Kenwood TS-870S Filters
SSB/CW 8.83 Mhz and 455 Khz Filters
I started this project some years ago when I decided to improve the receiver performance of this still today good rig.
This modification is based on Inrad Filters and precisely:
- #94 8'830Khz 2.IF 2.1Khz
- #98 8'830Khz 2.IF 400Hz
- #96 455Khz 3.IF 2.1Khz
This modification was published on June CQ-DL of 2002.
I attach to this site a brief English modification description with some helpful pictures.
Roofing Filter 73.05 Mhz
I introduced a second modification in Dec. 2011 with the insertion an Inrad Roofing Filter with 4-5 Khz bandwidth at first IF 73.05 Mhz. This modification improves your AM/SSB reception, but you almost lose the use of FM.
For me this drawback is acceptable.
If you insert the new filter, you have to remove C179 from the RF Unit (X44-3210-00) (A/9) Board. This operation is not complicated, but you can't make any mistake.
In my case I had to modify the Inrad Filter Board, because my TS-870S mounts two 8.83Mhz filters on this board and the place where the new filter is fastened is quite limited.
Here some pictures to show how I done it.
TS870S_73.05Mhz Roofing Filter Picture.pdf
Remember that you always do these modifications at your own risk.
Updated on 1. Jan 2012