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annoying noise in rx #bitx40help #signal #noise


 

Good evening
sorry for my English!
I have been hearing this fry for a few days
I attach a video
Before there was not and seems to have lost sensitivity in reception!
I do not know what to do...
Help
Greetings Sergio


 

Sergio

Those sound like FT8 emissions, digital signals to be received via computer. They can be decoded via PC soundcard and free software wsjtx.

Are SSB voice signals working okay?

Curt


 

Thanks Curt but the problem is not that! I positioned it on that frequency because it was the only signal I received, the problem is that it is scric like chips that fry on the bottom that was not there before!

Sergio


 

Sergio I am quite sure that your problem is caused by a not correct calibration of the transceiver, I suffer the same last month, try 15 for the calibration and 11.056,6 for the BFO if you have a v5 uBITX.
See you later
Edoardo

Il giorno mar 12 mag 2020 alle ore 08:28 SaMa photo SaMa photo <infosamaphoto@...> ha scritto:
Thanks Curt but the problem is not that! I positioned it on that frequency because it was the only signal I received, the problem is that it is scric like chips that fry on the bottom that was not there before!

Sergio


 

Could it be that a new station started doing JT65 near you? 7.076MHz is the "default" frequency for JT65 in the US (). Or are you hearing that same sound on other frequencies too?


Reed


 

He is talking about the background crackle.

Sergio, try a 1K - 10K (any) resistor in series with center lead of volume control.

Raj, vu2zap


 

Yes exactly I was talking about the background crackle!
I solved!!!
By chance I discovered that the problem was an external HD connected to the pc!
They are the HDs that have no switch on and off, but come on when you turn on the PC and if you don't use it they go into stanby
If I disconnect the power to the HD the background crackling disappears!
HD works perfectly, or has problems or it is the 12V 1,5A power supply that, under strain, sends some spurious out.
It is known that the BITX40 is sensitive to anything that happens on the power line. Turn on a light and hear the crackle in the BITX, turn on the air conditioner and hear the crackle ... I'd like to find some system to be able to eliminate this sensitivity.
Thank you all
Sergio