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View Full Version : How to lower output power on TS-2000 Kenwood?



K5AHH
08-19-2009, 07:39 PM
--Hi, all. I am wanting to try out some QRP on my Kenwood TS-2000, and was wondering if anyone out there that owns one of these rigs has ever gotten this radio to transmit less than 5 watts? I would like to try to make contacts using anywhere from 1/2 watt to 2 watts or so. So, any idea on how to do this? I will need to find the schematics for this radio, but they are hiding at the moment, haha. Thanks for any help.

KC0W
08-19-2009, 07:52 PM
Use 100' or so of cheap coax from Radio Shack. It will attenuate your signal just fine. Of course, what you receive will also be attenuated.



Tom KCW

N4KZ
08-19-2009, 07:55 PM
One easy way to lower the output of many 100-watt HF transceivers is to use a 9-volt battery and a potentiometer and feed the small voltage into the ALC output connector on your Kenwood. This is the same as running your rig with a linear amp and connecting the amp's ALC line to the transceiver so as not to overdrive the amp by reducing the transceiver's power output. The circuit is ultra simple. I suspect you could Google it and find it online.

73, N4KZ

KM3F
08-19-2009, 10:13 PM
Another way is to make a resistive non inductive pad connected to the output.
Feed it with 5 watts and set the output level you want..
Only need to provide a bypass around it for recieve.

KC8VWM
08-19-2009, 10:18 PM
Reduce the voltage on the transmitter finals. Reduce the voltage on the rigs power supply. Change the resistance values on the RF output circuitry. Internally readjust the RF circuitry.


There are several other methods...


:)

W9OE
08-20-2009, 01:11 AM
How about reading the owners manual where it tells you how to do just that. You can change the power setting down to an adjustable 1 to 5 watts using the the menu and multi switch. This will allow you to chose from 1 to 5 watts. I am not aware of any way to make the TS 2000 go below 1 watt unless you open up the radio. (not a good idea)

Go to page 20 of the owners manual. Look under Select transmit power. Go to menu 23, select "ON" then press +... Poof, now you can run as little as 1 watt. Additional information on page 79. Don't get much easier that that, takes about 4 seconds. As stated above with a little coax loss and other factors you may end up with less than a watt making it to the antenna.

Forget about the "9-volt battery and a potentiometer and feed the small voltage into the ALC ". Forget about making any changes to the RF output circuitry. The Ts 2000 is designed and capable of doing what you want without any of the afore mentioned modifications (unbelievable).

Have fun!

K5AHH
08-20-2009, 03:05 AM
Go to page 20 of the owners manual. Look under Select transmit power. Go to menu 23, select "ON" then press +... Poof, now you can run as little as 1 watt. Additional information on page 79. Don't get much easier that that, takes about 4 seconds. As stated above with a little coax loss and other factors you may end up with less than a watt making it to the antenna.

Have fun!

--Hi. I do have the manual here, and did just that, and while it allows the radio to adjust in increments of one watt at a time, instead of five, it will not go below 5 watts. It will do 5, 6, 7, etc., but not below 5. What am I reading wrong here? In fact, the only band that allows wattage below 5 watts is the 1296 band. The only wattage numbers listed from HF-2 meters is 5 -100, 70cM is listed as 5-50 watts (all in steps of 1 or 5), and 1.2Ghz is 1-10 watts. Thanks.

--When looking at the chart on page 79, under "TX POWER", only the 1.2Ghz band has 1-10 watts. I don't know what I am overlooking here.

W9OE
08-20-2009, 03:53 AM
Have you checked the output while set at the lowest wattage on your desired frequency? You maybe surprised to see it is less that 5 watts. Mine on 40 and 20 meters only puts out about 2.8 watts on the five watt setting, however it puts out 112 on the 100 watt setting. (factory settings not modified)

There is an adjustment like on most radios that allows you to lower the minimum power out and maximum power out. If the radio is still under warranty I would not touch it. Keep in mind that the power monitor will not indicate the correct power out if you make the adjustment. You can turn it down to 1 watt out but the monitor will still say 5 watts out.

I would not suggest trying to make any of the modifications as suggested by some others here. Running the radio at a lower voltage from the supply will shorten the life of many components in your radio. Remember heat kills radios and low voltage is just as bad as high voltage to these components. Under powering modern electronics cause the components to heat up!

Call Kenwood, they will help you identify the correct pot to adjust for low power. Or go on line there are several TS 2000 groups that also may have the information available. Once you identify the correct adjustment mark it so you can return the radio to specs if needed in the future.

K5AHH
08-20-2009, 04:11 AM
Have you checked the output while set at the lowest wattage on your desired frequency? You maybe surprised to see it is less that 5 watts. Mine on 40 and 20 meters only puts out about 2.8 watts on the five watt setting, however it puts out 112 on the 100 watt setting. (factory settings not modified)

There is an adjustment like on most radios that allows you to lower the minimum power out and maximum power out. If the radio is still under warranty I would not touch it. Keep in mind that the power monitor will not indicate the correct power out if you make the adjustment. You can turn it down to 1 watt out but the monitor will still say 5 watts out.

I would not suggest trying to make any of the modifications as suggested by some others here. Running the radio at a lower voltage from the supply will shorten the life of many components in your radio. Remember heat kills radios and low voltage is just as bad as high voltage to these components. Under powering modern electronics cause the components to heat up!

Call Kenwood, they will help you identify the correct pot to adjust for low power. Or go on line there are several TS 2000 groups that also may have the information available. Once you identify the correct adjustment mark it so you can return the radio to specs if needed in the future.

--Hi. I do appreciate the info. Indeed, my radio is well past its "expiration date", haha, so no worries about warranty voiding. I will ask around about the correct potentiometer to adjust for the low power setting. I've never messed with QRP before, and just thought it would be cool to try it out at least once. Should present a fun challenge! Thanks again.

WS2L
08-20-2009, 02:11 PM
There is also a menu function I think it's called "Fine TX" which allows you to adjust the power in one (1) watt intervals instead of the five (5) watt default.

But using 100" of Radioshack coax will probably do the same thing : )

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