Right Angles

Today, I hooked up the recently-acquired UHF duplexer from TX/RX Systems to our UHF D-STAR repeater.  I needed to program the machine to the new frequencies to match the duplexer and decided to try running the programming tool under Wine (well Crossover Office) instead of hauling out the old Win2k backup machine.  It appeared that the programming interfaces on the repeater were just FTDI USB-to-serial adapters and that the programming tool just talked to it as a serial device.  I figured that would be simple enough for Wine to handle.

The software installed under Wine, but I noticed that when I plugged my Linux machine into the programming port(s), the FTDI driver didn’t load.  If I loaded it manually, it didn’t recognize and take over the USB device.  It appears that the vendor of the FTDI chip in the repeater is non-standard, but that’s the only difference.  I reloaded the ftdi_sio module with the proper parameters to get it to notice the device and it worked.  I was able to program the machine under Wine, by linking dosdevices/com1 to the proper serial device.

To make it easier and more repeatable, I wrote a little script:

#!/bin/bash                                                                    
#                                                                              
# ICOM RPx000V serial helper script                                            
#                                                                              
# Copyright 2008 Dan Smith
# <dsmith.AT.danplanet.DOT.com>                              
#                                                                              
# This script will scan the USB bus on this system and determine               
# the product ID of any attached ICOM repeater modules.  It will               
# unload and then reload the FTDI serial driver with the proper                
# options to detect the device.  After that, it will determine the             
# device name and link /dev/icom to that device for easy access.               
                                                                               
LINK=”icom”                                                                    
VENDOR=”0x0c26″                                                                
DEVICE=$(lsusb -d ${VENDOR}: | cut -d ‘ ‘ -f 6 | cut -d : -f 2)                
                                                                               
if [ -z “$DEVICE” ]; then                                                      
    echo “No devices found”                                                    
    exit 1                                                                     
fi                                                                             
                                                                               
if echo $DEVICE | grep -q ‘ ‘; then                                            
    echo “Multiple devices found:”                                             
    for dev in $DEVICE; do                                                     
        echo $dev                                                              
    done                                                                       
                                                                               
    exit 1                                                                     
fi                                                                             
                                                                               
modprobe -r ftdi_sio || {                                                      
    echo “Unable to unload ftdi_sio”                                           
    exit 1                                                                     
}                                                                              
                                                                               
modprobe ftdi_sio vendor=${VENDOR} product=0x${DEVICE} || {                    
    echo “Failed to load ftdi_sio”                                             
    exit 1                                                                     
}                                                                              
                                                                               
info=$(lsusb -d ${VENDOR}:0x${DEVICE})                                         
bus=$(echo $info | cut -d ‘ ‘ -f 2 | sed ‘s/^0*//’                            
dev=$(echo $info | cut -d ‘ ‘ -f 4 | sed ‘s/^0*//’                            
                                                                               
for usbserial in /sys/class/tty/ttyUSB*; do                                    
    driver=$(basename $(readlink -f ${usbserial}/device/driver))               
    device=$(basename $usbserial)                                              
    if [ “$driver” = “ftdi_sio” ]; then                                        
        ln -sf /dev/${device} /dev/${LINK}                                     
        echo “Device is /dev/${device} -> /dev/${LINK}”                        
        break                                                                  
    fi                                                                         
done    

This works for both the TX and RX side of the RP4000V and I’m sure it works for the RP2000V, etc.  Just run the script and, if all goes as planned, it should print out the real device name and link /dev/icom to it for easy access.  If you just link your dosdevices/com1 to /dev/icom, then you don’t have to do much switching around to program the repeater.  Very cool!

Yesterday evening, the PIO for our local ARES group called me and asked about availability for the next couple hours.  It turns out that a KATU news crew was looking for some footage of how hams can offer assistance to disasters from 2500 miles away.  We rushed over there and tried to have something ready before they got there.

The plan was to try to use the new (as in, 48 hours new) D-STAR repeater to talk to someone in Florida, potentially about the hurricane.  Not too surprisingly, 45 minutes isn’t quite enough time to coordinate something like that, and it turned out that the Florida repeater was a little busy at the time with some weather traffic (imagine that?).

So, we pulled up N7IS on the D1 ARES repeater to talk about the floods last winter, and got someone from Arkansas on the IRLP node.  We also had screens up of the D-RATS map showing the last known position of the guy in Florida, but I think they were a little difficult to shoot.

Anyway, as a result, we were on the 11pm news last night.  Only a few short snippets made it through, of course, but they made it look pretty decent.  I was pleased.  You can watch the video below, but be sure to pay attention to the last few words where they mention some locally-written software.  That’s D-RATS!

At the recent Hillsboro Air Show , I operated a portable station from First Aid Tent 2 out on the airfield.  Although it was completely overkill, we used a Comet GP-3 mounted about ten feet up.  We used a couple of sections of standard TV mast connected to a tripod (which was then zip-tied to a canopy strut).  This worked extremely well and is part of Ed Clark, KC7ZBI’s standard portable setup.

More recent than the air show, I worked a shift on the Hood-To-Coast relay race.  The race is mostly through back roads in the very northern bits of Oregon countryside.  Cell service is spotty in most places, and completely absent in many.  I was in a place where there was no cell coverage, and even the small 2-meter magmount on the car wasn’t getting into the repeater very well.  This gave me the excuse I needed to assemble a ready-to-go portable setup like the one we used at the Air Show.

The GP-3 is an ideal antenna for this, but at $100, it’s definitely something you don’t want to just throw around.  So, I decided to formulate a mechanism for protecting it during transit.  Ed uses a fishing pole holder with tennis balls around the antenna shaft, which works pretty well.  However, I had the idea of using standard PVC pipe parts to make something a little more custom.  The result is pictured here:

The parts involved are:

• 1″ PVC schedule-40 pipe for the shaft (cut to length)
• A 1″ PVC cap for the tip
• A 2″ coupler
• A 1″x2″ PVC bushing on either side of the coupler
• A 1″ slide plug for the non-fixed bushing

I assembled all the pieces so that things fit snugly.  The bushing on the free end of the coupler makes a nice removable cap, and the SO-259 on bottom of the antenna slides into the plug in the hole of the bushing.  This means that everything fits snugly and doesn’t move around much.  I think that I will add some felt tape around the opening to the 1″ PVC shaft to keep from rubbing the antenna element too much.  The ground plane radials stay nicely attached to the exterior with some thick rubber bands.

All pieces are glued with PVC cement, except the end bushing that is supposed to remain free.  A few more pictures are available here.