Just got back from Dayton Hamvention

So in my newest hobby of Amateur Radio I decided that I was going to go to "The" convention for Amateur Radio and that was Dayton. It was my first experience with it and the forums were pretty good and had a lot of different topics. I had a whole list of ones that I wanted to do initially but ended up just only going to two of them.

My wife and I left on Thursday and ended up tent camping. Although this year it was raining almost every day and got down to 35 degrees at night in the tent. So needless to say we were both freezing. Ended up having to buy another sleeping bag, doubling up on socks stuffed with "hot hands" to keep us warm.

Most of is it is vendors showing off their technology and selling it. However outside is the flea market. I ended up enjoying those quite a bit because you never know what you're going to see. A lot of what you see, even at some of the smaller ones, is government surplus equipment. I have to say I enjoy the flea market part a bit more because you can get some stuff you wouldn't otherwise be able to. Most everything else I can just order online and have shipped to my house.

I managed to pick up some pretty interesting gear whilst I was there. I saw a mount for my CF-19 Toughbook, except they wanted $50 for it. I should have just offered $30 for it right there because after thinking about it and going back it was gone. However, it did lead me to 3 Kontron mobile computers that were most likely in police cruisers. I got them for $10 each so if nothing else the thing will be a good project box.

The units I got were a Kontron CVX-Server Model 300-166, and so far I can't seem to find anything on them. So I'm guessing they have been discontinued. It looks like they have about a 1.8 ghz cpu processor in them and I think if I can load linux onto them then they'll work pretty well. The question is what do I want to use them for? I'm thinking ham radio something. Perhaps a deploy-able unit with a mesh node. As you can see from the picture it looks like it has some pretty good cooling methods on it. So all I need to do is sort out power to this thing and it will be up and going. At any rate, I did some more digging on these and found the data sheet on them. Which will help me immensely in figuring out what I want to do with them.

That's my adventure in Dayton and not sure if I will go next year but I can at least say I've been once. Once I figure out the state of these computers I'll make an update on what I'm using them for.

Feild Day Mesh Network - Antenna, Distance, and Checking signal strength

I recently went out to our site, where Field Day will take place, with a few of our club members to see about how we are going to setup logging. A few of them are bringing RV's and things like that and so we need a way to network our systems together.

The preferred logging software is N1MM Logger which works rather well on PC, and seems to do "ok" under wine on Linux. The challenge is getting the data feeds from the internet and sharing them out amongst our dispersed stations. So I thought this is a great place to show case mesh net, and play around and see how it works in a real test environment.

To run my test I brought with me my laptop running a linux program called iwScanner that works in python. It works amazingly well, if you're looking for something on windows then I recommend ViStumbler. Unfortunately it doesn't work on Linux.

I also brought with me two routers to test out and the first one looked like the signal was going up and down. I ended up switching to the other one. We got out to probably about 300 or 400 yards with a -80 or so db in signal. Which I think would still put stuff through just not very fast. This was however just a router with it's stock antenna, chucked into the rafters and through light trees.

I think that's pretty promising that we will be able to connect these together. So when I got home I decided I was going to build a Omni directional Collinear antenna. Following the directions from Marty Bug's website (Which is a great resource for all wifi antenna design) I set out to build one. I wanted to get the most db gain possible so I just cut a super long piece of wire and started with that. It's about 5' long and I had a bit of trouble placing it into a electrical conduit (pvc). As a result the loops on the antenna probably got shrunk and I wouldn't be surprised if it is a bit twisted up inside.

With the stock antenna on my mesh node I got about -17 to -22 db. With the one I created I get a steady -33. Now this is only preliminary tests and I have some modifications to the end of the antenna to try out. Also because it is a lot bigger the vertical beamwidth is smaller.  So I probably have to try it upright and a bit farther away. Otherwise I'm back to the drawing board on the omni wifi antenna.

The next antenna that I'm going to build is either a bi-quad antenna or a quad-quad antenna, which can also be found on Marty's website. Also with this design at some point I plan to install it onto a dish to give it a bit more gain and direction.

Field Day isn't until the end of June so I definitely have quite a bit of time to get these solutions up and going. Of course it doesn't help when I plug in 48 volts power supply into one of my only 2 12volt rated nodes and just about catch it on fire.

At some point I'll post some pictures.