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How CB radio works / Re: Controlled Carrier Stuff
« on: August 24, 2013, 09:09:31 AM »
Good to see you Tommy...
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Signal Generators / Re: B&K 2040 thread
« on: August 06, 2013, 07:55:50 PM »
Keep me updated.. You know I am looking for one...
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CB Radio Repair Forum / Re: npc mod
« on: April 24, 2012, 08:00:35 AM »
A lot of people knock it, but what I have seen and found from person experience it works good as long as you follow instructions.
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CB Radio Repair Forum / Re: npc mod
« on: April 12, 2012, 12:21:25 AM »
There is more to it than just the diode mod. But not much. Try reading this link.
http://www.cbdoctorstudygroup.com/npc-rc-modification-for-3600xxx-board-t36.html
Billy has done a lot with this mod. He admits he is not the one to come up with it, but he has spent time with it.
http://www.cbdoctorstudygroup.com/npc-rc-modification-for-3600xxx-board-t36.html
Billy has done a lot with this mod. He admits he is not the one to come up with it, but he has spent time with it.
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CB Radio Repair Forum / Re: npc mod
« on: April 10, 2012, 08:18:11 PM »
The whole name for it is NPC-RC which stands for Negative Peak Conversion-Reduced Carrier. What it does is (as I under stand it) is compresses the negative peaks of your modulation. I had gotten into radios back in the mid 70's and learned a lot from a local tech, then learned more on my own later by experimentation. I even ran a small radio shop out of my house, but a ugly divorce ended that.
Any way I am now getting back into them and unfortunately have never done one of these conversions, but from what I have heard around the net, a lot of people like it. It makes your radio modulate louder without the distortion
Any way I am now getting back into them and unfortunately have never done one of these conversions, but from what I have heard around the net, a lot of people like it. It makes your radio modulate louder without the distortion
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CB Radio Repair Forum / Re: uniden washington
« on: March 16, 2012, 07:46:24 AM »
Thus have the 8719 chip in it. I assume it does if it is a Uniden. If it has the PC-385 PCB board, this should be the alignment for it
Attach frequency counter to TP1 (R157)which is located directly next to L27. Also make sure clarifier is dead center or you will be in never never land.
For the loop oscillator set radio as below and adust coil or cap for the frequency listed
AM L20 34.985
LSB L19 34.9825
USB CT3 34.9875
TX frequency VR3 34.985
once finished, check all frequencies again as sometimes they will change on you.
For the offset oscillator attach counter to Tp3 which is R101 in the middle of the board towards the rear
Am L17 27.185
LSB CT2 7.7975
USB Ct1 7.8025
Again recheck as they can change, especially with a tuner or you hand near to change the inductance.
VCO ALignment
Connect your meter or osciilsope (if you are lucky enough to have one) to TP9 which should be the top leg of R72 located just below the VCO card.
Set your radio to channel one (if you have extras put it on your lowest channel.). Adjust L13 so that the base voltage just starts to lift, (should be somewhere around 2 volts.)
Check for TX. If it will not TX, adjust L13 until it starts transmitting.
Go to your highest channel and check the voltage. It should be 6.8 or less and make sure that the radio transmits.
If the radio does not work by this point, let me know as there are more steps to be followed, but you should see some improvement by this point.
Sorry RT for jumping in front of you....
Attach frequency counter to TP1 (R157)which is located directly next to L27. Also make sure clarifier is dead center or you will be in never never land.
For the loop oscillator set radio as below and adust coil or cap for the frequency listed
AM L20 34.985
LSB L19 34.9825
USB CT3 34.9875
TX frequency VR3 34.985
once finished, check all frequencies again as sometimes they will change on you.
For the offset oscillator attach counter to Tp3 which is R101 in the middle of the board towards the rear
Am L17 27.185
LSB CT2 7.7975
USB Ct1 7.8025
Again recheck as they can change, especially with a tuner or you hand near to change the inductance.
VCO ALignment
Connect your meter or osciilsope (if you are lucky enough to have one) to TP9 which should be the top leg of R72 located just below the VCO card.
Set your radio to channel one (if you have extras put it on your lowest channel.). Adjust L13 so that the base voltage just starts to lift, (should be somewhere around 2 volts.)
Check for TX. If it will not TX, adjust L13 until it starts transmitting.
Go to your highest channel and check the voltage. It should be 6.8 or less and make sure that the radio transmits.
If the radio does not work by this point, let me know as there are more steps to be followed, but you should see some improvement by this point.
Sorry RT for jumping in front of you....
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Amateur Radio News and Activities / Texas Hamfeat
« on: March 12, 2012, 09:56:59 PM »
Anyone know of an upcoming event in Texas? Near San Antonio would be great. Takes a while to get from one side of the state to the other..
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CB Radio Repair Forum / Talk back for 25 and 29 Cobra radios
« on: March 05, 2012, 05:51:23 AM »
Cheap and easy
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CB Radio Repair Forum / Re: Service monitor
« on: March 05, 2012, 05:50:27 AM »
Is this a stable tone?
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Home Brew And Tech Forum / Re: Simple transistor tester
« on: March 05, 2012, 05:48:31 AM »
Thanks Radio Tech. Now you have made my big Sencore transistor tester an over priced doorstop.. lol
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New member welcome / Re: new here
« on: March 04, 2012, 09:28:20 AM »
Welcome to the site. You can get a lot of info and help on here, Just ask away
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CB Radio Repair Forum / Re: Service monitor
« on: February 07, 2012, 03:10:51 PM »
I got to thinking more about it last night. Some other things that could be added. I will have the 5 volt variable in it also, but I am also going to add a salt water dummy load to it. This way it can all be home brew and no oils to mess with. I think you could almost build just about everything you need inside a computer case, except a scope.
http://www.qsl.net/k5lxp/projects/SaltLoad/SaltLoad.html
http://www.qsl.net/k5lxp/projects/SaltLoad/SaltLoad.html
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