Friday 15 August 2014

Poorly Wispy

Wispy isnt quite ready to be let loose on the wide world of 10m just yet, its a bit poorly.

The receiver is not working as expected. Detectable receive audio starts at an input signal level of around -20dBm, which is frankly rubbish. I would have hoped for -100dBm at least.

The fact it is so poor suggests something fundamental. When I next work on it, i'll check the transistors (ensuring their the right way round!) etc, but also will remove the coax link from the LPF to the RF amp, in case this is upsetting it. I'll also bypass the antenna switching diodes and see what receive is like direct to the receiver input. This is something im likely to do anyway, since I wish to use a small linear amp to give me a few watts of power, and relay switching will probably be the way to go for that.

So for tonight, all is packed up. I will monitor 472kHz overnight again. Already some decent spots are coming in, from Germany and the Netherlands.

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