[WriteLog] WriteLog Digest, Vol 187, Issue 2

[Joe Subich, W4TV]

 > The computer is all plastic construction so no obvious earth point

Try the metal shell of the DB15HD (VGA), HDMI, or RJ45 (Ethernet)
connector.  In some cases an unused USB connector (shell) can also
be used - assuming the shells are tied to the motherboard ground-plane.

Check your USB cable for continuity between the shells on each end -
many inexpensive cables lack enough shield connectors or fail to
connect to the shell on one end or the other.

You may have better luck with a "shielded USB cable" or "heavy duty
USB cable" from a place like Amazon or some of the cable houses.

73,

    ... Joe, W4TV


On 2018-07-03 2:49 PM, geoff plucknett via WriteLog wrote:
> OK thanks Alan and Joe for suggestions. The computer is all plastic construction so no obvious earth point and the existing USB leads have ferrite clips at both ends. The same problem occurs with at least one other software package but I'll try some additional ferrites/toroids and seek out a screened cable as well.
> 
> Geoff
> 
> 
>>
>>      On 03 July 2018 at 19:37 Alan Maenchen <ad6e at arrl.net> wrote:
>>
>>      Geoff,
>>
>>      I suspect that USB cable is inactive UNLESS you run WL or some other rig
>>      control software. That would explain the noise.
>>      Suggest adding several ferrites to the USB cable. Also, you might try to
>>      add good heavy grounding (bonding) between the computer chassis and the
>>      radio. I certainly can't explain why that wasn't a problem before your
>>      upgrade.
>>
>>      GL & 73, Alan AD6E / KH6TU
>>
>>      >
>>
>>          > >
>>>          Message: 2
>>>          Date: Tue, 3 Jul 2018 16:34:21 +0100 (BST)
>>>          From: geoff plucknett <geoffg4fka at virginmedia.com>
>>>          To: Reflector Writelog <writelog at contesting.com>
>>>          Subject: [WriteLog] Generated noise
>>>          Message-ID: <585855656.1046415.1530632061867 at mail2.virginmedia.com>
>>>          Content-Type: text/plain; charset=UTF-8
>>>
>>>          I've only noticed this since updating to v12.29G in June. Computer is
>>>          connected to IC-7610 via USB lead with everything set for COM3 and 4 as
>>>          standard. When I bring up WL a load of hash noise of around S7 appears on
>>>          the receiver, specifically on 14 MHz but seems to cover at least 1 MHz
>>>          either side. The noise disappears when WL is switched off. Not something
>>>          I've seen before. Any thoughts?
>>>
>>>          Geoff G4FKA
>>>
>>>          _______________________________________________
>>>          WriteLog mailing list
>>>          WriteLog at contesting.com
>>>          http://lists.contesting.com/mailman/listinfo/writelog
>>>          WriteLog on the web: http://www.writelog.com/
>>>
>>>      >
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