[hpsdr] Filter Switching for Out of Band Band Use

[Jim Gailer]

Hi

I am using a PA3AKE receive filter set with Hermes
<http://martein.home.xs4all.nl/pa3ake/hmode/bpf_intro.html>. My filter unit
has band pass filters for the 160, 80, 40, 30, 20, 17, 15, 12, 10 and 6
metre bands, currently with a pass-through on 60 metres. I have built a new
decoder for the filters that decodes the band select lines on J12 (the I2C
interface seems not to cater for all separate band selects). These filters
are not much wider than the amateur bands and have >80dB out of band
rejection, so for use out of band, I need to select the pass-through
position.
As far as I can tell, when tuning departs from the amateur band or when GEN
or WWV is selected, the filter select lines set an appropriate (Alex based?
filter.
Does anyone know of a work-around for this? (For me, asserting one of the
spare open collector lines would be ideal!) I would prefer not to access the
CAT interface for this, but it may be the only solution.

Regards Jim G3RTD