[TowerTalk] Re: narrowband filters

[Lau, Zack, W1VT]

  I published two narrowband filter designs.  The 40M filter is 
29kHz wide two resonator filter with 6 dB loss. The coils are wound 
on 2.4" PVC pipe and enclosed in custom aluminum boxes.  I'd say this
would be a difficult construction project for the average ham, but no
big deal to a skilled machinist.

  The 80M filter is 59 kHz wide two resonator filter with 2.3 dB
of loss. A much simpler design using inductors wound on T130-6 toroidal
cores.

73--Zack Lau W1VT

Nov 1998 QEX 58 A Narrow-Bandwidth 40 Meter Band-pass Filter
(RF) Lau, Zack, W1VT 

Sep 1998 QEX 57 A Narrow 80 Meter Band-Pass Filter
(RF) Lau, Zack, W1VT