[R-390] Broadband RX Loop amplifier for experimentors

[Thomas Frobase]

About 5 years ago I distributed some kits, the kit consisted of two units
one at the radio the second in an attic or other sheltered place.  The
second unit contains a phantom powered broadband (HF) differential amplifier
feed by a single 50 ohm coax cable.  The inside unit by the radio connects
to a nominal 12 volt supply for power injection to the loop amplifier,
provides an antenna connection to the radio receiver and a third connection
to the loop amplifier.  The loop amplifier has an internal relay that is
engaged while 12 volts is available, when power is removed the loop is
shunted by a neon bulb.  So in essence, when transmitting nearby simply
remove the 12 to the power injector and the unit is protected.  The power
injector is also fused.  

 

I have used the unit pictured in the attached link for over 5 years, it is
permanently connected to my AFEDRE software defines radio, and sometimes my
R-390A, due to high noise here it provides access to 80 and 160 meters as
well as Standard Broadcast.  Rather than resurrecting the kit I have decided
to provide the loop package as a completed and tested package.  I have a
limited amount of completed units available for shipment.  The link to the
paper and kit instruction files are http://www.kitparts.com/loop  Please
contact me off the list for pricing and delivery options, thanks tom, N3LLL

 

tfrobase at gmail.com