New Mid-Atlantic DMR CS700 codeplug available

I’ve started publishing a CS700 (and soon, CS800) codeplug for the Mid-Atlantic region DMR network.  The latest version (from 2015-05-05) fixes some of the scan issues from the previous version.

You can download this file from my Mid-Atlantic DMR page.

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An interesting way to deploy a DMR c-Bridge

I made an inquiry to Rayfield regarding their c-Bridge product that can be used to join several (up to 50) Motorola DMR (MOTOTRBO) repeaters together.  Here’s what I found out:

There is a software option that is $600 less than the hardware solution.  The software runs on CentOS 5 or 6 (I’m assuming RHEL would also work here).  I was able to quickly stand up an un-licensed version (doesn’t actually do anything) to test with in a VM on my laptop and I didn’t see any resource problems.

I suspect one could easily run this on a 1GB Linode for $10/mo and have really good availability.  The best part of using a hosted virtual machine for this type of system is that you can duplicate it (to have a hot backup elsewhere), geographically move it around (to counter physical disasters) and be afforded a great deal of availability if needed (of which you’ll want since this is a radio system you’re dealing with).  Plus it’s easy to increase the resources afforded to the VM if needed (as the system expands to allow more repeater connections).

I may be incorrect on my assumptions, and if anyone has tried it I’d really like to know, but I think this sounds like a good and cheaper way to deploy a c-bridge.

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Dipping my toe into the DMR pool

A few weeks ago I ventured down to Cary and to RARSfest to see some friends.  It was a good event and the weekend was nice and relaxing.  While at RARSfest I noticed many of my friends carrying DMR portables.  They told me to go talk to the NC PRN guys who had a booth there.  Well, fast forward to today and I now have a DMR radio sitting on my desk.

What I know so far…

Well…  I did a lot of reading to try to understand how the system is setup.  As I used to have to deal with trunking systems [in a previous life] I understand talkgroups and the problems with having too many available without the channels to support them all when you have simultaneous use.  DMR is no different.  Throughout the world I see many different thoughts on how to allocate the talkgroups to make many options for the users without completely killing the system.  Some groups do it well, others… well, I’m not sure how their systems can even work.

They systems in the Mid-Atlantic seem to do well.  I’d probably make some adjustments but overall they seem to run smoothly.  The repeaters seem to have “local” on one timeslot and everything else on another.  That keeps local open all the time for conversations.  This is in contrast to the NC PRN network which lumps local onto a timeslot with a bunch of “on-demand” talkgroups.  Their system-wide talkgroup, PRN, is kept on its own timeslot without interference.  Again, it’s all about priorities.

The system’s efficiency is at risk when you put too many users on too many talkgroups, especially when those talkgroups occupy timeslots on all the repeaters all the time.  Of course someone thought of this and created TAC-310; an on-demand talkgroup that most everyone (globally) has access to but doesn’t occupy a timeslot on a repeater unless it’s been activated there.  Makes sense, correct?  You can get off the calling channel and get over on a discrete channel that doesn’t utilize that many resources.  Unfortunately there is only one of these talkgroups.  Even on a system the size of NC PRN their get-off-of-PRN talkgroup is named ‘Southeast’ where the talkgroup has many more potential off-network users.  Still it’s all about priorities and fulfilling a certain mission.

CalDMR seems to have a good way of separating communications onto their timeslots.  I guess the hope is that you won’t have too many conversations at each level happening simultaneously.

One system I’ve been quite impressed with the Connecticut’s DMR ARES system.  Designed to facilitate intra-state communications, they have added ten tactical on-demand tactical channels to help spread out the load away from system-wide channels while supporting many simultaneous communications.  Still, I wonder about the load and whether or not the repeater congestion will be a problem.

Most of these networks are young and I suspect some shifting around will be required on all networks as well as an understanding of the priorities of the network by its users.

So where are you hanging out?

As for me, I’m listening to the North America calling channel as well as local on the Upper Marlboro and Charlotte Hall repeaters.  Feel free to give me a shout!

Posted in Digital Mobile Radio (DMR), On the Air, Voice Operations | Leave a comment

The Radiobuster

The RadiobusterThe Radiobuster by Volney G. Mathison

My rating: 5 of 5 stars

This is a great book that I happened to stumble upon. I’ve been looking for a book that talks about life as a commercial radio operator but have found few. This book approaches my expectations although I wish the author would have spoken more on the radio operation itself. Still this is an excellent book for anyone interested in the life of a commercial radio operator in the 1920s.

View all my reviews

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Confirmed DXCC Entity #149: South Cook Islands

E51JD QSL CardThursday was QSL bureau day (the day in which I receive cards from the bureau).  If that wasn’t exciting enough, I also received an envelope with a return address of “Rarotonga, Cook islands”!  Oh yeah, I finally got E51JD confirmed!  This is my 149th confirmed DXCC entity.

The stamp on the envelope was quite neat with a snail on it.  But it was what was inside the envelope, other than the card, that made this QSL special.

Front of a Cook Island coin Front of a Cook Island coin




The paper enclosed with the coin says:

The coin portrays TANGAROA,
Lord of the sea and one of the
Great deities of the Polynesian
race. In ancient times this god
was one of the principal gods of
Rarotonga and adjacent islands.
This coin was withdrawn from
circulation some months after it
was issued when it was realized
that it was the same size as a ten
cent coin used in slot machines.

Honestly, I’m just happy that my card was received at the distant end with an address that went something like (Pacific Islands via New Zealand).

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Linux, the Yaesu FT-1D, and the SCU-18

I had almost given up on programming my Yaesu FT-1D on my Linux computer.  The software provided by Yaesu wouldn’t work on Linux and CHIRP didn’t support the radio.  Well, CHIRP didn’t support it until now.  While it’s not official, their daily build claims to support the radio and that makes me excited.  But there’s still a problem.

The programming cable that is provided by Yaesu, the SCU-18, doesn’t seem to be recognized by my Linux system.  Well, it’s recognized but it doesn’t actually attach the device to a port so I can use it.

usb 3-1: new full-speed USB device number 12 using xhci_hcd
usb 3-1: New USB device found, idVendor=0584, idProduct=b03a
usb 3-1: New USB device strings: Mfr=1, Product=2, SerialNumber=0
usb 3-1: Product: USB-Serial Converter
usb 3-1: Manufacturer: RATOC Systems,Inc.


Bus 003 Device 013: ID 0584:b03a RATOC System, Inc.

It turns out, the device appears to be a RATOC System USB60MB.  What Yaesu is shipping looks just like these devices except for where the 9-pin serial connector is there is actually some proprietary USB plug.

I think this is the only part that is holding me back.  I’m hoping to talk with a few people tomorrow that can hopefully help remedy the problem.  I feel that I’m really close to a solution, though, and hope to make this process easier for other Linux users out there.

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SKCC 1,000 Miles per Watt Award


It would appear that my K1 is stuck transmitting 6 to 7 watts no matter what the power output setting is.  I can only assume that the contacts I made for this award were not made using 100 mW but rather 7W.

I have already responded to the award coordinator and to the SKCC group, in general.  Now I need to figure out why the radio is doing this and how to fix it so I can actually go try to make these contacts.  *sigh*

Last night I dusted off my Elecraft K1 transceiver and hooked it up to my Carolina Windom antenna so I could work some locals on QRP.  On a whim I decided to call WB5KSD on a 40m frequency he was on using only 100 milliwatts.  To my surprise not only did he answer me but also gave me a signal report of 559.  Needless to say, I was in shock.  That is a distance of 1,875km (1,165mi)!

About fifty minutes later I decided to work K5TRI as we had tried to work QRP x2 a couple of nights before without luck.  He was operating as K3Y/7 and also responded with a 559 from near Redmond, WA.  Astounded, I let him know that I was running a tenth of a watt and he replied that the signal was good.  The distance between he and I, coast to coast, is about 3,768km (2341.4 mi).  We repeated the contact some forty minutes later although the band was starting to close by then and significant fading was present.

I submitted my award request to W0EJ who formally presented my award this morning.  According to the roster my contact puts me in fifth place behind KC9IL at 146,500 (who the heck did he talk to and at what power?), AK4JA at 98,500, K8PG at 70,500, and AC2C at 38,000.  I’ve got my eye on a couple of stations out in Hawaii so maybe I’ll be able to extend my endorsement one day.

Posted in Awards, CW, HF, QRP, SKCC | Leave a comment

SKCC: I now have my Centurion!

I received the following message from Ron Bower, AC2C, after submitting my SKCC award log last night:

Hear Ye! Hear Ye! Gather 'round and pay heed to the news of this

Let there be celebration to recognize a fellow SKCC member who 
has advanced to the Centurion level of SKCC achievement !!!

Having submitted a log and sworn statement, documenting the 
completion of QSOs with 100 other SKCC members, Eric Christensen, 
W4OTN, SKCC #7320, is duly proclaimed to be SKCC Centurion Number 
1107 effective at 0000Z on 21 Jan 2015. SKCC Centurions are 
encouraged to proclaim their accomplishment by appending a C to 
their SKCC Number.

The Master Centurion List has been duly scribed where all SKCC 
Members may reflect upon and pay tribute to this momentous 

Duly approved, recorded, and published.

I set forth my hand and key.

20 Jan 2015

Ron Bower, AC2C
SKCC 2748S
SKCC Centurion Administrator

Woot!  So as of tonight at 0001Z I now can append a “C” to my SKCC membership number!  I guess I’ll start working on my “T“, next.

Posted in Awards, CW, HF, SKCC | Leave a comment

Now on medium wave!

160m on Kenwood TS-2000XYears ago I purchased a 40-80-160m dipole antenna in hopes of getting a good signal out on the lower bands.  Unfortunately the antenna ended up being too large for my yard and I didn’t use it.  Fast forward to now and I’ve got plenty of room for antennas.  When I put up this antenna the trap for 160m on one leg broke off.  I had most of the antenna up in the air so I just didn’t do anything with it.  Now that it’s winter and 160m is supposed to be useful now I wanted to get on the air and make some contacts there.

As temperatures recently poked above freezing for the first time in some days I heated up the soldering iron, bundled up, and made my way out to the antenna to make the repair.  Luckily it was a simple fix and in less than an hour I was back inside with the antenna up in the trees like it’s supposed to be.

I did some tests and I’m disappointed that there is only one real sweet spot on the antenna (around 1860kHz).  The little tuner in my radio doesn’t handle the band very well but I guess this is better than not having anything at all.

I’m glad to be concentrating towards the bottom of the band and I’m hoping to find some CW down there.  I’d love to get a signal report if you do hear me on the band.

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Fifty years of transmitting at BBC Woofferton

I ran across a paper that was written discussing the shortwave broadcast station at Woofferton, UK, last year, and thought I’d share it.  It’s a really interesting read and gives you a perspective of what it took to maintain such a station with a near-constant change to technology.  It’s in PDF format so you should be able to read it on most any device.

Posted in British Broadcasting Corporation (BBC), Shortwave Listening | Leave a comment