Noise Levels and FT8 - My new 6600 seems to have poor hearing

Kevin Rich

Bill - With the antenna disconnected and preamp at +8 the noise level is 130 and connected it is at ~100 no matter what the RF Gain is set to. Taking the split out and changing cables makes no difference. I also tried moving the antenna to ANT2 and have the same results.

 

Kevin Rich

George - I am quite surprised by the results and have checked the settings you mention and have tried various AGC settings as well all without any significant changes. 

On a separate note we have several 6m QSOs and have also worked via 2m MSK144. Thanks for the QSOs OM

Bill W2PKY

So you have a lot of noise [almost 30 dbm]  coming from the attic antenna which would mask received signals. The SDRPlay looks like it's has a very good RF Blanker. If you turn off the RFB in SDRPlay does the noise go higher and decodes drop off?
Maybe experiment with the Flex NB and WNB again to see if you can get the noise down on the Flex Receiver. Also check other bands to see if the noise is less and then compare the decodes between Flex and SDRPlay.
Hope this helps.

Kevin Rich

Bill - I believe you are correct that the obvious answer is unfortunately probably the correct one; HDSDR just does a better job of noise reduction than SmartSDR is able to. And yes, if I turn the "NB RF" off on HDSDR the waterfall noise increases ~30dB and signals and decodes are greatly reduced on the SDRPlay.

I am still hopeful that I am incorrect and am continuing to work with the SSDR software and the tips I am getting online and here in the community. I don't expect that they will ever be identical but I am hopeful I can get to at least 80% - 90% of the results I am seeing on the other receiver.

Bill W2PKY

might be helpful to listen to the DAX channel to get an idea of the sound of the noise and maybe locate the source of the noise. Maybe turn off one circuit breaker at a time to see if the noise is emanating from inside the house. Is the antenna near any AC power lines in the attic? Maybe relocate the antenna for decreased noise?
Hope this helps get to the next step in eliminating the noise.

John KB4DU

I also high noise level, and the WNB doesn't do anything for it. The NR helps when listening, but it is in the audio chain. The WNB is in the RF chain, but being ineffective on my noise, the weaker signals are buried and can't be detected in many cases.

Kevin Rich

UPDATE: I changed to a portable MFJ Ham-tenna vertical a few feet in the air with a pretty bad RF ground plane and the noise floor on the 6600 has dropped to abt 120dB is now displaying very similar results to the other receiver. For whatever noise I am picking up on the dipole HDSDR just has a better algorithm in that specific case. I'll continue with antenna work and trying to identify the noise. Thanks to everyone who helped out.

The WNB still doesn't do much for me but that is because I just don't have that type of noise. I'm loving the remote operation and other features and when I get some antenna issues addressed I hope to be a long time satisfied user.

David Decoons, wo2x

Nice talking to you on the phone today. 

Glad you are on the right path. For now you can use the Ham-Tenna on RXb and have transmit on ANT1.

Sounds like the noise source is closer to the dipole. Hopefully you can locate and mitigate it.

Dave wo2x

Kevin Rich

Thanks Dave - I am reading up on how to operate it with xmit/recv on different antennas. It looks like it is as simple as just selecting them like you indicate.

Michael N3LI

Interesting, Kevin. check air conditioning, modern furnace blower motors, and wall warts. The noise looked pretty broadband though, so I'm not certain this will help. 

But you're on the right path. A noise survey is always a good thing. The great thing about the Flex is that it sees everything. The bad thing is that it sees everything.

Kevin Rich

UPDATE 2: I found the noise and am now able to again use the dipole with good results for transmit and receive. The noise was coming from a treadmill that also has a cheap tablet display and Internet wireless connection in it. I suspect it was generating all kinds of other noise as well and I will continue to try and track it down to whatever component is at fault. 

Thanks again to everyone who helped. For now the solution is to turn it off and not exercise :-)

-Kevin

Bill W2PKY

Most likely a switching power supply.

David Decoons, wo2x

Excellent! Great job Kevin. Now you can really enjoy the new radio. Dave wo2x