G'day
I've got my act together better and, as suggested, have visited the Inrad
web site and looked at the specifications of the various filters. I've
also reseated the Ten Tec #217 500Hz CW filter, which has improved things
with regard to insertion loss...
It seems there is a choice of three filters I could add to the radio, in
the 1.8KHz filter slot, which might be useful/different for CW DXing and
compliment the Ten Tec #217.
1. Fit a Inrad #766 1KHz filter (approx. 4dB insertion loss, rejection of
60dB at around 2KHz, 750Hz offset)
2. Fit a Inrad #765 600Hz filter (approx. 4dB insertion loss, rejection of
60dB at 2KHz, 500Hz offset)
3. Fit a Inrad #763 600Hz filter (approx. 2 to 3dB loss, rejection of 60dB
at 2.5KHz, 700Hz offset).
Choices 2 and 3 are both four-pole filters, which have less insertion loss
than six-pole filters, are narrow at the top but have wide skirts. Choice
1 is a six-pole filter, wider at the top than the other two, but with a
similar skirt and similar insertion loss.
The aim is to have a filter with lower insertion loss that is going to give
some advantages under some conditions from the Ten Tec#217 500Hz, which I
will keep fitted to the radio. The extra filter will go into the 1.8KHz
slot, so the insertion loss needs to remain low.
Please, I would really appreciate feedback from anyone who has used any of
the above filters, or tried something similar to the above.
Vy 73
Steve, VK6VZ
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