Monday, May 11, 2015

Don't ask, just do

I was out running errands over lunch and I had my VHF radio scanning the local ham repeaters. It was almost noon, which meant it was time for all of the talking controllers to start telling me the time. It's a bit annoying - some of these systems only transmit to tell the time, as their users have either passed away or moved away. Even more annoying to me was the fact that none of their clocks were synced to an accurate time source. And then one of the repeaters started rebroadcasting the NWS severe weather outlook for this afternoon.

What may be annoying to me is experimentation and fun for others. I'm sure that the repeater builder that did the NWS radio interfacing had a good afternoon, weekend, or even week of experimentation to get it all to work. And the ham that programmed his custom macros into his controller probably had a hoot getting it all setup and customized.

I got to wondering...are all of these automated and retransmissions legal? This led me down one of my favorite rabbit holes - There I found this posting from WA6ILQ, The article is about weather radio interfacing to repeaters....but the fun part is near the bottom where he quotes an old ham about don't asking for permission...just go do it.
> The words were "Don't even (expletive deleted) THINK about it".
> As in don't make that (expletive deleted) phone call, don't write 
> that (expletive deleted) letter. Just build your wondertoy and use 
> it - but do it carefully, and cleanly (as in spectrally clean), and 
> make sure that you have your technical and legal arguments worked 
> out well in advance. Make sure that you aren't doing the A, B, or C 
> that the FCC forbids amateurs to do. If the FCC does't like your 
> brand new wondertoy or it's effects or emmissions they will send a 
> certified and return-receipt-requested cease-and-desist letter telling 
> you to stop doing it. At that point you stop doing it and send a 
> registered and certified and return-receipt-requested letter back  
> the next day (call in sick to work if you have to). In that letter 
> you say "I received  your letter on date (X) and at time (Y) 
> and at time (Y+5 minutes) I shut off the offending transmitter and I am sorry, 
> I didn't realize it was illegal and my thinking was (yadda yadda yadda) 
> and (yadda yadda yadda) and (yadda yadda yadda) and how can we resolve this?".
> (and you thought that those creative writing classes in college and 
> university were a waste of time...)
Words to live by. In ham radio, don't ask, just do. And who am I to complain? I can always update my scan list. I'm glad I'm a part of a hobby that lets this stuff happen!

Wednesday, May 6, 2015

Skunked at the park

Daughter #3 needed a ride to the big city and then picked up 2 hours later. Rather than adding extra miles to the jeep, I took along the kx3 and end fed portable antenna. A quiet spot was found at Maxwell Park and up went the antenna in a white pine. That was the end of the success for the night though as I got skunked - not a single contact. I did fight with the antenna a bit. I didn't bring the counterpoise wire and so that meant the coax and me were the ground. The bands seemed awful. Maybe everyone was out enjoying the nice weather, or that solar flare yesterday was worse than I thought. Don't worry...I'll be back!

Tuesday, April 28, 2015

An FM pileup

Last night was a big drill night for us on the Heyworth fire department. We have a large gas terminal located in our fire district. A pipeline runs to a tank farm where fuel products are stored and then loaded onto semi-trailers for transportation to other storage areas, gas stations, or private tanks. We had the terminal owners and three other mutual aid departments participating in the drill.

Communications is almost always a problem when you get that many people on scene. Radio communications become clogged as 10 apparatus arrive on scene. "Where do you want us? Send me this....Can you go here?" These message repeat over and over, all the while the firefighters performing work are unable to get back to command. Why is this a problem? Because everyone wants to hear all traffic, we stay on ONE frequency. You've got 10 trucks and 25+ people all trying to talk on one VHF FM analog frequency.

If only more of our members were hams, maybe we wouldn't have to discuss why talking over other transmissions doesn't work. Or why putting 25 people on a single channel is not a good idea if we expect two-way communications between more than 5 of them! Nothing like a good 'ole FM pileup to make you want to smack your head against the wall. If nothing else, maybe the single command officer trying to work the pileup WHILE managing the event would realize that we need to work differently.

Friday, April 24, 2015

AREDN first site on the air

I've installed the first of what I hope are many AREDN (Amateur Radio Emergency Data Network) mesh nodes. This site is located on a large grain elevator in Heyworth, IL. It's at the 150 foot level, with two yagi antennas. One antenna is pointed north towards Bloomington, and the other is pointed northeast.

I'm still going some testing with the antenna configuration - with guidance from the AREDN group, it looks like I need point both antennas in the same direction to take advantage of how 802.11 works. I wanted to try to reach two distant locations with this node...the better way to do that is to have two nodes with directional antennas - at least that's what I'm going to try next.

The node is made up of a Ubiquiti Rocket M900 node, two RP-SMA to N jumpers, and two yagi antennas. The node is fed with a CAT5E cable that provides Power over Ethernet (POE) up to the node, and data in both directions. This arrangement results in very little loss - there's nearly no coax. 

This site also houses a UHF analog repeater and the KD9AKF D-STAR repeater. Using vlan capable switch, I am able to create a connection to the internet from this mesh node. It isn't meant to be a replacement for personal use internet - but having the ability to route to and from the internet means I can access services from either side of the mesh as allowed by amateur Part 97 rules.

What's next? I'm working on two more nodes - one is a portable setup that I'm still experimenting with. I'm going to try a 12 mile link to the top of a parking garage sometime. What's interesting to me is playing in the 900MHz ham allocation. So far, 900MHz for this application behaves much more like microwaves than UHF - it does penetrate some structures and obstructions. 

Friday, April 10, 2015

A getting started guide for AREDN

I'm enjoying experimentation with AREDN. Using off-the-shelf equipment, you can build a mesh IP network running in ham frequency allocations. Getting started is a bit tricky at the moment...I've joined the project team to help with some documentation and to do some release testing. Here's a link to a Getting Started guide I'm working on.

If you're interested in playing with mesh networks, take a look at the guide and let me know what you think!