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Texan
New member
Username: Texan

Post Number: 1
Registered: 2-2009
Posted on Saturday, February 21, 2009 - 3:52 am:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

I have a TRC 457 with 2sc1969 in it. I have tried everything to get more modulation out of this radio. I was reading a website that said you could mod this 858 pll to get 200 chanels and replace the stock final to a MRF 477. Now checking around I can not find a Mrf 477 but I did find a website that claimed the MRF 497 is a good replacement for the mrf 477. Is this right. can I go from a 2sc1969 to a MRF497. And if so Will it be a drop in replacement. My modulation is peaked as good as I can get it and turning my am power down to 2 watts turns down audio also. I can not find a risistor or diode that limits audio and have not saw a website that lists one. I think am power is limited by a cap but do not know which one yet. I am sure of one thing my final is not pushed as for as it will go and power mikes do not seem to make any diferance. { I am using a D104 now} any info on this. What else can I try.
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Teham
Member
Username: Teham

Post Number: 74
Registered: 1-2004
Posted on Monday, June 07, 2010 - 1:33 pm:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

first do not use anything other than the erf as they r designed specifically for rf application. going to 4 watts on a 1969 final is fine. the r designed for that. also u will find that turning it up to 4 watts will help when talking over 10 miles. tony cef 259
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Press_man
Intermediate Member
Username: Press_man

Post Number: 144
Registered: 5-2008
Posted on Friday, June 11, 2010 - 7:14 pm:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

Texan:
I know this is an old post and you probably have fixed your radio but I found the following for you. BTW the MRF 477 is a 40 watt transistor while the 2sc 1969 is 22w on ssb. You need a bigger power supply to run the 477.

Here goes as per Secret CB: TRC 457
VR 8 AM power
CT 7 SSB ALC
VR 7 AM MODULATION CONTROL
VR 12 pwr meter
L 27 TVI trap
Tune L39, L37, L32, L30 for max on ch 20 USB

I make no claim to the accuracy of Secret CB.
Wally/Pressman/KC4ZWM

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