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Copper_Fan
Posted on Friday, April 27, 2001 - 4:21 pm:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

i am trying to install a low pass filter ( VECTRONICS VEC-802)and i made the 3 foot jumper out of LMR400 and before the filter was installed my SWR was flat on my 2970DX meter after i installed the filter my SWR was max bars (8 i think?) on the 2970DX meter!!!!! what did i do wrong??????
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307 (307)
Posted on Friday, April 27, 2001 - 8:13 pm:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

Well, this is a touchy subject and I will try to steer you in the right direction. In theory most "accessories" that are made for the CB band are supposed to be created with an impedance of 52 ohms. Unfortunatly this is not always the case. By adding a jumper in line the impedance changed. To fix the problem you either have to add / subtract length to the coax to reach the desired impedance. Without getting into it in great detail , remove the 3 foot jumper and add a 6 foot jumper. This most likely will fix the problem.
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Badintermod
Posted on Saturday, July 14, 2001 - 2:54 pm:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

Also, Check the jumper you made!!!! If your swr went through the roof There could be a short in your jumper cable. If you have a multi meter check your jumper to make sure that there is no continuity between the sheild and the center conducter, if there is, You have just found the problem,
73' and take care
Bobby, KG6ANB

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