From: Stan Goldstein, N6ULU (email@example.com)
Hi Dr Rick, I haven't played with my 9 too much yet , but here is
my thought on the matter of filtering.
It seems to me that the front end has none ! And in any situation
where there are adjacent signals, serious distortion occurs to the
point of not being able to copy at all.
Because the audio already has a narrow filter and doesn't help at
all in those situations, I conclude that any additional audio filter-
ing will not help. ( If you achieve any degree of success with audio
filtering, please let me know .)
I have been looking for ways to improve the IF filter and come up with
the following alternatives
1 KB1MJ, Paul , Paul put together a filter kit some years ago which
consisted of matched crystal filters and either a change or an
additional IF amp to compensate for insertion loss and impedance
This kit , at $ 28, was in my opinion "The way to go".
( Was it you who told me you had one of these kits but didnt want
sell it ? )
2 The IF frequency is 8.807 Mhz, the same as some Kenwood rigs.
There are several mods out to use a Kenwood filter with an additional
(or 2 ) stage of IF amplification , to make up for the insertion loss.
The problem with this is the cost of the Kenwood filters. A bit over
$ 100. I haven't found a used one for a fair price yet.
International Filters, make a direct substitute ( I think they
claim steeper skirts ). I haven't checked their prices yet, but expect
them to close to Kenwood.
If any one has a kb1mj filter kit they are not going to use, please
let me buy it from you.
-- 72.25 (I still use high power when I need it) Stan Goldstein , N6ULU
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