i have had mine since new,it is one of the best ssb's made, right now getting
sparky tuned,yeaaaaaa
The TRC 449, and its brothers, the TRC 457 and 458, differ in small (but significant) ways from the models produced by Cobra, President, Robyn, and Teaberry that used the same Uniden 858 Chassis.
In the Realistic units, D23 in the AMC circuit is replaced by a 220 ohm resistor, and the the value of C87 is reduced from 10uf to 2.2uf. This has the effect of tightening up the AMC circuit so the Realistic sets don't really modulate as well as the sets from the other manufacturers. To correct this, replace the 220 ohm resistor with a 1N914 diode, and parallel a 10uf/16v cap across C87. C87 adds compression to the audio for greater talk power.
Defeating the AMC in these sets is a no-no, and it will be interesting to me to see what Sparky does to the limiters in your 449. The limiters can be modified, but should not be defeated. Bypassing D21 and D22 will look good on a meter, but will sound like crap on the air. Likewise, bypassing L10 and L11 will look good on a meter, but will result in a ton of harmonics and distortion on SSB with NO increase in performance. I hope that Sparky leaves this stuff alone.
The other difference with the TRC-449 is that FT2 and L26 are not in the circuit and are replaced by a jumper wire. Because of this, the adjacent channel rejection in the 449s totally sucks. These parts are still available from Dynascan (Cobra). Check Sam's # 127 for the part numbers. Get 2 FT2s and hook them in series for even better rejection.
In my opinion, the Uniden 858 chassis was the best 40 channel CB radio ever made. So, STONEMAN, you got a good deal when you bought one.
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