Mod for Higher Dead Key With Cobra After ERF 2030 mod

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StrightClaw
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Mod for Higher Dead Key With Cobra After ERF 2030 mod

Post by StrightClaw » Sunday 30th Mar 2008, 23:56

I ran across this on another forum and found it to work realy good for the Cobra 29.It may be of use to some.

Add a 1/4 watt 4.7 ohm resistor from the + side of C116 to the gate of the 2030 this is the left leg looking at the face of it. Replace C62 with a 390 PF Cap. The post suggest to jump D8 but I left mine alone. Went from 2 watt dead key to 8 watt.This will also incress the swing.

Now my question is does anyone know if this can be done to the Cobra 25 and how ?

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speedracer6g
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Post by speedracer6g » Wednesday 7th May 2008, 12:07

Sure can!!

-instead of using a 4.7k use a 10k pot or 100k. set your gate voltage to about 2.7 to 3volts. Do this by putting a voltmeter on left most leg of the mosfet final when looking at the face of the transistor.

-remove C45

-remove C46 and install a 480pf capacitor.

Also do not put a jumper on D8 because that is bad I have seen radios go up in smoke that diode is there to prevent feedback into the audio ciruit.

happy modding

Mike 8)

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Shadow
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Post by Shadow » Saturday 4th Oct 2008, 7:32

speedracer6g wrote:Sure can!!

-instead of using a 4.7k use a 10k pot or 100k. set your gate voltage to about 2.7 to 3volts. Do this by putting a voltmeter on left most leg of the mosfet final when looking at the face of the transistor.

-remove C45

-remove C46 and install a 480pf capacitor.
Call me blind, but I don't see a C116 in the Cobra 25. Can someone tell me where it is located?

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Shadow
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Post by Shadow » Wednesday 22nd Oct 2008, 1:02

speedracer6g wrote:Sure can!!

-instead of using a 4.7k use a 10k pot or 100k. set your gate voltage to about 2.7 to 3volts.
Hey Mike, since there is no C116 on the Cobra 25, where do you solder the other end of the pot?

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speedracer6g
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Re: Mod for Higher Dead Key With Cobra After ERF 2030 mod

Post by speedracer6g » Sunday 14th Jun 2009, 5:54

Sorry I might have that wrong I will check that agian and get back to you.

MIKE

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speedracer6g
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Re: Mod for Higher Dead Key With Cobra After ERF 2030 mod

Post by speedracer6g » Tuesday 16th Jun 2009, 7:18

On a Cobra 25 it goes on the center leg of tr16. Sorry about that.

MIKE

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