[Kenwood] RE: Replacing filter in TS 870

Tue, 15 Oct 2002 17:03:28 -0700

Yuri Blanarovich, K3BU, has a webpage dedicated to improving the TS-870.  This includes a modification for receive overload and for changing the two IF filters.

You can find his page at...
  http://members.aol.com/ve3bmv/

The direct link to the 870 mods is...
  http://members.aol.com/ve3bmv/TS870mods.htm

Don't have an 870 myself (happy with my two 850's), but I've kept his webpage handy just in case.

73,

  - Aaron Hsu, NN6O (ex-KD6DAE)
    {nn6o}@arrl.net
    {athsu}@unistudios.com
    No-QRO Int'l #1,000,006
    . -..- - .-. .-   ".... . .- ...- -.--"

-----Original Message-----
From: Duncan Cameron [mailto:[email protected]]
Sent: Tuesday, October 15, 2002 10:23 AM
To: [email protected]
Subject: [Kenwood] Replacing filter in TS 870

Does anyone out there have any experience with replacing the YK88S2 (8.83) 
filter in the Kenwood TS-870 with another filter. In looking at the service 
manual, I feel it would not too badly affect the DSP if the replacement 
filter were only slightly narrower or slightly wider. Kenwood parts lists 
the YK88S2 as a 3K bandwidth filter. I am thinking of replacing it with a 4K 
and a 2.1K filter on a small board with relays and a switch.  This would 
allow me to open up the 870 (more like the 850 which the 870 takes much of 
its design from) and narrow it down to reduce the adjacent channel 
interference that has been a bit of a problem in using the 870 for 
contesting. My hope is that the DSP filter selection for xmit and recv will 
operate as effectively with after a change in the filters.
Any thoughts or tips among list subscribers?
Thanks
Scott C.
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