Hello, Marinus.
I've used some six different Ten-Tec radios but none newer than the Corsair
II. With all of them except the Argosy which only holds one CW filter, I've
had both the 500 and 250Hz filters installed. I also have the 1.8kHz filter
installed in the rigs that will hold that many filters.
Currently I have the Omni-C on the desk. I do not work SSB at all but only
CW. I don't work contests or listen for very weak DX signals.
I've switched in the 1.8kHz filters in all my rigs to see the effect on the
SSB audio. I don't like the result! I see no advantage in using the 1.8
filter on CW.
In almost all cases I use only the wider audio filter. Sometimes I'll
switch to the narrow audio filter. Only on rare occasions will I use the
500Hz filter and I NEVER use the 250Hz filter. I have never used an Inrad
filter, not because I've avoided them but because I've just always used the
Ten-Tec filters and have been completely satisfied with them. I cannot
imagine a need for a 1kHz Inrad filter.
Based on my experience, given an Omni-C I'd use it stock for a while to see
how I liked it with no crystal filters installed. Then if I felt the need
for the additional filtering, I'd get a 500Hz and try it until I determined
if I needed more. I hear from people that the original Ten-Tec ladder
filters handle noise like lightning much better than crystal lattice filters
with less ringing. I don't know what sort of filter you can get from Inrad.
The other day I saw on the reflector someone who indicated it might be
impossible to work CW without a 500Hz filter. That is bunk! When I started
out, if a receiver had more selectivity than perhaps 15kHz, we were lucky,
but our ears quickly became selective. One thing to note with the Omni-C
audio filter is that it is in the audio chain prior to the AGC sampling.
The AGC is audio-derived. That means that signals outside the audio
passband have a much lower effect on the AGC. It is just an excellent
sounding radio in all respects.
Regards,
Mike N4NT
----- Original Message -----
From: "Marinus Loewensteijn" <mjloewensteijn@hotmail.com>
To: <tentec@contesting.com>
Sent: Tuesday, April 29, 2008 9:16 AM
Subject: [TenTec] Inrad 1000 Hz filter #766
I am reading up on new technology that has come about since I left ham
radio back in 1985. Interesting to read about using multiple filters and
then controlling the bandwidth by "shifting" one filter's passband in
regards to the other.
In the Omni-C filters are "cascaded" and (if I am correct) the bandwidth
is the same as the narrowest filter. I have been thinking about getting
a 500 Hz (400 Hz) CW filter while being well aware that the audio filters
do an admirable job.
Browsing the old Inrad website I find that there is a 1000 Hz filter. I
wonder what the benefits of using such a filter could be in the Omni-C. (I
am asking since I saw one posting in which the gentleman mentioned he was
using a 1.8 Khz filter and the 500 Hz audio filter and thought that was
about the perfect combination)
Many thanks in advance
Marinus,ZL2ML
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