[TenTec] paragon II performance on longwave band??

[Dr. Gerald N. Johnson]

On Wed, 2007-09-26 at 23:02 -0500, Bob McGraw - K4TAX wrote:
> The Paragon does have an overload issue derived from nearby BC stations 
> {50KW at 30 miles or less} when used with long antennas for the 100 KHz to 
> 1.7 MHz band.  Long antennas as in 1/2 wave for 0.5 MHz or so. (900 to 1500 
> ft}  The Paragon II does not have this problem as the front end design was 
> changed as stated to prevent overload from BC stations.  Yes, there is some 
> sacrifice with performance below 1.7 MHz.  There is also some different 
> switching configuration for the attenuator on the input between the Paragon 
> and Paragon II.
> 
> 73
> Bob, K4TAX
> 
Perhaps the Paragons would benefit from the combination of a low pass
filter and a preamp when listening to LF. Many editions of the ARRL
Handbook have included such a low pass filter and likely a preamp with
larger coils and coupling capacitors designed for use with a 160 meter
Beverage antenna would serve well. 

I know when using a double balanced mixer and LO for listening at LF (as
an up converter) that without that low pass filter, I get mostly
broadcast signals.

The MMIC MAV06 or equivalent would make a decent preamp. 3 dB NF and 12
dB gain with an output P1 of +17 dBm... Would need larger coupling
capacitors than used for HF, and its good to at least 1 GHz for other
projects. Two coupling capacitors, a bias resistor, a power supply
bypass and the 4 terminal MMIC. Hard to be simpler.
-- 
73, Jerry, K0CQ,
All content copyright Dr. Gerald N. Johnson, electrical engineer