Re: #ubitx-help #ubitx-help

Mike Woods

Nice build Ron!

I suspect you have noise from the display getting into your audio.  This may be an earth loop issue, or it may be leaking directly in to your speaker as it is shown in the photo located alongside the display. Those of us with BITx40s will recognise that sound!  It is not normally a problem on the uBITx.

Caps (0.1uF and perhaps a 45uF) each side of  the Raduino regulator may help ... it works on the BITx40 for many.  Others may have better ideas about potential solutions. At my place the noise from the antenna is more than enough to drown out this racket, so never was an issue until the antenna was unplugged.   If it was me I would pull those curled up unused wires on your audio and Raduino jacks as these can also generate hash.  Push on the little window on the reverse side of the jack with a flat-bladed screwdriver to release the pin.   They can easily be reinserted later if you store them in the junk box, when you need them to do something.

73 Mike ZL1AXG

On 19/03/18 12:16 PM, R S via Groups.Io wrote:
Opinions of help needed badly here.  About the 5th or 6th time I have turn it on, I was listening to Tom E3TH (I know the call is wrong.  All I could get) the entire 40 meter band has these sounds.  Even if volume all the way down.  I have attached an audio file.  Hope it works.  I did not try any other bands.  I can touch the finals and reduce the loudness dramatically, but still audible.  Can touch anywhere and reduce it.  Antenna and final PA are the most affecting.  The heat sink I put on the Raduino board is warm with only receiving.  I have also attached a few pictures internal.  I have a 1.5 swr on 7.277 MHz using my MFJ269C Pro.
Using a Turner +2 now amplified.  Nothing done from day one without antenna connected.


Mike Woods

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