From Joe WB9SBD
if i'm listening to a dead quiet band, and i turn on a computer, any computer, I hear the difference. weak signals WILL be masked.
My local club was operating CQ world wide DX contest just last year. State of the art systems all around. Great antennas multi monobanders all at 100 feet plus.
They had the station networked with computers, for logging duping etc. when i got there do do my shift in the contest, they all complained how dead the bands were. i got on, and in a half hour agreed that we were not hearing hardly anything. BUT
as soon as we shut down the puters, we sat on one freq and started running a pile up of JAPAN Stations, qso rate was in excess of 120 per hour minimum. we were paper logging then,
then someone turned the puters back on, for logging and duping and the qso rate immediately dropped to less than 30 per hour we were just NOT hearing them anymore,, again shut it down and the qso rate doubled if not tripled.
now everyone in our club is a believer and never runs a computer when operating on any band.
Wayne Estes wrote:
Joe (no callsign given) wrote:
Computers are also extremely noisy! When operating HF I never use a computer, every one I have ever had or used, adds at least 10 DB to the noise floor.
Wayne replies:
How close are your HF antennas to you computers? I don't notice an increase in the HF noise level from the computers in my house, but my HF vertical and HF dipole feedpoint are both 60 feet from the house (and even further from neighbor's houses). At the closest point the dipole's wire is less than 30 feet from two computers in the house.
Do you use CRT monitors with your computers? I found that CRT monitors generate much more RF noise than the average home computer. LCD monitors produce far less RFI. Weak-signal ham operators should NEVER use CRT monitors.
Wayne Estes W9AE Oakland, Oregon, USA, CN83ik
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