TS-570  Mods
 

From: PA3HGA

I bought last year a Kenwood TS-570D HF transceiver. After a few months of good working i got a problem : Everytime if i switch off the power i lost all the memories, including the value for the IF filter bandwidth (menu item 46) which is normally held even if you reset the transceiver! I thought immediately on a battery problem. It was, but there was more. I got garanty to this transceiver so i brought it away for a repair. They tell me it was a known problem by Kenwood that "a reset IC" was causing this trouble. They replaced a battery and an IC. Remember this if you got problems with your transceiver !

73, Reg de PA3HGA

1. Alle Kabel abmontieren ( Ant , Stromversorgung , ALC , Paddle usw. )
   
   Deckel und Boden abschrauben
   
   seitlich Schrauben des Bedienteils abschrauben .
   
   Bedienteil wegklappen , evtl. ganz abtrennen .
   
   Auf der am Geraet verbliebenen Platine ( X53-3690-10 ) den IC CXD1095Q suchen.
   
   Den 1KOhm - SMD - Widerstand ( Aufdruck 102 ) finden und ausloeten . Er befindet sich links unterhalb des o.g. ICs , rechts neben einer Schraube .
   
   Das Geraet wieder zusammenbauen und verkabeln .
   
   Beim Einschalten auf A=B druecken und damit einen RESET ausloesen . ( Evtl. die alten Voreinstellungen notieren ... )

Fuer die Richtigkeit uebernehme ich keine Garantie , diese erlischt vermutl. beim Oeffnen des Geraetes . Ich habe auch keine weiteren Mod. - Tips .

It is illegal to operate outside the limits of your class license or permits.
 

1. Disconnect the power cord and antenna coax from the transceiver.
   
    
2. Remove the top and bottom covers.
   
    
3. Remove the top screw from each side of the front panel assembly.
   
    
4. Loosen the bottom screw from each side of the front panel assembly.
   
    
5. Carefully rotate the front panel forward to gain access to the Control board (X53-3690-10).
   This board is mounted vertically against the body of the transceiver. It is not the board that is mounted in the front panel assembly.
   
    
6. Locate and remove the chip resistor R41 from the Control board.
   
    
7. Assemble the transceiver then perform the CPU reset procedure by holding the A=B button depressed as power is turned on.

This modification requires soldering equipment rated for CMOS type circuits. It also requires familiarity with surface mount soldering techniques. If you do not have the proper equipment or knowledge do not attempt this modification yourself. Seek qualified assistance.
 

The MARS/CAP TS-570D Modification can be done without any need of surface mounted desoldering tools. The modification will also work by simply cutting the PC-board run running from the memory chip to R-41, this is a 5 minute job. Please use, however a static discharge strap, at least grounded to the radio chassis.

73/Alex Hernandez/NU1T/AAV4GP

The procedure for modifying the TS 570 for MARS/ CAP coverage, also work just as well for the TS 570S, the 6M version, and extend the transmission range down to 49 Mhz.
Follow the same steps as for the normal HF version 570.

It seems incredible, but there is a lithium battery in the Kenwood TS570 that apparently lasts about 6 months. Replacing it is a major trip into the innards of your radio.

Clif of AVVID (a Kenwood Service center) was kind enough to tell me what to do, and I thought I would write up his instructions and my experience in case someone else needs it.

According to Clif, the microprocessor must reset correctly or the battery will drain quickly. Therefore you must follow these instructions, as odd as they seem.

Before you begin, you need the radio on a nonconductive surface, a phillips screwdriver and a CR2032 battery (Radio Shack has them). You also need the radio's power supply hooked up.

1. Have the radio hooked up to 12V. Turn the radio off but leave the supply on.
2. Remove the four screws from the top of the case.
3. Then remove the 4 screws on the side and lift the top free.
4. Turn the radio over and remove the 4 screws from the bottom that holds the entire case on. Don't bother with the service panel.
5. Turn the radio right side up and notice there are 4 screws (2 on each side) that hold the front panel on. Two of these are in slots, and two are in holes. Remove all 4 screws. BE CAREFUL. The panel is attached with several cables and yanking them loose is probably not a good idea.
6. Carefully separate the panel from the radio chassis. Note the battery in the little holder. The + side of the battery is facing out.
7. The battery holder is spring-loaded; you don't need to open it. Just gently push the battery and slide it upwards, freeing it of the holder and replace it with the new battery (remember + faces you).
8. Reseat the panel, lining up the screw holes and replace the screws.
9. If you want, at this point, turn the radio on and off again.
10. Replace the covers. Remember, don't put the side screws in until the top and bottom are in place.

That's it! According to Clif the problem won't reoccur. We'll see! Just be careful when you attempt this. Lots of things can go wrong. The case is very tight fitting, so don't drop the pieces and bend them out of shape or you will be sorry. Good luck!

UPDATE

As of March 29th, my battery failed again (yep, about 6 months). I have a month left on my warantee, so I'm planning on trying to get something resolved. I'll post here about what I find out.

Kenwood did in fact take the Radio back and apparently installed a diode at no charge. With any luck, this will fix the problem.

1. Disconnect the power cord and antenna coax from the transceiver.
   
    
2. Remove the top and bottom covers.
   
    
3. Remove the top screw from each side of the front panel assembly.
   
    
4. Loosen the bottom screw from each side of the front panel assembly.
   
    
5. Carefully rotate the front panel forward to gain access to the Control board (X53-3690-10). This board is mounted vertically against the body of the transceiver. It is not the board that is mounted in the front panel assembly.
   
    
6. Remove the square cover with 4 screws on it. LOCATE IC 5 go to the lowest point by ic 5 there are 2 resistors between the is 5 chip and the screw hole REMOVE the HORIZONTAL ONE
   
    
7. Assemble the transceiver then perform the CPU reset procedure by holding the A=B button depressed as power is turned on.

You will now have all the other frequencys you couldent transmit on now...

Thanks to Mike Faucheaux mikef@sat.net.MODIFICATION.NET for the picture below.

 

When the transceiver is turned off, there is a momentary increase in back-up battery current drain. In addition, if a personal computer is connected to the transceiver, excessive back-up battery current drain can occur when the transceiver is turned off. The following circuit changes will eliminate the increased current drain.

Caution: This modification requires soldering equipment rated for CMOS type circuits. It also requires familiarity with surface mount soldering techniques. If you do not have the proper equipment or knowledge do not attempt this modification yourself. Seek qualified assistance.

Parts required:

Qty   Description                      New Part No.
 2    10 Kohm resistor                 RK73FB2A103J
 1    Diode                            1SS355         *
 1    470 ohm resistor                 RK73FB2A471J   **

* You can substitute an MA110 diode in place of the 1SS355 diode.
** The 470 ohm resistor is only required for S/N 903xxxxx and higher.

Procedure:

1. Disconnect the power cable and remove the covers of the transceiver.
   
   Access the foil side of control board X53-3690-11.
   
    
2. Remove the solder resist from three foil locations.
   
    
3. Cut one foil trace. Do not cut too deep.
   
    
4. Add the two 10 Kohm resistors and one diode.
   
    
5. On the component side of the Control board, replace R36 with a 470 ohm resistor if a 10 Kohm resistor is installed (This must be done from S/N 903xxxxx and higher).
   
    
6. Remove the lithium battery and measure it's voltage. If it measure 2.8 V or less, you need to replace the battery with a new one (part number W09-0873-05).

Battery installation procedure:

Perform the following steps when installing the original or replacement lithium battery.

1. Once the battery is removed from it's socket, wait 20 seconds or more before going to the next step.
   
    
2. Connect a power supply to the transceiver. The transceiver should turn on by itself.
   
    
3. Install the original or replacement battery.
   
    
4. Turn off the transceiver from the front panel power switch.
   
    
5. Reset the transceiver by holding A=B key depressed while turning on the transceiver from the front panel power switch.

Units with a number 3 stamp on the outside box were already modified at the factory.

  1) Push MENU key on front panel.

   Find optional CW filter setting menu.

   If there are more menu Nr. like NR1 LEVEL, over CW filter setting Nr. this set is G type.

   If next to CW filter setting is 1st menu item, it is not G type.

   2) In SSB mode, push BC key to turn on BC.

   Then push and hold pushing BC key and if you hear beep, this set is G type.

   If there is no beep it is not G type.

The Kenwood TS-570 comes from the factory with it's modulation limiters set to allow only about 80 to 90% (PEAK) of modulation to be transmitted. But only 65 to 80% while talking.

The following modification to the TS-570 will add aprox. 10 to 15% modulation without distortion. This also depends on the frequency response of your microphone. The above results were gained using a D-104 with NO AMP. TX-EO set to "bb". Processor on and set to "10db". and Mic gain set to "100"

1. 1- Disconnect the radio from DC power supply.
   
    
2. 2- Turn radio bottom side up. with front panel facing you.
   
    
3. 3- Remove the 8 screws that hold the bottom half of the case on.
   
    
4. 4- Remove the bottom half case.
   
    
5. 5- Locate the 2 VR controls on the main board marked VR-4, and VR-5. You will find them near the right side front corner. They are very small. and they do not have built in stop's. They will turn all the way around without stopping. So be carefull when making your adjustments.
   
    
6. You will need to make 2 cuts on the PC board, and adjust both VR's.
   
    
7. Follow the diagram for instructions.

After completing these four steps, you are finished. If you are not sure that you adjusted the VR's correctly, you might want to adjust them while powered up and transmitting, using a 1000 Hz tone. The VR controls are very tricky to set because they do not stop turning at each side.

I'm sure there is a better way to stop the audio limiters from working, but I haven't found it yet. If you know a better way, please let me know.
 

ATTENTION
The KB2LJJ takes no responsibility for any damage during the modification or for any wrong information made on this modification.