An intriguing radio which looks great for unattended HF data use, since it is engineered for 100% duty cycle at 25W.

Has no data port on the back, but an accessory breakout cable can be added. Pinout is on p14 of the service manual, linked below.

Kenwood TK-90 instructions

Kenwood TK-90 ALE feature instructions

Kenwood TK-90 service manual

Requires programming. Both serial and USB-serial mic jack programming cable is available as a Kenwood part (see below) or off brand USB versions are also available. This implies it is just straight serial so a generic USB serial cable with an RJ45 plug crimped on the end may be suitable.

Has a “VFO mode” which implies it might not always have a “VFO mode” available.

Is ALE-capable, presumably with add-on.

Accessories

• KAT-1 - B51-8304-00 - Automatic antenna tuner
• KRK-5/6DH - B51-8445-20 - Remote kit
• KCT-31 - B51-8573-00 - PC interface cable
• VGS-1 - B51-8669-00 - Voice guide & storage unit
• KCT-39 - Accessory breakout cable (stocked by radioswap)
• KPG-102D - Programming Disc (CD)
• KPG-46 / KPG-46A - Serial programming cable
• KPG-46U - USB programming cable
• KCT-18 - Ignition sense cable
• KES-3 - External speaker
• KIF-2 - 2.7kHz SSB filter
• YF-107C - 500Hz CW Filter for TS-480HX/SAT
• KLF-2 - Line noise filter
• KMB-10 - Key lock adapter
• KMB-9 - Mounting bracket
• KMC-30 - Standard hand microphone
• KMC-32 - Hand microphone with keypad
• KMC-35 - Slim-line hand microphone
• KMC-36 - Slim-line hand microphone with keypad
• KPE-2 - ALE unit
• KRK-5 - Panel Separation Kit (Requires KCT-22M, 22M2 or 22M3)
• PG-20 - DC cable (7m)
• VGS-1 - Voice guide/Storage unit

For best results it has been recommended to use a KMC-32 keypad microphone for ease of use with the menus.

Software

Remove the top lid of the radio- 8 screws.

While there, turn VR852 fully clockwise, for max sensitivity to TX audio input.

Install KCT-39 - accessory breakout cable.

Boot radio into dealer mode by holding down B while powering up. Scroll down to FUNCTION, and press D. Scroll to menu item 19: DI LEVEL and press D. Turn up to 9, maximum. Press the square button. Press the red button twice to exit and reboot.

Build a cable:

• RX Audio → pin 14 (sky blue)
• TX Audio → pin 15 (turquoise)
• PTT → pin 6 (yellow)
• Ground → pin 8 (blue)

NB - currently feeding 2.2V P-P is resulting in rather low RF output- cause as yet unknown.