GB3HV status

GB3HV status

23cms rx - aerial selection

GB3HV statusPosted by Noel - G8GTZ Tue, June 17, 2014 18:58:38
In an attempt to put aerial selection on 23cms, I think I have sort of broken it....

I modified the mast head boxes 18 months ago for 12v up the co-ax operation but it seems I did not take in to account what would happen when we went to steered operation by applying volts up a separate multicore cable....

As a result I put 12v where only 5volts should have been and wondered why it was drawing loads of current :-( This was OK OK until the big 6.2 volt zener melted the solder and fell off the board on one pre-amp putting 9ish volts on the device...

So, situation is the switch is installed and appears to work using DTMF on the control channel or Skype input as follows:

*50# puts all aerials on - like what it used to be, except one unit is dead...
*51# selects antennae one
*52~ deselects ant one
*53# selects antennae two
*54# deselects ant two
*55# selects antennae three
*56# deselects ant three
*57# selects antennae four
*58# deselects ant four

Due to lack of time I have no idea which antennae is which...

I did see it working properly before the diodes melted and there was a significant improvement by using the correctly selected antennae over using all of them - so we will persevere!

Also there's only about 3.5 volts getting to the working pre-amps so they are probably under par at the moment...

Plan is to go back this Thursday and put 5v regs on each pre-amp DC line and then see what damage there is...

In the mean time - have a play... but please ALWAYS use *50# to put it back to normal when finished...

Oh and I did fix the VNC and web page issues so we can now use Tuitoune etc...





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