Western Washington Cooperative Interference Committee
Interference Announcements and Inquiries
The following report was submitted by Curt Kyle:
Midnight at Mt. Spokane
8-18-99
Division Emergency Management (DEM) ( Curt Kyle, 253-512-7036) has a 60 db
site noise problem on Mt. Spokane. This is up from the 20 db that Karl found
on 2-11-93.
Additionally, our VHF de-sense due to site noise has been rising to the
point where now AREA is 13 db, STATE is 7 db, and LERN is 7 db.
I called KXLY Engineering Manager Tim Anderson, 324-4000, and requested the
times his 37 KW FM station (99.9 Mhz) would be off the air as well as his 48
KW TV station (Ch 4). I also asked him when his 23 KW HD TV station would
be on line. He said in about 30 days. This station produces white noise
from 210 to 216 MHZ.
Tim said we were in luck. They were taking down the transmitters for 3
hours in the wee hours of 8-18-99 to make some power distribution changes.
This is a very unusual event.
At the appointed time of 0105, the transmitters indeed went down and I was
able to do site noise checks on our equipment.
All our VHF bases went down to 0-1 db site noise readings.
The DEM base, however, still had 30 db of site noise. With the continued
increase of lowband RF pollution, perhaps this is to be expected. I would
be interested in hearing what our other DEM bases are hit with.
I warned the AVISTA techs and they had a tech there doing checks when I
left.
When the Digital Transmitter comes on line, of course, I will do further
checks. For now, I am grateful for my other voted AREA receivers. I do not
have an answer for DEM. I assume that the site noise on low band can vary
from day to night with the ionosphere.
Any suggestions would be gratefully accepted.
Chris Dallman
509-456-4101
If you hear an interference related story or if you are experiencing interference and do not want to wait until the next meeting to discuss it you can e-mail it to Alan Robinson at alanr@wwcic.org and he will place it on this page.