| Author |
Message |
    
Larryb
New member
Username: Larryb
Post Number: 1
Registered: 2-2004
| | Posted on Sunday, February 06, 2005 - 11:03 am: | 
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Can anyone tell me how to set up an o-scope for reading modulation? I bought a 100mz scope but have no manual and none of the books i have on radios give any explanations on hook up or test points. Thanks Larryb |
Bruce
Senior Member
Username: Bruce
Post Number: 2181
Registered: 9-2003
| | Posted on Sunday, February 06, 2005 - 11:37 am: |
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you should be able to sample the rf by loose coupling the scope to the radio ( rap a wire around the coax ) |
Therealporkchop
Intermediate Member
Username: Therealporkchop
Post Number: 138
Registered: 11-2002
| | Posted on Sunday, February 06, 2005 - 1:51 pm: |
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If found that the easiest way was this: That a T connector and remove the pin from the male part. It just unscrews with needle nose pliers. You will need to mark where the pin meets the insulator when it's screwed flush back into the connector. Take a hacksaw and cut it off at your mark. Then use the saw to cut a slot into it, this is so you can use a screwdriver and install it back into the connector. If you do this correct, it will be flush. You have just made a capacitive pick point. You can then take a female connector like what is in the back of an amp and screw it onto the male side of the connector. Then you can take an old probe cable and cut off the probe. You won't need the probe anymore for resistance or capacatance. Strip the cable back like you would a piece of coax and solder the center cable to the center pin and the shield to the outside.
There you do. That is how I did mine. I can see my modulation and my view carrier. I see exactly what is going on when I key and speak into the mic. This will let you see how distorted the siganl gets from all those mods you are doing. So try not to let it worry you too much.
Bruce, I'm not trying to knock you brother, your way works too. |
Jose22
Member
Username: Jose22
Post Number: 87
Registered: 2-2002
| | Posted on Sunday, February 06, 2005 - 5:48 pm: |
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Any good pictures of "clean" modulation, noise, over modulations? Maybe some of you techs can attach a short wav file for us dummies.
thanks |
Larryb
New member
Username: Larryb
Post Number: 2
Registered: 2-2004
| | Posted on Tuesday, February 08, 2005 - 9:02 am: |
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Thanks for the response.You are right about all those mods i have done for years but now I want to learn how to set up a radio the correct way. On the back of my scope there are 4 connection points, z axis input, channel 1 signal output and gates a&b outputs.I am assuming I want to hook to the z axis input? Also any suggestions on an audio signal generator? Thanks |
