Saturday, 13 April 2013

Shack move

The cold winter weather convinced me that I should do something about my cold shack. Even with heating on it was difficult to a achieve higher than about 12C some days. Clearly, this is far too cold for any serious operating, building or testing. I will be adding extra insulation ( already have double glazing and 18inches of roof insulation plus insulated dry lined walls!) but not until later this year.

I have looked at the possibility of operating from inside the house for a number of years. In fact every time it gets too cold to work in the existing shack! Clearly, remote control of the shack would be necessary.

These days there are lots of ways to operate a remote shack from the comfort of a warm room in the house. In general this would mean using a wireless or wired LAN.

I was unhappy about using a PC to control and operate any of my radios ( K3, TS2000X, FT817, FT7800, IC207). I much prefer to have the radio in front of me. The cost of a pair of Remote Rigs and an K3/0 or RC2000 was regarded as unjustified.

An additional problem was that I also wanted control of 9 microwave band transverters & PAs, the main rotator and the possibility of 23cm and up EME, with control of dish azimuth and elevation. Controlling that lot would require a deal of effort!

Since I don't have any requirement for operating beyond the boundaries of my own property it made more sense to look at some alternative method(s) of remote control than using full control over the internet as others have done.

A quick solution, suitable for HF only, was to run a single 30m low loss coaxial cable from the outside shack into the house. In my case I had two suitable lengths of FSJ4-50 and FSJ1-50 available that were both able to reach from the front room of the house to the cable cabinet outside the shack. From there is was easy to extend the long cables into the shack and onto the cable frame where I could interconnect with the existing antennas, transverters and PAs. The cable enter the house through a neat 50mm hole drilled in the house brick wall, and terminated inside on a diecast box with two back to back panel mount lightning surge arresters. The box is earthed to a copper earth spike outside the house. Another connector will be added to the box in due course, if required.

The FSJ4-50 is the main cable and is used to extend the HF antennas to the indoor shack. The smaller cable is suitable for extending the K3 or TS2000 2m to the shack where it can either connect to the transverters via the existing remote switch or to the 2m masthead preamp and shack-located 2m PA for 2m operation.

It is also possible to connect the K3 via the indoor 4m transverter and extend the antenna connection over either of the coaxial cables to the shack where the 4m PA, with low noise preamp, is located. Finally the low loss coax can be used to extend either radio's 6m antenna connection to the mast mounted 6/4m dual band yagi for 6 or 4m operation.

All this still requires that the rotator be controlled remotely, of course. Here control over the home WiFi is used in preference to extending the control cable into the house.

My rotator is a Yaesu G1000DXC. In order to control this an ERC USB/RS232 remote control unit is plugged into the G1000DXC 6-pin mini-DIN and connected to the shack PC. Control is in conjunction with a suitable application, such as PSTRotor running on the shack PC. Using Logmein the shack PC can be remotely controlled, and hence the rotator, from an indoor laptop or even an iPad.

Remote control of the transverter switch is still under consideration. I am currently leaning towards control with DTMF on 70cm at low power using the low power on-premises control privileges that we are allowed. This would also allow me to switch PAs on and off etc.

Control of the EME dish is more straightforward as long as all that is required is simple moon or sun tracking since the control application (Moonsked) can also be accessed by Logmein from the indoor shack. However, anything other than simple control, such as 'nudging ' to track moon noise will be a bit trickier and a solution is still being worked on.

I will update the blog with details as the project progresses.

In the meantime it is nice to operate 40 and 15m, using the 40m dipole, from the comfort of the indoor shack. No more expeditions to the cold, windy, wet, north pole!












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1 comment:

  1. I am doing something similar - K3 in shack, all transverters remote in the conservatory at the base of the mast. I pipe the 2/70cm IFs about 20m and because the transverter drive is modified for milliwatts and the pre-amps have lots of gain, the loss isn't very important. I could also do the same with 28MHz. Transverters are selected by 12V signals on a multicore cable. These drive 12V relays that do the hard work based on relay logic. The signals are generated from the K3 with G4FREs band decoder. The GX1000 rotator is controlled by using a longer rotator cable. I intend to remote it with an Arduino but have not got around to it. Then I could run the entire system over the internet if I shelled out for one of those expensive remote rig boxes, but I haven't done that yet.

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