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Update:

MOSFET conversion for MB8719 board (Single conversion board, found in Uniden Washington, President McKinley, Realistic TRC-450, Cobra 142GTL, etc)

Parts you will need:
IRF520 MOSFET
EKL companion part EN-369FN
56k ohm 1/2 watt resistor
470pf disc or mica capacitor
68pf disc or mica capacitor (optional, see installation text)
small jumper wire

Installation:
Remove old transistor at TR41
Remove R163
Remove L34
Install jumper wire at R163
Install IRF520 at TR41
Install EN-369FN across final, positive side to gate, unmarked side to source
Install 56k ohm resistor from gate of final to far side of L35 (furthest side away from final, 13.8V)
Install 470pf capacitor across C173
Install 68pf capacitor across C148 (Optional, will bump up output in some radios, check without first)
Check voltage at gate of final, should be approx. 3.85V + or - .1V
Retune TX

Done! You should have same output as before, if not more. Did this on my Uniden Washington, was doing 21W before conversion, does 26W after conversion. ~Cheers~

<blockquote data-quote="ExitThirteen" data-source="post: 268521" data-attributes="member: 6878">Update:&nbsp;MOSFET conversion for MB8719 board (Single conversion board, found in Uniden Washington, President McKinley, Realistic TRC-450, Cobra 142GTL, etc)&nbsp;Parts you will need:IRF520 MOSFETEKL companion part EN-369FN56k ohm 1/2 watt resistor470pf disc or mica capacitor68pf disc or mica capacitor (optional, see installation text)small jumper wire&nbsp;Installation:Remove old transistor at TR41Remove R163Remove L34Install jumper wire at R163Install IRF520 at TR41Install EN-369FN across final, positive side to gate, unmarked side to sourceInstall 56k ohm resistor from gate of final to far side of L35 (furthest side away from final, 13.8V)Install 470pf capacitor across C173Install 68pf capacitor across C148 (Optional, will bump up output in some radios, check without first)Check voltage at gate of final, should be approx. 3.85V + or - .1VRetune TX&nbsp;Done! You should have same output as before, if not more. Did this on my Uniden Washington, was doing 21W before conversion, does 26W after conversion. ~Cheers~</blockquote>

[QUOTE="ExitThirteen, post: 268521, member: 6878"] Update: MOSFET conversion for MB8719 board (Single conversion board, found in Uniden Washington, President McKinley, Realistic TRC-450, Cobra 142GTL, etc) Parts you will need: IRF520 MOSFET EKL companion part EN-369FN 56k ohm 1/2 watt resistor 470pf disc or mica capacitor 68pf disc or mica capacitor (optional, see installation text) small jumper wire Installation: Remove old transistor at TR41 Remove R163 Remove L34 Install jumper wire at R163 Install IRF520 at TR41 Install EN-369FN across final, positive side to gate, unmarked side to source Install 56k ohm resistor from gate of final to far side of L35 (furthest side away from final, 13.8V) Install 470pf capacitor across C173 Install 68pf capacitor across C148 (Optional, will bump up output in some radios, check without first) Check voltage at gate of final, should be approx. 3.85V + or - .1V Retune TX Done! You should have same output as before, if not more. Did this on my Uniden Washington, was doing 21W before conversion, does 26W after conversion. ~Cheers~ [/QUOTE]

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