Everything posted by Repeater Tech
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Band edge operation safety - why stay away from the edges?
Three main reasons to stay away from band edges: calibration error in your radio, frequency drift as the transmitter warms up, and modulation sidebands extending beyond your carrier frequency. Most experienced hams stay at least a few kHz inside the band edges as a safety margin - better to err on the side of caution than risk an FCC citation for operating out of band!
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RTL-SDR vs SDRplay for general HF listening — worth the price jump?
i have the RSPdx and like it a lot but tbh for MW DX the antenna matters way more than the radio. im using a 40 foot longwire out back and even the rtl-sdr pulled in some decent catches on it. the SDRplay just makes it less frustrating when the bands are busy. also SDRuno crashes on my machine like once every hour or so which is annoying, some people swear by it but i keep going back to SDR# with the SDRplay ExtIO plugin just because its more stable for me. ymmv
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RF in shack despite proper bonding - ground loops or common mode currents?
I had similar issues on 40m until I added a second choke right at the antenna feedpoint. The first choke wasn't enough - needed one at each end of the transmission line to fully break the CMC path. Also check for any ground loops between your shack ground and AC safety ground.
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AO-91 doppler shift driving me crazy
Yeah the 9700 can be tricky with sat mode. You need to make sure you have the right CAT commands set up in gpredict and that your uplink/downlink frequencies are exactly right. I had the same problem until I realized I was using the wrong beacon frequency as reference. Also check that your doppler.dat file is current - old keps will throw everything off
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finally did my first WWFF activation last weekend, few questions
oh man i did my first one like three months ago and had the same questions, the 44 QSO thing threw me off too. i ended up on the WWFF facebook group and people there are super helpful if you ever get stuck. also i didnt realize til after my first one that you should try to spot yourself on the WWFF spotter network before you start, makes a huge difference for how fast the QSOs come in. i only got like 28 my first time because nobody knew i was out there and i was just calling CQ into the void for a while lol. second time i spotted myself and hit 44 in like 35 minutes, totally different experience.
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first solo POTA activation went way better than expected
so i finally did it, been putting it off for like 6 months because i kept telling myself i wasnt ready or my setup wasnt good enough or whatever excuse i could think of. went out to a state forest park near me saturday morning with my KX2 and a random wire thrown up in a tree and just... did it. logged 32 QSOs in about an hour and a half which i know isnt a huge number but for a first activation i was pretty happy with it. the thing that surprised me most was how many hunters were already waiting once i spotted myself on pota.app. like within 2 minutes of putting the spot up i had a small pileup going on 40m. wasnt expecting that at all, had to slow down and actually work a bit of a system instead of just casually chatting like i normally do. ended up doing a bit of running which i've never really done before. one thing i wasn't sure about — do you need to log the park reference on every single QSO entry or just note it somewhere in your log? i was using my phone with hamrs and it seemed like it attached the park ref to all of them automatically but i want to make sure before i upload to the pota website. anyway if anyone else has been on the fence about doing an activation just go do it, totally worth it
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APRS beacon showing up on aprs.fi but messages not getting through??
so ive been running APRS for about 6 months now, got a TM-D710G in the truck and its been working pretty well for tracking purposes. i can see my position updating on aprs.fi no problem, usually every 2-3 minutes depending on how fast im moving with the smart beaconing turned on. but the messaging part is driving me nuts. sent a message to a buddy of mine who was running Xastir on his laptop at home through his igate setup and he never got it. i could see my message packet going out in the log but nothing on his end. he tried sending back to me and i got nothing either. we both show up on the network just fine, its just the two-way messaging that isnt working. is there something specific i need to do for messaging to work vs just tracking? i assumed if im beaconing and getting digipeated that messages would work the same way but maybe thats not how it works. been googling for an hour and getting kinda mixed results on what the actual flow is for APRS messages
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SO2R Interference Issues - Need Band Filter Recommendations
Don't skip the filters! Never try SO2R without band filters or stubs - learned this the hard way when I nearly fried my IC-706's front end during CQWW. Even simple homebrew filters made a huge difference in my setup.
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using an arduino to key my radio automatically — ran into a weird issue
so ive been working on this little project for a few weeks now, basically trying to get an arduino uno to key my IC-7300 via the CI-V interface and also trigger the PTT line with a transistor. the idea is to automate some beacon transmissions on 10m while im at work, nothing fancy just ID every 10 minutes or so with a CW message. anyway everything was going fine, i had the timing worked out and the morse code library was doing its thing, but now whenever the arduino tries to key up i get this nasty voltage spike on the audio line and it ends up with a weird chirp at the start of every transmission. i measured the PTT line and its clean but somewhere between the arduino firing and the final RF going out something is causing that audio artifact. i put a 100 ohm resistor inline thinking it was a grounding issue but no dice. has anyone dealt with this before? im using a 2N2222 as the switching transistor and the arduino is powered off a separate USB supply from the radio. maybe thats the problem actually, ground loops are the bane of my existence with this stuff.
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First-time Go Kit build - Looking for advice!
Don't forget the boring stuff that kills go-kits! Extra coax, Anderson Powerpoles, fuses, electrical tape, and a basic multimeter. Nothing worse than being sidelined by a blown fuse during an activation. Ask me how I know...
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dipole vs vertical for 40m — is it even worth debating anymore
so ive been going back and forth on this for probably three months now and i cant make up my mind. currently running a 40m dipole fed with ladder line through a tuner, its up about 30 feet which i know isnt ideal but its what i can do with my lot. works okay but i keep reading about how a vertical with a good radial field can outperform a dipole at low angles for DX and that kind of makes sense to me propagation-wise but then i also read the opposite from other people so who knows the thing is i dont have a ton of space for radials either. my backyard is pretty small and the neighbors are already suspicious about the wire going to my fence post. was thinking maybe 16-20 buried radials could work but digging in this clay soil is brutal. anyone actually done a comparison or am i just going to keep reading conflicting stuff forever not really interested in a beam right now, thats a whole other conversation about towers and money i dont want to have
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thinking about going for the extra but not sure if its worth the effort
so ive been a general for about two years now and honestly i dont use most of the privileges i have as it is, mostly just do some casual HF on 40m and occasionally 20m when the bands cooperate. my buddy keeps telling me to just go for the extra already but i looked at the question pool and some of that stuff is... a lot. like the filter theory and the whole section on transmission lines and impedance matching, i mean i passed calc in college but that was a long time ago. is the extra actually worth studying for if i'm not planning to do a ton of contesting or DX? i guess what im really asking is does the extra open up stuff that a normal general operator would actually care about, or is it mostly just the prestige thing and a few khz of extra band space. also how hard is the theory portion really compared to the general, like on a scale of actual difficulty not just 'oh its not that bad' because people always say that
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finally putting together a go-kit, what am I missing
So ive been meaning to do this for like two years and after the storm we had last month kind of rattled me into actually doing it. I got a Yaesu FT-891 I was gonna use as my base but thinking it makes more sense to make it the centerpiece of the go-kit since I have the IC-7300 at home anyway. Right now I have the radio, a 40ah LiFePO4 battery, anderson powerpole distribution block, a few different coax jumpers, and im building out a cheap pelican-style case to fit it all. I think I have the basics but honestly I dont know what experienced emcomm guys actually reach for when things get real. Like the stuff you forget about until you need it. Antenna situation is kind of a mess right now - I have an EFHW and a buddistick but neither is really set up for rapid deploy. anyone running something they can throw up in under 10 minutes without thinking about it? thats kind of the goal here.
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Common Mic Habits That Drive Other Hams Crazy
Some radios are more sensitive than others when it comes to audio level. And it is possible to have too much audio, so ask other hams for a signal report. Ask specifically about your audio level…loud enough, too loud? For most of us, that's the only way we are going to find out how we sound.