Interesting!
I have been plagued by a similar QRM for over three years, which seems
to be centred on the 14MHz band.
It is distributed over an area of a couple of miles mainly by the
telephone lines. I have had a description of this QRM on my website for
some time now but no one has been able to identify it as yet. It has
even been described in the the EMC column in RadCom and has still not
been identified.
I would appreciate any help on this matter. All details can be found on
my website (including wav files) - click on QRM REPORT on the index page
to be found at
http://web.ukonline.co.uk/g3ldo
or from Google enter g3ldo, click G3LDO Index.
In the meantime I will check all wall warts
Regards
Peter G3LDO
Gw3UEP wrote:
Failed Wart: Post Mortem...
Its dc-o/p is modulated with 100pps pulses. These contain an RF-burst
envelope, chirping from MF to HF.
System had been working fine for 3yrs - then owner lost sync & B/B
connection; village became qrm hot-spot via BT-lines.
The routers appeared to be powered-up as normal - hours had been spent
arguing with BT who were oblivious to the problem.
Confusingly, the routers had been tested elsewhere & were ok. It
finally emerged that a spare/second wart had been used for these tests.
Rog.
|
