>>> On 12/18/2011 2:36 PM, Dave W5UN wrote:
>>>> I'm looking for input from someone who has experienced a similar
>>>> situation as I describe below.
>>>>
>>>> About 3 months ago I began experiencing severe noise on top
>>>> band. It's a constant white noise which begins to drop off above
>>>> 2.5 mHz,
> On 12/20/2011 2:30 PM, David Raymond wrote:
>>
>> Jon. . .great advice, particularly about going to higher frequencies
>> as you get closer to the noise source. We've spent considerable time
>> chasing noise at our contest station. I addition to using RF we also
>> use a high range audio device with a highly directional dish antenna
>> which listens in the 20 - 40 KHz range. It is an excellent tool to
>> have in the arsenal when you get in close (say, 100 yards or so). You
>> can usually pinpoint the noise right down to the specific insulator,
>> lightning arrestor, etc. In some cases it would be worth borrowing one.
>> 73. .. Dave
>> W0FLS
>(Jon, AA1K): tnx info Dave ....where can those be had?
For those who wish to build an ultrasonic detector (or in the absence of DX
locate bats!) an article was published by ARRL in 2006
http://www.arrl.org/files/file/Technology/PLN/Ultrasonic_Pinpointer.pdf
I have built a couple of this design using the Far Circuits pcb and they
work well, needs a small parabolic dish and piezo electric detector at its
focal point.
Also I should mention that Jerry K4SAV has designed some improvements in
sensistivity and mixing if needed.
re. Dave's noise problem, it sounds bad , not the usual switchmode etc. we
suffer on 160m.. Any progress Dave?
73
John G3PQA
_______________________________________________
UR RST IS ... ... ..9 QSB QSB - hw? BK
|