Kenwood Ts-830 Filter Modification - Kenwood TS-830 Survival Manual

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Power supply drift and stability may be improved by these optional component changes and
additions.
On the AF AVR unit X49-1140-00 (Vicinity of Q27-Q30) change:
R124 from 1K to 1.5K (RD14CB2E152J)*
R127 from 470 to 390 (RD14CB2E391J)*
R130 from 47K to 33K (RD14CB2E333J)#
D25 from WZ-061 to XZ-053 (V11-4101-60)*
(*This will improve temperature drift from a maximum of about 100 mV to a maximum of
1 mV, and may be applied to any unit before serial # 201xxxx.)
Add two 22 KOhm ½ W resistors (RD14CB2E223J0, one each across Q30, and Q34, collector
to emitter.#
(#This will improve overall stability and may be applied to any unit before serial #105xxxx.)
Note: These changes are at the owners option and may not be performed in-warranty.
9.6

Kenwood TS-830 filter modification

Here is an easy filter modification for the Kenwood TS-830S. First to use this mod, your rig
need the YK-88C and to make it even better, the YG-455C installed. In short what we are going
to do, is move around a 9 volt switching voltage. This voltage comes from the AF board,
connector no. 7, pin no. 5. Its marked RLR on the schematic. This voltage ends up at the PLL
assembly, connector no. 8, pin no. 2. Please do try this modification by cutting in this circuit at
he source, because this same switching voltage feeds the IF SHIFT circuit, and the VBT circuit,
and the PLL. So cutting the wire at the AF board will make the PLL unlock when the mode
switch is anywhere but in the CW positions.
Now to the procedures:
1. Remove the top and bottom covers, and turn the radio upside down with front facing you.
2. Locate the mode switch, and on the middle wafer set of contacts, cut the white wire with the
blue stripe. It is located next to the terminal with no connection, on the middle wafer set of
contacts9)3-;3 about 1/4 inch ox wire on t switch contact, so you can make a connection there
later.
3. You will need another switch, one with at least three terminals, with the center terminal
always in contact with one or the other of the outside contacts. Its best to use a toggle type so
you can mount it in one of the spare holes on the back of the radio.
4. Splice into the wire removed from the mode switch, and connect this wire to the center of
your new switch.
5. From one (you select) of the side terminals of the new switch, connect a wire and run it back
to the mode switch. Connect this wire to the terminal on the mode switch from which you
removed the white wire with the blue stripe. You did leave that 1/4 inch of wire didn't you?
Take care here, the gray wire next to the one you are working on carries 110 volts, so don't
make any solder shorts!
6. Now from the remaining terminal of your new switch, connect and run a wire to the if board
to pins cw1-cw4. connect this wire to the green wire, that is connected to one of these pins. You
will then have two wires connected to one of these terminals.