6600 noise levels +10dB higher on my new 6600 vs. my older 6500

K9SO

During testing of my brand new 6600, I see a higher noise floor than I had on my 6500. With no antenna connected (unterminated), a 400Hz CW BW and 0dB gain on the preamps, I have a -110dBm noise floor on the 6600 as compared to -123dBm on the 6500 ( measured on the S meters).

The displayed noise line is lower of course but is consistently almost 10dB higher on the 6600 than the 6500 with no antenna. 

There may be SW issues as I'm running the 6600 on the latest V2 software and the 6500 on V1 for this comparison (I had not upgraded the 6500). 

I'm in a very quiet rural location and my 40m noise level is about -108dBm  with the antenna connected. In other words, I see very nearly the same noise levels with and without the external antennas connected. Nothing wrong with the antenna in TX. 

So I'm concerned that the 6600's internal noise is close to my atmospheric noise levels which would not be very good.

Does my 6600 have a problem or am I being overly critical?

Joe N3HEE

Gerald-K5SDR

Joe N3HEE

Gerald.  Thanks for the detailed response and information.  I totally agree with this.  However it did not answer what we are seeing when the receiver is in WIDE with RXA antenna input connected.    Does RXA go through the bandpass filters ?  Why are we seeing better receiver performance in WIDE mode on 160 meters ?  Can you please shed some light on how signals routed from various antenna inputs. Thanks -Joe N3HEE

Gerald-K5SDR

Joe N3HEE

K9SO