The RFI forum is a good source of information on tracking down sources of QRN
(not QRM) in your house. Wall warts are a common source of noise. They
recommend a technique similar to the one you described.
Stan, K4SBZ
"Real radio bounces off the sky."
> On Nov 11, 2016, at 5:24 PM, William Lisk <wglisk@outlook.com> wrote:
>
> Just some thoughts regarding QRM--maybe a walk-around with a small
> portable radio would reveal a noisy appliance, poor utility connection
> nearby, etc. I have a cheap, home brew wire antenna here, and the noise
> typically runs around S4 on 160 meters and S2, S3 or less on higher
> frequency bands--generally the higher the band, the less it is. We are
> in an average residential neighborhood.
>
> Recently, I was testing reception at home by sending audio via USB from
> my Icom IC-7100 (with built-in sound card) to my laptop PC running
> MMTTY. I had around S9 across several bands that night. It turned out
> that a different USB cable with a better ferrite bead/slug for RF
> suppression drove the noise down to S4. Removing the USB cable entirely
> took the noise down to S1 (think I was on 40 meters then). When I
> thought about it, it made sense, because there's a lot of digital
> chatter on USB that could splatter into HF bands without proper
> grounding and attenuation.
>
> Operating at our remote cabin at the family camp in the woods, with no
> utilities, we use 12 volt solar power with batteries for 12 VDC and an
> inverter for 120 VAC. HF QRM is terrible with the inverter running and
> is much reduced when shutting it off to operate the IC-7100 on the
> batteries.
>
> 73,
>
> Bill/KC2EMH
>
>
>> On 11/11/2016 3:06 PM, Thom wrote:
>> I cannot hear them....darn
>>
>> I have S-5 noise though
>>
>>
>>> On 11/11/2016 18:06, Lee Roberts wrote:
>>> 14.08910 for veterans day special event - turns out i had to invert my
>>> FSK transmit in order for him/her to copy me though.
>>> _______________________________________________
>>> RTTY mailing list
>>> RTTY@contesting.com
>>> http://lists.contesting.com/mailman/listinfo/rtty
>>
>
>
_______________________________________________
RTTY mailing list
RTTY@contesting.com
http://lists.contesting.com/mailman/listinfo/rtty
|