Dear Group,
Last summer, my VLF CW signals were copied outside my back yard. Today,
using a Marconi XH-100 with a SRA-8 mixer & AD9850/Arduino LO and a
National LF-10 preselector, the sigs could be clearly heard outside my town
with a 20 metre wire aerial strung between the car and a road sign. For
TX, the 100m wire (~15 m high) was coupled with 425 mH to a variac (2:1) in
series with a 5:1 ferrite xfmr to the keyboard amp with the volume control
set to 5 (about 30 watts).
This is DX record on 8.277 kHz for this station -- 1.25 km! I wonder how
far away it could be copied with QRSS? Any TA attempt will have to wait
until a higher Q tuning coil appears. The DC resistance of the current one
is almost 1k and I think it has much series capacitance. It gets warm
and emits an stench of ozone when in use.
73
Joe VO1NA
|
