Friday, 3 May 2013

Noise

The background noise level on HF (especially 28MHz) has dropped today, something must have been switched off nearby.
At 28.125 MHz, the noise is now -106dBm in a 2.5KHz bandwidth (Antron 99 on the back of the house), recently it was in the -90s which was making it impossible to receive any weak signals.
At 50.295 MHz it was -116dBm on the Comet GP15 tri-bander on the chimney, same bandwidth.
I tried WSPR on 50MHz today but got no transmit or receive reports.

On 14MHz, the Antron 99 and wire antennas are within 1dB of each other on receive (both tuned for minimum SWR with the LDG Z-11Pro II tuner) for a local signal. The background noise level is lower on the Antron though.
On 14MHz the Antron's SWR is very high but the tuner still handles it without any problems. The wire isn't designed for 14MHz either, it's acting more like a 10MHz half wave/20MHz full wave.

 Antron 99, all tuned for best SWR, 7:40pm local time. 2.5KHz bandwidth.
14.095 MHz = -102dBm
18.140 MHz = -94dBm
21.095 MHz = -91dBm
24.925 MHz = -96dBm
28.125 MHz = -105dBm
29.695 MHz = -107dBm





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