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Sunday, 30 October 2016

The SWR tripping issue

Well,

You may recall that back here I was starting to construct the SWR trip mechanism for the 23cm linear I built back here.  I've finished this and tested it today; as soon as the RF level on the reflected port reaches 10.8dBW my amplifier trips.

It looks like this in reality:


The return loss bridge is connected to the ANT socket of the linear and the forward and reflected ports are connected back to the amp box with SMA leads. Inside the box is the RF detector board that converts the RF into a -ve voltage and that has been adjusted in accordance with the calculations I did back here. So assuming the maths was correct I the linear will now trip if the SWR exceeds 1.8:1.

I also note there is good propagation on 2M today; looking out the window I see slightly misty but very still weather, often a sign on tropo:



The situation with Chopsey (AKA Git Bastard Cat from Hell) using my desk as his bed is now completely out of hand:



Florrie the ham cat has also taken to sleeping terribly close to my nixie clock which I am very fearful for:


Local conditions.

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