David Davis44

so ive been trying to work some DX on 17 and 20m this week and the conditions have just been completely unpredictable. like monday afternoon 20m was wide open, i was hearing stations from japan and australia like they were next door, logged a bunch of JA's without even trying that hard. then tuesday morning i go to check the band and its completely dead. like nothing. not even noise really. i've been watching the solar flux index on dxmaps and it was sitting around 145-150 which i thought was supposed to be pretty decent? but then the K index jumped up to 4 or 5 and i think that killed everything. i'm still learning how to read all this stuff so maybe im misunderstanding what the numbers actually mean in practice. does a high solar flux not matter as much when the K index spikes like that? feels like two steps forward one step back with this hobby sometimes

so ive been working on this double sideband transmitter for 40m on and off for like three months now, mostly following the W7ZOI designs from Experimental Methods but tweaking a few things based on what i had in the junk box. got it actually putting out a signal last weekend and made a couple contacts which was pretty wild honestly. my balanced modulator is a diode ring using 1N4148s, nothing fancy, and the carrier null is sitting around 40dB down which i think is decent for what it is. the final is a single IRF510 running class E, getting somewhere between 3 and 4 watts out depending on the supply voltage i feed it. my question is about the low pass filter after the final. i just threw in a 7-element chebyshev i calculated with one of those online tools and it seems to be working but ive never actually verified the harmonic suppression with anything better than my cheapo rtlsdr. does anyone have experience eyeballing whether a lpf design is trustworthy or do i really need to throw it on a real spectrum analyzer before i start using it on the air regularly. i dont want to be that guy lighting up harmonics all over the place

so ive been trying to learn CW for about 4 months now and i can copy at around 12-13 wpm when im relaxed and listening to W1AW or just random QSOs on 40m but my sending is just... embarrassing. i got a cheap Taiwanese iambic paddle off ebay and i think the tension is set way too light but i cant figure out if thats the problem or if its just me being inconsistent with squeezing. my keyer is set to iambic mode B and honestly i dont even fully understand the difference between mode A and mode B yet. like when i try to squeeze both paddles for the intersymbol stuff i just get a jumbled mess. been practicing with the keyer hooked up to a sidetone amp so i can hear myself without actually transmitting, which is good because nobody wants to hear what im putting out right now lol. should i just go back to a straight key for a while? some people online say that builds better habits but then other people say just stick with the paddle. getting conflicting advice everywhere i look.

yep thats alternator whine, classic. the RPM thing is the dead giveaway. first thing i'd try before anything else is running a dedicated ground wire all the way back to the battery negative instead of using the chassis. i know it sounds like overkill but newer trucks especially toyotas have all kinds of weird ground loops because of the electronics everywhere. the chassis ground on those is fine for a lot of things but for radio it can pick up noise from the ABS module, the ECU, all kinds of stuff. also double check where your power wire runs — if it's anywhere near the factory wiring harness for any significant length that can also introduce noise. i had a similar deal in my tundra a few years back and just rerouting the power cable solved about 80% of it, then a small choke on the audio line got the rest. mag mount probably isnt helping either since the ground plane isnt great but that shouldnt cause the whine specifically.

im pretty new too but i started listening to nets on my scanner before i even got my license just to figure out how they worked and that helped a lot. maybe find a recording of the net online if they archive it, some clubs do that. or just listen a few more times before checking in again so you get a feel for the rhythm of that specific net because they can vary quite a bit.

one thing i'll add is that 7.175 to 7.225 tends to get pretty congested with SSB, lot of rag chewing and some nets in there. if youre just starting out and want to make some contacts without stepping on stuff, somewhere in the middle of your allocation is usually fine. i had the same confusion when i upgraded and spent like a week just listening before i ever keyed up, that helped a lot more than reading about it tbh

yeah the mode A vs B thing confused me too when i started. im still pretty new to CW myself but one thing that really helped me was slowing way down on a straight key first just to get the rhythm of each character in my head before going back to the paddle. probably not what everyone says to do but it worked for me. also there are some youtube videos from guys doing slow CW demonstrations and just watching how relaxed their hand looks kind of showed me i was gripping the paddle way too hard

yeah 40m at night in the suburbs is just rough, nothing you did wrong. i live in a pretty dense area and my S-meter is basically pegged until like 2am sometimes. i use the bandscope mostly for contests when i need to find a run frequency fast, otherwise i kind of forget its there honestly

so ive been a licensed ham for about 8 months now (general class) and i joined my local ARES group back in the spring mostly because i wanted to do something useful with the hobby instead of just calling CQ into the void. did a couple of the training nets and the SET exercise back in october which was mostly just check-ins and passing some simulated health and welfare traffic, nothing crazy. anyway they just activated us for real to support the county emergency management office during the flooding that's been going on. nothing like a full disaster situation but the EOC wanted some extra comms support and our EC called us up. im set up for this in theory — i have my go-bag with a Yaesu FT-60 and a roll of coax and a mag mount, laptop with Winlink Express, all the stuff they told us to bring to the exercises. but actually doing it for real has me second guessing everything. like what if i forget something or mess up a message or dont understand a net control instruction. anybody else felt like this their first real activation? did it just kind of click once you were actually there or was it a rough learning curve?

yeah i did the mars mod on mine probably three years ago, same deal with the diodes being a little confusing to locate if you dont have the right revision of the manual. the thing i'd caution is just making sure you're documenting exactly what you clipped before reassembly because i had a buddy who did it on an 897 and couldn't remember afterward which ones he'd touched and had to trace the whole board again. on the noise floor question, i messed around with the IF filter mods for a while and honestly the biggest bang for my buck was just putting a decent external preamp on weak signal VHF rather than touching anything internal. the stock preamp in the 857 is fine for HF but for 2m SSB weak signal stuff it's just not great. collins filter swap on SSB is legit though if you do a lot of crowded contest operating, made a real difference in a pileup situation for me.

same thing happened to me lol, spent like an hour one evening wondering why i couldnt find my downlink and it turned out i was tuning the wrong direction the whole time because of the inversion. once that clicked it made way more sense. also make sure gpredict is actually connected and sending tuning commands to your radio, sometimes the CAT link drops and you dont notice and then youre manually tuning a moving target which is basically impossible

yeah the door jamb pinch is almost certainly your problem on UHF. coax is way more sensitive to that kind of thing at 440 than at 146, the wavelength is short enough that even a small kink or compression point can mess with the impedance. i did the same thing on my Tacoma years ago and had almost the exact same symptom, 2m was fine, 70cm was off. what i ended up doing was routing through the actual rubber grommet on the firewall instead and going under the truck instead of through the cab. took an extra hour but SWR on 440 dropped right down. the Tram 1185 is a decent antenna, shouldn't be the issue. if you really dont want to re-route, you could try to very carefully open that door jamb section back up and see if the coax looks pinched or has any weird bends. sometimes you can get away with repositioning it just slightly and the problem goes away.

yeah i had the same confusion when i started. one thing that helped me was just remembering that phonetics exist because letters get garbled, so if you wouldnt have any trouble understanding the letter just say the letter. its not like the phonetic police are gonna come after you. i mostly use full phonetics when im giving my call at the start of a contact or if someone asks me to repeat something. mid-conversation i just say the letters normally most of the time

mode A vs B honestly doesnt matter much when youre learning, dont get too hung up on it. most people find one that clicks with them eventually but at 8-10 wpm its not gonna make a real difference. just leave it on A for now and focus on getting comfortable with the paddle. the hand-brain disconnect thing you mentioned is totally normal and actually a sign youre doing it right — youre trying to send from memory rather than thinking about each dit and dah. that feeling goes away with time. i remember feeling the same way around that speed and then somewhere around 13-14 wpm something just kind of clicked. keep at lcwo, its a solid tool. also dont neglect actual on-air time, even just listening to slow CW nets. there are a few good ones on 40m in the evenings if you poke around.

so ive been running a pretty standard 40m dipole at about 25 feet for the past two years, fed with coax, nothing fancy. works okay for regional stuff but DX has always been kind of hit or miss. a buddy of mine keeps telling me i should put up a vertical instead and says the low angle radiation will make a big difference for working anything more than a few hundred miles out. thing is i dont really have a great spot for a vertical unless i put it near the fence which is probably not ideal and i'd have to lay a bunch of radials under there. not sure if a 4:1 unun and some random length wire would be just as good or if thats a completely different animal. anyone actually done a side by side comparison or switched from one to the other and noticed a real difference on 40? wondering if its worth the hassle of redoing everything.