of two TV rotators. not perfect but gpredict drives it and i can actually focus on the radio part now instead of trying to be the antenna. one thing that helped me early on was doing a few passes just listening, not transmitting at all. just tune around the passband and hear where other people are and how the doppler moves everything over the course of the pass. gives you a feel for how fast things shift at different elevations. LEO passes are fast and the doppler curve is steepest at AOS and LOS, middle of the pass is actually pretty calm. so if you're just starting out maybe make your contacts near max elevation and give yourself a break.

yeah the Q codes go way back to maritime and telegraph use, so youre right that 73 has old roots. the ITU actually standardized most of them. QTH is your location, QSL is acknowledgment or confirmation (also the cards people send), QRM is interference from other stations, QRN is natural noise like static, QSB is signal fading, QRP means low power operation... theres a bunch of them and honestly after a while they just become second nature. ARRL has a decent reference page and most general study guides have a table of the common ones. the ones you'll hear most on HF are probably QSL, QTH, QRM, QRN, QSY (change frequency), and QRZ (who is calling me). 73 is best regards and 88 is love and kisses, though 88 is kinda... well people have opinions about when thats appropriate to use. just lurk a bit more and youll start picking them up fast, it clicks pretty quick once you hear them in context enough times

yeah what he said, LoTW is the key thing to get sorted first. i waited like two years before i set it up and kicking myself for all those early contacts that never got confirmed. the certificate request process through the ARRL is a bit of paperwork but its worth doing early so you dont lose those qsos honestly chasing WAS first might be a good gateway because working all 50 states feels really tangible and you'll start to understand propagation a lot better just from doing it. some of the rarer states like ND and WY took me forever to snag on certain bands. then once you catch the bug you'll find yourself staying up way too late trying to work some tiny island in the pacific for a new entity and thats when you know DXing has got you