Packet Radio

Building a compact 5-band QRP CW transceiver around an Si5351A clock generator for VFO/BFO duties. Using Arduino Nano control similar to ZL2PD's single-band design but extending to cover 20M through 10M. Experiencing frequency drift issues during portable operation - roughly 200Hz drift over first 10 minutes of operation in cold weather. The VFO draws only 30mA at 3.3V which is great for QRP work, but temperature compensation seems inadequate for field use. Currently using the internal 25MHz crystal reference. Has anyone implemented TCXO references with the Si5351A successfully?Alternative: software temperature compensation routines?Worth switching to a GPS-disciplined reference for portable work?

i built almost the exact same thing last spring and had mine up as an inverted V too. one thing i wish i had done differently was make the legs a little longer than calculated and then trim down instead of cutting exact and hoping. its way easier to shorten than to splice more wire on later. i ended up having to do a janky splice on one leg and it bugs me every time i think about it even though it probably doesnt actually matter electrically. also on the pvc center insulator — how are you sealing the holes where the wire goes through? i left mine open and after a few rain cycles moisture got in and i kept getting weird readings. a little silicone caulk or even electrical tape wrapped around it goes a long way. might be overthinking it but just something i learned the hard way

the sealant question — yeah do it, self amalgamating tape is what most people use and its cheap. coax seal or even just a few wraps of regular electrical tape over self-fusing tape works fine. water getting into that center connector is the number one way to slowly ruin your SWR over a season and you wont even notice at first. on the inverted V vs flat top thing for 40m with those heights, honestly at 30 feet center and 8-10 foot ends the inverted V is still going to work. youre not going to be winning any DX contests with it but for general use it puts out a decent signal. the takeoff angle will be higher than ideal but on 40m at night when the band opens up youll still be getting out. flat top at 6 feet on the ends is probably worse honestly, the whole antenna is just too close to ground. id go inverted V. 73 ohm feedpoint impedance is close enough to 50 that you might get away without a tuner depending on how well you cut it. if your radio has a built in tuner it'll handle it no problem. nice work just going ahead and building it, most people talk about it for years.

yeah the jump from 5 to 7 is weirdly harder than it sounds lol. one thing i did was stop trying to copy every single letter and just let stuff go when i miss it. sounds counterintuitive but chasing a missed character is what kills you because then youre behind on everything after it. just move on and catch the next one. your brain fills in more than you think once you get some context. also RufzXP is good once you get a bit higher, its designed for callsign copying and it kind of gamifies the speed building which helped keep me motivated. good luck with it, 20wpm is totally doable dont give up

Try experimenting at home first - set up something portable in your yard. I've done simple activations with a homemade dipole tossed 15 feet up in a tree. Start simple and build from there.

I had the same experience my first time, thought 44 would be easy and then just... sat there calling CQ into what felt like an empty band for like 45 minutes lol. The pre-announcing thing is real, i didn't believe it would matter that much but the difference between going in cold vs having a few chasers who know you're coming is night and day. Also have you looked at whether your reference is activated before? Some of the rarer or first-time references get way more attention from chasers who are trying to collect new ones.

Recent major DXpeditions seem to be using increasingly wide split ranges, some spanning 20+ kHz on SSB. It is NOT necessary to use more than 10 – 15 kHz for a SSB pileup and 5-8 kHz for a CW pileup. If a pileup of this width creates difficulty for the DXpedition operator, it will be necessary to pare the pile in such a way as to reduce the number of callers. The bands don't belong solely to DXers. To believe that they do is nothing if not arrogant. What are reasonable bandwidth limits, and how should DXpedition operators better manage oversized pileups? The 'by numbers' approach seems underutilized compared to endless wide splits.

so i just passed my tech exam last week and im starting to look at handheld radios and honestly the options are overwhelming. everybody seems to have an opinion and half the people on youtube are clearly just doing sponsored stuff so i dont really trust those videos. i keep seeing the Baofeng UV-5R recommended everywhere as a starter radio and its like $25 which is tempting, but then i also see people saying dont bother and just save up for a Yaesu or Kenwood. i dont even know what features i actually need at this point. im probably just going to be hitting local repeaters for now, maybe some simplex with a friend who lives about 8 miles away. dual band seems useful i guess? i have no idea if i need all the extra stuff like APRS or whatever. is the cheap Baofeng route actually fine to start or am i going to regret it in 6 months and wish i spent more. genuinely no idea what im doing here, any advice appreciated

I had the exact same problem when I started! If you're not hitting a repeater when you think you should be, first check to see that you're transmitting the correct CTCSS tone. Also verify you have the correct input frequency programmed - the offset should be -600 kHz on 2m.

yeah 15 has been pretty good this week, worked a couple JA stations on it tuesday morning around 0100z which i wasnt expecting. the flux being up helps a lot, we're definitely on the upswing of cycle 25 and honestly its been better than a lot of people predicted a couple years ago. for tracking openings i use DXmaps and also just watch the cluster — when you start seeing spots from your region to a particular part of the world, thats usually your cue to point the beam that direction and see whats there. pskreporter is great too especially if you run any digital modes, you can actually see your signal getting decoded in places even when you cant hear anything coming back. also your point about the K index is spot on, anything above 3 or 4 and the higher bands start getting squirrely. geomagnetic activity is the enemy of good DX. congrats on getting the beam sorted out by the way, a phasing issue can rob you blind without you ever knowing it.

so ive been going back and forth on this for like two months now and i need to just make a decision. currently running a 40m half wave dipole up about 25 feet, fed with coax, center at maybe 25 feet with the ends drooping a bit cause i ran out of real estate. its working okay but i keep reading about verticals and how they have a lower takeoff angle for dx and i got bit by the dx bug pretty hard lately. thing is i live on a small lot, maybe 60x100 feet, and the dipole is already kind of crammed in there. a vertical might actually be easier to fit physically. but then i read all the stuff about ground radials and how you need like 60 of them to make it work right and my yard just isnt set up for that. i could do elevated radials maybe. anyway is the vertical actually going to do better for dx or is 25 feet just too low for the dipole to be competitive at all. feel like im going in circles reading antenna modeling threads

Had the same problem last month. Solution was reducing the LNA gain and running a homemade AM broadcast blocking filter to eliminate intermodulation. Those V4s have very broadband front ends that can get overwhelmed by strong local signals.

yeah the Farnsworth method that other person mentioned is legit, thats basically what LCWO does. i went through the same thing going for my extra and wanted CW even though its not required anymore just because it seemed like a cool skill. honestly the thing that helped me most was just getting on the air even when i wasnt ready. i started calling CQ real slow on 40m and when people came back too fast i just sent QRS and asked them to slow down. most guys are really cool about it and some of them became my regular skeds. nothing beats actual QSOs for building speed, copying practice files is fine but real contacts have that pressure that somehow makes your brain work harder.

congrats on the build, the QCX kits are really satisfying when they just work. i did the regular QCX on 20m a couple years back and felt the same way. re: the antenna thing yeah what the previous guy said is right but also dont sleep on just operating more with what you have for now. like part of learning QRP is learning to work with marginal conditions and it makes you a better operator tbh. i spent a whole winter working 40m QRP with a compromised antenna and it taught me a lot about timing, propagation, calling CQ vs hunting, all that stuff. the DX will come eventually, dont get discouraged if it takes a while

honest answer — it took me almost a full contest season before SO2R felt natural rather than like i was actively making my score worse. the first few times i tried it i was so focused on managing the second radio that my run rate actually dropped, which kind of defeats the whole point. what helped me was only using the second radio for S&P during the slower periods, not trying to do anything fancy, just tune around on 15 while i was running 40 during a lull. baby steps. the hardware side is real though. bandpass filters are not optional if your two bands are anywhere close to each other. i run a pair of 4O3A monoband filters and even then i had to be careful about antenna placement. if you're on a hex beam you're probably okay since it's directional and you can at least point the two signals somewhat away from each other, but dont expect it to be plug and play. the station integration piece takes time to sort out. W5XD has some good writeups on the logging side if you're using writelog or N1MM, the SO2R support in N1MM is pretty solid now actually.

QRO and QRP are ones that come up a lot too, high power vs low power, theres actually a whole subculture around QRP operating with like 5 watts or less which is kind of a cool challenge once you get more comfortable. and honestly dont stress too much about memorizing all of them, half the time even experienced operators have to look stuff up if someone uses an obscure one

yeah i run basically exactly that setup, N1MM for contests and Log4OM for everything else. been doing it probably 18 months or so. the ADIF import/export works fine honestly, i just make sure to export from Log4OM before a contest weekend and import into N1MM so the dupe checking is current. after the contest i export the N1MM log and pull it back into Log4OM. takes maybe 5 minutes and ive never had a serious problem with duplicate QSOs showing up. you do need to pay attention to the date/time fields because i had one weird thing early on where a few QSOs got the wrong timezone but thats a Log4OM settings thing and once you fix it its fine. the WSJT-X integration with Log4OM is actually pretty decent now, it wasnt great a couple versions back but they fixed a lot of it. you can point the UDP logging at Log4OM the same way you do with N1MM, just change the port in WSJT-X settings and set Log4OM to listen on that port. only thing is you cant run both at the same time listening on the same port obviously so on contest weekends when im using N1MM i just switch the WSJT-X UDP back. not a big deal.

the thing that always gets people is the small stuff honestly. like yeah everyone thinks about the radio and the battery but then youre out there and your coax connector is loose and you didnt bring any electrical tape or a small crescent wrench. i keep a little ziplock bag in mine with some tape, a few spare PL-259s, a barrel connector, and those little anderson powerpole spares. also a headlamp with extra batteries because somehow it always ends up being dark when stuff goes wrong. the solar panel thing is worth dealing with even if its bulky. i have a 50 watt panel that folds up and honestly once you get used to dragging it around you stop thinking about it. pairs really well with a lifepo4 setup. also if youre doing ARES or RACES stuff check with your EC about what frequencies they actually use day of because the laminated sheet is great but sometimes things change and you want to know who to call to get updated info. sounds like youre in better shape than most people who show up to their first activation with a handheld and a prayer though so youre ahead of the game

ok so i passed my general a few weeks ago and ive been trying to figure out exactly where i can operate on 40 meters. i know technicians are pretty limited but i thought generals had most of the hf bands... anyway i pulled up the arrl band plan and also the fcc part 97 allocations and they dont quite match up, or at least they look different to me and im not sure which one actually matters legally. like the band plan shows certain modes in certain parts of the band but is that actually a rule or just kind of a gentlemans agreement thing? and also someone at my club said to stay away from the band edges which makes sense i guess but how far away are we talking. my rig shows 7.000 and i dont want to accidentally transmit out of band if my vfo drifts or whatever

the lifepo4 route sounds solid to me honestly. i did a similar thing last summer for a 24 hour public service event and ran two 100ah battleborn batteries in parallel feeding everything through a west mountain epic pwrgate. the IC-7300 was our main rig too and we barely touched 60% state of charge over the whole event running a mix of digital and voice. your math on the average current draw sounds about right, maybe a little conservative depending on how much receive time vs transmit you have. the thermal thing is real though. lifepo4 doesn't like sitting in direct sun baking all day, not because it'll catch fire like some of the older lithium chemistries but the BMS in most of those batteries will start derate or even shut things down if the cells get too hot. we threw a cheap moving blanket over ours and it made a noticeable difference. just dont seal it up completely obviously you still want some airflow. personally id bring the honda anyway as a backup even if you dont plan to use it. fuel logistics for 12 hours on a 2200 is like, what, 2 gallons? thats nothing. but yeah try to run on batteries first, generators at exercises always seem to bring drama, spilled fuel, noise complaints from the served agency, someone flooding the carb, you know how it goes.

headlamp. seriously. I dont know why its not the first thing people think of but half the emergencies where you need radio comms are at night or in a building with no power and youre trying to tune something or read a meter and you need both hands. my kit has a headlamp with fresh batteries duct taped right to the inside lid of the case so I literally cannot open the thing and not see it. also snacks lol. sounds dumb but if you get deployed for 8 hours you will be very grateful for the granola bars you packed six months ago

honestly just download morse-it or one of those phone apps and mess around on your commute or whatever. thats what i did and i mean im not great at it but i can pull calls out of a pileup now which is more than i could do a year ago. the thing nobody tells you is its just repetition, like theres no trick, you just have to hear the same letters so many times your brain stops thinking about it. i still count dits sometimes when im tired lol but it does get better

Had this exact problem last month! Switched from Windows time sync to Meinberg and went from 10% decode rate to 95% overnight. Also helped that most FT8 users take advantage of online time servers using NTP or GPS signals for automatic time accuracy.

dont stress too much about memorizing the whole list honestly, you just kind of pick them up as you go. i was maybe a year in before QSB clicked for me as fading because i kept confusing it with something else. one thing that tripped me up early on was people saying QRZ as like a question when someone called CQ and they didnt catch the callsign, took me a while to realize thats just standard and not like a formal procedure or anything. just listen to a few nets and itll start sinking in pretty fast

oh man, six weeks and already copying 12wpm is actually pretty solid, dont be too hard on yourself. the sending thing takes longer than people expect because youre basically training muscle memory and that doesnt happen fast. the paddle tension and spacing adjustment makes a huge difference though — if its a cheap ebay paddle the contact gap might be inconsistent or the tension spring is just garbage. try backing the gap off a little wider than you think you need and slow the keyer way down, like 8 or 9 wpm, and just drill your problem letters over and over until they feel automatic before speeding back up. on the iambic mode A vs B thing, mode B keeps sending the last element when you release the paddle which some people like but a lot of folks find it creates extra dits or dahs they didnt intend especially when first learning. mode A stops cleaner. i'd just stick with A for now, less to think about.