It seems Kenwood has finally listened to the complaints from all over the world about the TS-590S ALC issues:

Attention all Kenwood Dealers,

We understand that there are TS-590S owners that are still having problems with the ALC spike issue, even after a firmware upgrade lowered the spike. If you have a customer with an amp that is shutting off and going into standby please share this info with them. The radio must be sent to a Kenwood Service center for the modification, it takes approximately 1.5 hours to complete and takes several parts, it is not doable by the end user.

There is no charge for this modification, in or out of warranty.
Kenwood will pay the return shipping from the service center.
The owner pays for shipping to the service center, and we take care of the rest!
The U.S. service centers will be ready to perform the modification in late April.
Serial number range: B09xxxxx to BC3xxxxx
From SN B4100001 the modification has been applied.

Thanks for your support.
Kenwood USA

In Germany at least two official dealers can implement the ALC modification. So if you have problems with the ALC overshoot, please contact one of them:

  • SARIKAYA Funktechnik, Hattinger Str. 57, 44789 Bochum, Fon 0234-79213600
  • Dieter Knauer Funkelektronik, Waldblick 28, 96158 Frensdorf (OT Birkach)

If you know other German dealers who take care of the TS-590S ALC modification, please let me know and contact me by email.

Please note:
Kenwood Germany takes over the costs for the modification, at least in my case. To get the modification you must have purchased your TS-590S at an official Kenwood dealer. I was told grey imports will not get a paid modification by Kenwood Germany. Kenwood wants to know the date of purchase, serial number and which device is affected by the overshoot. In my case it’s an Acom 2000A amplifier. If you don’t have an amplifier which is affected by the overshoot, you might not get a paid modification by Kenwood Germany.

The modification takes about 2,5 hours and includes hardware changes and a new alignment. I don’t know the current situation in other European countries, but my best guess is a similar procedure as here in Germany. Just contact your Kenwood dealer and ask for the modification.