Revisiting D-STAR and the GB7TE repeater

Back in March 2011 I wrote about three different modes of communications, EchoLink, D-STAR and QSONet. In that piece, I discounted all of them and although I said that D-STAR was the one which most interested me, I wasn’t planning on using it due to a lack of any D-STAR repeaters nearby.

Fast forward to earlier this year and I received a telephone call from Tony, G0MBA who had seen an article in the RSGB magazine, RadCom about Icom offering to donate D-STAR equipment to groups to help them set up repeaters.  We discussed it at length and decided to try and get involved with this.  We talked to the rest of the Martello Tower Group members and an application was made to Icom.

We were successful and on the 14th April 2015 Icom told us that they would provide us with a VHF Repeater Module and Controller for a D-STAR repeater.  Our plan was to remove the GB3TE repeater which had served the local area for over twenty five years and replace it with D-STAR.  We submitted an application for an NoV for GB7TE and that was issued on 28th May 2015, a very quick turnaround.

On the 4th June, a big box arrived from Icom containing all the repeater hardware.

A big box arrived, all wrapped in Icom tape

A big box arrived, all wrapped in Icom tape

We’d been doing some background work, looking at documentation and sorting out hardware for the server which was going to run GB7TE and on the 13th June, Tony G0MBA, Peter M1BRR and myself all met up to start assembling and setting up the repeater.

Tony with the new kit for GB7TE - The first time we've had brand new hardware for a repeater

Tony with the new kit for GB7TE – The first time we’ve had brand new hardware for a repeater

We had quite a few problems getting GB7TE actually built.  We went through three or four different PCs and servers and around six or seven different versions of Linux until we got the one which worked as intended. It was a major learning curve as none of us really knew anything about setting up a D-STAR repeater until we started this project.

Finally, after multiple false starts, quite a few bottles of beer, some cakes and even a curry, on the 5th of July we had a working system and on the 8th July, it was fully connected to the D-STAR network and on test at Tony’s workshop into a dummy load.

On the 17th July, the new GB7TE rack was installed on site at Holland-on-Sea, at the bottom of the radar tower.  We were almost ready to go.

GB7TE on site at Holland-on-Sea

GB7TE on site at Holland-on-Sea

The repeater ran for one day as a single, stand alone box before the ADSL connection went live and on Saturday the 18th July 2015 at 14:25z it was connected into the D-STAR network.  We were live!

G6NHU and G0MBA looking happy while testing the new GB7TE

G6NHU and G0MBA looking happy while testing the new GB7TE

It wasn’t all plain sailing though and the next few weeks saw repeated visits back to the tower to make tweaks to the setup.  We had quite a few problems which were eventually all tracked back to a faulty ADSL router and once that was finally replaced, everything has been working well since.  We also persuaded some local radio and TV personalities to record some voice announcements for us and they’ve been on air identifying the repeater every fifteen minutes since the 11th November 2015.

As a result of all this, I borrowed an Icom ID-51E handheld radio and after having used that for a couple of weeks, I decided to buy my own D-STAR wireless and I bought an Icom ID-5100E, removed the Kenwood TM-D710GE from my car and installed the 5100 instead.

Icom ID-5100E installed in G6NHU's car

Icom ID-5100E installed in G6NHU’s car

Despite the fact that Icom don’t supply a proper mobile mounting bracket for the control head, I bought their MBA-2 and paired it with a RAM Mount RAM-B-102U-A which I imported from the USA and that does a great job of fixing the head to the dashboard.  For what it’s worth, I think it’s pretty crazy that the only bracket Icom produce is a suction mount.

So how am I finding D-STAR?

Honestly, I still don’t really care for the internet part of it.  I’m more than happy to use D-STAR but my normal procedure when I get in the car is to unlink GB7TE from any reflector it’s connected to and have a shout through it.  If nobody replies, I’ll link it back to a reflector to listen for a few minutes and undoubtedly, after a while, I’ll repeat the procedure.  I don’t mind listening to other people chatting but as I said in my previous entry, I’m not interested in talking to someone thousands of miles away as I’m driving to and from work. Conversations through repeaters are normally just people talking fluff to pass the time as they’re driving around.  I don’t mean that offensively, I’m sure I’m just the same as I waffle on about nothing in particular to local friends!

As for the Icom ID-5100E though, that’s a different matter.  It’s an absolutely superb wireless.  Once programmed, it’s incredibly easy to use and the touch screen is a real joy.  I was originally going to set up the Kenwood I took out of the car in my shack but I’ve decided to get another ID-5100 to use indoors instead.

Perhaps my opinions on using D-STAR through the internet will change as I become more familiar with it.  If you have D-STAR and want to give me a shout to tell me I’m wrong or just for a quick chat (about nothing in general), I’m normally on in the mornings as I drive to work for half an hour or so at any time from 05:30 (UK time) onwards and listening to GB7TE which is generally linked to reflector REF001C.  You can check the status of GB7TE by clicking here and I’ll always transmit something to it when I get in the car so my callsign should show on the list of last heard stations.  I’m travelling home from work and in range normally from around 16:15 (UK time) on weekdays.

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Building a QRP Labs OCXO

I’ve not posted much this year because I’ve not been doing much new stuff. I’m still messing around with the very low power modes and enjoying that a lot. I’m transmitting WSPR and QRSS all the time and tend to leave the transmitter running on one band/mode for a month or so at a time.

In the last week, I’ve built a QRP Labs OCXO (oven controlled crystal oscillator). I originally started building one of these quite some time ago but I made a big mistake and ended up just binning it and forgetting about it.  This time I was determined to do better.

I started off with this kit of parts.

Kit of parts for the OCXO

Kit of parts for the OCXO

After a while, I’d managed to assemble the two boxes for the oven and fit the oven components.  This is small and fiddly work, to give an idea of scale, I’ve added a 5p coin.

The OCXO partly assembled

The OCXO partly assembled

A few hours later, everything was done.  Here you can see the two halves of the oven, one each side of the main PCB.

Side view of the finished OCXO

Side view of the finished OCXO

The top of the completed OCXO

The top of the completed OCXO

To build this oscillator took around six hours and on top of that, once I got it into the final box and then into a transmitter, it took another couple of hours of gentle tweaking to get the temperature control set correctly.  It’s a case of adjusting it, waiting for ten to fifteen minutes for it to stabilise and then adjusting it again, repeating that process over and over until the minimum frequency is reached.  It’s a slow job but worth it.

I also built a replacement transmitter, a Hans Summers Ultimate 3S and fitted the OCXO to that.  I’ve been running it for a few days now and the stability is really quite incredible for such a low priced unit.  The previous transmitter used a DDS module which took a while to warm up and then tended to drift depending on room temperature and even just breathing on it could cause it to drift.  I’d sort of worked out the foibles of it and it wasn’t actually bad, I had it all built into a sealed case which was an effective oven anyway.  But this new OCXO is absolutely amazing.  It’s calibrated by GPS and once it’s reached operating temperature in around ten minutes, the stability is superb.  I’m monitoring myself and have noticed less than 0.1Hz drift over the last 24 hours!

G6NHU monitored on 40m

G6NHU monitored on 40m

At time of posting, conditions haven’t been great on 40m and the best WSPR spot I’ve had has only been to the east coast of the USA.  I’m hoping to be received by ZL2IK’s QRSS grabber once things improve a bit.

The original output power of the U3S was around 150mW but I wanted a little more.  I’ve added a second PSU to the box with a slightly higher voltage for the output stage (three BS170 FETs) and fitted some heatsinks and I’m now running about 500mW output.

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It’s been a while since I made a semi-serious contest entry and I happened to notice a couple of weeks ago that the CQ WPX RTTY contest was coming up.  I currently hold the England record for the 15m high power section and so I planned to try and beat that this year.

I was on the air prior to sunrise on Saturday and operated until after sunset the same day, making a total of 436 QSOs which I thought was well on the way to being able to beat my previous record.

Sunday was a different matter though.  Conditions were poor and I struggled to get up to 630 QSOs by mid afternoon.  I went out for a walk to get some fresh air and clear my head and then worked another twenty when I got back for a total of 650 contacts.  I’m told that the band did still stay open for another couple of hours to the west but I’d really had enough by that time.

My final tally was:

  • 650 QSOs including six duplicates
  • 71 countries
  • 6 continents
  • 427 prefixes

My claimed score is 693,875 which is only a few thousand below my current record but there are duplicates to remove and I’m sure there will be a few logging errors.  Interestingly, I managed around 35 more multipliers this year than I’ve ever worked before.

One thing I really need to sort out is my logging software.  I use fldigi because there’s a native Mac version but although it’s good enough for normal data comms, it really doesn’t cut it for contesting.  I’ve done OK using it in the past but the big thing I really need to make the next step is DXCluster integration along with the ability to flag new stations seen on the cluster, mark whether they’re new multipliers and just generally help boost my score.  I’m sure that with decent tools, I could have worked a lot more stations and picked up a lot of new multipliers.  Out of my 650 QSOs, 645 of them were worked by running a frequency and just five by search and pounce.

To wrap, here’s my QSO map for the contest.  You can click for a full size version.

Stations worked during CQ WPX RTTY 2015

Stations worked during CQ WPX RTTY 2015

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20m QRSS warmup

I’ve had this screenshot sitting on my desktop for a while because I think it’s quite interesting.

It shows my 20m QRSS signal from when I switched the transmitter on, for a period of nearly four hours.  You can see how it takes almost an hour to warm up and calibrate itself to the correct frequency and then it’s nice and stable.

This is nothing unusual really, the Hans Summers Ultimate 3 transmitter takes a while to stabilise and end up on the exact frequency.  What’s a little unusual is that the station who captured this warmup was ZK2IK, Pete in New Zealand, so not exactly a local station to me.

I was transmitting with about 200mW on 20m through my Hexbeam which was pointing due north.  It’s quite incredible to see my very low powered transmission was such a good signal on the other side of the world for such a long period.

My 20m QRSS signal warming up as received in ZL

My 20m QRSS signal warming up as received in ZL

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I’m not dead!

I know I’ve not updated this blog for some months but don’t panic, I’m not actually dead!

Although I’ve not done much operating this year, I have still been playing radio.  I’ve been melting a lot of solder building WSPR and QRSS transmitters and there’s normally some RF being transmitted on an HF band somewhere running very low power from this QTH.  I’m having a lot of fun testing different aerials and different power levels and still enjoying radio.

Everything goes in cycles and as a result, I’ve hardly had any QSOs this year – A quick check of my log shows that I’ve made just 220 contacts in 2014.

I changed my car about six months ago and I fitted a new Kenwood TM-D710GE wireless.  My old Kenwood TM-D700E has been retired and the new model does a lot more.  I’d had some problems getting the GPS working but the GE model has a GPS built in so as a result, I can be tracked as G6NHU-9 pretty much every time I’m out and about.

Posted in Amateur radio, FM, HF, QRSS, VHF, WSPR | Leave a comment

My 10m vertical broke in the storms

Friday night was very windy over here on the east coast and when I went to bed I noticed that there was more noise than normal coming through my aerials.  Normally I can hear the wind gently whistling through the mast and the Hexbeam but there was an actual rattle coming from somewhere which is unusual.

The wind had dropped a bit by Saturday morning but I could still hear some rattling from the outside which I quickly traced to be coming from the area where my 10m vertical is located and by looking out of the window I could see the top part of the aerial hanging down.

A quick trip outside confirmed that my Sirio Gain Master vertical for 10m had folded over completely, having broken just above the bottom join.  You can see it here and I’ve highlighted the fold.

Broken 10m vertical

Broken 10m vertical

The pole is mounted on the side of the house above a flat roof and the area where I normally put the ladder is well shielded from the wind so with the help of M6DHU I was able to quickly get up there, unbolt the pole and lower the aerial.  Here’s a closer version of the break with the same area highlighted.

Close up of the broken section of my Sirio Gain Master 10m vertical

Close up of the broken section of my Sirio Gain Master 10m vertical

The centre radiating element appears undamaged so technically it’s repairable but I’m not sure what I’m going to do yet as I don’t really use it too much.  When I’m operating on 10m, I tend to use the Hexbeam although it can be handy with the vertical during contests.  A good friend, M0YNK has a Sirio 2016 and I’m thinking it might be a better option, if I decide to replace it.

I’m not too upset about the aerial breaking as I suspected it was going to snap when the winds really kicked up towards the end of last year, I’m surprised it lasted as long as it did!

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Statistics – December 2013

December was another month where I did very little on the wireless regarding actual QSOs made but I did operate QRSS/WSPR on various bands for most of the time. My interests are shifting slightly towards low power experimentation but I’m still keen on trying to increase my DXCC count. In December, I worked one new entity – Lakshadweep Islands.

QSOs made: 73
DXCC entities worked: 20
New DXCC entities worked: 1

Total DXCC worked: 265
Total DXCC confirmed using LoTW: 245
Total DXCC confirmed using LoTW/QSL cards: 261

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