Re: QRPing the TS-50


From: H Smith (
Date: Fri Mar 10 1995 - 13:08:07 EST

On Thu, 9 Mar 1995, Brogdon, Al, K3KMO wrote:
> Since I use a TS-50, I thought it would be nice to reduce the rig's
> low-power output from the preset 10 watts to 5 watts, to participate in the
> QRP division of some contests. Lo and behold, it's duck soup!
> ... etc ...
> After adjusting the low setting to 5 watts, the three power levels on
> my TS-50 are now 5, 25, and 50 watts (rather than the original 10, 50, and
> 100 watts). Aw right!

Notice that the adjustment above will change all three of the power
outputs. And yes, you can boost the high power to over 200w if you dare.

The low and medium power settings can be changed independently. My TS50
is set up for a low power output of 5w, medium power output of 50w and
high power output of 100w.

I have included the mod below for those who might be interested.


Smitty, NA5K


If you check the schematics, you will see on the TX/RX board two
potentiometers to set the Low 10 watt (pot VR15) and Medium 50 watt (pot
VR16) power levels. The high power level is fixed at 100 watts by
resistor R214. We want to get to VR15 and set it for 5 watts. Note that
VR15 and VR16 are not interactive. Changing the low power setting does
not change the medium (or hi) power setting and vice versa.

First remove the top cover, set aside the speaker and remove the latched
speaker bracket (gives you better operating room).

Locate two teeny-weeny pots next to the IF filter module in the middle of
the TX/RX board. The pot closest to the front panel is VR15 (low power
adjust) and the one closest to the back of the rig is VR16 (medium power
adjust). The pots are somewhat marked on the PC board.

Kenwood sez that their automatic antenna tuner needs 10 watts to actuate
so this adjustment may affect the AT operation.

The rig will draw about 4 Amps at 5 watts.

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