[Drakelist] R4A-B Detector Amp Q5
GM All: Has anyone else had trouble getting a general purpose sub working in the Q5 AM detector amp position? I tried several close NTE GP subs and also a 3393 which is same parameters ex Hfe which is slightly different. The transistor comes on but with the grounded emitter, pulls the collector voltage to near zero. As soon as I put in a real orignal 3394 from a R4A, it works as it should--good fidelity and collector voltage at about 5V from the supply rail of 10V. Is this design so sensitive to Hfe as to be marginal or need to be hand selected? Certainly the 3393 is well within the spec range of the 3394. Thanks Curt KU8L ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] R4A-B Detector Amp Q5
HI Curt.. It almost sounds like there is a different lead arrangement on the 3393. Any well designed circuit of that era would have had to tolerate the typical high variability of Hfe to avoid tedious hand picking of parts, although that may have been done in this case. Tom Holmes, N8ZM Tipp City, OH EM79 -Original Message- From: drakelist-boun...@zerobeat.net [mailto:drakelist-boun...@zerobeat.net] On Behalf Of Curt Nixon Sent: Tuesday, February 26, 2013 10:40 AM To: Drake Forum Subject: [Drakelist] R4A-B Detector Amp Q5 GM All: Has anyone else had trouble getting a general purpose sub working in the Q5 AM detector amp position? I tried several close NTE GP subs and also a 3393 which is same parameters ex Hfe which is slightly different. The transistor comes on but with the grounded emitter, pulls the collector voltage to near zero. As soon as I put in a real orignal 3394 from a R4A, it works as it should--good fidelity and collector voltage at about 5V from the supply rail of 10V. Is this design so sensitive to Hfe as to be marginal or need to be hand selected? Certainly the 3393 is well within the spec range of the 3394. Thanks Curt KU8L ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] R4A-B Detector Amp Q5
Hi Tom: Yes...there are the lead arrangement issues but I accounted for them. The typical EBC Vs ECB issue. Easy in this case because they used the triangular hole pattern instead of the inline pattern on both the R4A and B version modules. Curt On 2/26/2013 10:49 AM, Tom Holmes wrote: HI Curt.. It almost sounds like there is a different lead arrangement on the 3393. Any well designed circuit of that era would have had to tolerate the typical high variability of Hfe to avoid tedious hand picking of parts, although that may have been done in this case. Tom Holmes, N8ZM Tipp City, OH EM79 -Original Message- From: drakelist-boun...@zerobeat.net [mailto:drakelist-boun...@zerobeat.net] On Behalf Of Curt Nixon Sent: Tuesday, February 26, 2013 10:40 AM To: Drake Forum Subject: [Drakelist] R4A-B Detector Amp Q5 GM All: Has anyone else had trouble getting a general purpose sub working in the Q5 AM detector amp position? I tried several close NTE GP subs and also a 3393 which is same parameters ex Hfe which is slightly different. The transistor comes on but with the grounded emitter, pulls the collector voltage to near zero. As soon as I put in a real orignal 3394 from a R4A, it works as it should--good fidelity and collector voltage at about 5V from the supply rail of 10V. Is this design so sensitive to Hfe as to be marginal or need to be hand selected? Certainly the 3393 is well within the spec range of the 3394. Thanks Curt KU8L ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] R4A-B Detector Amp Q5
Well, it was worth a shot. Since I don't have the circuit in front of me I can't make a more educated guess. Since you caught the lead issue, I'll assume that you also did the diode test on the replacement parts. I have seen a few cases where the NTE doc's are wrong about the leads though. When the collector voltage goes to near zero, is it .2 V or .6 V? The first case is a saturated transistor; the second is a diode junction, which would suggest the pinout info is wrong. When I get back from some errands, I'll look in my NTE book to see if I can find any other clues. Happy hunting! Tom Holmes, N8ZM Tipp City, OH EM79 -Original Message- From: drakelist-boun...@zerobeat.net [mailto:drakelist-boun...@zerobeat.net] On Behalf Of Curt Nixon Sent: Tuesday, February 26, 2013 11:43 AM To: drakelist@zerobeat.net Subject: Re: [Drakelist] R4A-B Detector Amp Q5 Hi Tom: Yes...there are the lead arrangement issues but I accounted for them. The typical EBC Vs ECB issue. Easy in this case because they used the triangular hole pattern instead of the inline pattern on both the R4A and B version modules. Curt On 2/26/2013 10:49 AM, Tom Holmes wrote: HI Curt.. It almost sounds like there is a different lead arrangement on the 3393. Any well designed circuit of that era would have had to tolerate the typical high variability of Hfe to avoid tedious hand picking of parts, although that may have been done in this case. Tom Holmes, N8ZM Tipp City, OH EM79 -Original Message- From: drakelist-boun...@zerobeat.net [mailto:drakelist-boun...@zerobeat.net] On Behalf Of Curt Nixon Sent: Tuesday, February 26, 2013 10:40 AM To: Drake Forum Subject: [Drakelist] R4A-B Detector Amp Q5 GM All: Has anyone else had trouble getting a general purpose sub working in the Q5 AM detector amp position? I tried several close NTE GP subs and also a 3393 which is same parameters ex Hfe which is slightly different. The transistor comes on but with the grounded emitter, pulls the collector voltage to near zero. As soon as I put in a real orignal 3394 from a R4A, it works as it should--good fidelity and collector voltage at about 5V from the supply rail of 10V. Is this design so sensitive to Hfe as to be marginal or need to be hand selected? Certainly the 3393 is well within the spec range of the 3394. Thanks Curt KU8L ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] R4A-B Detector Amp Q5
Hi Tom: The collector goes to hard saturation value. Less than .2V. I did the test using a Huntron on a few of the swaps just to be sure. I also carefully watched the base voltage established thru the detector diode. It stays right around .5-.6V. Even repalced the diode to see if that might be the case but same result. At this point, I guess I am going to try to find a genuine 3394 and call it a day. It all works fine when I put in a working device from another R4 so suspect something particular about the device. Transistors were a lot less controlled in 1968 so it may not be close. Dont have a curve tracer and not going to remove it again to do an Hfe test on it the hard way. It is just a curiosity now. I taught solid-state design and theory in Navy and later in college and thought I had seen most issues. ;) Curt KU8L On 2/26/2013 12:02 PM, Tom Holmes wrote: Well, it was worth a shot. Since I don't have the circuit in front of me I can't make a more educated guess. Since you caught the lead issue, I'll assume that you also did the diode test on the replacement parts. I have seen a few cases where the NTE doc's are wrong about the leads though. When the collector voltage goes to near zero, is it .2 V or .6 V? The first case is a saturated transistor; the second is a diode junction, which would suggest the pinout info is wrong. When I get back from some errands, I'll look in my NTE book to see if I can find any other clues. Happy hunting! Tom Holmes, N8ZM Tipp City, OH EM79 -Original Message- From: drakelist-boun...@zerobeat.net [mailto:drakelist-boun...@zerobeat.net] On Behalf Of Curt Nixon Sent: Tuesday, February 26, 2013 11:43 AM To: drakelist@zerobeat.net Subject: Re: [Drakelist] R4A-B Detector Amp Q5 Hi Tom: Yes...there are the lead arrangement issues but I accounted for them. The typical EBC Vs ECB issue. Easy in this case because they used the triangular hole pattern instead of the inline pattern on both the R4A and B version modules. Curt On 2/26/2013 10:49 AM, Tom Holmes wrote: HI Curt.. It almost sounds like there is a different lead arrangement on the 3393. Any well designed circuit of that era would have had to tolerate the typical high variability of Hfe to avoid tedious hand picking of parts, although that may have been done in this case. Tom Holmes, N8ZM Tipp City, OH EM79 -Original Message- From: drakelist-boun...@zerobeat.net [mailto:drakelist-boun...@zerobeat.net] On Behalf Of Curt Nixon Sent: Tuesday, February 26, 2013 10:40 AM To: Drake Forum Subject: [Drakelist] R4A-B Detector Amp Q5 GM All: Has anyone else had trouble getting a general purpose sub working in the Q5 AM detector amp position? I tried several close NTE GP subs and also a 3393 which is same parameters ex Hfe which is slightly different. The transistor comes on but with the grounded emitter, pulls the collector voltage to near zero. As soon as I put in a real orignal 3394 from a R4A, it works as it should--good fidelity and collector voltage at about 5V from the supply rail of 10V. Is this design so sensitive to Hfe as to be marginal or need to be hand selected? Certainly the 3393 is well within the spec range of the 3394. Thanks Curt KU8L ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] R4A-B Detector Amp Q5
:-). I wonder if there is an asterisk on the schematic next to some bias resistor that says hand chosen. Oh well. Have fun! Tom Holmes, N8ZM Tipp City, OH EM79 -Original Message- From: drakelist-boun...@zerobeat.net [mailto:drakelist-boun...@zerobeat.net] On Behalf Of Curt Nixon Sent: Tuesday, February 26, 2013 12:30 PM To: drakelist@zerobeat.net Subject: Re: [Drakelist] R4A-B Detector Amp Q5 Hi Tom: The collector goes to hard saturation value. Less than .2V. I did the test using a Huntron on a few of the swaps just to be sure. I also carefully watched the base voltage established thru the detector diode. It stays right around .5-.6V. Even repalced the diode to see if that might be the case but same result. At this point, I guess I am going to try to find a genuine 3394 and call it a day. It all works fine when I put in a working device from another R4 so suspect something particular about the device. Transistors were a lot less controlled in 1968 so it may not be close. Dont have a curve tracer and not going to remove it again to do an Hfe test on it the hard way. It is just a curiosity now. I taught solid-state design and theory in Navy and later in college and thought I had seen most issues. ;) Curt KU8L On 2/26/2013 12:02 PM, Tom Holmes wrote: Well, it was worth a shot. Since I don't have the circuit in front of me I can't make a more educated guess. Since you caught the lead issue, I'll assume that you also did the diode test on the replacement parts. I have seen a few cases where the NTE doc's are wrong about the leads though. When the collector voltage goes to near zero, is it .2 V or .6 V? The first case is a saturated transistor; the second is a diode junction, which would suggest the pinout info is wrong. When I get back from some errands, I'll look in my NTE book to see if I can find any other clues. Happy hunting! Tom Holmes, N8ZM Tipp City, OH EM79 -Original Message- From: drakelist-boun...@zerobeat.net [mailto:drakelist-boun...@zerobeat.net] On Behalf Of Curt Nixon Sent: Tuesday, February 26, 2013 11:43 AM To: drakelist@zerobeat.net Subject: Re: [Drakelist] R4A-B Detector Amp Q5 Hi Tom: Yes...there are the lead arrangement issues but I accounted for them. The typical EBC Vs ECB issue. Easy in this case because they used the triangular hole pattern instead of the inline pattern on both the R4A and B version modules. Curt On 2/26/2013 10:49 AM, Tom Holmes wrote: HI Curt.. It almost sounds like there is a different lead arrangement on the 3393. Any well designed circuit of that era would have had to tolerate the typical high variability of Hfe to avoid tedious hand picking of parts, although that may have been done in this case. Tom Holmes, N8ZM Tipp City, OH EM79 -Original Message- From: drakelist-boun...@zerobeat.net [mailto:drakelist-boun...@zerobeat.net] On Behalf Of Curt Nixon Sent: Tuesday, February 26, 2013 10:40 AM To: Drake Forum Subject: [Drakelist] R4A-B Detector Amp Q5 GM All: Has anyone else had trouble getting a general purpose sub working in the Q5 AM detector amp position? I tried several close NTE GP subs and also a 3393 which is same parameters ex Hfe which is slightly different. The transistor comes on but with the grounded emitter, pulls the collector voltage to near zero. As soon as I put in a real orignal 3394 from a R4A, it works as it should--good fidelity and collector voltage at about 5V from the supply rail of 10V. Is this design so sensitive to Hfe as to be marginal or need to be hand selected? Certainly the 3393 is well within the spec range of the 3394. Thanks Curt KU8L ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] R4A-B Detector Amp Q5
The saturation you are seeing should not be happening based upon simple DC specs. Either the pinout is not correct as has been suggested or perhaps the new transistor is oscillating due to a higher gain-bandwidth product. The circuit does use a feedback connection. Dennis AE6C On Tue, Feb 26, 2013 at 12:06 PM, Tom Holmes thol...@woh.rr.com wrote: :-). I wonder if there is an asterisk on the schematic next to some bias resistor that says hand chosen. Oh well. Have fun! Tom Holmes, N8ZM Tipp City, OH EM79 -Original Message- From: drakelist-boun...@zerobeat.net [mailto:drakelist-boun...@zerobeat.net] On Behalf Of Curt Nixon Sent: Tuesday, February 26, 2013 12:30 PM To: drakelist@zerobeat.net Subject: Re: [Drakelist] R4A-B Detector Amp Q5 Hi Tom: The collector goes to hard saturation value. Less than .2V. I did the test using a Huntron on a few of the swaps just to be sure. I also carefully watched the base voltage established thru the detector diode. It stays right around .5-.6V. Even repalced the diode to see if that might be the case but same result. At this point, I guess I am going to try to find a genuine 3394 and call it a day. It all works fine when I put in a working device from another R4 so suspect something particular about the device. Transistors were a lot less controlled in 1968 so it may not be close. Dont have a curve tracer and not going to remove it again to do an Hfe test on it the hard way. It is just a curiosity now. I taught solid-state design and theory in Navy and later in college and thought I had seen most issues. ;) Curt KU8L On 2/26/2013 12:02 PM, Tom Holmes wrote: Well, it was worth a shot. Since I don't have the circuit in front of me I can't make a more educated guess. Since you caught the lead issue, I'll assume that you also did the diode test on the replacement parts. I have seen a few cases where the NTE doc's are wrong about the leads though. When the collector voltage goes to near zero, is it .2 V or .6 V? The first case is a saturated transistor; the second is a diode junction, which would suggest the pinout info is wrong. When I get back from some errands, I'll look in my NTE book to see if I can find any other clues. Happy hunting! Tom Holmes, N8ZM Tipp City, OH EM79 -Original Message- From: drakelist-boun...@zerobeat.net [mailto:drakelist-boun...@zerobeat.net] On Behalf Of Curt Nixon Sent: Tuesday, February 26, 2013 11:43 AM To: drakelist@zerobeat.net Subject: Re: [Drakelist] R4A-B Detector Amp Q5 Hi Tom: Yes...there are the lead arrangement issues but I accounted for them. The typical EBC Vs ECB issue. Easy in this case because they used the triangular hole pattern instead of the inline pattern on both the R4A and B version modules. Curt On 2/26/2013 10:49 AM, Tom Holmes wrote: HI Curt.. It almost sounds like there is a different lead arrangement on the 3393. Any well designed circuit of that era would have had to tolerate the typical high variability of Hfe to avoid tedious hand picking of parts, although that may have been done in this case. Tom Holmes, N8ZM Tipp City, OH EM79 -Original Message- From: drakelist-boun...@zerobeat.net [mailto:drakelist-boun...@zerobeat.net] On Behalf Of Curt Nixon Sent: Tuesday, February 26, 2013 10:40 AM To: Drake Forum Subject: [Drakelist] R4A-B Detector Amp Q5 GM All: Has anyone else had trouble getting a general purpose sub working in the Q5 AM detector amp position? I tried several close NTE GP subs and also a 3393 which is same parameters ex Hfe which is slightly different. The transistor comes on but with the grounded emitter, pulls the collector voltage to near zero. As soon as I put in a real orignal 3394 from a R4A, it works as it should--good fidelity and collector voltage at about 5V from the supply rail of 10V. Is this design so sensitive to Hfe as to be marginal or need to be hand selected? Certainly the 3393 is well within the spec range of the 3394. Thanks Curt KU8L ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
