Re: Kiwi front end protection.


Glenn Elmore
 

I think it wasn't a Kiwi at the time, just two collocated antennas with the receiver running continuously.  The rx may have been an analog radio or an Apache/Anan dual-ADC board, I can't remember any longer, just that I could manage with a receiver running continuously while I was transmitting. It's possible that it was the Anan board with some delay.

It's possible to help a Kiwi somewhat by turning down the abuf but that doesn't solve the problem, it only helps somewhat. I often run with abuf=0.25.  Full QSK with fast CW, or even listening to one's own signal isn't very useful with any SDR I've tried.


On 7/24/21 9:50 AM, VE3VXO wrote:
On Sat, Jul 24, 2021 at 11:14 AM, Glenn Elmore wrote:
It was rather fun to be 'full QSK' on SSB or CW.
Glenn, how did you deal with the processing delay?  Here it is almost a full second through the Kiwi.  I can't handle that, my fist stops in an instant when my delayed CW hits my ears.  Turning volume knobs up and down on two sets of speakers isn't practical and is hardly QSK! I thought of using some sort of PTT/mute on the Kiwi audio but got stalled on that project.

On Kiwi protection, I added an optocoupler output to the green terminal block which is tied in with my local PTT.  The on resistance of the opto is ~5 ohms so it only gives a little extra attenuation rather than shorting the antenna directly to ground. It has handled local 500w transmitter no problem.

Joe

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