Signal Bar Problem

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elitejibninja

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I have about 4 months of expereince under my belt with my BCD396XT. I am somewhat inclined in programing my previous BCT8 on my own, but the digital scanner was a new world. I HAD mannaged to figure out this system but unfortunately i'm stummped on this one.

I live within almost eyesight of one of the main repeaters in the area (police, fire, EMS), with signal strength at full 90% of the time with some exception of dead spots in valleys and sutch, the signal was so good that I could use the original ducky antenna with great results. I was working in a machine and at the end of the day noticed that the signal strength was continuously low,1 or 2 bars, even in the areas that were great signal strength before.

I thought that i had maby bumped something by accedent, so, I checked the squelch setting, that was were it should be, lock out of any frequencys, none locked out, I even went far enough to wash all freq out of the scanner and re-enter everything back into the unit and no sucess. I have a digital Motorola type 2 trunked freq's, trunked analog Motorola type 2 freq's, and plain ol' conventioal freq's plugged into my scanner.

I hope this enough info for someone to help me, I can still recieve transmissions but the signal bars are only 1 or 2 max so at least im not dead in the water.

Please help, any suggestions are appreciated!
 

james812

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What signals are you referring to? the trunked signals or the conventional?

The things you checked squelch, lockouts... wouldn't have any effect on signal strength in my opinion,

Could the repeater be having issues?
 

kruser

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How about the attenuator? Did you accidently turn that on?

I would think that would have been cleared when you re-entered everything unless the 396XT has a global attenuator feature in which case it may have remained enabled.

I've never played with my 396 that much other than letting the computer program the thing so I can't say how easy it would be too accidently turn the attenuator on.

What W8RMH said is a possibility as well. I seem to read a lot of reports having to do with faulty antenna connections on today's portables but it seems the most common posts involve the GRE made radios.
 

elitejibninja

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The machine was an excavator, but the scanner was mounted on a C.B. mic holster so the possibility of the connection to the antenna being broken is likely from any jostling. The bars that signify the strength of transmission I am recieving is what I am really talking about, which is making me think more and more of a antenna problem.

The attenuator is turned off, I just checked.

I do appreciate everyones help!
 

kruser

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The machine was an excavator, but the scanner was mounted on a C.B. mic holster so the possibility of the connection to the antenna being broken is likely from any jostling. The bars that signify the strength of transmission I am recieving is what I am really talking about, which is making me think more and more of a antenna problem.

The attenuator is turned off, I just checked.

I do appreciate everyones help!

Those darn excavotor's will get ya every time.
Just kidding!

If you look into the connector end of the antenna, is the center pin still intact?
Is there any play when you try and wiggle the SMA connector on the 396?
I find the antenna jack pretty solid on the 396 but it could still bust the solder free where it is soldered to the main RF board.
I forget if my 396 came with the SMA to BNC adapter but I had one in my little carry case. If you have one also, try using another bnc antenna attached via the adapter. That should prove internal antenna damage although the jack is the likely culprit.
The stock antenna is pretty ridgid so I'd guess a sharp bend could have caused something inside the antenna to snap. If another antenna restores your signal levels, the antenna is the likely cause.
Does the inside of the SMA socket on the radio look ok and no broken pin from the antenna stuck in the center hole.
If the antenna's center pin did break off and is stuck in the socket, that should prevent you from screwing an sma to bnc adapter in without forcing it which would surely ruin the sma socket.

I also suspect the vibrations from the machine could have knocked something loose or out of alignment but I'd think it should have been able to handle it without damage. Unless it dropped out of the mic holder and hit antenna first.

Thinking about this more, the antenna is very stiff so I could see something being ripped loose if you accidently put a fair amount of sideways pressure on the stock antenna. Like say if your arm went flying into the scanners antenna. It's stiff enough that it may even have ripped the radio out of the cb mic holder clip.

While monitoring say one of the weather channels that is not showing full signal, try flexing the base of the antenna in all directions slightly. Not a lot of force but just a small amount. If it is a broken solder joint, you may see a spot where the signal picks back up indicating a broken solder joint.
Repairs of this kind are not that hard really.
Getting the radio apart is more fragile than the actual repair. The case halves need to be seperated (six external black screws) and then the lower board needs to be loosened (six internal silver screws) so it can be raised which will then allow the RF board to be lifted and removed from the logic board and rest of the case. Once the RF board is removed, the antenna jack solder points are easily accessible.
Anyone good with a low wattage fine tipped iron should be able to resolder the connection for you.
Assembly is the reverse. The six internal silver screws are all the same but the black external screws use two that are shorter, those two are the two located inside the battery compartment.

I've attached two pics showing the solder points that should be checked and reflowed if they appear cracked or loose.
One is viewed from the top of the board and the other is from the bottom.
Hopefully they will be large enough to see.

The areas of interest are circled in red.
Also before you reassemble the radio, check the nuts on the SMA jack to make sure they are both tight. One needs to be removed first in order to remove the black plastic top of the radio under the squelch/volume knob (which pulls straight off). Tighten the nut under the black plastic part and then tighten the second nut when you replace the black plastic top of the radio.
The SMA jack is double nutted so it is pretty strong but a good blow to the antenna could have caused the steel plate that is is mounted too to bend or flex so check that also if you do find a cracked or broken solder joint. The metal plate can be removed after also removing the squelch control nut and one small silver screw if you find yours bent. Don't try and straighten it while it is mounted to the circuit board otherwise you will ruun the circuit board.
 

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sjlamb

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I would strongly suggest that you not open up a your (4) month old, still under warranty $500 handheld. If symptoms persist and seem to be hardware related; send it in for service.
 

kruser

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I would strongly suggest that you not open up a your (4) month old, still under warranty $500 handheld. If symptoms persist and seem to be hardware related; send it in for service.

The OP did not state the radio was only four months old. He stated HE only has four months "experience" with it so it could very well have been purchased used.
If it is only four months old then I fully agree that it should be sent in for service under warranty unless it has obvious signs of abuse that would invalidate the warranty.
Same goes for anything out of warranty for anyone that is the least bit scared of what they are doing. Especially if it is an expensive item.
Many current electronic items have a flat rate repair cost no matter what the cause even if out of warranty as they don't even troubleshoot them. They just replace an entire board that they know the flat rate will cover.

I myself have rarely had anything fail while under warranty.
I repair everything myself (and have done such since around seven years old) and that number is in the thousands if not tens of thousands but that is also what I do for a living in my 2nd job as well as my primary job. Sure - I've fried a few things in my time but after almost 50 years under my belt, I have a pretty damn good success rate that far exceeds many of the so called "trained" techs out there. I've read the horror stories (tons of them) claiming an entire board needs to be replaced etc. when it's just a cracked solder joint or failed component that is at fault that is also very easy to replace or repair. I trust my own experience way more than I'd ever trust some tech that I do not know that will not even troubleshoot a board at the component level. Most are not trained for component level troubleshooting these days.

I posted this info for anyone who may be in the same boat with an out of warranty radio and is not scared to dive in and make the repair. Or for those that may have dropped the radio and are ashamed to admit it. That in itself will invalidate most warranties when the service center opens the radio and finds a cracked board or other signs of rough handling.

I'm sure many here ask for help due to stupid mistakes or accidents such as those caused by drops, or who knows what, that cause them to be ashamed or embarrassed to admit their mistake.
So I post the info for those that are not scared to try and repair themselves. I leave it up to the owner to determine if they are skilled enough to attempt the repair.
And NO, I'm not saying the OP in this thread did anything stupid but am offering the info that may help him/her or anyone else for that matter, repair their radio should they choose to try themselves.

Only they know their own skill level and only they know the circumstances surrounding the failure so it is solely their decision to attempt the (simple in this case) repair or not.

With that said, I should have put a disclaimer before anything else stating the facts or possibility of totally destroying your radio should you go in there with a 120 watt soldering gun.
 
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elitejibninja

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Thanks kruser, a lot of information duly noted. It is a relitively new scanner for me so I think i'm going to send it in for warranty and see what Uniden thinks.
 

kruser

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Thanks kruser, a lot of information duly noted. It is a relitively new scanner for me so I think i'm going to send it in for warranty and see what Uniden thinks.

That is by far the best solution now that I know it is under warranty.

If you ever come by any of the GRE or their RadioShack clones and have the same problem, the same area as in the 396 pictures is the culprit in many cases. Of course only attempt the repair if out of warranty and you feel comfortable working with the tiny units of today.
The GRE's pretty much use the same looking setup but I think the solder point may be a tad harder to reach without removing a shield plate.

Back when I started, nothing was marked and the sets contained tubes. Parts were marked with values but no R1 or Q3 or IC201 for example as they did not contain circuit boards. And then the biggie was worrying about killing yourself as many sets carried a fair amount of high voltage.

For myself, the satisfaction of repairing something is sometimes more fun than actually using whatever it was that I repaired!
There is a lot of joy in bringing something back to life that had been wrote off as dead forever.

I hope Uniden treats you well. I'm sure they will.
Report back if they tell you the what they did to repair.
 
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