More about the K3 NB and my apology.

[wa9fvp]

Yesterday when I posted my thread about the K3 Noise test, I didn't know that it was posting multiple times when I had probelms with formatting and spelling errors.  I deleted the post and reposted not knowing it was already sent to an email list.  For some people it was annoying and for that I apologize.  It won’t happen again.  

Today I was trying to work a European station on 40 meters and when I pointed my beam to 45 degrees, I was getting the typical pulse noise.  This noise is so bad that WID6 and 7 are the only settings that will squash it.

This time I connected my oscilloscope the receive IF inside the K3 on P51.  The pin is marked RXIF-.  The faded yellow trace (in the background) is the frozen waveform when the NB was off.  The bright yellow trace is the active trace when the NB was turned on.  Using a “T” connector on the back of the K3, the green trace (oscilloscope channel 2) is connected to the antenna.  In the aggregate of RF signals, you can barely make out the interfering pulse.  The Peak to Peak on the antenna is about 15mv and I was geting an S9 noise level.  

I think the pulses are comming from a switching "wall wart" power supply.  We have two that power the under cabinet lightening and creates a similar noise.  They're always off when I'm on the air.  The problem with the WID5 and 6 settings is that it reduces the pulse but it creates a hash sound on the received signal.  I think that noise with multiple pulses are the worst kind and more difficult to squash.  The blanker performs better on a single pulse ignition noise.

I'm not putting down the K3 or complaining.  I'm hearing the same noise on my Icom.  I hope this will help others with their noise problems.   I'm still waiting for the young guy to drive by in his wreck:-)