TK-790 & Pyramid SVR 200 vehicle repeater problems

[Ett1033]

I have a TK-790 (H) interfaced with a SVR 200 pyramid repeater. I have gone through lots of troubleshooting and still get vehicle whine during transmission. It whines even if you use an outside power source. Pyramid has had us do several things that reduced this noise, but it has not been eliminated. Sometimes it works perfectly, and other times it has the whine. I don't know what else to do. I was told that we may never eliminate the whine (from Pyramid). Sounds like problems may exist with the pyramid unit and they are not admitting to them. Does anybody have ideas or experiences with this?
Thanks.

[n5tbu]

I had the same problem on a 690 lowband,I did the mod in the book,ie replaced r13 with a 100k,installed a big motorola line filter to the kenwood and readjusted the repeat audio sens.
Cured it for me.

[deputy1102]

It not only occurs in the Tk 790 but most kenwoods. I ran a seperate ground wire from the chasis of the mobile repeater to the (-) on the battery. Also run a seperate ground for the radio the same way. It doesn't completly get rid of the whine, but it helps it a great deal

[nmfire10]

I guess I lucked out. We have SVR-200 / TK-690's in use on 4 apparatus and have no whine from any of them. We have a TK-630 on another unit, it had some noise, but I unplugged and removed everything, put all back, and the noise was gone. They all sound perfect.