[Elecraft] OT what the heck is this?

Guy Olinger K2AV olinger at bellsouth.net
Sun Oct 24 10:19:17 EDT 2010


If one has a battery K2, or can otherwise set up mobile then something
like this can be quickly identified as ground or sky wave.  Using a
rubber duckie from 2 meters on the K2 input makes it weak enough to
determine if driving around weakens it or strengthens it.  If it is
the same on signal peaks over a large driving area then it's sky wave
and is distant.  However, I suspect this will be LOCAL to you, if for
no other reason it is not widely reported, and you seem to hear it
WITH or WITHOUT propagation to bring it in.

With a sufficiently poor antenna, or an inline step attenuator, you
should be able to drive around and get it to a block.

I bring up the K2 with ducky, because once you have it to a small
area, you can hold the K2 tight to your chest, and in back of you will
be attenuated much more than in front of you, and you can DF, even
with this blunt of an instrument (done this myself many times
successfully).  You may find when you get close that you need to
remove the antenna to continue DFing.

This could be something related to CB gear converted to ten meters, or
from the CPU in a washing machine, or any number of strange sources
reported these days.  I'm not nearly so inclined to automatically
relegate every imaginable observation to some weakness in the K3 as
some reflector residents.

73, Guy.

On Sun, Oct 24, 2010 at 8:52 AM, Geoffrey Mackenzie-Kennedy
<gm4esd at btinternet.com> wrote:
> Bill,
>
> One possibility is that this rogue signal's frequency is not actually at
> 28.002 MHz, but at some other frequency which coincides with one of the K3
> receiver's spurious responses when the K3 is tuned to 28.002 MHz. An example
> of one spurious response is the so-called image, which in the case of a K3
> receiver tuned to 28.002 MHz would be at 44.432 MHz. Typical Superhets have
> many other spurious responses above, below and sometimes in the band being
> tuned.
>
> Because you also hear this signal at 28.002 MHz when using another battery
> powered rig, at first glance my thought that the signal is not at 28.002 MHz
> would seem to be nonsense because the frequency used in the IF of your
> battery powered rig and the K3 are probably not the same, therefore the
> spurious response pattern in terms of frequencies of the two receivers would
> not be the same. But there is the possibility that some responses might in
> part cover the same frequencies.
>
> If I can be of any help, please contact me off-list.
>
> 73,
>
> Geoff
> GM4ESD
>
>
>
>
> Bill Hammond wrote on Saturday, October 23, 2010 at 18:40 + 0100:
>
>> It has been there for years, but isn't really a problem until someone
>> happens to be on that frequency and you want to talk to them. Like this
>> morning when FO8RZ was working up 1 from 28.002 and with the receiver set
>> on 28.003 I had the pleasure of listening to this repetitive tone until I
>> worked him :)
>>
>> So what the heck is it??  Obviously local, it is always there and never
>> misses a beat.  I have pulled the big switch and listening with a battery
>> powered rig, it is still there.  I assume some consumer product uses 10
>> meters for some unknown purpose...ever encounter this Elecrafters?
>
>
>
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