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RCI 2970N4 Amp Switch ?

bevis

Member
Sep 28, 2020
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Does anyone know how the typical amp switch mod is done on the 2970N4 ? Its the non colorized model.
I bought a new in the box 2017 model and Bells has their card inside with the radios wattage as tested.
The person that I bought the radio from did not have the amp off switch mod done to it so it could be used with a low drive amp and for just barefoot talking local. I have searched the web for a couple of hours and coming up with a blank. Its a new radio thats never been turned on and i dont want to do the mod incorrectly. I see the Bells vids where they are installing a mini toggle switch that appears to not be switching very much current and it appears to work well for them. Any help on this specific model mod would be appreciated.
Thanks in advance.
 
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Can you see the mirror board at the top right in the first photo ?
Yellow wire and green wire running to a plug on the board just above the mirror board.
Generally, if you cut the green wire, and splice the on/off switch into that wire, it will turn off the power to engage the the small relay on the amplifier board.
The radio will operate normally on low power without the amplifier.
These photos are the inside of a Ranger RCI-2995DXCF, but the main PCB is the same as the 2970N4 .....

rci_2995dx_01.jpg



rci_2995dx_02.jpg



rci_2995dx_09.jpg


rci_2995dx_10.jpg
 
I also have a virgin 2995DX that could use the same amp cut off mod. Is the wiring color the same in the 2995dx as the 2995dxcf ?
 
probably......
But they are the same wires in the same location.

thanks for all the great help.
just to make sure im understanding this correctly, you are not killing the power to the amp but the relay that feeds the amp, correct ? Im just making sure i understand what im doing.
 
Yes, I just did one on my Galaxy DX98VHP. Mine was a blue wire yours is the brown. The switch cuts power to the amp section. Mine now dead keys .5 to roughly 10 and swings to 42 watts without the amp section. When the amp switch is turned on PEP AM is 290ish.

Be very careful not to get metal shavings inside your radio. I used a piece of duct tape inside folded back with the sticky side up. I did the same thing on the outside. This caught all the metal shavings. Not many fall inside since your drilling the hole from the outside. Go SLOW…VERY SLOW when drilling the hole.

Measure your wire length to the switch carefully sometimes there’s just barely enough. If the wires you need are under that long (1.5-2 inch)RF blocking shield that is slid into place between 3 pinch clips, you can gentle pull that out…sometimes the wires are routed underneath that.

Brad
 
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Yes, I just did one on my Galaxy DX98VHP. Mine was a blue wire yours is the brown. The switch cuts power to the amp section. Mine now dead keys .5 to roughly 10 and swings to 42 watts without the amp section. When the amp switch is turned on PEP AM is 290ish.

Be very careful not to get metal shavings inside your radio. I used a piece of duct tape inside folded back with the stick side up. I did the same thing on the outside. This caught all the metal shavings. Not many fall inside since your drilling the hole from the outside. Go SLOW…VERY SLOW when drilling the hole.

Measure your wire length to the switch carefully sometimes there’s just barely enough. If the wires you need are under that long (1.5-2 inch)RF blocking shield that is slid into place between 3 pinch clips, you can gentle pull that out…sometimes the wires are routed underneath that.

Brad

Well, Brad...... Good Morning.
No, this procedure does not cut power to the amplifier section.
What this does is cut the electrical DC voltage to the relay on the amp board.
EDIT: It doesn't actually cut the DC voltage to the relay, it cuts the signal to the transistor that goes to ground to key the relay....
This prevents the relay engaging, which in turn prevents the RF power from the radio entering the amplifier section.
The radio RF power just passes through the unkeyed relay straight to the antenna out connector.
Hope this explanation helps ......
 
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thanks for all the great help.
just to make sure im understanding this correctly, you are not killing the power to the amp but the relay that feeds the amp, correct ? Im just making sure i understand what im doing.

Yes, that is correct.
 
Can you see the mirror board at the top right in the first photo ?
Yellow wire and green wire running to a plug on the board just above the mirror board.
Generally, if you cut the green wire, and splice the on/off switch into that wire, it will turn off the power to engage the the small relay on the amplifier board.
The radio will operate normally on low power without the amplifier.
These photos are the inside of a Ranger RCI-2995DXCF, but the main PCB is the same as the 2970N4 .....

rci_2995dx_01.jpg



rci_2995dx_02.jpg



rci_2995dx_09.jpg


rci_2995dx_10.jpg
I am guessing that for the RC1 2970N3 that it may be the same color wires as the N4 but in any case the same two wires shown. I would like to add this feature to my RCI2970N3
 

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