wrote:

Hi

I've been away from this group for a few years but I'm just getting
back into SWLing again. Anyway, I have an Icom R71 with the Kiwa audio
upgrade, a Kiwa LF-H4S 6KHz AM filter, an Icom FlL-33 6KHz filter and
have performed the passband tuning mod from Don Moman's R71
performance manual. I also recently re-aligned it and fine-tuned its
sensitivity so that its running sweetly.

I'm curious about the 6 kHz filters. Why two?

dxAce
Michigan
USA

I'm curious about the 6 kHz filters. Why two?

dxAce
Michigan
USA

Hi dxAce

The ceramic 6KHz Kiwa filter is at the 455 KHz stage whereas the FL-33
is at the 9 MHz stage and is a crystal filter. The plan was to get
better ultimate rejection and I'm happy with the results. The FL-33
goes in the vacant CW narrow filter slot and mod requires cutting two
resistors and soldering 2 wires. One additional bonus is that in the
narrow bandwidth setting you get proper passband tuning and can rock
from LSB to USB without retuning.

Cheers

Andy