LF: SAQ 17.2 kHz

["Peter Martinez" <peter.martinez@btinternet.com>]

From G3PLX:

 

After seeing the posting about the SAQ transmissions on 17.2kHz here, I thought I would try patching my audio spectrum analyser program to sample at 48kHz instead of it's usual 8kHz. This would let me copy up to 24kHz without having to plug in the soldering iron. It seemed to work find on my new laptop, which it wouldn't have done on the slow old machine for which I originally wrote the program. With a 6m whip plugged straight into the laptop mike socket, the result was surprisingly good:-

 

 

What puzzles me is the UPWARD chirp. If putting the key down increases the load on the generator, wouldn't this slow it down and make the transmission chirp downwards?  Or is it that the generator is free-running slightly low and when the key goes down the generator is pulled UPWARDS onto the antenna resonant frequency?

 

73

Peter G3PLX