Adding an Artillery Command Post to a Military Vehicle Collection – Part 11 –December 2013 to March 2014

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Winter Tasks

Automotive Work

Progress in the shed has been steady – the engine oil and filter have been changed and the front axle oil sucked out and replaced.  I had to look at the dashboard as there were only about 30% of the fixings in place and it rattled like mad on tick over as well as when driving along.  I also needed to look at the engine temperature gauge as it was not reading at all.  Having prised the dash off, I realised immediately why the speedometer was not working.  The crimped end of the cable that has the screw thread to hold the inner and outer of the cable to the instrument had completely separated.  Given the other problems I found behind there, I imagine that the whole panel had been pulled back too far without freeing off the cables.  Anyway, a couple of small bolts and self tappers as well as resealing the oil pressure feed pipe and the job was much improved.  I tested the temperature gauge and could not see a problem with that, although there might have been a loose connection.

I replaced the temperature sensor in the engine and that made no difference at all.  I then replaced the thermostat in case it had stuck open, but this also made no difference. It seems as if the engine runs cool and there is not a lot that can be done.  I will look at making a blanking sheet to cover some of the radiator and see whether that helps.  There does not seem to be a problem, the engine runs well although probably not as efficiently as it might.

Given the onset of winter I have changed the antifreeze as well, and once it warms up in the shed I will work towards the rear changing oil and filters as I go.  There are a couple of small dribbles from various sections so I will have to assess them.  The chassis looks sound although it could do with a rub down and paint in some areas.  I mention all this as a counterpoint to the radio progress and to give an idea of the whole project.

Review of Progress

It’s about eight months now since I brought the truck back, and about 18 months since I first began the project so I thought I would review progress.  My first objective was to find a vehicle that I could drive and maintain more easily than the Scorpion. I did have some concerns over the size of it and the fact that it weighs nearly five tons, but so far this has not been an issue. Compared to a Land Rover, which was my alternative, it is more comfortable and I can stand almost upright in the back.  I struggle in the back of hard top Rovers. It also drives very easily, not particularly fast but able to keep up with traffic until I face a hill.

My second aim was to have something that had something “going on” when I was parked up at a rally. The public like to see something different, and it is not always possible to show the vehicles moving so being able to have some radio traffic and some context seemed like a good idea. As I have said I like the command and control side, so this fitted in, and having obtained the licence I could pass the time trying to communicate with other amateurs.

On Compromises

Two ticks out of two!  Having bought the vehicle, the question then is can I display it accurately?  This is where I have had to look carefully and make certain compromises.  The first was that there was no prospect of my obtaining the BMETs equipment, so re-creating that was impossible.  I did toy with the idea of letting off helium filled balloons every so often but I could only see red party balloons which undermined the overall effect. I was lucky in that I could identify the unit from which the truck came and this at least gave me a framework.  It belonged to the Headquarters battery of an artillery regiment, which fitted perfectly with the idea of command and control.  I decided therefore not to go down the route of a specialist vehicle (BMETS,BATES) but to depict a vehicle that could have formed the basis of the communications network which passed orders and decisions from senior officers to the rest of the regiment as well as allowing the passage of information back to inform the decision making process. This also introduced an element of compromise as in reality this sort of traffic would be passed along various larger systems such as Ptarmigan or using rebroadcast stations to cover distances on VHF.  I had to go with what I could get hold of and what I was licensed to use.

Radio Fits

Hence I ended up with the almost standard fit of 2 VRC 353s and a VRC 321.  The 321 is perhaps a bit out of the normal as I am not sure that HF is used in these circumstances.  However, I put it in to give me something to do as the VHF frequencies in the Amateur Band covered by the 353s are limited. If I am able I will set the HF set up and see how far around the world I can get.  I am also interested in developing my knowledge of NVIS and playing with antenna to help with that.

Objectives Met

So – compromise aside, the objectives are pretty well achieved.  I have three working sets installed and the ability to run the VHF either using an elevated mast or the vehicle whips.  The HF set can be used with the truck’s attached mast or the SCAMs although I have some work to do to get the HF whip installed and working. I have a rugged laptop that I hope to link to the radios and use that for PSK, but I am still working on the theory for that.  It needs an inverter at least as well as some means of establishing how to connect the lot together.  I think that will look pretty good – it is a nod towards the modern C&C computerisation and data networking.

Complete Equipment Schedule (CES)

In terms of a static display I have the vehicle and sufficient tentage to make up a command post.  The truck itself has a porch adaptor to connect to a 9×9 and I have a trailer to drag this around.  I also have a few masts – 8m, 5.4m and two SCAM 12 as well as the 12m on the back of the truck.  This should allow me to fix up most HF options, dipoles/end fed/NVIS and I am collecting cables and antenna wire to enable me to pre-make these to save time. I also have the VHF pineapple which works well and there are another couple of VHF options that I will get around to.  I have a 24volt compressor to raise the masts (saves pumping like a madman) so there is a nod to making the job slightly easier.  Overall then I reckon that have achieved pretty well what I set out to do and this year I will be able to use it.

Back down to Earth

The weather here has been pretty grim.  Whilst we did not get the flooding of some parts of the country it was very wet, and this has a knock on to what I can do as the shed is not completely weatherproof.  Taking the truck out over the field was possible as I did it once, but the damage that it did to the field was not worth an unnecessary trip.  It did show however that the truck is reasonably capable off road.

Radio Fit

The radio fit is consolidating and small details are being improved.  I have mounted the sets on rubber shock mounts as they should be and I have tidied the cabling up and made runs that use the existing cable tie mountings.  I wondered about whether a control harness was necessary in a vehicle like this and in the end decided to fit one.  In the Scorpion the crew are connected all the time and because of the internal noise communication without an intercom is impossible. It is the same with the radios, there is little prospect of being able to run them other than through the headsets.  However the RB44 is different as there is much less background noise and it is possible to hear and have a conversation without an intercom.  However, I do struggle to make out some transmissions through the handset and when that is multiplied across the two sets I felt that I needed to work out a way to improve on this and to make it easier for me. I also wanted to look at how the sets could be controlled from outside the vehicle – from within an attached 9×9 for example and how I could fit a loudspeaker system as well.

A Veh Harness and CSSH

I decided in the end to replicate the AFV set up and to have an IB3 with two CB3s connected. The three sets would then feed into this and allow for any combination of 2 to be monitored and used. I have set it up so that the A&B sets are one of the 353s and the 321, and the other 353 is the C set.  This is a reasonable start as it’s unlikely that I will be using two 353s together; more likely that I will be using the HF and monitoring the VHF. I intend to get a DMU at some stage and link this to one of the 353’s to represent the secure speech/data option.  As it will never work, it does not matter whether it is really connected or just a dummy.

Future Work

I have one 353 fully connected to the antenna and the parts to connect the second.  The antenna base is finished and the TUUAM connected. I have the cables and the ARFAT, but the mounting plate on the truck has been used to support an electrical filter unit.  I will need to remove this, but that involves making a hefty bypass lead to reroute the power from the main input panel to the distribution box.  It should not be difficult, I hope to be able to adapt the existing cables, but it might take some time.

I am trying to get the HF set to run from a whip, but there are two major problems.  The antenna base for the HF system is slightly different from the VHF so I cannot use the same one.  There is a small transformer in the antenna base for the VHF whereas the HF base simply connects straight to the tuner.  Incidentally, although the antenna base for the HF looks identical to the VHF base, it is not.  Because the HF base has to take a 4m whip when stationary and a 3m whip when on the move, the rubber compound is a different composition.  You learn something every day.

Radio Fun

The HF set can run from any external wire antenna and I have enough masts to do this.  The bare minimum is to connect it to the rear mast on the truck in an inverted V and this works well.  I have run a low loss coaxial through to the rear to give me an external take off for the mast cable and this means I can shut the pod door if it gets cold or wet. However, the second problem is that the antenna bases on the RB44 are supported by a special fitting which bolts to the corner of the pod.  I have not been able to get one so far. They are not so complicated that they cannot be fabricated as they are effectively two pieces of bent metal, so I will have a chat with the engineer who made the radio mounts and see what we can do.

Carrying the Kit

Refurbishing the trailer is taking longer than I hoped, but that is my fault.  I have allowed the momentum to stop and having run into a couple of problems, it has stalled.  I need a bit of a kick up the backside to get it moving again so that is my top priority now. Otherwise we are more or less on target.

Looking Forward

So – looking back it has been a pretty successful project and certainly one that has given me pleasure.  I have learned a lot so far and my skills have improved considerably.  It is not over yet – there is the question of painting the truck once the better weather sets in and there are some other internal jobs that I would like to do.  I plan to book her into War and Peace soon, so that will give me a real point to aim for. After that it is a question of enjoying what I have.  Last year I managed to take her up on to the Moor a couple of times, so that will continue.  I have been invited to a couple of field days by the local radio club which will be fun and I hope informative.  This will give me a chance to experiment with different antenna configurations and to have some expertise on hand to give me ideas and guidance.  I am looking at buying a portable VHF set (probably a 351) so that I can test the output from the VHF side and use it to work out what the best configuration is.  I am not picking up a great deal when I use the 353s so I need to validate that.  I think that it is a problem with the frequencies covered by Clansman as there is only a small band within the range that can be used by amateurs, and it does not seem to be very popular locally.  When I have set up tests with a friend to monitor a particular frequency it has worked well, so I just need the capability at hand.

That is all for the moment, I hope that the next instalment will be more weighted to actually using the set up and will give some detail of how it performs.

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