Topband: Help for Preamplifier and RX pass band filters for low bands

Sergio Cartoceti sergio.cartoceti at
Thu Mar 23 16:23:22 EST 2006

Just in case you wish to read the full story, and see some pictures, about my
March/April 2003 QEX article "A High-Level Accessory Front-End for 
The HF Amateur Bands"
is now downloadable as .pdf file from my faster personal website at 
for your personal interest:

The elliptical-Cauer pb filters are intended only for RX path. Our 
preampl shown and tested has
12 dB of gain, enough to compensate well for loss found i.e. in low 
band beverages.
I'm also glad that John, ON4UN, mentioned briefly, just the preampl 
circuit from my QEX article,
in his latest 4th edition Low Band Dxing book(ARRL).

I recall that another preamplifier, a commercial one, is mentioned as 
well in the above book,
beside mine, it looks similar in design and in active devices used 
and I believe it is without
noiseless feedback technique so, for that, it has some dBs of more 
gain (16dB), but still close in IMD performance
to our preampl (verified by IMD tests) and it is manufactured in USA 
by DX Engineering, model is, DXE-RPA-1.
Hope that's of help or interest to someone.

Sergio Cartoceti, IK4AUY (IR4B, AC7PC, and operator at IY4FGM Marconi 
Memorial Station)
<mailto:ik4auy at>ik4auy at 

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