Been along time

Well to say the least this blog has been on the back burner for a while. Some personal issues and work related moves have kept me tied up. Also my primary OHV rig was recently destroyed by an unattentive driver and I have been spending my free time getting my new rig up and running, which I hope to have photos uploaded soon.

Meanwhile shutouts to my buddy DynoTronics for winning the LayerOne 2013 badge hacking contest.

Raspberry Pi and radio.

I have been playing around with this small Raspberry Pi "box" for a few weeks now, and it's a lot of fun. It's not so much a "get business done" machine, but a simple $35 Linux computer that can fit almost anywhere, and run simple tasks using little power.

The Raspberry Pi was introduced in February in the UK, but has taken the hacker/maker/gadget/nerd world by storm. Right now my R-Pi is running xbmc, but I want to get another one set up to run OP25, but there are literally thousands of things you can do with a Raspberry Pi.

"Raspberry Pi and Ham Radio"

raspberrypi.org

DIY tactical repeater for $100

Wiring / physical mod instructions can be found here.

Instructional video on how to downband an LPH for 144MHz

How to scan a trunking network on Astro 25 radios

Cool technique to monitor frequencies of a trunking system, without affiliating, on a Motorola FPP Astro 25 radio. 

Mighty Fine Junk hack

So I went by H.R.O. today and picked up an inexpensive MFJ duplexer  diplexer. It is designed to split 2M and 70cm, but will work to split any high band VHF from UHF 430 to 520.

The first thing I did was pull it apart. At $24 it's the cheapest diplexer I have found, so I figure it can't be too hard to DIY.

Inside you have what you would expect to find, a series of inductor coils and caps. The VHF side uses a 100nF cap the UHF side 47nF. Unfortunately my Fluke doesn't do mH so I'll have to measure the inductors some other time.

DIY BK tactical repeater

Here is a pdf file explaining how to convert old Bendix King HT's into a low power tactical repeater. I have done this before with a MPH and LPH I bought off eBay for about $10 each. I'll post more info later.

http://www.repeater-builder.com/bendix-king/pdf/bk-repeater.pdf