Ham Radio / Off-grid communication

[888Flux]

I have a friend who's college offers that stuff for free.
my only concer though is its ability to stand up in heat, I had some 3d printed boxes ordered when I was making some experimental EFHW it held up for a couple of days until the heat and tension ripped it in two.
Im pretty sure it'll hold up better on this set up since there wont be any strain on it but im concerned that it'll eventually start to sag do to the outside heat and heat directly from the coil (600W PEP)

Would you like an OpenSCAD file for printing one? I can model it so you can change all of the parameters (diameter, thread spacing, etc).

PLA+ or carbon fiber nylon should be able to withstand high temperature over long periods of time with minimal or no deformation. Add 99% infill and you should be good to go. What was the source of the heat issue btw? Was it just sun exposure for too long?

If you are printing for anything in PLA / PLA+ that is going outdoors with high ambient temperatures and UV exposure you should anneal your prints. Look for a mini stove oven at any second hand store or on Craigslist, facebook marketplace, etc, and you can probably find one. It only needs to get up to 110 C (230 F).

 

[Jotch]

It's impahsible!

As additional, here's a great recording from 7200 on the 28th featuring Liquid Joe:

 

[WanderingFarmer]

Has anyone ever used one of these?

I keep seeing these and their variants touted on various HAM channels on YT and everyone seems to be fairly positive about them. The only problem is that the people singing their praises are usually the ones with affiliate links and/or discount codes in the description. So its always a little sussy.

This seems like a great bit of kit to have in your bag if you're going mobile if it does what its supposed to.

I have one! It let me build my EFHW and tune it to a 1.1-1.2 SWR
They're nifty, powerful, and require an arcane ritual to tune properly for it to be effective, but you can write the steps on a notecard to keep with it and be just fine. For me it was a much better option that getting a "proper" antenna analyzer.

If you look sites like Thingiverse & Printables you can also find some 3D printable protective cases for it

https://www.printables.com/tag/nanovna

https://www.thingiverse.com/search?q=nanovna&page=1

Here's storage for the calibration connectors: https://www.thingiverse.com/thing:4798780

Well I have my next printing project. mine just lives in a pocket in my portable electronics repair bag,

 

[WanderingFarmer]

I'm not sure if any of y'all have heard of the GHOSTNET or not, but its some monotone dude that's trying to put out his "signal analysis" of events going on around the world and where he sees trouble brewing. I can't tell how much of it is LARP and how much is him genuinely trying to help normies with a psudo-prepper vibe, but he's out there trying to get folks thinking about infosec and how to communicate without cell networks or the internet.

His ghostnet project, while horribly formatted as a PDF my printer refuses to play nice with, is an interesting idea, at least, and makes use of a less popular digital mode called JS8CALL. Think FT8, but you can type out messages to send to individuals or to a full list of people that voluntarily subscribe to the notification. The short version is he writes up a bi-weekly newsletter and sends it out, encouraging every recipient along the way to copy and resend the newsletter to be sure it has worldwide propagation. I just set it up tonight in preparation for the Thursday net, so we'll see how it goes. BTW if any of you are using Linux and WSJT-X or JS8CALL giver you permission denied errors, that means your user profile isn't in the `dialout` group. Took me hours to figure out and ruined a POTA attempt.

Anyways, S2 Underground has got me thinking though, that we could set up something like that for the Farms here. I could take the community happenings and on a weekly basis turn it into a newsletter to send out at a certain time, like Sunday Morning 0230 UTC for example. I propose the tag to follow as `@KFALL` for the global tag that would be for disseminating the community happenings newsletter, and then a regional tag of `@KFUSA` for discussing regionally appropriate news and happenings, and down to the state level for local lolcows to be discussed like `@KFUSAFL` if dear feeder ever decided to burn his sheckles to get an HF rig.

As with any HAM stuff, you'll have to have a callsign to transmit (unless you want to tinker with the software and figure out that workaround), but you're able to receive without an FCC permission slip.
Now that I have my radio playing nice with my laptop and decoding FT8 and JS8CALL, I'm going to make sure my radio is transmitting right, get FT8, JS8CALL, and WinLink email working for TX & RX, and hopefully before the end of the month I'll be set up to try browsing KF through my radio.

 

[888Flux]

nyways, S2 Underground has got me thinking though, that we could set up something like that for the Farms here. I could take the community happenings and on a weekly basis turn it into a newsletter to send out at a certain time, like Sunday Morning 0230 UTC for example. I propose the tag to follow as `@KFALL` for the global tag that would be for disseminating the community happenings newsletter, and then a regional tag of `@KFUSA` for discussing regionally appropriate news and happenings, and down to the state level for local lolcows to be discussed like `@KFUSAFL` if dear feeder ever decided to burn his sheckles to get an HF rig.

YES!!!!!!

20m daytime / 40m night from anywhere in the lower 48 United States will work for something like that. Global broadcast will depend on band conditions but JS8call is very permissive. Could also experiment with some of the teletype contest modes in fldigi for text transmission.

I'm currently limited to portable ops but will absolutely participate in this. A monthly or twice a month schedule i think would be reasonable. There are still some logistics to work out, but this sounds like a very cool idea.

 

[Muad'Dick]

I have one! It let me build my EFHW and tune it to a 1.1-1.2 SWR
They're nifty, powerful, and require an arcane ritual to tune properly for it to be effective, but you can write the steps on a notecard to keep with it and be just fine. For me it was a much better option that getting a "proper" antenna analyzer.

I caved and bought one, and they really are a fantastic bit of kit. In fact, after using it for a few days, I would say they fit the "essential" category in terms of what you take with you when you go mobile.

I'm a big EFHW fan. I've run them many times in the wild while hooked up to a Chinesium handheld of some description (I've as good as started collecting these things now for how much they cost) and had some great contacts. I like seeing how far I can get out there on a low power setup. Thats been a thing since my old CB days and probably why I've got a bit of an obsession with throwing wire up a tree.

One thing I've been running for about a year now is one of those "spark plug" antennas. They can take a good battering and because of their size you can just throw one in your bag alongside a spool of wire. Its basically just a semi-ruggedized unun.

 

[Polock]

I'm currently limited to portable ops but will absolutely participate in this. A monthly or twice a month schedule i think would be reasonable. There are still some logistics to work out, but this sounds like a very cool idea.

I've been mildly interested in participating in ghostnet but would totally be on board for kiwinet.

However you'd need to spoonfeed me how to set it up, since I've been prioritizing other things other than radio stuff. I'm sure I'm not the only one here who'd benefit.

I can't tell how much of it is LARP and how much is him genuinely trying to help normies with a psudo-prepper vibe, but he's out there trying to get folks thinking about infosec and how to communicate without cell networks or the internet.

I think he's mostly genuine, in an autistic way without going full politisperg. I really like his global happenings map.

 

[WanderingFarmer]

I'm currently limited to portable ops but will absolutely participate in this. A monthly or twice a month schedule i think would be reasonable. There are still some logistics to work out, but this sounds like a very cool idea.

So am I! I'm limited to 5W, but that should be enough. I'd like to try for weekly till I'm sure things are working, but once that's confirmed I wouldn't mind dropping back to monthly or twice a month.

I've been mildly interested in participating in ghostnet but would totally be on board for kiwinet.

However you'd need to spoonfeed me how to set it up, since I've been prioritizing other things other than radio stuff. I'm sure I'm not the only one here who'd benefit.

You got it. I'll put together a doc. It's not much harder than WSJT-X, but I ran into issues myself. Instructions and preliminary configs to come soon.

I wouldn't mind some "be sure to talk about 'x'" DMs so I can figure out what y'all want to be covered besides the community happenings. Like, I need to dig into the 7200 drama and try to tune in myself.

I caved and bought one, and they really are a fantastic bit of kit.

Good! Same conclusion I came to, and I'm glad it's working out for ya.

One thing I've been running for about a year now is one of those "spark plug" antennas. They can take a good battering and because of their size you can just throw one in your bag alongside a spool of wire. Its basically just a semi-ruggedized unun.

Yeah those look neat! If you get one built you'll have to let me know how it works for ya.
I'm wanting to try building my own coil loaded whip like elecraft makes. I'd like to have one for ultra portable ops, even if it's not the most efficient I'd like to be a mega dork and use my X6200 as an HF HT.

I think he's mostly genuine, in an autistic way without going full politisperg. I really like his global happenings map.

It's a good map. I like to think he's genuine too, he certainly doesn't go for ads, monetization, or promoted reads at least.
Plus I like that he's experimenting with different means of communication rather than a podcast only and different platforms.

 

[Muad'Dick]

Yeah those look neat! If you get one built you'll have to let me know how it works for ya.
I'm wanting to try building my own coil loaded whip like elecraft makes. I'd like to have one for ultra portable ops, even if it's not the most efficient I'd like to be a mega dork and use my X6200 as an HF HT.

I'd recommend one of these to anyone. Its my goto antenna if I'm camping etc and its a permanent fixture in my bag of tricks.

Its a 64:1 unun, so on a half-wave you end up with a perfectly serviceable multi-band antenna. I'd recommend at least 25ft of coax as a counterpoise (I take 30ft and all of my wires are tuned to that) and a choke at the radio end of things. I have 4 different wires on kite spools in my bag that are tuned so that one band is optimum. 20-meters is my usual haunt, but its nice to have options.

You can easily work it outside of your intended band. The SWR isn't crazy but like any other antenna, if you stray too far from the optimum then things start to get dicey. That being said, I was shocked at how forgiving an EFHW using one of these would be. If your radio has an onboard tuner you're golden.

The main reason I love these so much is that you can just throw it in a bag and forget about it. You would have to take a hammer to it or throw it against a wall before you inflicted any damage, which is exactly what you need for the kind of set ups you'll be using it for.

Just for reference I bought the 50W version. Its been used in anger about 20 times or more now and it's never failed me.

10/10 would throw into a tree.

 

[WanderingFarmer]

You can easily work it outside of your intended band. The SWR isn't crazy but like any other antenna, if you stray too far from the optimum then things start to get dicey. That being said, I was shocked at how forgiving an EFHW using one of these would be. If your radio has an onboard tuner you're golden.

The main reason I love these so much is that you can just throw it in a bag and forget about it. You would have to take a hammer to it or throw it against a wall before you inflicted any damage, which is exactly what you need for the kind of set ups you'll be using it for.

Oh yeah I have an EFHW now, tuned to 20m, and I'm attempting to convince a new HAM friend of mine to let me print him the winder and give him the ferrite core he needs to make one, but he's insisting on a half wave dipole setup because some forum he was reading told him that was the best way to start.
Thankfully I have a tuner built in to my chinesium brick. His set up won't have one so I'll be insisting on helping with the final tuning, firing up the NanoVNA again or loaning it out.
Still the mini-vertical whip should be a fun project. With luck I have everything I need.

 

[Muad'Dick]

Oh yeah I have an EFHW now, tuned to 20m, and I'm attempting to convince a new HAM friend of mine to let me print him the winder and give him the ferrite core he needs to make one, but he's insisting on a half wave dipole setup because some forum he was reading told him that was the best way to start.

Half-wave dipoles aren't too shabby. They're good for cutting your teeth on if you're starting out.

I didn't make my spark plug. I got it from here. After seeing one for the first time at a meet and seeing how well made they were, there was no way I'd be putting something together that well, and for the money it's a steal. I made my own 49:1 years ago with its own sealed enclosure, but when I first saw this guy's work it was an instabuy. They're all handmade too, which is a nice touch.

 

[888Flux]

Oh yeah I have an EFHW now, tuned to 20m,

If you have an end fed half wave, check this out btw:

https://www.thingiverse.com/thing:4674180

A 110 microhenry coil can get a 20 meter (65 ft) EFHW operating on 80 meters. Perhaps the perfect NVIS antenna when in a horizontal configuration. You just wind some enameled magnet wire around a printable coil, and then add 2 meters of wire at the end. It doesn't change any of the tuning and functions as an antenna trap.

I am going to do some WSPR tests here soon with my EFHW + the 110 microhenry coil.

 

[Jotch]

A woman hops on 7200 to tell the dark truth about Alex.

 

[Perm]

Would you like an OpenSCAD file for printing one? I can model it so you can change all of the parameters (diameter, thread spacing, etc).

PLA+ or carbon fiber nylon should be able to withstand high temperature over long periods of time with minimal or no deformation. Add 99% infill and you should be good to go. What was the source of the heat issue btw? Was it just sun exposure for too long?

If you are printing for anything in PLA / PLA+ that is going outdoors with high ambient temperatures and UV exposure you should anneal your prints. Look for a mini stove oven at any second hand store or on Craigslist, facebook marketplace, etc, and you can probably find one. It only needs to get up to 110 C (230 F).

Im not very familiar with 3d printing, the more idiot proof the better. For the specs as long as it can load down to the the CW/FT8 section of 160m but if theres anything specific you need to know from me just ask (complete noob at 3d printing here) so I dont know what info you'll need from me

Both sun and ambient temperature did the damage, during the summers here it consistently hits 120F

 

[Channel Catfish]

I'd be interested in a KiwiNet. Wouldn't be able to repropagate it all the time, depends if I can receive it, but if I can I'd be able to.
You'd have to keep in mind that you'd be doxing yourself with your callsign though, so you'd either have to not identify your call or deanonymize yourself if you want that kinda thing to work

A woman hops on 7200 to tell the dark truth about Alex.

whoa.ogg

I haven't laughed this hard in a while. The boomers know how to shitpost.

 

[WanderingFarmer]

You'd have to keep in mind that you'd be doxing yourself with your callsign though, so you'd either have to not identify your call or deanonymize yourself if you want that kinda thing to work

Yeah I was going to transmit the kiwinet without a call sign. I know I know how dare I, but the transmission will be long enough without that too.
I'm curious to see tomorrow's ghost net and if S2 uses a call sign or not.

 

[888Flux]

I'm curious to see tomorrow's ghost net and if S2 uses a call sign or not.

Most do not, and my guess is the ones who do are "borrowing" them. The good news is is that any hypothetical KiwiNet will in fact take place over the worlds largest tin-can-string setup, so there is no need for the FCC to be concerned.

 

[Jotch]

turns out square CW (huge spectrum) is really easy to do, you can just hook up a wire to the output of an FPGA and toggle it at the right frequency.
For the longest time I was under the impression that radio was impossible to do without precise antenna stuff, but I guess if you're happy with 50 foot transmission then I guess it doesn't matter.
Funnily enough, if you only want to work in square waves, you can use an AND gate as a multiplier for AM modulation and similarly use and XOR gate for DSBSC modulation.
I want to see if I can do something more sophisticated with a DAC on the output and DSP path inside the chip. So I can put out an actual tone and possibly phone over it if I use an audio input ADC and mic.

If I can get that DAC's output to be nice enough I can just skip buying a radio and only buy an amp.

 

[Mikoyan]

turns out square CW (huge spectrum) is really easy to do, you can just hook up a wire to the output of an FPGA and toggle it at the right frequency.
For the longest time I was under the impression that radio was impossible to do without precise antenna stuff, but I guess if you're happy with 50 foot transmission then I guess it doesn't matter.
Funnily enough, if you only want to work in square waves, you can use an AND gate as a multiplier for AM modulation and similarly use and XOR gate for DSBSC modulation.
I want to see if I can do something more sophisticated with a DAC on the output and DSP path inside the chip. So I can put out an actual tone and possibly phone over it if I use an audio input ADC and mic.

If I can get that DAC's output to be nice enough I can just skip buying a radio and only buy an amp.

I'm pretty sure this is the whole thought process of the Chinese 'SDR' transmitters.

 

[Jotch]

I'm pretty sure this is the whole thought process of the Chinese 'SDR' transmitters.

Hey I can do it with $30 of hardware, so can they!
Difference being I will actually give a shit and probably spend almost $100 on a really good DAC.