Saturday, 11 June 2016

CW(W) to LSB mod proven

I had my doubts about whether this mod had worked, as my newly added white 'LSB Select' wire, which at present has no where to go as ive no LSB module, was reading 0v all the time, and i'd sort of expected to see 3 or 6v on it when in any other mode but CW(W),

So after proving the 2kHz offset mod was working in both USB (SSB) and CW(N), I revisited the mod documentation from Martin G8JNJ, and the circuit diagrams...

...ah! When selecting CW(W), yes the line is pulled down to ground, as the switch grounds it. But - in any other mode... its floating! and since it doesnt connect to anything other than an unselected switch contact, theres clearly no voltage on it from anywhere! I'd for some reason thought that since the mod write up said that the line is pulled low, that it implied that in other modes it was pulled high!

It just hadnt occurred to me that my nice new wire didnt actually connect to anything when not in CW(W) mode!

A check with the multimeter with the radio off shows that it does indeed connect to ground when in CW(W) mode. So, it is in fact working as it should.

Nice to know, since these mods are pretty scary to do!

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