International Radio filter

dave_hoaglin at dave_hoaglin at
Fri Jun 14 16:57:37 EDT 1996

I'd like some advice on a problem I've encountered.

For my TS-850 I bought the International Radio 400Hz and 1.8KHz
filters for the 8.83MHz IF.  The 400Hz filter seems to be
intermittent.  Sometimes the radio sounds fine, but then I hear a
change: the audio has a lot of "static" in it -- it's not the same as
the usual QRN, but that's the closest I can come to describing it.
When the static is present, transmitting is also affected.  The ALC
indicator drops from its usual half-scale setting to 0, and power
drops from 100 watts to about 75 watts (though I can bring the power
back up to 100 watts by increasing the carrier control).

Do these symptoms suggest a bad filter?  The IRCI 400Hz filter
replaced a 500Hz Kenwood filter, and swapping the Kenwood filter back
in seems to have cured the problem.  (I haven't had time to use the
radio for hours and hours since the swap; but so far, in about three
hours of steady use, the "static" has not returned.)  I'd be grateful
for advice from folks who know the technical details of the TS-850.

BTW, the 1.8KHz IRCI filter is wide enough that I could not install it
after installing the 400Hz filter.  I had a 1.8KHz Kenwood filter, and
I just left that in place.

I phoned IRCI, and they'll trade me a new filter for the one that I
have.  The person that I spoke with mentioned that they had had one
bad filter in the latest batch (from their new manufacturer).  So I'll
send the filter back and see what happens.  I was just surprised when
the problem showed up -- after a number of favorable reports on this

Thanks for the help!

Dave, K8JLF    dave_hoaglin at

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