Sunday, 25 October 2015

DV4 Mini Review

A week after receiving my DV4 Mini dongle I thought it would be helpful to give a review and my experiences with it.

Firstly, a note of caution if it is intended to use the dongle with a PC running Windows XP - Helitron don't recommend using XP, even though they supply software, and I can confirm that on two of my XP equipped laptops the software isn't suitable. It works fine on Vista and above but I have found the most reliable platform is via a Raspberry Pi.

The control software is good and easy to follow, and is relatively straightforward to use. It gives options for power levels and which server to connect to as well as giving a display as to which reflector you are connected to and the traffic through.

On the Pi (and Windows Vista on) the dongle needs no drivers as it is automatically recognised  (with XP a driver has to be downloaded - although I haven't been able to run the software on XP).

As a result of monitoring and using the DV4 Mini, I have observed that users accessing via Dstar have good connection and superb audio, and Fusion users have reported that it works very well on that system. DMR is a different matter though. The connection suffers from drop outs and missing syncs, which makes the use of the dongle very challenging. I have used various methods to try to address these problems; low power on the handheld, wrapping the dongle in foil and using an external antenna and siting it well away from the dongle to minimise excess RF getting to the dongle, but it would seem that these measures haven't improved matters much; which leads me to believe that the software needs some attention. Fusion and Dstar users report that it works fine. I have investigated my Internet connection and although connecting via wi-fi is ok, a direct connection through an ethernet cable is marginally more reliable.

So, my conclusion is :-

Very good idea and it works reasonably well. Software glitches need to be sorted for DMR use and once these are addressed the whole experience will be improved. It's early days for the DV4 Mini and I'm sure that the Amateur Radio Community and the software developers will work towards a solution - let's hope that it comes soon.


Saturday, 24 October 2015

DV and Scouting Ramblings

It's been a busy couple of weeks radio wise lately. Last week we at SKARS visited the 1st Barrowby Scouts to enable the Cubs to gain their communications badges. After a short talk about radio we set about getting them to pass greetings messages. We couldn't raise anybody on 2m so I went into the car park and carried out QSO's from my car. A great time was had by all and, more importantly, a good rapport was established with the Group.

Last weekend saw SKARS again involved with the Scouts, this time it was with the 1st Foston Scouts for Jamboree on the Air. Saturday and Sunday were occupied with the event and Andrew, Stewart and myself ran both HF and VHF stations from the Scout Hut. This is my favourite of all the events we cover - the enthusiasm and willingness to participate from all of the kids is infectious and goes to prove that radio really does affect us all.

My DV4 MINI dongle arrived last week and it is now running on a Raspberry Pi in the shack. It's a little disappointing as the performance on DMR is poor when compared to Dstar and Fusion. Drop outs and missing syncs are the major issues - perhaps a software update might improve things but we will have to wait and see.

Last Wednesday I gave a talk and demonstration on DMR to the Club and guests. It all went surprisingly well and as a result we gained four new members. I have ordered another DMR handheld (bringing the total to three) and the next major radio purchase will be a DMR mobile set to put in the shack. I can access the GB7RR DMR repeater so I will reinstate my X50 collinear on a 6 metre pole in the garden to be dedicated to this task.

As Christmas looms ahead we at the Club have decided not to have a Christmas Bash as such, we will be having fish and chips and fizzy pop at our December meeting instead. I'm very much looking forward to that, there's a particularly good Chippy close to the Church Hall and it will be good to get everyone together for a fish supper.

73 for now de 2E0ENN

Sunday, 11 October 2015

Happy Ramblings

It looks like, at long last, my issues with TVI with the neighbours has been cured. After consulting the RSGB EMC helpline I got an almost instantaneous reply and after explaining the situation I was advised to replace the Y adaptor on their TV with a UHF distribution amp. They recommended a particular unit and I duly ordered one. The Y adaptor was taking the input from the aerial and effectively splitting the signal in half - sending half to their lounge TV and half to the one in their kitchen. With only half the signal getting to either TV my RF signals were over riding anything going to the telly. The dedicated UHF TV distribution box ensures that the full signal is distributed to both tellies, which also ensures that their received signal is far stronger than any of my RF emissions. Upon disconnecting the Y adaptor, it disintegrated in my hands (see photo) and it became instantly obvious as to where the TV was picking up the RFI. So, the box was fitted, keeping the high pass filter in the line, and my XYL stayed with the neighbours whilst I went back home to conduct some test transmissions. No interference was noted so I think we can say "mission accomplished". The remaining issue is with their pesky touch lamps - I think an axe and a tin of lighter fluid might be the best solution there (only kidding).

This morning I had a drive over to the home QTH of David (2E0RVV) to program his DMR radio. Having searched online for a suitable codeplug, and not coming up with anything, I took my own handheld with a view to cloning the Codeplug on that to his new radio (just as long as the programming software was compatible). The radio had a rudimentary codeplug installed and I was able to modify the contents of that one to suit his needs. The dreaded Prolific driver issue reared it's ugly head but was soon overcome by switching to another computer running Windows XP. My advice is to have a cheap laptop handy with XP on it - you never know when it will come in handy. Duly programmed, I conducted a few test calls from my handheld and all was working as it should. Before I left, David had a QSO with another DMR user, so, again "mission accomplished".

I had another opportunity to help an EchoLink user get to grips with his system and now he can ragchew to his hearts content as well.

After all the help I have received from the Amateur community, it has been an exceptionally rewarding weekend where I have helped a fellow Ham in his quest for radio enjoyment and given just a little back to a community of helpful and friendly people.

73 for now de 2E0ENN