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Listening in to TB and a station around 1942 is very clear
with no typical local noises. How do I get it to tune down to cw
portion? I've tried typing in and dragging but neither are working for me,
perhaps there's a trick I'm missing
----- Original Message -----
Sent: Tuesday, February 27, 2018 6:10
Subject: [CrossCountryWireless] New
amplifier design for HF Active and Active Vee antennas
The amplifier design for both these antennas has remained the
same since launch as the HF Active antenna was the reference receive antenna
for the RSGB Noise Measurement project.
As that project is now
completed it's allowed me to look again at the amplifier design to see what
improvements could be made after receiving a lot of customer feedback and
learning what customers do with our antennas.
We are now launching a
new version of each antenna with a re-designed amplifier. It's a push pull
design with 20 dB more output that the original version with higher common
mode rejection and IP3 performance.
The base unit has two RF outputs
one at full level suitable for use with long feeder runs up to 305m and the
second with a 20 dB attenuator for short cable runs including the 20m cable
supplied with the antenna.
The amplifier in the head unit has a voltage
regulator so we recommend that with short feeder runs a 12 to 15V power supply
is used and with long runs a 24V supply is used.
The improved common
mode rejection is very useful when used close to other electrical equipment in
an urban or suburban environment.
The prototype Vee antenna using the
new amplifier is now set up as part of a WebSDR server on the 160m amateur
band using a SDR-4+ Special Edition receiver. The local ADSL/VDSLnoise has
been nulled out by rotating the antenna for the position of minimum noise. The
capacitive coupled local noise sources have been canceled out in the
amplifier. The background noise is now S6 making it usable again.
160m WebSDR server is at: http://g4hyg.ddns.net:8901/