TK-890H Extremely poor sensitivity in receiver, RX audio pulled from DB25 unreadable through white noise

[cudjeri]

Hi everybody, i have some questions pertaining to some issues with my Kenwood TK-890H. I'm experiencing very very poor performance of this units' receiver. I'm somewhat new to the hobby/industry so forgive me for my possibly incorrect terminology in advance.

Signals from the repeater that can be received by a handheld UHF radio indoors are dropping out of the squelch of my TK-890H which is connected to my high 4.5 dBd commercial co-linear antenna with high quality LMR-400 feedline and the squelch setting is currently set to 2. SWR on the antenna is perfect and other radios connected to the exact same antenna/coax combination have no problem receiving the repeater.

Are there any settings in the programming software I should check? Also, I have this radio interfaced to a Signalink USB for remote use and I am pulling audio from the DB25 with shielded cable and feeding it to the Signalink but the amount of white noise completely drowns out the receive audio and is barely coherent.

When the kenwood external speaker is plugged in there is still an element of what i perceive to be "poor audio" despite seeing reports in other forums of these radios having "amazing audio" but it's still a vast improvement from the DB25 ports' audio.

Are these radios renowned for poor RX or does my radio have a mis-configuration . Perhaps it is broken and/or needs a tune-up?

Thanks for the advice in advance, and sorry if this was posted in the wrong section.

 

[mmckenna]

Are these radios renowned for poor RX or does my radio have a mis-configuration . Perhaps it is broken and/or needs a tune-up?

They are good radios, but like used cars, you never know how it was treated by the original owner.

Too many variables for us to really answer that question, though.

-Could be a programming issue, make sure you have your wide/narrow set correctly.
-Could be an alignment issue.
-If you are using this outside it's designed frequency, they can be pretty deaf.

Without some info on who/what you are trying to listen to and how your radio is set up, we'd just be guessing.

 

[cmdrwill]

the DB25 ports' audio.

This raises a RED FLAG.

 

[mmckenna]

Are there any settings in the programming software I should check? Also, I have this radio interfaced to a Signalink USB for remote use and I am pulling audio from the DB25 with shielded cable and feeding it to the Signalink but the amount of white noise completely drowns out the receive audio and is barely coherent.

This raises a RED FLAG.

Which pin are you pulling audio off of?

 

[a417]

IIRC, it should be pin 17 on the D-sub connector for him, yes?

 

[mmckenna]

IIRC, it should be pin 17 on the D-sub connector for him, yes?

Depends on what he's doing, that's why I was asking him. One is the detector out, one is audio out.

 

[KK6ZTE]

These radios require alignment during wide frequency changes. The receiver only works on a 20MHz wide passband and must be realigned (front end filters and VCO) if frequencies are changed--ESPECIALLY since you are using it on the ham band. This is all part of the manual. Squelch probably needs alignment as well.

Download the service manual and get to work. They work fantastic when configured properly.