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			#1  
			
			
			 
		
	   
			
			
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			Don't know if this is the right group, but I'll give it a shot.... 
		
		
		
		
		
		
		
		
	
	My mother-in-law was given a PRO 2020, and programmed the scanner, but can't hear anything but static. She has asked me if I can repair it (since I'm a former Navy RADAR tech). I think I'm on the right track here, but need some tech support since I have been unsuccesful in locating a service manual. The scanner does pick up the carrier and very faint audio/no static. I have verified this by programming in the NOAA freq and turning the volume all the way up. When I programmed in city police channel 1, all I get is static until they key up, then it goes to the very faint audio/no static, until key is released then static again. The squelch has no function at all. Also doesn't scan, but this is most likely because of no squelch. I am leaning toward the discriminator chip, has the functions of audio pre-amp, squelch, and scan. Am I going in the right direction? Any techies out there? Jim  | 
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			#2  
			
			
			 
		
	   
			
			
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			Go here and you can get the Order Number 
		
		
		
		
		
		
		
		
	
	for the service manual: Call 1-800-THE-SHAC http://support.radioshack.com/suppor...oc21/21316.htm Most scanners pack the Disc/Squelch/Mute/Scan Control all on the same chip. By looking at the parts list, it looks as if our scanner uses a TD62501P for this, but without the service manual, I cant tell. A google search for this part didn't find any free datasheets. Good luck.  | 
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			#3  
			
			
			 
		
	   
			
			
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			Tried that, even though it's listed in the parts list, RAD SHACK doesn't 
		
		
		
		
		
		
		
		
	
	show it in their system. Jim  | 
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			#4  
			
			
			 
		
	   
			
			
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			TD62501 is just a transistor array. Datasheet is at 
		
		
		
		
		
		
		
		
	
	http://doc.semicon.toshiba.co.jp/pdf...23/e005666.pdf Another source I have shows the IF chip is MC3357. "N3KCT" wrote in message ... Go here and you can get the Order Number for the service manual: Call 1-800-THE-SHAC http://support.radioshack.com/suppor...oc21/21316.htm Most scanners pack the Disc/Squelch/Mute/Scan Control all on the same chip. By looking at the parts list, it looks as if our scanner uses a TD62501P for this, but without the service manual, I cant tell. A google search for this part didn't find any free datasheets. Good luck.  | 
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			#5  
			
			
			 
		
	   
			
			
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			Great!  The Motorola MC33XX chips should be easy 
		
		
		
		
		
		
		
		
	
	to source. I was going by the parts list off of the 'Shack's site that listed the TD62501 as: IC103 10896413 TD62501P SQUELCH CIR MX4299  | 
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			#6  
			
			
			 
		
	   
			
			
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			Found an mc3357 for around $4 I'll have to order it friday. Thanx for the 
		
		
		
		
		
		
		
		
	
	help.  | 
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