reducing output power on a trio tr 9000

Author Post

Dave, GM6JUA

Wed Jan 20 2010, 05:20PM
Hi,
I am looking for information on how to reduce the output power from 10 watts to 5 watts on ssb as it is fixed on ssb mode and I want to use the radio to drive a 70 mhz transverter
thanks in advance
Dave
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Dai, G8FXM
Thu Jan 21 2010, 09:04AM
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Joined: Mon Mar 17 2008, 06:10PM

Posts: 204
Does this radio have an ALC input on the accessory sockets? if so you could apply a variable voltage to the ALC connection to adjust your output power.
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Dave, GM6JUA
Thu Jan 21 2010, 11:27AM
Dave, GM6JUA
Registered Member #1052
Joined: Fri Sep 18 2009, 08:44AM

Posts: 9
Thanks Dai,
this is an old 2 metre multimode,it doesn't have an acc socket unfortunately,and although it is 10 watt / 1 watt on fm , it is fixed at 10watts on ssb, th eonly options I can see at present are to either find a supplier for a -3db 10 watt attenuator or adjust the internal mike gain to reduce the output to 5 watts.
regards
Dave
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Andy, GD1MIP
Thu Jan 21 2010, 11:48AM
Andy, GD1MIP
Registered Member #1103
Joined: Tue Dec 01 2009, 12:31AM

Posts: 20
Dave I use a similar beast a TR9130 to drive my transverter. Have a look at the links below. The 9000 and 9130 are in my opinion pretty close. Look at the links below and compare the line / circuit digrams. if they are the same inside there is a mod for the 9130 listed on the first link. It makes the power high / low switch operate on SSB too. The mod is a simple cut a wire jobbie then turn the low power to your desired level.

Andy

Trio TR-9130 Switch able low power SSB
Normal Tx power on SSB is 25w. This is not adjustable with the High/Low switch. FM is adjustable 25w or 5w.
To make SSB adjustable you need to cut the red/white wire on Pin 1 connector J33 on the Rx board.
If you wish to reduce the low power setting to below 5w-VR3 on the Tx board will require turning anti-clockwise.
I have turned mine to fully anti-clockwise in order to drive a transverter at the level of 1w













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Ian, G7RIS
Fri Jan 22 2010, 12:19PM
Ian, G7RIS
Registered Member #149
Joined: Fri Apr 04 2008, 12:27PM

Posts: 18
Hi Dave,
I have a manual and a circuit diagram for a TR9000 if it is any use to you.
Cheers
Ian
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Dave, GM6JUA
Fri Jan 22 2010, 12:39PM
Dave, GM6JUA
Registered Member #1052
Joined: Fri Sep 18 2009, 08:44AM

Posts: 9
thanks for all replies,
as far as I can see the 9000 and 9130 are very similar so hopefully this weekend I will try and see if Andies solution works
thanks to all
Dave
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Colin, G0DNQ
Wed Jul 30 2014, 02:57PM
Colin, G0DNQ
Registered Member #2256
Joined: Wed Jul 30 2014, 10:45AM

Posts: 9
hello I am new to the six mtr group joined today, anyway I read the suggestion on cutting the red wire on J33 on the RX board, I have the Kenwood TR-9130 and cut the same wire which is red/white and can confirm it does work. Now got to sort out my Trio TR-9300 which is the same rig to look at but not the same inside, I would like to add a CTCSS tone board to it like the 9130 purchased with this already fitted.
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