High Noise Floor

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  • Problem
  • Updated 5 years ago
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About 25% of the time my 6700 starts up with a high noise floor. This is even with no antenna. Rebooting the 6700 solves it. It seems to have started since upgrading to 1.1.
Is anybody else having this problem???
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Mark - NU6X

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Posted 5 years ago

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Greg

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Yes....about 20-30 dB higher.  It did not happen right at start up though I don't think.  I just noticed it while experimenting with skimmer.

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k0eoo

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I don't know if this is the case here but I saw the same behavior with my 6500 before V1.1 and it turned out to be the preamp's in the antenna panel being toggled off/on when you slide in/out of the ham band or vise versa....
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Steve - N5AC, VP Engineering / CTO

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Mark, can you confirm or deny if your issue is preamp related?
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Mark - NU6X

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Sorry for the slow reply. The problem occurs always at startup. It starts up with no preamp. Moving the pre-amp.attenutor (-10 thu +30) yeilds a noise floor from -70 to -110. It makes no difference if the antenna is connected or not.  Switching to Ant 2 and then back to Ant1 caused the radio  to crash with a "Connect was lost" error. Subsequent attempts produce the same Connection error. All was good  after rebooting the 6700. I don't know if it is related,, but I don't remember this happening before 1.1.
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Greg

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Not obviously preamp related as I checked that and the preamp was at zero while the NF around 85-90 dB vice the normal 120.
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k0eoo

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Steve, I had it happen like it did several months ago.  I was on 80m at the high end of the band and as I tuned up past 4.000 the noise floor went up 20dB or so.  If I tune back and forth across the 4.000MHz boundary the noise floor goes up and down 20dB.  I looked at the preamps and they were off all the time.  I'm wondering if something is happening with the BW filters?  This happened with 3 slices open, 40m, 17m and 80m and with just 80m open.  I have a 6500 running V1.1 and I made sure the antenna was not switching.  Dennis, k0eoo
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Ken - NM9P, Elmer

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K0EOO,

On 1.0.24, when tuning past 4.000 MHz, the rig goes into a different "band" with its own set of display parameters, i.e. the RH scale, floor, pan and preamp settings are different from what is set for the rest of 80 meters.  This confused me to no end until I was able to go back and forth a number of times with my Flex Control knob and carefully observe the behavior.  Then I figured it out.  It was not a problem, just the way it works.  Frequencies outside the ham bands use their own set of parameters. 

I don't know if this relates to the Original Post, but I thought it was interesting.

Ken - NM9P



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k0eoo

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Sorry for not remembering this the first time.  Two things are happening on my 6500 when this happens.  First the BW filter is switching to a different setting causing me to hear the very strong local BC station as I cross the 4.000MHz boundary, and, the vertical scale on the right side of the panadapter is jumping up almost 20dB.  If I look at the actual noise floor level in dBm it doesn't change, as long as I turn on my outboard BCI filter in Loop A.  What Greg is experiencing might be all together different....
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k0eoo

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Hi Ken, looks like we experienced the same behavior.....  

PS.  it was nice working you the other day....
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Tim - W4TME, Customer Experience Manager

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Official Response
Mark - I have converted this post to a support HelpDesk ticket (http://helpdesk.flexradio.com) for expedited issue resolution.  If anyone else is experiencing an issue similar to this one, please submit a HelpDesk support ticket for issue resolution.

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