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Jer
Posted on Wednesday, September 10, 2003 - 8:55 pm:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

I recieved my vr9000 a couple of weeks ago put it in my slip seat box and went to work to see how good it was. Well people were telling me I sound like I'm in a bucket, its muffled then the next day it started to squeal. Stop at CB shop and he said it didn't have RF gain so it needed a limiter on it. I didn't feel like that was the answer so thought I'd see what you think. The coax pluggin is loose and so is the mic pluggin could that be part of it? Also I drive for big R and don't have best ground sometimes. Thanks jer
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Kc0gxz
Posted on Thursday, September 11, 2003 - 12:02 am:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

Jer

Poor grounding can be a major cause of feedback. Also, because of the lack of a mic-gain on the 9000s, using the talkback WILL create feedback especially when using a power mic on those radios.

For starters, you can tighten up the mic socket and the SO-239 coax plug on the back of the radio. They shouldn't be loose.

If your antenna system isn't properly grounded, high SWR problems along with squealing will be the result.

The RF Gain that your tech is speaking of has nothing to do with your transmit problems. Also, it doesn't make any difference how well a tech tuned your radio. It will never work well without a properly grounded and tuned antenna system. Period.

Don't skimp on coax and antennas. Always use quality componets when putting together a mobile system. The antenna system that's on that truck could very well be the source of your problems.

Jeff, kc0gxz.
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Tech671
Posted on Thursday, September 11, 2003 - 6:13 am:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

With the 9000 (since it has no mike gain control) it's really nice to either run a microphone that has a gain control (D104m6b or Road Devil) setting the microphone's gain to about 25% or an Astatic 636 noise cancelling.

When you turn the echo on it gives automatic talkback that isn't adjustable. This has a tendancy to feed back with a stock mike and can also give the "boxy" sound. These other mikes help alleviate that.

The typical truckstop CB shop "supertune" or whatever they call it will only make this worse.
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Jer
Posted on Thursday, September 11, 2003 - 4:45 am:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

Jeff the match on the antenna was ok but the antenna is on vise gripe for always switching trucks, so hard to get to complex. I'm using a 4.5' frances and using the stock mic. Jer
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Kc0gxz
Posted on Thursday, September 11, 2003 - 12:04 pm:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

Jer

Oh wow. It's too bad that you are forced to run a antenna setup like that. Try one of the mics that Tech671 suggested in his post above. That just might clean your audio up.

Good luck and 73s.

Jeff, kc0gxz.
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Thunderbolt
Posted on Thursday, September 18, 2003 - 4:48 pm:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

Just to let you guys know. On the VR9000 there is a red wire soldered to a resistor on the board under the echo board. If you put a switch between that wire and the resistor you can turn your talkback off and your echo on. You can change the value of the resistor to try and lower the talkback when using a power mic if you want.

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