Saturday, 2 November 2013

Tuner Fishing

Finally, today ive had a few moments free to complete the wiring of the copy RT-remote unit needed for my new LDG RT-11 remote Auto-ATU. However, it does seem that i've not got it completely right!

It doesnt look too bad, ok so the holes for the switches are a little big, but its so tight in the box I couldnt get the buttons through otherwise! And its very compact, I think probably a little smaller than the LDG original
A possible improvement with mine over the original is the buttons ive used, each has its own built on little green LED. I havent connected them, but that may be an option in the future if I find having them backlit for night use might be useful.

At first however, I couldnt get anything to operate! After a while I realised that, since I hadnt marked the controls up, I had put it into some odd mode without knowing. Starting again, I managed to get some control from the box only, without the Alinco connected (other than for power). I soon realised that I had the VSWR OK and TUNING LEDs transposed, not much of a problem, but I did want red to show tuning in progress and green to show good SWR, so I later swapped these over.

The RT-11 is set up, with this control box, on the shack desk, with the RF from the Alinco going  via the MFJ manual tuner, in bypass mode, to the RT-11. This allows me to monitor whats going on on the MFJs SWR meter. Since the first PL259 patch lead I found was a 5m RG-213, Its a tad untidy

Ive tried the RT-11, and the control box, at 10w from 80m up to 10m, on my doublet, and the RT-11 has so far matched the lot!

The only problem now is that the control from the Alinco DX-70TH is not functional. Im pretty sure this will be a simple wiring problem, Ive probably got a couple of the connections the wrong way around. I'll maybe sort this tomorrow.

Ive made good progress on dismantling that old 120kHz test set as well, since Julie has been nagging me to do so, and salvaged a lot of good parts from it. Trouble is, now I need to go through all the salvaged components and test them and put them in their correct containers! Probably the most useful things to have come from this though are the brass nuts and bolts, as these will solder into PCB material boxes to make good mounting fixtures.

I need to add some suitable labels to the RT control box. These will just be hand written, but on a white background so I can actually read them! Although the RT-11 and the RBA-4 are weather proof, I need to get a IP rated housing for them, as there may also be a switching system to add a loop of extra 450ohm ladder to improve the match, and perhaps a relay to link the two sides to make a T for topband use. Both the tuner and the balun will be mounted with wing nuts, so they can be easily disconnected when needed for field/SES use.

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