NQ0M's Ham Radio and SWL Blog Ham radio and SWL related info


Keep forgetting to update here!

So it's been a while again since I updated things here. Lots of things have changed. First off, I finally took the plunge and upgraded to a 1x2 callsign - I now hold the callsign N9PH. For the forseeable future, I'll keep the existing domain name - maybe I'll register up n9ph.com at a later time and make it also point here.

Also have been getting into a little kit building lately. I joined the 4-states QRP group, and a while back built one of their kits, the NS-40 transmitter. This is a very simple kit, and I'd recommend it to anyone as their first kit build. Also last weekend was their annual Ozarkcon QRP convention in Branson, MO. WA6CML & I made the drive down there, and had a lot of fun. Got to meet up with some friends, like Tom (N2UHC), my elmer Paul (N0NBD), Johnny (AC0BQ), and Terry (WA0ITP). They do an annual build-a-thon each year, and I took part in that as well. This year, the build-a-thon project was the group's new 4S-Link digital interface. The build went really smooth thanks to the experts there helping, and I can't wait to try it out - I just need to build the cables to interface with my radios. Also picked up some other new toys there. Picked up 2 more new kits to build from the 4State kit collection - the AA0ZZ EZ-Keyer and the QRPometer. Other goodies I picked up was the KI0BK Low-loss PWRgate as well as a set of 4 12v 17Ah SLA batteries. These will be used as battery backup while here at home, as well as battery power for when we're camping.

Also, a few months ago, I picked up a used FT-817. What a nice little radio! However, after playing a little with one at Ozarkcon, I think the 817 will be replaced later this year with a Elecraft KX3, and will become my new portable radio. And, when the 100w amplifier is made available for it, I'll probably use the KX3 as my home radio as well, and sell the FT920.

That's enough for now. Hope to see you on the bands!

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APRS I-Gate/Digi with my new Raspberry Pi

Recently I picked up a Raspberry Pi computer and have been setting it up to take on the Digi/Igate duties for WI0LA-10.  For those of you who don't know, the R-Pi is a $35 computer based on an ARM processor (similar to the processor used in smartphones).  It includes 2 USB ports, an ethernet jack, a HDMI video output (to plug into your HDTV), and an SD card slot.  The SD card serves in leiu of the hard drive.  This is how I set up my raspberry Pi Digipeater/I-gate.

First, all the various pieces of hardware.  I had everything I needed already on hand, but I'll run down all the parts that make it all work.

For the purposes of this document, I will assume that you've gotten the radio and TNC talking to one another over serial (minicom is a good tool for this) - Setting that up is a little beyond the scope of my document, and there's already plenty of good information on doing that is available elsewhere.  I'll also assume you've put your KPC+ (or other TNC) into KISS mode.  I will be using the linux built-in AX.25 network support in the building of this system, which requires KISS mode.  If you're starting from scratch, and not using a TNC you already own, you might be better off getting a pre-built TNC-X, as it should work great with this setup, and perhaps allow you to completely eliminate the USB-Serial adapter.  Also, all Linux commands are assumed to be entered as root.

First, we need to get our ax.25 userland applications installed onto the R-Pi:

apt-get install libax25 libax25-dev ax25-apps ax25-tools

Also, we need to get and comple the aprx digi/igate software - I'm using version 2.04 (svn 474) - there may be a newer version.

cd /usr/src
wget http://ham.zmailer.org/oh2mqk/aprx/aprx-2.04.svn474.tar.gz
tar xvf aprx-2.04.svn474.tar.gz
cd aprx-2.04.svn474/
./configure && make && make install

I like to run the AX.25 mheard daemon as well, so I can easily see what other stations my system is hearing.  For this to work correctly, we need to do the following:

mkdir /var/ax25/mheard/

The mheard daemon will create a file within this directory storing information about stations heard.  Without creating it first, that process will fail to function.

Prior to setting up the AX.25 stack, you must create the /etc/ax25/axports file.  It will look like the following:

packet  WI0LA-10        9600    128     2       144.390MHz 1200bps

The fields are as follows:  interface name, callsign, serial port speed, packet length, tx window, and a description of the interface.

Configuration of the /etc/aprx.conf file is next.  I usually make a backup of the original config file before editing it:

cp /etc/aprx.conf /etc/aprx.conf.orig
vi /etc/aprx.conf

Below is some of the various changes I made to the default aprx.conf.  It's quite well-commented, and documentation is also available on the project's web site listed above.  What I outline below should get you a functional configuration.

mycall  WI0LA-10
server   noam.aprs2.net
pidfile /var/run/aprx.pid
rflog /var/log/aprx/aprx-rf.log
aprxlog /var/log/aprx/aprx.log
ax25-device $mycall
tx-ok true
beaconmode both
cycle-size 10m
beacon symbol "/#" lat "3755.69N" lon "09523.32W" comment "IARC Digi/I-Gate Local Repeater 147.375 179.9Hz"
transmitter $mycall
source $mycall
relay-type digipeated

You should also create the directory for the aprx log files:

mkdir /var/log/aprx

Last, I create a simple shell script for starting up the AX.25 networking.  More enterprising users could probably integrate this into a bootscript to automatically start on boot, but this seems to work for me.  I call this script tnc_start:

#Create the AX.25 interface
kissattach /dev/ttyUSB0 packet
#Set some optional parameters
#700ms txdelay (-t)
#200ms slottime (-s)
#persist of 32 (-r)
#100ms txtail (-l)
#half-duplex mode (-f)
kissparms -p packet -t 700 -s 200 -r 32 -l 100 -f n
#Start the aprx digipeater daemon
#Start the mheardd daemon

And, that about does it!

One thing to note - aprx can interface directly with a KISS TNC (without the use of the Linux AX.25 stack), however, if you do utilize the Linux AX.25 support, you can also have other applications accessing the TNC at the same time.  For example, I can have aprx accessing the TNC, with the callsign-ssid of WI0LA-10 (our club call used for the digi & igate), and I could also run Xastir using my personal call KE0MD.  Both can transmit, both can receive, each doing it's own thing, which is a hallmark of Linux.

Hope this information helps you, and if you find it useful, or have any corrections, feel free to let me know!


Been a while…

So it's been a while since I last blogged here.  I haven't really been all that active on the radio for a while now, but I think that's about to change.  Last weekend I did my first kit build - it was the NS-40 (None Simpler 40) transmitter kit from the 4-states QRP group.  Was a quite simple build - One bug I still need to work out on it (I goofed and put the oscillator transistor in backwards!).  Also sat down tonite and ordered up a Cherkassey straight key off Ebay.  I haven't run with a straight key for a long time, but the NS-40 has a little too much keying current for me to risk trying my MFJ keyer or my K1EL Winkey USB.  Next up i think will be a receiver, perhaps the SS-40 kit from 4SQRP, and perhaps their Magic Box as well.  Also new for me is my new desk mic - WA6CML bought me a used Heil Goldline with PTT base...so pretty sitting on the desk.  Also have been working on the local APRS digipeater - Currently it's up and on the air here at home as WI0LA-10.

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Heil Proset-4 – new equipment

Sunday night, I ordered up a new Heil Proset-4 headset, and the AD-1Y adapter to match it to my FT-920.  Played around with it a little bit today, and it's a very comfortable headset.  I can't wait to use it during a contest!

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This weekend at KE0MD

Hey all!

So this weekend, I managed to get in a little radio time, when I wasn't helping WA6CML with housecleaning HI HI.  Friday night, I took my first dive into running the JT65 mode - what an interesting mode.  Worked a couple guys on 40, then down to 80 and worked a couple more.  Also on Friday night I ran across the 4A4A DX-pedition to Revilla Gigedo, and worked them on 17M SSB (still surprises me that my un-modified 5-BTV will tune up there!)

Saturday, worked 4A4A on 10 CW and 20 SSB, plus picked up the Caymans on 12 and Cuba on 15.  Nothing too special, but all interesting stuff.

One of these days I need to get the dipole up for 30M, and do some digi modes on that band.

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Welcome to my new radio blog!!!

Hello, everyone and welcome to my new ham radio blog.   I'm Jeremy, KE0MD, and I'll be blogging here with my exploits in radio and shortwave listening. You also might get a little computer-related info here, as i am very big into the digital modes as well.

A little about me:

I've been licensed since 1993, originally holding the callsign N0YAX.   Other calls I have held include KK7IC, KF3EH, KF3EL, and NW7JU.  I am an avid contester, and usually work all the major HF phone contests.  I am blessed by a wonderful XYL who understands the hobby.  She is licensed as WA6CML, which was her SK grandfather's call.

My Station equipment:

  • Yaesu FT-920 primary radio
  • Icom IC-730 backup radio
  • LDG AT-100 Pro auto-tuner
  • Astron RS-35M power supply
  • Signalink USB
  • Wouxun KG-UVD1P dual-band HT
  • Alinco DJ-175T 2m HT
  • Relm RH-256N re-programmed to 2m
  • FT-2400m in the car
  • Radio Shack HTX-10 10m mobile
  • KB9VBR 2m J-Pole at 35ft
  • Hustler 5-BTV ground-mounted