BC780XLT Scanning S L O W

[paramedszaf]

I have 5 in my fleet, one in particular is scanning so S L O W you can count the channel numbers as they scan....

All the scanner-wide settings are the same per the ProScan I use to program it..

Anyone?

 

[n4yek]

Check your squelch and make sure its not completely open.

 

[sjlamb]

I have 5 in my fleet, one in particular is scanning so S L O W you can count the channel numbers as they scan....

All the scanner-wide settings are the same per the ProScan I use to program it..

Anyone?

Sounds like you may have a bad CPU clock or bad solder joint on that device, which is the crystal that that determines the scan speed. The device could either look like a standard metal crystal or could also be a blue colored device known as a resonator. If the device itself is actually failing/damaged, not a very difficult repair to replace and the part only costs a few bucks.

 

[paramedszaf]

Sounds like you may have a bad CPU clock or bad solder joint on that device, which is the crystal that that determines the scan speed. The device could either look like a standard metal crystal or could also be a blue colored device known as a resonator. If the device itself is actually failing/damaged, not a very difficult repair to replace and the part only costs a few bucks.

Alright, any idea what I am looking for once I open the case?

 

[sjlamb]

Alright, any idea what I am looking for once I open the case?

Have not looked inside a BC780XLT, so I can't say for sure. If it's a metal cased crystal; it would be marked on the board as "X-1", "X-2" or such. It would NOT be the one that is marked as "10.7" on the body of the crystal as this would be the 10.7 mHz IF crystal... assuming that Uniden still uses 10.7 mHz crystals as the IF oscillator.

In later models, it is more likely however, that it would be a blue or tan colored ceramic resonator somewhere between 4-8 mHz (could be higher too) and would likely be marked on the board as "Y-1", "Y-2", etc. See attached pic of ceramic resonators. Would really be best if you had a copy of the service manual.

May not be the source of your problem at all but, these devices (and their associated circuit) are certainly possible suspects when citing scan speed problems.

 

[sjlamb]

Alright, any idea what I am looking for once I open the case?

If you do have a look inside, you could also try gently pressing on the foil side of the PCB with the unit scanning to see if it resumes normal scan speed, which would suggest a bad solder joint somewhere on the board. Another test would be to use a blow dryer and freeze spray (Radio Shack) to see if you can locate any component failures that respond to heat or cold.