| Author |
Message |
    
Kid_vicious
Senior Member
Username: Kid_vicious
Post Number: 1922
Registered: 9-2004
| | Posted on Thursday, July 27, 2006 - 12:52 am: | 
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im fixing up a 139xlr that i bought cheap
this is my third one, and i figure that its ok to experiment a bit with this one.
i would like to try an NPC mod on this radio, but i dont know how to do it, and cant find the info on the web, or here on the forum.
if someone has done this, and/or has the info i sure would appreciate some help.
also, any other mods that are "out of the ordinary" would be cool to discuss.
thanks in advance,
matt |
2600
Advanced Member
Username: 2600
Post Number: 575
Registered: 7-2002
| | Posted on Thursday, July 27, 2006 - 11:20 pm: |
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Sorry, but there is no "NPC" mod for that radio. That trick is done to radios where the AM modulator is a power transistor. Your radio is modulated by a step-up transformer, driven by the audio power-amp chip, the same one that drives the speaker on receive.
The AM 'regulator' transistor is just that, a voltage-regulator circuit, like the larger one that provides 13.8 Volts DC to the radio itself. Since no audio is fed to this circuit, it won't respond to that sort of modification. Turn down the carrier, and the AM peaks turn down with it.
73 |
Kid_vicious
Senior Member
Username: Kid_vicious
Post Number: 1924
Registered: 9-2004
| | Posted on Saturday, July 29, 2006 - 9:14 pm: |
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thanks very much for the reply 2600.
i was kinda hoping you would be one of the people responding to this thread.
no NPC mod. bummer.
i thought i remembered reading a post by you from a couple of years ago, where you mentioned that you had a set of mods for this chassis, that you were going to put online.
do you still have the info?
im interested in pretty much anything besides the channel mods.
dont need to make the clarifier slide too far either, but i do want to unlock it.
ive seen three different methods which all vary just a bit from eachother.
which is your favorite?
like i said, im wanting to experiment with this one. its a poject radio, and i dont mind messing with it.
ever volted the final on one?
BTW, if you dont mind, i just noticed today that i dont have any SSB transmit. i did when i was testing the radio, about 11-12 watts. put the radio in the car, and no SSB TX.
am TX is fine, with good modulation.
i have replaced all the 1419's with NTE152's, and have replaced C179 with the 2.2uF electrolytic cap.
SSB worked after this, and now it doesnt.
any tips?
thanks for any help,
matt |
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