Chuck,
What a cool idea, RFI from RX in one ear, and re-transmitted RFI in the
other... I have to try that.
I guess I am lucky... For some reason, (I know not why), I have been
able to match RFI source noises easily by ear, from memory. I can hear
several sources at once, and as I turn the loop easily pick out which
one is dropping into the null, even if it is far, far, below the other
sources in level...
While helping hams in the past, I have asked others if they hear any RFI
in the static, and they say no, they hear nothing but static, while at
the same time I hear the RFI at what seems an unmissable level... I
have never been able to figure out why. In any case, thank you for the
new tool! I have used a cell to listen to RFI at the same time as a
portable rig, looking for on/off times, but never thought to use
Headphones, and 440, biaural. Better than a cell any day! THANKS AGAIN!
73, and thanks,
Dave (NK7Z)
https://www.nk7z.net
ARRL Volunteer Examiner
ARRL Technical Specialist, RFI
ARRL Asst. Director, NW Division, Technical Resources
On 6/16/21 10:50 PM, Charles Plunk wrote:
Lots of good tools available nowadays to track this stuff.
Agree Dave. Lots of noise out there.
Of the last 2 power line issues I successfully found, the single thing
that helped me the most to find the correct pole was matching the noise
pattern by ear of the portable receiver (I currently use a FT817 or
FT60, AM mode, yagi or loop) to the re-transmitted noise (440mhz
transmitter with mic held close to the hf receiver to another portable
HT) and listening to both portable receivers at the same time. Using the
analytical tool between my ears.
Next time I may rig up a set of stereo headphones. Triangulation
receiver on one side and re-transmitted noise on the other. Its also
helpful to use a HF station receiver with squelch capability, receiving
the noise, to squelch it just above background noise. Thus no noise on
the re-transmitted signal and the rfi noise is not active. It gets a bit
confusing hearing re-transmitted normal background noise if your RFI
source is intermittent.
Chuck
W4NBO
Tonight on TS830s with doublet at ~35' (no RFI)
80m Around S5 not including TStorm crashes
40m S4-S5
30m S1-S2
20m -10m S1 or less
On 6/16/21 11:24 PM, Dave Hachadorian wrote:
Another thing about the Tiny SA is that the screen is very difficult
to see in bright light.
When you get out in the field tracking down a noise, you will
encounter many noise sources. You don't want to be watching squiggly
lines on a dim screen, trying to figure out if that's the same
signature you saw at home. If you track a noise by ear, with
directional antennas such as an HF loop or flag with a SW receiver, or
a yagi/AM VHF receiver, you are pretty much assured by the sound of it
that you are onto the specific noise of interest.
Dave Hachadorian, K6LL
Yuma, AZ
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