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2510 recieve problem. Help!!!!

D

Detail man

Guest
Did an absolutely bonehead mistake. Was inside my 2510 with screwdrive like an idiot and shorted between L101 and d127 and lost recieve. Checked everything in that area to no avail. d126 was bad so I thought that would fix the problem but it did not.

D101,102 are ok as is Q101.Q118 and caps check ok.

Squelch circuit seems to be working and rf gain seems ok, both circuits change the noise level. All I'm hearing is hash.

S-meter is not working, like I'm not getting any signals. Transmit is ok all modes.

Checked and rechecked my work without luck.

Could L101 be shorted out? Would that cause the symptoms?

Anybody got any ideas? Will wind up bald soon if I pull any more hair out!!!!



All help is appreciated.

Thanks



Detailman

aka 932




</p>
 

Did an absolutely bonehead mistake. Was inside my 2510 with screwdrive like an idiot and shorted between L101 and d127 and lost recieve. Checked everything in that area to no avail. d126 was bad so I thought that would fix the problem but it did not.

D101,102 are ok as is Q101.Q118 and caps check ok.

Squelch circuit seems to be working and rf gain seems ok, both circuits change the noise level. All I'm hearing is hash.

S-meter is not working, like I'm not getting any signals. Transmit is ok all modes.

Checked and rechecked my work without luck.

Could L101 be shorted out? Would that cause the symptoms?

Anybody got any ideas? Will wind up bald soon if I pull any more hair out!!!!



All help is appreciated.

Thanks



Detailman

aka 932




</p>
 
I will see If I can shed some light..



Check Q127 the RX Switch transistor..

TX Emitter Should be: 0.1v

Collector Should be: 8.0v

Base Should be: 0.0v



RX Emitter Should be: 7.2v

Collector Should be: 8.0v

Base Should be: 7.9v

-------------------------------------------

Check Q101 -RF gain at Full

RX Emitter Should be: 1.7v

Collector Should be: 6.6v

Base Should be: 2.4v

-------------------------------------------

Check Q102 -

RX Emitter Should be: 3.2v

Collector Should be: 7.2v

Base Should be: 0.0v

------------------------------------------

Make sure D101 and D102 are not Open or Shorted.



Lets start there, For a Board layout see CBtrick's site..

www.cbtricks.com/uniden/hr2510/graphics/hr2510_pb111ab_main_pcb.gif



Roger

<img src=http://www.ezboard.com/intl/aenglish/images/emoticons/glasses.gif ALT="8)">


</p>
 
I will see If I can shed some light..



Check Q127 the RX Switch transistor..

TX Emitter Should be: 0.1v

Collector Should be: 8.0v

Base Should be: 0.0v



RX Emitter Should be: 7.2v

Collector Should be: 8.0v

Base Should be: 7.9v

-------------------------------------------

Check Q101 -RF gain at Full

RX Emitter Should be: 1.7v

Collector Should be: 6.6v

Base Should be: 2.4v

-------------------------------------------

Check Q102 -

RX Emitter Should be: 3.2v

Collector Should be: 7.2v

Base Should be: 0.0v

------------------------------------------

Make sure D101 and D102 are not Open or Shorted.



Lets start there, For a Board layout see CBtrick's site..

www.cbtricks.com/uniden/hr2510/graphics/hr2510_pb111ab_main_pcb.gif



Roger

<img src=http://www.ezboard.com/intl/aenglish/images/emoticons/glasses.gif ALT="8)">


</p>
 
Re: 2510 tx problem.

Check Q125 the TX Switch transistor..

TX Emitter Should be: 7.3v

Collector Should be: 7.8v

Base Should be: 8.0v



RX Emitter Should be: 7.3v

Collector Should be: 0.0v

Base Should be: 8.0v

-------------------------------------------

if Q125 is not right..

Check Q136

TX Emitter Should be: 0.0v

Collector Should be: 0.0v

Base Should be: 0.7v



RX Emitter Should be: 0.0v

Collector Should be: 8.0v

Base Should be: 0.0v

-------------------------------------------

This is the TX/RX regulator Switching Transistors..

Let me know.. the results..

Roger


</p>
 
Re: 2510 tx problem.

Check Q125 the TX Switch transistor..

TX Emitter Should be: 7.3v

Collector Should be: 7.8v

Base Should be: 8.0v



RX Emitter Should be: 7.3v

Collector Should be: 0.0v

Base Should be: 8.0v

-------------------------------------------

if Q125 is not right..

Check Q136

TX Emitter Should be: 0.0v

Collector Should be: 0.0v

Base Should be: 0.7v



RX Emitter Should be: 0.0v

Collector Should be: 8.0v

Base Should be: 0.0v

-------------------------------------------

This is the TX/RX regulator Switching Transistors..

Let me know.. the results..

Roger


</p>
 
you wrote... Hope I'm not pressing my luck and should probably start another post but the one that won't transmit gives me strange readings on a couple transistors.

Q134 correct on tx and rx

Q124 ok rx

Tx 7.9vE 7.9vC 7.9vB

Q133 TX 0E 0C 0.7B



It looks like the Collector Voltage to Q133(also check the collector of Q132) is missing.. It gets its volts from the Calibration Board..PB-100 at TP2 if you do not have 12 to 13v at TP2 TX & RX That is where we will start..

Make sure the Shorting PCB(PB-100) is making contact with the Metal Fingers.. also make sure the Fingers are Soldered into the PCB(common to have loose solder). If all is well ther, trace the circuit back to the input (C154+ and T101, D152 and Power jack.). There may be an open circuit trace.



If the Shorting board is 12 to 13V .. check L134, Should be passing 12v on all 3 legs. If not there but on the Shorting board, It must be and open L131 . or a shorted Q133.

see: www.cbtricks.com/uniden/h...in_pcb.gif



Roger










</p>
 
you wrote... Hope I'm not pressing my luck and should probably start another post but the one that won't transmit gives me strange readings on a couple transistors.

Q134 correct on tx and rx

Q124 ok rx

Tx 7.9vE 7.9vC 7.9vB

Q133 TX 0E 0C 0.7B



It looks like the Collector Voltage to Q133(also check the collector of Q132) is missing.. It gets its volts from the Calibration Board..PB-100 at TP2 if you do not have 12 to 13v at TP2 TX & RX That is where we will start..

Make sure the Shorting PCB(PB-100) is making contact with the Metal Fingers.. also make sure the Fingers are Soldered into the PCB(common to have loose solder). If all is well ther, trace the circuit back to the input (C154+ and T101, D152 and Power jack.). There may be an open circuit trace.



If the Shorting board is 12 to 13V .. check L134, Should be passing 12v on all 3 legs. If not there but on the Shorting board, It must be and open L131 . or a shorted Q133.

see: www.cbtricks.com/uniden/h...in_pcb.gif



Roger










</p>
 
Re: 2510 TX problem. Help!!!!

Hello, One more thing..

This is probably it...



Check Pin 1 of IC104 it should be 7.6v in RX (and if you were transmitting it drops to 7.2v)



But If Pin 1 is not 7 volts.. there are two 220uf 10v caps that one or more may be shorted.. Causing the tx problem..

C60 an C75 (I suggest using a little higher Volt cap, 12 - 35v .. Radio Shack has 220uf 35v that will work.. RS P/N 272-1029 for $0.99 )



see the layout - the IC and Caps are in the middle front of the main PCB:

www.cbtricks.com/uniden/hr2510/graphics/hr2510_pb111ab_main_pcb.gif



FYI:

IC104(Pin 8. ) feeds the TX signal( PTT ) to Q136 and it sends it to Q127..



Let me know if that was it...



Roger




</p>Edited by: <A HREF=http://pub86.ezboard.com/bworldwidecbradioclub.showUserPublicProfile?gid=rogerbird1>Rogerbird1</A> at: 12/7/03 4:05 pm
 
Re: 2510 TX problem. Help!!!!

Hello, One more thing..

This is probably it...



Check Pin 1 of IC104 it should be 7.6v in RX (and if you were transmitting it drops to 7.2v)



But If Pin 1 is not 7 volts.. there are two 220uf 10v caps that one or more may be shorted.. Causing the tx problem..

C60 an C75 (I suggest using a little higher Volt cap, 12 - 35v .. Radio Shack has 220uf 35v that will work.. RS P/N 272-1029 for $0.99 )



see the layout - the IC and Caps are in the middle front of the main PCB:

www.cbtricks.com/uniden/hr2510/graphics/hr2510_pb111ab_main_pcb.gif



FYI:

IC104(Pin 8. ) feeds the TX signal( PTT ) to Q136 and it sends it to Q127..



Let me know if that was it...



Roger




</p>Edited by: <A HREF=http://pub86.ezboard.com/bworldwidecbradioclub.showUserPublicProfile?gid=rogerbird1>Rogerbird1</A> at: 12/7/03 4:05 pm
 
Re: 2510 TX problem. Help!!!!

.....

That may be the trouble.. with the Shorting Board in you should be seeing the same volts on the input of T101 As on TP2.. I would look closely at the traces.



L134 should show continuity across all 3 legs.. It is just 2 windings of wire that meet in the middle around a ferrite core.



Not sure about C126... it may be showing a short across Q133 (Collector to base) Pull the shorting board and measure the cap again and see if it is the same..



Roger



=============

(Sorry I hit Edit before Reply..)




</p>
 
Re: 2510 TX problem. Help!!!!

.....

That may be the trouble.. with the Shorting Board in you should be seeing the same volts on the input of T101 As on TP2.. I would look closely at the traces.



L134 should show continuity across all 3 legs.. It is just 2 windings of wire that meet in the middle around a ferrite core.



Not sure about C126... it may be showing a short across Q133 (Collector to base) Pull the shorting board and measure the cap again and see if it is the same..



Roger



=============

(Sorry I hit Edit before Reply..)




</p>
 

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