On May 1, 2007, at 8:29 PM, Richard Lim wrote:
I can't count how many times K2 customers have told me that their
"other" rig (I won't list them) was useless in the presence of strong
signals, while the K2, with its narrow roofing filters, completely
eliminated this effect. The K3 also has this advantage.
73,
Wayne
N6KR
Wayne for reference, what is the width of the roofing filter in a K2?
Typically 200 - 2000 Hz (variable). You can get as low as 100 Hz, but
with a lot of passband loss.
Are we adjusting the roofing filters when we set FL1, FL2 etc in the
K2?
Yes.
"Roofing Filter" simply refers to the first very narrow filter in the
receiver -- i.e. at the first I.F. In some rigs the first I.F. may be
30-70 MHz, and that's why their roofing filters are limited to very
wide bandwidths (3 kHz minimum, typically, and often as wide as 20
kHz). Rigs with such wide roofing filters sometimes have narrower
filters at a second or third I.F. (or both). However, some portion of
the I.F. circuitry will be exposed to the area in the roofing filter
passband, which is why
In the K3 the roofing filters *are* the narrow filters, since we
down-convert to a low I.F. These narrow roofing filters have several
advantages.
73,
Wayne
N6KR
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