|
Bearcat Repairs
Anyone here with "in-depth" knowledge of the Bearcat 250 Scanner and
repairs? I am way out of tune with these things. Haven't seen one - let alone worked on one for close to 10 years if not much longer. I have a model here just came in the door for repair. I've had a manual from days gone by. There appears to be some differences - not shown in the manual. I'm wondering if I can pick someone's brains about this model or it's differences. 1. Was there more than one version of service manual? At the time I purchased this, I don't believe I was told of anymore than the one - I usually ask about revisions. 2. Did the updates in this model produce differences in circuitry (I'm sure they probably did) - and how? 3. The issue I "currently" see - is I have "low level" audio, no squelch action, no receive, no display, no dot. I started troubleshooting it and this book has a Q206 listed in it as providing a particular voltage to the circuit (can't recall which part of the circuit - without the book in front of me). THIS unit shows NO Q206 where the book shows it to be. I can be more specific in parts layout in that area if someone asks - but for now - I'm missing some voltage and need to find out why Q206 is not there OR whatever. The "Q204" is putting out like 4 - 6 volts less than it should. I'm not sure that is the "only" issue here - but the first I found thus far. I'm just trying to clear up the mystery of Q206 for the moment. The book shows it "supposedly" on the "Features" board. Along with that issue, there is in the same leg of circuit - according to my manual - a 47K ohm resistor there tied to Q204 and a wire coming from the 18V supply - with an 9v Zener in that area also. This model has a 1xxxx ohm resistor there OR at least it appears to. It is burned in the center from heat - but the first band is clearly "brown" - so this isn't the 47K as called for in my manual. Basically, the circuit leg is all there - minus Q206! There's not even a place for it "to" be, from what I'm seeing. IF I'm in error of voltages/values specified - its' only I'm going from memory - the book is in the shop - but I"m not off in my description otherwise. I can provide more specific info such as Serial Number, Board numbers and/or revisions, whatever - if requested, I just don't have it in front of me at the moment. I realize some parts of this radio are impossible to get now-days - so - I want to make sure I can trace this down to something repairable and get it done OR find out quick it isn't possible and hand it back without wasting much more time. Any info? Please answer here - my address is a spam catcher only. Thanks, Lou |
Bearcat Repairs
Lou,
Not wishing to appear rude, but if you have to spend this much time on a 10 year old model is it worth repairing or should it be written off as beyond economical repair. Dave |
Bearcat Repairs
"Dave Healey" wrote in message
... Lou, Not wishing to appear rude, but if you have to spend this much time on a 10 year old model is it worth repairing or should it be written off as beyond economical repair. Dave Dave, You're not being rude..... Trust me, the thought crossed my mind........ but it is for a good friend of mine - as a favor. I did tell them that "some" parts are no longer available and it might be time to toss it. But, I didn't want to just toss it without the ole "college try". Any time I ever needed any help - they were quick to jump to my aid, so I'd like to try to return the favor - especially now that they are blind - due to diabetes. Were it not for that - it would have probably been handed back immediately - with an I"m sorry. I waste valuable time on misadventures of my own - so I can't be too much for the wear and tear for the little time I've spent on this to date. I would much rather do this for a good friend than to lift a finger for half of my idiotic relatives. I'm sure you know how that works out. Thanks just the same for your reply. Lou |
Bearcat Repairs
Dave,
You're not being rude..... Trust me, the thought crossed my mind........ but it is for a good friend of mine - as a favor. I did tell them that "some" parts are no longer available and it might be time to toss it. But, I didn't want to just toss it without the ole "college try". Any time I ever needed any help - they were quick to jump to my aid, so I'd like to try to return the favor - especially now that they are blind - due to diabetes. Were it not for that - it would have probably been handed back immediately - with an I"m sorry. I waste valuable time on misadventures of my own - so I can't be too much for the wear and tear for the little time I've spent on this to date. I would much rather do this for a good friend than to lift a finger for half of my idiotic relatives. I'm sure you know how that works out. Thanks just the same for your reply. Lou Lou, Having read the above I'm sorry I can't help you with any info on it and I see your perfectly good reason for carrying on. Regards Dave |
Bearcat Repairs
Lou -
http://www.notpurfect.com/main/bearcat.html I assume that you have gone through these repair FAQ steps? (complied by Bob Parnass from 1999) http://www.repairfaq.org/REPAIR/F_BC_Repair.html http://www.scancat.com/newbscn.html BTW, I always start with the power supply section --- looking closely at electrolytic capacitors, diodes, etc. - Bearcat 250 heat problem. Kit includes power transformer, regulator, and instructions to cure overheating problems. G&G COMMUNICATIONS Gerry Oliver - Owner 7825 Black Street Rd., LeRoy, N.Y. 14482 Phone: 585-768-8151 / Fax: 585-768-7175 http://www.iinc.com/ggcomm/mods.html http://www.scannermaster.com/Product...Code=01-550787 The Electra/Bearcat BC350, BC300, BC250, BC220, BC20/20, BC211, BC210, and BC210XL models were hand assembled, and every one I've serviced had several connections that were either soldered poorly, or not soldered at all. Resoldering joints on the ribbon cable connecting the RF and keyboard logic circuit boards in a BC250 attenuated the microprocessor/synthesizer hash noise noticeably. http://www.firecommunications.com/sample/bearcat.txt gb "Radiosrfun" wrote in message ... Anyone here with "in-depth" knowledge of the Bearcat 250 Scanner and repairs? I am way out of tune with these things. Haven't seen one - let alone worked on one for close to 10 years if not much longer. I have a model here just came in the door for repair. I've had a manual from days gone by. There appears to be some differences - not shown in the manual. I'm wondering if I can pick someone's brains about this model or it's differences. 1. Was there more than one version of service manual? At the time I purchased this, I don't believe I was told of anymore than the one - I usually ask about revisions. 2. Did the updates in this model produce differences in circuitry (I'm sure they probably did) - and how? 3. The issue I "currently" see - is I have "low level" audio, no squelch action, no receive, no display, no dot. I started troubleshooting it and this book has a Q206 listed in it as providing a particular voltage to the circuit (can't recall which part of the circuit - without the book in front of me). THIS unit shows NO Q206 where the book shows it to be. I can be more specific in parts layout in that area if someone asks - but for now - I'm missing some voltage and need to find out why Q206 is not there OR whatever. The "Q204" is putting out like 4 - 6 volts less than it should. I'm not sure that is the "only" issue here - but the first I found thus far. I'm just trying to clear up the mystery of Q206 for the moment. The book shows it "supposedly" on the "Features" board. Along with that issue, there is in the same leg of circuit - according to my manual - a 47K ohm resistor there tied to Q204 and a wire coming from the 18V supply - with an 9v Zener in that area also. This model has a 1xxxx ohm resistor there OR at least it appears to. It is burned in the center from heat - but the first band is clearly "brown" - so this isn't the 47K as called for in my manual. Basically, the circuit leg is all there - minus Q206! There's not even a place for it "to" be, from what I'm seeing. IF I'm in error of voltages/values specified - its' only I'm going from memory - the book is in the shop - but I"m not off in my description otherwise. I can provide more specific info such as Serial Number, Board numbers and/or revisions, whatever - if requested, I just don't have it in front of me at the moment. I realize some parts of this radio are impossible to get now-days - so - I want to make sure I can trace this down to something repairable and get it done OR find out quick it isn't possible and hand it back without wasting much more time. Any info? Please answer here - my address is a spam catcher only. Thanks, Lou |
Bearcat Repairs
"Radiosrfun" wrote in message ... Anyone here with "in-depth" knowledge of the Bearcat 250 Scanner and repairs? The service manual you have is the only one I know of. Scanner manufacturers never update the manuals until there is a catalog number or model number change. During the life of a product there are changes made in production. I have an Electra schematic (engineering drawing) for the BC300 and it went through a dozen changes at the time the drawing was made. Finding a drawing like this for the 250 would be nearly impossible now. Electra often tack-soldered parts to the back of the boards. Maybe Q206 is on the back in your 250. Q206 serves as an amplifier to reduce the current in the Zener and improve regulation. If the voltage at the emitter of Q204 is much less than 8.4 volts, a good portion of the circuitry in the radio will not operate. You can try replacing the Q204 regulator with a 9 volt three terminal regulator feeding into a 1 amp diode. That should give you about 8.4 volts and has the bonus of overcurrent and thermal protection. The original design ran Q204 way too hot and it is a common failure point. Adding a heatsink and drilling a few vent holes helps. Many of the IC's in the radio are custom and very hard to find if one needs to be replaced. When I had a 250, I recall it being very sensitive to disturbances on the AC line, often hanging the scan cycle or corrupting the programming. With all the negatives about the 250, I'd look for a more recent model on Ebay to replace it. Something simple with 50 or 100 channels should be available cheap and it will perform better than the 250 ever did. |
Q Bearcat Repairs
"Frank346" wrote in message
... "Radiosrfun" wrote in message ... Anyone here with "in-depth" knowledge of the Bearcat 250 Scanner and repairs? The service manual you have is the only one I know of. Scanner manufacturers never update the manuals until there is a catalog number or model number change. During the life of a product there are changes made in production. I have an Electra schematic (engineering drawing) for the BC300 and it went through a dozen changes at the time the drawing was made. Finding a drawing like this for the 250 would be nearly impossible now. Electra often tack-soldered parts to the back of the boards. Maybe Q206 is on the back in your 250. Q206 serves as an amplifier to reduce the current in the Zener and improve regulation. If the voltage at the emitter of Q204 is much less than 8.4 volts, a good portion of the circuitry in the radio will not operate. You can try replacing the Q204 regulator with a 9 volt three terminal regulator feeding into a 1 amp diode. That should give you about 8.4 volts and has the bonus of overcurrent and thermal protection. The original design ran Q204 way too hot and it is a common failure point. Adding a heatsink and drilling a few vent holes helps. Many of the IC's in the radio are custom and very hard to find if one needs to be replaced. When I had a 250, I recall it being very sensitive to disturbances on the AC line, often hanging the scan cycle or corrupting the programming. With all the negatives about the 250, I'd look for a more recent model on Ebay to replace it. Something simple with 50 or 100 channels should be available cheap and it will perform better than the 250 ever did. Therein lays "part" of the problem... Q204's voltage is ok at input but significantly slacks off on output. MY issue at the moment is - the book "shows" a Q206 - but there is not one there! IF you have the manual - refer to it - you'll see the 9v zener etc, there. ALL is there but Q206. It is weird....... It doesn't appear to have been "placed" there to begin with. I was shooting for trying to figure that out - then finish troubleshooting. As for someone's posting of starting with the power supply, that is exactly what I've been doing til I ran into parts not there - as shown. That is usually where I start - with ANY issues I have unless directed otherwise by symptoms. I was eliminating all the parts as the book lists as suspects. I believe I'm in a definate problem area with the voltages - but still - where the hell did Q206 disappear to? IF there is no other info to be had, I'll take a nice LONG look at it in the morning and see if there is something else I can work out. I'm 99.9% sure I have a new Q204 to pop in if this one is weak. I just stopped where I was to try to figure out what the heck was going on. I've researched most of the info - if not all - available by Parness(sp?) - that I could find. I'll just take a good close look tomorrow and see what is what. Was just hanging back to see what replies I might get to help out. THANK YOU FOLKS for your input. Lou |
Bearcat Repairs
Hi,
I have "I believe" - all of his info downloaded and have reviewed it. I'm going to check your links to be sure I have all. I "usually" do start with the power supply in any case - unless symptoms guide me elsewhere. In this case in particular - being "almost" dead - that was the "first" place I headed. Situation is - I am at a component which is producing less than it should - and I look to changing it, but in the manual - there is a transistor shown in the same circuit along with a zener. The zener is there - the other transistor Q206 "appears" to not have been placed there. Was just trying to find out what is with that. I'll look again - but it didn't appear to be on the bottom of the board - and "all" (as I can see them) traces of the parts shown interconnect on top minus Q206. So - was wondering of any changes, etc. And then too - the resistor which was burned in the center is showing with the first band (not discolored) to not be as listed in the book. Well anyway, I'll replace the transistor which isn't pumping out enough and see what it does for me. I can't make out the resistor other than the first band, so I'll stick one in which the book called for - and see what goes on. I'll study the thing to see what was in their mind - then I'll go from there. I've wasted better time on my own so - trying to help a friend - won't bother me. If I"m not doing this, I'll be playing taxi driver for family. Would rather play at the bench! Lou "w9gb" wrote in message . .. Lou - http://www.notpurfect.com/main/bearcat.html I assume that you have gone through these repair FAQ steps? (complied by Bob Parnass from 1999) http://www.repairfaq.org/REPAIR/F_BC_Repair.html http://www.scancat.com/newbscn.html BTW, I always start with the power supply section --- looking closely at electrolytic capacitors, diodes, etc. - Bearcat 250 heat problem. Kit includes power transformer, regulator, and instructions to cure overheating problems. G&G COMMUNICATIONS Gerry Oliver - Owner 7825 Black Street Rd., LeRoy, N.Y. 14482 Phone: 585-768-8151 / Fax: 585-768-7175 http://www.iinc.com/ggcomm/mods.html http://www.scannermaster.com/Product...Code=01-550787 The Electra/Bearcat BC350, BC300, BC250, BC220, BC20/20, BC211, BC210, and BC210XL models were hand assembled, and every one I've serviced had several connections that were either soldered poorly, or not soldered at all. Resoldering joints on the ribbon cable connecting the RF and keyboard logic circuit boards in a BC250 attenuated the microprocessor/synthesizer hash noise noticeably. http://www.firecommunications.com/sample/bearcat.txt gb "Radiosrfun" wrote in message ... Anyone here with "in-depth" knowledge of the Bearcat 250 Scanner and repairs? I am way out of tune with these things. Haven't seen one - let alone worked on one for close to 10 years if not much longer. I have a model here just came in the door for repair. I've had a manual from days gone by. There appears to be some differences - not shown in the manual. I'm wondering if I can pick someone's brains about this model or it's differences. 1. Was there more than one version of service manual? At the time I purchased this, I don't believe I was told of anymore than the one - I usually ask about revisions. 2. Did the updates in this model produce differences in circuitry (I'm sure they probably did) - and how? 3. The issue I "currently" see - is I have "low level" audio, no squelch action, no receive, no display, no dot. I started troubleshooting it and this book has a Q206 listed in it as providing a particular voltage to the circuit (can't recall which part of the circuit - without the book in front of me). THIS unit shows NO Q206 where the book shows it to be. I can be more specific in parts layout in that area if someone asks - but for now - I'm missing some voltage and need to find out why Q206 is not there OR whatever. The "Q204" is putting out like 4 - 6 volts less than it should. I'm not sure that is the "only" issue here - but the first I found thus far. I'm just trying to clear up the mystery of Q206 for the moment. The book shows it "supposedly" on the "Features" board. Along with that issue, there is in the same leg of circuit - according to my manual - a 47K ohm resistor there tied to Q204 and a wire coming from the 18V supply - with an 9v Zener in that area also. This model has a 1xxxx ohm resistor there OR at least it appears to. It is burned in the center from heat - but the first band is clearly "brown" - so this isn't the 47K as called for in my manual. Basically, the circuit leg is all there - minus Q206! There's not even a place for it "to" be, from what I'm seeing. IF I'm in error of voltages/values specified - its' only I'm going from memory - the book is in the shop - but I"m not off in my description otherwise. I can provide more specific info such as Serial Number, Board numbers and/or revisions, whatever - if requested, I just don't have it in front of me at the moment. I realize some parts of this radio are impossible to get now-days - so - I want to make sure I can trace this down to something repairable and get it done OR find out quick it isn't possible and hand it back without wasting much more time. Any info? Please answer here - my address is a spam catcher only. Thanks, Lou |
Bearcat Repairs
"Radiosrfun" wrote in message ... Hi, I have "I believe" - all of his info downloaded and have reviewed it. I'm going to check your links to be sure I have all. I "usually" do start with the power supply in any case - unless symptoms guide me elsewhere. In this case in particular - being "almost" dead - that was the "first" place I headed. Situation is - I am at a component which is producing less than it should - and I look to changing it, but in the manual - there is a transistor shown in the same circuit along with a zener. The zener is there - the other transistor Q206 "appears" to not have been placed there. Was just trying to find out what is with that. I'll look again - but it didn't appear to be on the bottom of the board - and "all" (as I can see them) traces of the parts shown interconnect on top minus Q206. So - was wondering of any changes, etc. And then too - the resistor which was burned in the center is showing with the first band (not discolored) to not be as listed in the book. Well anyway, I'll replace the transistor which isn't pumping out enough and see what it does for me. I can't make out the resistor other than the first band, so I'll stick one in which the book called for - and see what goes on. I'll study the thing to see what was in their mind - then I'll go from there. I've wasted better time on my own so - trying to help a friend - won't bother me. If I"m not doing this, I'll be playing taxi driver for family. Would rather play at the bench! Lou Seems like you might have a very early production radio that just doesn't have Q206. The date code on the back of the radio might confirm this. The circuit is just an amplified Zener regulator and it isn't extremely critical if the amplifier is one transistor or two. The service manual shows a 8.2V Zener and you mentioned having a 9.1V Zener in the radio so they evidently didn't intend to put Q206 in the circuit. Replace Q204 and add a small heatsink to keep it from burning out again. The resistor may look like band one is brown, but heat can change an orange band to brown over time. Try a 470 Ohm resistor initially. If the output voltage is too far below 8.4V, the Zener is being starved and the resistor will have to be reduced. In that case try 330 Ohms and measure the output again. |
Bearcat Repairs
"Frank346" wrote in message
... "Radiosrfun" wrote in message ... Hi, I have "I believe" - all of his info downloaded and have reviewed it. I'm going to check your links to be sure I have all. I "usually" do start with the power supply in any case - unless symptoms guide me elsewhere. In this case in particular - being "almost" dead - that was the "first" place I headed. Situation is - I am at a component which is producing less than it should - and I look to changing it, but in the manual - there is a transistor shown in the same circuit along with a zener. The zener is there - the other transistor Q206 "appears" to not have been placed there. Was just trying to find out what is with that. I'll look again - but it didn't appear to be on the bottom of the board - and "all" (as I can see them) traces of the parts shown interconnect on top minus Q206. So - was wondering of any changes, etc. And then too - the resistor which was burned in the center is showing with the first band (not discolored) to not be as listed in the book. Well anyway, I'll replace the transistor which isn't pumping out enough and see what it does for me. I can't make out the resistor other than the first band, so I'll stick one in which the book called for - and see what goes on. I'll study the thing to see what was in their mind - then I'll go from there. I've wasted better time on my own so - trying to help a friend - won't bother me. If I"m not doing this, I'll be playing taxi driver for family. Would rather play at the bench! Lou Seems like you might have a very early production radio that just doesn't have Q206. The date code on the back of the radio might confirm this. The circuit is just an amplified Zener regulator and it isn't extremely critical if the amplifier is one transistor or two. The service manual shows a 8.2V Zener and you mentioned having a 9.1V Zener in the radio so they evidently didn't intend to put Q206 in the circuit. Replace Q204 and add a small heatsink to keep it from burning out again. The resistor may look like band one is brown, but heat can change an orange band to brown over time. Try a 470 Ohm resistor initially. If the output voltage is too far below 8.4V, the Zener is being starved and the resistor will have to be reduced. In that case try 330 Ohms and measure the output again. THANK YOU - very much................. I'll look at the band again, you may be right - it "was" late! Yeah, I've seen this before - quite a bit in other radios. But the rest was as stated. As to the Zener - I may be in error - the book "shows" an 8.2 vdc. I seen the schematic was calling for 9.1 vdc off one leg of one of the transistors and that stuck in my head. I'll have to remeasure that too as it seems to me I may just have gotten 9.1 +/- vdc. I didn't make notes as I usually do. I'll give this a whirl since I know definately the voltage is "way" off on the transistor. But as I said - I simply stopped there to try to find out what the heck was going on with the missing transistor. I definately have to make notes on this one - regardless if it is fixed or not - JUST in case! Thanks again.......... Lou |
Bearcat Repairs
I just threw two Bearcat 250s in my garbage can this morning. I had
purchased them as defective units years ago. I assumed I could use parts from each to make a good one, but they both had repairwork damage on the circuitboard under the keyboard. That was a wonderful scanner because of the feature that would search a section of band and record a list of hits through the day. You could then program the hit frequencies into a bank, or two, and find something interesting. "Radiosrfun" wrote in message ... Anyone here with "in-depth" knowledge of the Bearcat 250 Scanner and repairs? I am way out of tune with these things. Haven't seen one - let alone worked on one for close to 10 years if not much longer. I have a model here just came in the door for repair. I've had a manual from days gone by. There appears to be some differences - not shown in the manual. I'm wondering if I can pick someone's brains about this model or it's differences. 1. Was there more than one version of service manual? At the time I purchased this, I don't believe I was told of anymore than the one - I usually ask about revisions. 2. Did the updates in this model produce differences in circuitry (I'm sure they probably did) - and how? 3. The issue I "currently" see - is I have "low level" audio, no squelch action, no receive, no display, no dot. I started troubleshooting it and this book has a Q206 listed in it as providing a particular voltage to the circuit (can't recall which part of the circuit - without the book in front of me). THIS unit shows NO Q206 where the book shows it to be. I can be more specific in parts layout in that area if someone asks - but for now - I'm missing some voltage and need to find out why Q206 is not there OR whatever. The "Q204" is putting out like 4 - 6 volts less than it should. I'm not sure that is the "only" issue here - but the first I found thus far. I'm just trying to clear up the mystery of Q206 for the moment. The book shows it "supposedly" on the "Features" board. Along with that issue, there is in the same leg of circuit - according to my manual - a 47K ohm resistor there tied to Q204 and a wire coming from the 18V supply - with an 9v Zener in that area also. This model has a 1xxxx ohm resistor there OR at least it appears to. It is burned in the center from heat - but the first band is clearly "brown" - so this isn't the 47K as called for in my manual. Basically, the circuit leg is all there - minus Q206! There's not even a place for it "to" be, from what I'm seeing. IF I'm in error of voltages/values specified - its' only I'm going from memory - the book is in the shop - but I"m not off in my description otherwise. I can provide more specific info such as Serial Number, Board numbers and/or revisions, whatever - if requested, I just don't have it in front of me at the moment. I realize some parts of this radio are impossible to get now-days - so - I want to make sure I can trace this down to something repairable and get it done OR find out quick it isn't possible and hand it back without wasting much more time. Any info? Please answer here - my address is a spam catcher only. Thanks, Lou |
Bearcat Repairs
Yeah, they were nice! I sold mine just before any issues developed, I
figured I may as well get my cash out before it went **** can. Lou "Cubit" wrote in message . net... I just threw two Bearcat 250s in my garbage can this morning. I had purchased them as defective units years ago. I assumed I could use parts from each to make a good one, but they both had repairwork damage on the circuitboard under the keyboard. That was a wonderful scanner because of the feature that would search a section of band and record a list of hits through the day. You could then program the hit frequencies into a bank, or two, and find something interesting. "Radiosrfun" wrote in message ... Anyone here with "in-depth" knowledge of the Bearcat 250 Scanner and repairs? I am way out of tune with these things. Haven't seen one - let alone worked on one for close to 10 years if not much longer. I have a model here just came in the door for repair. I've had a manual from days gone by. There appears to be some differences - not shown in the manual. I'm wondering if I can pick someone's brains about this model or it's differences. 1. Was there more than one version of service manual? At the time I purchased this, I don't believe I was told of anymore than the one - I usually ask about revisions. 2. Did the updates in this model produce differences in circuitry (I'm sure they probably did) - and how? 3. The issue I "currently" see - is I have "low level" audio, no squelch action, no receive, no display, no dot. I started troubleshooting it and this book has a Q206 listed in it as providing a particular voltage to the circuit (can't recall which part of the circuit - without the book in front of me). THIS unit shows NO Q206 where the book shows it to be. I can be more specific in parts layout in that area if someone asks - but for now - I'm missing some voltage and need to find out why Q206 is not there OR whatever. The "Q204" is putting out like 4 - 6 volts less than it should. I'm not sure that is the "only" issue here - but the first I found thus far. I'm just trying to clear up the mystery of Q206 for the moment. The book shows it "supposedly" on the "Features" board. Along with that issue, there is in the same leg of circuit - according to my manual - a 47K ohm resistor there tied to Q204 and a wire coming from the 18V supply - with an 9v Zener in that area also. This model has a 1xxxx ohm resistor there OR at least it appears to. It is burned in the center from heat - but the first band is clearly "brown" - so this isn't the 47K as called for in my manual. Basically, the circuit leg is all there - minus Q206! There's not even a place for it "to" be, from what I'm seeing. IF I'm in error of voltages/values specified - its' only I'm going from memory - the book is in the shop - but I"m not off in my description otherwise. I can provide more specific info such as Serial Number, Board numbers and/or revisions, whatever - if requested, I just don't have it in front of me at the moment. I realize some parts of this radio are impossible to get now-days - so - I want to make sure I can trace this down to something repairable and get it done OR find out quick it isn't possible and hand it back without wasting much more time. Any info? Please answer here - my address is a spam catcher only. Thanks, Lou |
Bearcat Repairs
hi if your in the usa g+g communcations might be able to help you.
|
Bearcat Repairs
"blake jones" wrote in message
... hi if your in the usa g+g communcations might be able to help you. Yes I am......... in the USA. I'm aware of G & G - Thanks! I was just checking the thing out for a friend - found an issue and at the same time the puzzling item and stopped to see if anyone had info regarding it. Aside from information - I doubt my friend will want to "invest" much into it. I"m merely doing it as a favor to him short of telling him to scrap it. Been kind of busy since getting these e-mails - so haven't had a chance to get back to it. I'm going to be free after tomorrow afternoon - so I can take another "closer" look at it and make a decision - one way or another. |
Bearcat Repairs
"Radiosrfun" wrote in message ... Anyone here with "in-depth" knowledge of the Bearcat 250 Scanner and repairs? I am way out of tune with these things. Haven't seen one - let alone worked on one for close to 10 years if not much longer. I have a model here just came in the door for repair. I've had a manual from days gone by. There appears to be some differences - not shown in the manual. I'm wondering if I can pick someone's brains about this model or it's differences. 1. Was there more than one version of service manual? At the time I purchased this, I don't believe I was told of anymore than the one - I usually ask about revisions. 2. Did the updates in this model produce differences in circuitry (I'm sure they probably did) - and how? 3. The issue I "currently" see - is I have "low level" audio, no squelch action, no receive, no display, no dot. I started troubleshooting it and this book has a Q206 listed in it as providing a particular voltage to the circuit (can't recall which part of the circuit - without the book in front of me). THIS unit shows NO Q206 where the book shows it to be. I can be more specific in parts layout in that area if someone asks - but for now - I'm missing some voltage and need to find out why Q206 is not there OR whatever. The "Q204" is putting out like 4 - 6 volts less than it should. I'm not sure that is the "only" issue here - but the first I found thus far. I'm just trying to clear up the mystery of Q206 for the moment. The book shows it "supposedly" on the "Features" board. Along with that issue, there is in the same leg of circuit - according to my manual - a 47K ohm resistor there tied to Q204 and a wire coming from the 18V supply - with an 9v Zener in that area also. This model has a 1xxxx ohm resistor there OR at least it appears to. It is burned in the center from heat - but the first band is clearly "brown" - so this isn't the 47K as called for in my manual. Basically, the circuit leg is all there - minus Q206! There's not even a place for it "to" be, from what I'm seeing. IF I'm in error of voltages/values specified - its' only I'm going from memory - the book is in the shop - but I"m not off in my description otherwise. I can provide more specific info such as Serial Number, Board numbers and/or revisions, whatever - if requested, I just don't have it in front of me at the moment. I realize some parts of this radio are impossible to get now-days - so - I want to make sure I can trace this down to something repairable and get it done OR find out quick it isn't possible and hand it back without wasting much more time. Any info? Please answer here - my address is a spam catcher only. Thanks, Lou Lou, maybe this info will help. In looking through my Bearcat info, I found a schematic for a "250A". The feature board is constructed a little differently than what they show in the 250 service manual and I have seen both boards used in 250s. The red wire still goes to the collector of Q204 (NPN). The emitter of Q204 should have 8.4 Volts there. The base circuit of Q204 is a little different on the "A" version. A 9.1 Volt 1 watt zener runs from the base of Q204 to ground. (Cathode connects to the base of Q204). Now, the collector of Q206 (PNP) connects to the base of Q204 through R239, a 150 ohm 1/2 watt resistor. That's the only connection on the collector of Q206. Q206's base has R220, a 100 ohm 1/2 watt resistor that is connected to the cathode of D212, a 10 Volt 1 watt zener. Hope this info helps you out. Keep us posted on your progress. Mac |
Bearcat Repairs
"Mike" wrote in message et... "Radiosrfun" wrote in message ... Anyone here with "in-depth" knowledge of the Bearcat 250 Scanner and repairs? I am way out of tune with these things. Haven't seen one - let alone worked on one for close to 10 years if not much longer. I have a model here just came in the door for repair. I've had a manual from days gone by. There appears to be some differences - not shown in the manual. I'm wondering if I can pick someone's brains about this model or it's differences. 1. Was there more than one version of service manual? At the time I purchased this, I don't believe I was told of anymore than the one - I usually ask about revisions. 2. Did the updates in this model produce differences in circuitry (I'm sure they probably did) - and how? 3. The issue I "currently" see - is I have "low level" audio, no squelch action, no receive, no display, no dot. I started troubleshooting it and this book has a Q206 listed in it as providing a particular voltage to the circuit (can't recall which part of the circuit - without the book in front of me). THIS unit shows NO Q206 where the book shows it to be. I can be more specific in parts layout in that area if someone asks - but for now - I'm missing some voltage and need to find out why Q206 is not there OR whatever. The "Q204" is putting out like 4 - 6 volts less than it should. I'm not sure that is the "only" issue here - but the first I found thus far. I'm just trying to clear up the mystery of Q206 for the moment. The book shows it "supposedly" on the "Features" board. Along with that issue, there is in the same leg of circuit - according to my manual - a 47K ohm resistor there tied to Q204 and a wire coming from the 18V supply - with an 9v Zener in that area also. This model has a 1xxxx ohm resistor there OR at least it appears to. It is burned in the center from heat - but the first band is clearly "brown" - so this isn't the 47K as called for in my manual. Basically, the circuit leg is all there - minus Q206! There's not even a place for it "to" be, from what I'm seeing. IF I'm in error of voltages/values specified - its' only I'm going from memory - the book is in the shop - but I"m not off in my description otherwise. I can provide more specific info such as Serial Number, Board numbers and/or revisions, whatever - if requested, I just don't have it in front of me at the moment. I realize some parts of this radio are impossible to get now-days - so - I want to make sure I can trace this down to something repairable and get it done OR find out quick it isn't possible and hand it back without wasting much more time. Any info? Please answer here - my address is a spam catcher only. Thanks, Lou Lou, maybe this info will help. In looking through my Bearcat info, I found a schematic for a "250A". The feature board is constructed a little differently than what they show in the 250 service manual and I have seen both boards used in 250s. The red wire still goes to the collector of Q204 (NPN). The emitter of Q204 should have 8.4 Volts there. The base circuit of Q204 is a little different on the "A" version. A 9.1 Volt 1 watt zener runs from the base of Q204 to ground. (Cathode connects to the base of Q204). Now, the collector of Q206 (PNP) connects to the base of Q204 through R239, a 150 ohm 1/2 watt resistor. That's the only connection on the collector of Q206. Q206's base has R220, a 100 ohm 1/2 watt resistor that is connected to the cathode of D212, a 10 Volt 1 watt zener. Hope this info helps you out. Keep us posted on your progress. Mac Sorry, I forgot to mention in my first response that the emitter of Q206 connects to the collector of Q204 (the red wire - 16 volts). Meanwhile, I found another schematic for the 250 that shows the same circuit I described, but also adds one resistor on Q206, between the emitter and base. The resistor is labeled R242 and is a 1K 5% (wattage is not indicated). Do you have the correct voltages at the output of the switching power supply? (plus and minus 25 volts). If not, you probably need to diagnose that problem first. Depending on what has failed there may determine whether or not the scanner is repairable. If it's just a capacitor failure (common) or a failure with IC-8 (it happens) then it is probably repairable, but if the problem goes on back to IC-9, IC-7, or IC-6, the prognosis is not so good. Good luck! Mac |
Bearcat Repairs
"Mike" wrote in message
... "Mike" wrote in message et... "Radiosrfun" wrote in message ... Anyone here with "in-depth" knowledge of the Bearcat 250 Scanner and repairs? I am way out of tune with these things. Haven't seen one - let alone worked on one for close to 10 years if not much longer. I have a model here just came in the door for repair. I've had a manual from days gone by. There appears to be some differences - not shown in the manual. I'm wondering if I can pick someone's brains about this model or it's differences. 1. Was there more than one version of service manual? At the time I purchased this, I don't believe I was told of anymore than the one - I usually ask about revisions. 2. Did the updates in this model produce differences in circuitry (I'm sure they probably did) - and how? 3. The issue I "currently" see - is I have "low level" audio, no squelch action, no receive, no display, no dot. I started troubleshooting it and this book has a Q206 listed in it as providing a particular voltage to the circuit (can't recall which part of the circuit - without the book in front of me). THIS unit shows NO Q206 where the book shows it to be. I can be more specific in parts layout in that area if someone asks - but for now - I'm missing some voltage and need to find out why Q206 is not there OR whatever. The "Q204" is putting out like 4 - 6 volts less than it should. I'm not sure that is the "only" issue here - but the first I found thus far. I'm just trying to clear up the mystery of Q206 for the moment. The book shows it "supposedly" on the "Features" board. Along with that issue, there is in the same leg of circuit - according to my manual - a 47K ohm resistor there tied to Q204 and a wire coming from the 18V supply - with an 9v Zener in that area also. This model has a 1xxxx ohm resistor there OR at least it appears to. It is burned in the center from heat - but the first band is clearly "brown" - so this isn't the 47K as called for in my manual. Basically, the circuit leg is all there - minus Q206! There's not even a place for it "to" be, from what I'm seeing. IF I'm in error of voltages/values specified - its' only I'm going from memory - the book is in the shop - but I"m not off in my description otherwise. I can provide more specific info such as Serial Number, Board numbers and/or revisions, whatever - if requested, I just don't have it in front of me at the moment. I realize some parts of this radio are impossible to get now-days - so - I want to make sure I can trace this down to something repairable and get it done OR find out quick it isn't possible and hand it back without wasting much more time. Any info? Please answer here - my address is a spam catcher only. Thanks, Lou Lou, maybe this info will help. In looking through my Bearcat info, I found a schematic for a "250A". The feature board is constructed a little differently than what they show in the 250 service manual and I have seen both boards used in 250s. The red wire still goes to the collector of Q204 (NPN). The emitter of Q204 should have 8.4 Volts there. The base circuit of Q204 is a little different on the "A" version. A 9.1 Volt 1 watt zener runs from the base of Q204 to ground. (Cathode connects to the base of Q204). Now, the collector of Q206 (PNP) connects to the base of Q204 through R239, a 150 ohm 1/2 watt resistor. That's the only connection on the collector of Q206. Q206's base has R220, a 100 ohm 1/2 watt resistor that is connected to the cathode of D212, a 10 Volt 1 watt zener. Hope this info helps you out. Keep us posted on your progress. Mac Sorry, I forgot to mention in my first response that the emitter of Q206 connects to the collector of Q204 (the red wire - 16 volts). Meanwhile, I found another schematic for the 250 that shows the same circuit I described, but also adds one resistor on Q206, between the emitter and base. The resistor is labeled R242 and is a 1K 5% (wattage is not indicated). Do you have the correct voltages at the output of the switching power supply? (plus and minus 25 volts). If not, you probably need to diagnose that problem first. Depending on what has failed there may determine whether or not the scanner is repairable. If it's just a capacitor failure (common) or a failure with IC-8 (it happens) then it is probably repairable, but if the problem goes on back to IC-9, IC-7, or IC-6, the prognosis is not so good. Good luck! Mac Mike, read all your replies to date.. since this is a "side" project to help a friend - have gotten busy - didn't get back to it just yet. This is my first week of free time. Please take note - where Q204 is, in the book - it "shows" a Q206 and the schematic shows parts going between Q204/206. In "this" model - there appears to be NO Q206 OR even a place for one. I can elaborate more - but my previous posts pretty much spell it out. Thanks, Lou |
Bearcat Repairs
"Radiosrfun" wrote in message ... "Mike" wrote in message ... "Mike" wrote in message et... "Radiosrfun" wrote in message ... Anyone here with "in-depth" knowledge of the Bearcat 250 Scanner and repairs? I am way out of tune with these things. Haven't seen one - let alone worked on one for close to 10 years if not much longer. I have a model here just came in the door for repair. I've had a manual from days gone by. There appears to be some differences - not shown in the manual. I'm wondering if I can pick someone's brains about this model or it's differences. 1. Was there more than one version of service manual? At the time I purchased this, I don't believe I was told of anymore than the one - I usually ask about revisions. 2. Did the updates in this model produce differences in circuitry (I'm sure they probably did) - and how? 3. The issue I "currently" see - is I have "low level" audio, no squelch action, no receive, no display, no dot. I started troubleshooting it and this book has a Q206 listed in it as providing a particular voltage to the circuit (can't recall which part of the circuit - without the book in front of me). THIS unit shows NO Q206 where the book shows it to be. I can be more specific in parts layout in that area if someone asks - but for now - I'm missing some voltage and need to find out why Q206 is not there OR whatever. The "Q204" is putting out like 4 - 6 volts less than it should. I'm not sure that is the "only" issue here - but the first I found thus far. I'm just trying to clear up the mystery of Q206 for the moment. The book shows it "supposedly" on the "Features" board. Along with that issue, there is in the same leg of circuit - according to my manual - a 47K ohm resistor there tied to Q204 and a wire coming from the 18V supply - with an 9v Zener in that area also. This model has a 1xxxx ohm resistor there OR at least it appears to. It is burned in the center from heat - but the first band is clearly "brown" - so this isn't the 47K as called for in my manual. Basically, the circuit leg is all there - minus Q206! There's not even a place for it "to" be, from what I'm seeing. IF I'm in error of voltages/values specified - its' only I'm going from memory - the book is in the shop - but I"m not off in my description otherwise. I can provide more specific info such as Serial Number, Board numbers and/or revisions, whatever - if requested, I just don't have it in front of me at the moment. I realize some parts of this radio are impossible to get now-days - so - I want to make sure I can trace this down to something repairable and get it done OR find out quick it isn't possible and hand it back without wasting much more time. Any info? Please answer here - my address is a spam catcher only. Thanks, Lou Lou, maybe this info will help. In looking through my Bearcat info, I found a schematic for a "250A". The feature board is constructed a little differently than what they show in the 250 service manual and I have seen both boards used in 250s. The red wire still goes to the collector of Q204 (NPN). The emitter of Q204 should have 8.4 Volts there. The base circuit of Q204 is a little different on the "A" version. A 9.1 Volt 1 watt zener runs from the base of Q204 to ground. (Cathode connects to the base of Q204). Now, the collector of Q206 (PNP) connects to the base of Q204 through R239, a 150 ohm 1/2 watt resistor. That's the only connection on the collector of Q206. Q206's base has R220, a 100 ohm 1/2 watt resistor that is connected to the cathode of D212, a 10 Volt 1 watt zener. Hope this info helps you out. Keep us posted on your progress. Mac Sorry, I forgot to mention in my first response that the emitter of Q206 connects to the collector of Q204 (the red wire - 16 volts). Meanwhile, I found another schematic for the 250 that shows the same circuit I described, but also adds one resistor on Q206, between the emitter and base. The resistor is labeled R242 and is a 1K 5% (wattage is not indicated). Do you have the correct voltages at the output of the switching power supply? (plus and minus 25 volts). If not, you probably need to diagnose that problem first. Depending on what has failed there may determine whether or not the scanner is repairable. If it's just a capacitor failure (common) or a failure with IC-8 (it happens) then it is probably repairable, but if the problem goes on back to IC-9, IC-7, or IC-6, the prognosis is not so good. Good luck! Mac Mike, read all your replies to date.. since this is a "side" project to help a friend - have gotten busy - didn't get back to it just yet. This is my first week of free time. Please take note - where Q204 is, in the book - it "shows" a Q206 and the schematic shows parts going between Q204/206. In "this" model - there appears to be NO Q206 OR even a place for one. I can elaborate more - but my previous posts pretty much spell it out. Thanks, Lou Can you give us a part number off of the feature circuit board? |
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