Re: [time-nuts] Opening an Isotemp OCXO
if its the yellow tantalum. then yes 39 uf at 10V. S sort of surprised it didn't go nuclear on you. Makes for a serious mess. Regards Paul WB8TSL On Sat, Oct 29, 2016 at 9:59 AM, Bob Camp wrote: > Hi > > If the OCXO was designed for a ~70 C upper end temperature spec, then a > ~90C crystal > would make sense. > > When you feed +12 into the oven control, you are increasing the effective > gain of the control > loop (it has more power). The cycling you see is the loop going into > oscillation. It’s the same thing that happens if > you put way to much insulation around an OCXO. > > I *hope* the 4 amps below is a typo. 20W into the beast is way to much. > 0.4 A at 5V would be > 2W. That is a fairly normal number for an OCXO like you have at room > temperature. > > Bob > > > > On Oct 29, 2016, at 9:51 AM, Peter Reilley > wrote: > > > > More information; > > > > I added a picture to the dropbox from my Flir IR camera. The picture > shows the copper block > > that the crystal is attached to running at about 200 F. In the IR shot > the copper block is to the > > right.In most of the regular pictures it is toward the bottom of the > picture.This is with the > > unit (minus the S30 chip) running on 5 volts for more than 10 hours. > Is that too hot? > > > > While running at 5 volts the current is constant at about 4. amps, no > cycling. At 12 volts > > it cycled between .9 to .1 amps. I would not expect cycling for the > temperature control > > of an OCXO. I would expect a linear temperature control circuit. > > > > I looked at the tantalum capacitor on the bottom of the board. The > marking is 39-10. > > Does that mean 39 uF and 10 volts? If so then it must be a 5 volt > unit. The capacitor > > did not explode at 12 volts. > > > > Dropbox link: > > https://www.dropbox.com/sh/52e9d1rva9kpb3w/ > AABmbIj1aK7Zk2J9SNMmu-JAa?dl=0 > > > > Pete. > > > > On 10/18/2016 9:11 AM, Peter Reilley wrote: > >> I bought an Isotemp OCXO82-59 with a frequency of 10 MHz for a $3 at > the MIT flea market. > >> As expected it was dead. It heats up as expected but looking at the > output with a scope there > >> is nothing. However looking at the output with a spectrum analyzer I > can see a faint 10 MHz > >> signal. It seems that the oscillator is running but the output > circuitry is dead. Reasonable > >> assumption? > >> > >> Anyway, has anyone had any luck unsoldering the tin case without > destroying it? > >> > >> Pete. > >> > >> ___ > >> time-nuts mailing list -- time-nuts@febo.com > >> To unsubscribe, go to https://www.febo.com/cgi-bin/ > mailman/listinfo/time-nuts > >> and follow the instructions there. > >> > > > > ___ > > time-nuts mailing list -- time-nuts@febo.com > > To unsubscribe, go to https://www.febo.com/cgi-bin/ > mailman/listinfo/time-nuts > > and follow the instructions there. > > ___ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/ > mailman/listinfo/time-nuts > and follow the instructions there. > ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Opening an Isotemp OCXO
Hi If the OCXO was designed for a ~70 C upper end temperature spec, then a ~90C crystal would make sense. When you feed +12 into the oven control, you are increasing the effective gain of the control loop (it has more power). The cycling you see is the loop going into oscillation. It’s the same thing that happens if you put way to much insulation around an OCXO. I *hope* the 4 amps below is a typo. 20W into the beast is way to much. 0.4 A at 5V would be 2W. That is a fairly normal number for an OCXO like you have at room temperature. Bob > On Oct 29, 2016, at 9:51 AM, Peter Reilley wrote: > > More information; > > I added a picture to the dropbox from my Flir IR camera. The picture shows > the copper block > that the crystal is attached to running at about 200 F. In the IR shot the > copper block is to the > right.In most of the regular pictures it is toward the bottom of the > picture.This is with the > unit (minus the S30 chip) running on 5 volts for more than 10 hours. Is > that too hot? > > While running at 5 volts the current is constant at about 4. amps, no > cycling. At 12 volts > it cycled between .9 to .1 amps. I would not expect cycling for the > temperature control > of an OCXO. I would expect a linear temperature control circuit. > > I looked at the tantalum capacitor on the bottom of the board. The marking > is 39-10. > Does that mean 39 uF and 10 volts? If so then it must be a 5 volt unit. > The capacitor > did not explode at 12 volts. > > Dropbox link: > https://www.dropbox.com/sh/52e9d1rva9kpb3w/AABmbIj1aK7Zk2J9SNMmu-JAa?dl=0 > > Pete. > > On 10/18/2016 9:11 AM, Peter Reilley wrote: >> I bought an Isotemp OCXO82-59 with a frequency of 10 MHz for a $3 at the MIT >> flea market. >> As expected it was dead. It heats up as expected but looking at the output >> with a scope there >> is nothing. However looking at the output with a spectrum analyzer I can >> see a faint 10 MHz >> signal. It seems that the oscillator is running but the output circuitry >> is dead. Reasonable >> assumption? >> >> Anyway, has anyone had any luck unsoldering the tin case without destroying >> it? >> >> Pete. >> >> ___ >> time-nuts mailing list -- time-nuts@febo.com >> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >> and follow the instructions there. >> > > ___ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Opening an Isotemp OCXO
More information; I added a picture to the dropbox from my Flir IR camera. The picture shows the copper block that the crystal is attached to running at about 200 F. In the IR shot the copper block is to the right.In most of the regular pictures it is toward the bottom of the picture.This is with the unit (minus the S30 chip) running on 5 volts for more than 10 hours. Is that too hot? While running at 5 volts the current is constant at about 4. amps, no cycling. At 12 volts it cycled between .9 to .1 amps. I would not expect cycling for the temperature control of an OCXO. I would expect a linear temperature control circuit. I looked at the tantalum capacitor on the bottom of the board. The marking is 39-10. Does that mean 39 uF and 10 volts? If so then it must be a 5 volt unit. The capacitor did not explode at 12 volts. Dropbox link: https://www.dropbox.com/sh/52e9d1rva9kpb3w/AABmbIj1aK7Zk2J9SNMmu-JAa?dl=0 Pete. On 10/18/2016 9:11 AM, Peter Reilley wrote: I bought an Isotemp OCXO82-59 with a frequency of 10 MHz for a $3 at the MIT flea market. As expected it was dead. It heats up as expected but looking at the output with a scope there is nothing. However looking at the output with a spectrum analyzer I can see a faint 10 MHz signal. It seems that the oscillator is running but the output circuitry is dead. Reasonable assumption? Anyway, has anyone had any luck unsoldering the tin case without destroying it? Pete. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Opening an Isotemp OCXO
Oh never mind. MAJOR BF!!! How I 'morphed' S30 into S05 I can't explain. I suspect it is a 74S30 but I can't prove it. Sorry. Joe -Original Message- From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of J. L. Trantham Sent: Friday, October 28, 2016 5:57 PM To: 'Discussion of precise time and frequency measurement' Subject: Re: [time-nuts] Opening an Isotemp OCXO Sorry. 74S05D. Joe -Original Message- From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of J. L. Trantham Sent: Friday, October 28, 2016 5:50 PM To: 'Tom Miller'; 'Discussion of precise time and frequency measurement' Subject: Re: [time-nuts] Opening an Isotemp OCXO I have emailed Peter separately earlier today. The top side marking of the chip appears to indicate it is a TI 74LS05D. The datasheet is here: http://www.ti.com/lit/ds/symlink/sn74ls05.pdf If it is indeed a 'HEX Inverter', perhaps another 'channel' can be wired in place to see if it would work without having to find another chip. Also, I, too, was wondering if it was 5 V or if there was a 5 V regulator on the board somewhere. Hope this helps. Joe -Original Message- From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Tom Miller Sent: Friday, October 28, 2016 4:18 PM To: pe...@reilley.com; Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Opening an Isotemp OCXO Can you see the voltage on the yellow dipped tantalum under the board? I think that is what it is. - Original Message - From: "Peter Reilley" To: "Discussion of precise time and frequency measurement" Sent: Friday, October 28, 2016 3:28 PM Subject: Re: [time-nuts] Opening an Isotemp OCXO > That seems the most reasonable thing to do. > > Pete > > > On 10/28/2016 3:20 PM, Tom Miller wrote: >> It looks like that is the only device that could be damaged by 12 volts. >> Can you find a replacement and try running at 5 volts? >> >> >> - Original Message - From: "Peter Reilley" >> >> To: "Discussion of precise time and frequency measurement" >> >> Sent: Friday, October 28, 2016 3:10 PM >> Subject: Re: [time-nuts] Opening an Isotemp OCXO >> >> >>> The reason that there was 12 volts on the unit was because I put it >>> there. I should >>> have tried 5 volts first but the only datasheet that I could find said >>> 12 volts. >>> All the eBay units that look the same say 12 volts. >>> >>> Pete. >>> >>> On 10/28/2016 12:53 PM, paul swed wrote: >>>> I confirmed the pin out matches a 74s30 also. An S30 is TTL. Great pix >>>> to >>>> look at. >>>> So 12 V on a 5 V chip is indeed a smoker. Find out why there was 12 V. >>>> OK crazy talk I see a 1K resistor next to the VCC chip. Would anyone be >>>> crazy enough to use a dropping resistor from 12 V to get 5?? Really bad >>>> engineering and I don't actually believe they would. But if true a open >>>> 74s30 would indeed show 12 V on pin 14. >>>> Good luck. >>>> Paul >>>> WB8TSL >>>> >>>> On Fri, Oct 28, 2016 at 12:48 PM, jimlux wrote: >>>> >>>>> On 10/28/16 9:13 AM, Scott Stobbe wrote: >>>>> >>>>>> The OCXO82-59 datasheet lists 12V supply, 5V clock out, could also be >>>>>> a >>>>>> blown regulator in your ocxo, if it is indeed a 12v model. >>>>>> >>>>>> There you go..the design could use a 74S30 as a driver - it's fast, >>>>> fairly good drive, but runs off 5V. If the regulator is shorted, and >>>>> you >>>>> put 12V on it, it will cook. >>>>> >>>>> >>>>> ___ >>>>> time-nuts mailing list -- time-nuts@febo.com >>>>> To unsubscribe, go to https://www.febo.com/cgi-bin/m >>>>> ailman/listinfo/time-nuts >>>>> and follow the instructions there. >>>>> >>>> ___ >>>> time-nuts mailing list -- time-nuts@febo.com >>>> To unsubscribe, go to >>>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >>>> and follow the instructions there. >>>> >>> >>> ___ >>> time-nuts mailing list -- time-nuts@febo.com >>> To unsubscribe, go to >>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] Opening an Isotemp OCXO
Not S05 but S30. A 74S30 is an 8 input NAND and the foot pint on the board, looking at the inputs and outputs, seems to confirm it. There is no 5 volt regulator. The power pin is connected directly to the power pin of a 74S30. Pete. On 10/28/2016 6:50 PM, J. L. Trantham wrote: I have emailed Peter separately earlier today. The top side marking of the chip appears to indicate it is a TI 74LS05D. The datasheet is here: http://www.ti.com/lit/ds/symlink/sn74ls05.pdf If it is indeed a 'HEX Inverter', perhaps another 'channel' can be wired in place to see if it would work without having to find another chip. Also, I, too, was wondering if it was 5 V or if there was a 5 V regulator on the board somewhere. Hope this helps. Joe -Original Message- From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Tom Miller Sent: Friday, October 28, 2016 4:18 PM To: pe...@reilley.com; Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Opening an Isotemp OCXO Can you see the voltage on the yellow dipped tantalum under the board? I think that is what it is. - Original Message - From: "Peter Reilley" To: "Discussion of precise time and frequency measurement" Sent: Friday, October 28, 2016 3:28 PM Subject: Re: [time-nuts] Opening an Isotemp OCXO That seems the most reasonable thing to do. Pete On 10/28/2016 3:20 PM, Tom Miller wrote: It looks like that is the only device that could be damaged by 12 volts. Can you find a replacement and try running at 5 volts? - Original Message - From: "Peter Reilley" To: "Discussion of precise time and frequency measurement" Sent: Friday, October 28, 2016 3:10 PM Subject: Re: [time-nuts] Opening an Isotemp OCXO The reason that there was 12 volts on the unit was because I put it there. I should have tried 5 volts first but the only datasheet that I could find said 12 volts. All the eBay units that look the same say 12 volts. Pete. On 10/28/2016 12:53 PM, paul swed wrote: I confirmed the pin out matches a 74s30 also. An S30 is TTL. Great pix to look at. So 12 V on a 5 V chip is indeed a smoker. Find out why there was 12 V. OK crazy talk I see a 1K resistor next to the VCC chip. Would anyone be crazy enough to use a dropping resistor from 12 V to get 5?? Really bad engineering and I don't actually believe they would. But if true a open 74s30 would indeed show 12 V on pin 14. Good luck. Paul WB8TSL On Fri, Oct 28, 2016 at 12:48 PM, jimlux wrote: On 10/28/16 9:13 AM, Scott Stobbe wrote: The OCXO82-59 datasheet lists 12V supply, 5V clock out, could also be a blown regulator in your ocxo, if it is indeed a 12v model. There you go..the design could use a 74S30 as a driver - it's fast, fairly good drive, but runs off 5V. If the regulator is shorted, and you put 12V on it, it will cook. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/m ailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Opening an Isotemp OCXO
Sorry. 74S05D. Joe -Original Message- From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of J. L. Trantham Sent: Friday, October 28, 2016 5:50 PM To: 'Tom Miller'; 'Discussion of precise time and frequency measurement' Subject: Re: [time-nuts] Opening an Isotemp OCXO I have emailed Peter separately earlier today. The top side marking of the chip appears to indicate it is a TI 74LS05D. The datasheet is here: http://www.ti.com/lit/ds/symlink/sn74ls05.pdf If it is indeed a 'HEX Inverter', perhaps another 'channel' can be wired in place to see if it would work without having to find another chip. Also, I, too, was wondering if it was 5 V or if there was a 5 V regulator on the board somewhere. Hope this helps. Joe -Original Message- From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Tom Miller Sent: Friday, October 28, 2016 4:18 PM To: pe...@reilley.com; Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Opening an Isotemp OCXO Can you see the voltage on the yellow dipped tantalum under the board? I think that is what it is. - Original Message - From: "Peter Reilley" To: "Discussion of precise time and frequency measurement" Sent: Friday, October 28, 2016 3:28 PM Subject: Re: [time-nuts] Opening an Isotemp OCXO > That seems the most reasonable thing to do. > > Pete > > > On 10/28/2016 3:20 PM, Tom Miller wrote: >> It looks like that is the only device that could be damaged by 12 volts. >> Can you find a replacement and try running at 5 volts? >> >> >> - Original Message - From: "Peter Reilley" >> >> To: "Discussion of precise time and frequency measurement" >> >> Sent: Friday, October 28, 2016 3:10 PM >> Subject: Re: [time-nuts] Opening an Isotemp OCXO >> >> >>> The reason that there was 12 volts on the unit was because I put it >>> there. I should >>> have tried 5 volts first but the only datasheet that I could find said >>> 12 volts. >>> All the eBay units that look the same say 12 volts. >>> >>> Pete. >>> >>> On 10/28/2016 12:53 PM, paul swed wrote: >>>> I confirmed the pin out matches a 74s30 also. An S30 is TTL. Great pix >>>> to >>>> look at. >>>> So 12 V on a 5 V chip is indeed a smoker. Find out why there was 12 V. >>>> OK crazy talk I see a 1K resistor next to the VCC chip. Would anyone be >>>> crazy enough to use a dropping resistor from 12 V to get 5?? Really bad >>>> engineering and I don't actually believe they would. But if true a open >>>> 74s30 would indeed show 12 V on pin 14. >>>> Good luck. >>>> Paul >>>> WB8TSL >>>> >>>> On Fri, Oct 28, 2016 at 12:48 PM, jimlux wrote: >>>> >>>>> On 10/28/16 9:13 AM, Scott Stobbe wrote: >>>>> >>>>>> The OCXO82-59 datasheet lists 12V supply, 5V clock out, could also be >>>>>> a >>>>>> blown regulator in your ocxo, if it is indeed a 12v model. >>>>>> >>>>>> There you go..the design could use a 74S30 as a driver - it's fast, >>>>> fairly good drive, but runs off 5V. If the regulator is shorted, and >>>>> you >>>>> put 12V on it, it will cook. >>>>> >>>>> >>>>> ___ >>>>> time-nuts mailing list -- time-nuts@febo.com >>>>> To unsubscribe, go to https://www.febo.com/cgi-bin/m >>>>> ailman/listinfo/time-nuts >>>>> and follow the instructions there. >>>>> >>>> ___ >>>> time-nuts mailing list -- time-nuts@febo.com >>>> To unsubscribe, go to >>>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >>>> and follow the instructions there. >>>> >>> >>> ___ >>> time-nuts mailing list -- time-nuts@febo.com >>> To unsubscribe, go to >>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >>> and follow the instructions there. >> >> > > ___ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Opening an Isotemp OCXO
I have emailed Peter separately earlier today. The top side marking of the chip appears to indicate it is a TI 74LS05D. The datasheet is here: http://www.ti.com/lit/ds/symlink/sn74ls05.pdf If it is indeed a 'HEX Inverter', perhaps another 'channel' can be wired in place to see if it would work without having to find another chip. Also, I, too, was wondering if it was 5 V or if there was a 5 V regulator on the board somewhere. Hope this helps. Joe -Original Message- From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Tom Miller Sent: Friday, October 28, 2016 4:18 PM To: pe...@reilley.com; Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Opening an Isotemp OCXO Can you see the voltage on the yellow dipped tantalum under the board? I think that is what it is. - Original Message - From: "Peter Reilley" To: "Discussion of precise time and frequency measurement" Sent: Friday, October 28, 2016 3:28 PM Subject: Re: [time-nuts] Opening an Isotemp OCXO > That seems the most reasonable thing to do. > > Pete > > > On 10/28/2016 3:20 PM, Tom Miller wrote: >> It looks like that is the only device that could be damaged by 12 volts. >> Can you find a replacement and try running at 5 volts? >> >> >> - Original Message - From: "Peter Reilley" >> >> To: "Discussion of precise time and frequency measurement" >> >> Sent: Friday, October 28, 2016 3:10 PM >> Subject: Re: [time-nuts] Opening an Isotemp OCXO >> >> >>> The reason that there was 12 volts on the unit was because I put it >>> there. I should >>> have tried 5 volts first but the only datasheet that I could find said >>> 12 volts. >>> All the eBay units that look the same say 12 volts. >>> >>> Pete. >>> >>> On 10/28/2016 12:53 PM, paul swed wrote: >>>> I confirmed the pin out matches a 74s30 also. An S30 is TTL. Great pix >>>> to >>>> look at. >>>> So 12 V on a 5 V chip is indeed a smoker. Find out why there was 12 V. >>>> OK crazy talk I see a 1K resistor next to the VCC chip. Would anyone be >>>> crazy enough to use a dropping resistor from 12 V to get 5?? Really bad >>>> engineering and I don't actually believe they would. But if true a open >>>> 74s30 would indeed show 12 V on pin 14. >>>> Good luck. >>>> Paul >>>> WB8TSL >>>> >>>> On Fri, Oct 28, 2016 at 12:48 PM, jimlux wrote: >>>> >>>>> On 10/28/16 9:13 AM, Scott Stobbe wrote: >>>>> >>>>>> The OCXO82-59 datasheet lists 12V supply, 5V clock out, could also be >>>>>> a >>>>>> blown regulator in your ocxo, if it is indeed a 12v model. >>>>>> >>>>>> There you go..the design could use a 74S30 as a driver - it's fast, >>>>> fairly good drive, but runs off 5V. If the regulator is shorted, and >>>>> you >>>>> put 12V on it, it will cook. >>>>> >>>>> >>>>> ___ >>>>> time-nuts mailing list -- time-nuts@febo.com >>>>> To unsubscribe, go to https://www.febo.com/cgi-bin/m >>>>> ailman/listinfo/time-nuts >>>>> and follow the instructions there. >>>>> >>>> ___ >>>> time-nuts mailing list -- time-nuts@febo.com >>>> To unsubscribe, go to >>>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >>>> and follow the instructions there. >>>> >>> >>> ___ >>> time-nuts mailing list -- time-nuts@febo.com >>> To unsubscribe, go to >>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >>> and follow the instructions there. >> >> > > ___ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Opening an Isotemp OCXO
Can you see the voltage on the yellow dipped tantalum under the board? I think that is what it is. - Original Message - From: "Peter Reilley" To: "Discussion of precise time and frequency measurement" Sent: Friday, October 28, 2016 3:28 PM Subject: Re: [time-nuts] Opening an Isotemp OCXO That seems the most reasonable thing to do. Pete On 10/28/2016 3:20 PM, Tom Miller wrote: It looks like that is the only device that could be damaged by 12 volts. Can you find a replacement and try running at 5 volts? - Original Message - From: "Peter Reilley" To: "Discussion of precise time and frequency measurement" Sent: Friday, October 28, 2016 3:10 PM Subject: Re: [time-nuts] Opening an Isotemp OCXO The reason that there was 12 volts on the unit was because I put it there. I should have tried 5 volts first but the only datasheet that I could find said 12 volts. All the eBay units that look the same say 12 volts. Pete. On 10/28/2016 12:53 PM, paul swed wrote: I confirmed the pin out matches a 74s30 also. An S30 is TTL. Great pix to look at. So 12 V on a 5 V chip is indeed a smoker. Find out why there was 12 V. OK crazy talk I see a 1K resistor next to the VCC chip. Would anyone be crazy enough to use a dropping resistor from 12 V to get 5?? Really bad engineering and I don't actually believe they would. But if true a open 74s30 would indeed show 12 V on pin 14. Good luck. Paul WB8TSL On Fri, Oct 28, 2016 at 12:48 PM, jimlux wrote: On 10/28/16 9:13 AM, Scott Stobbe wrote: The OCXO82-59 datasheet lists 12V supply, 5V clock out, could also be a blown regulator in your ocxo, if it is indeed a 12v model. There you go..the design could use a 74S30 as a driver - it's fast, fairly good drive, but runs off 5V. If the regulator is shorted, and you put 12V on it, it will cook. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/m ailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Opening an Isotemp OCXO
On 10/28/16 1:09 PM, Bob Stewart wrote: Hi Bob, Can't the OCXOs be characterized pretty closely by someone with the right tools and staff? I don't have a big sample to speak from, but the Trimbles I use only have a couple of ceramic coated pieces, and those can be exposed down to the die by hand and then characterized, can't they? Granted, that's beyond my capabilities, but given the right tools and employees... The real thing is "which requirement do I really, really care about" beyond the straightforward frequency stability/phase noise specs. You might have a specific "I care about 1 Hz to 100 Hz, but don't much are about >100 Hz or <1Hz" and you're willing to let the mfr do pretty much anything else for the rest. I recently had a requirement where I don't much care about absolute frequency accuracy, but I do care about phase noise and short term (<3 seconds) stability. We got some quotes for OCXOs with the oven disabled, figuring that we don't need to burn the power for the oven, since that's more about frequency accuracy, and our environment (in space) doesn't vary more than a couple degrees over hours. That's something you'll never see in a catalog. We buy oscillators at JPL for things like landing radars - the operating life is minutes, but it had better work for those minutes - we care not what the aging or frequency accuracy is in this situation. I know people that have bought parts for telemetry transmitters on devices with life measured in seconds - there, the critical requirement was "must start from -80C and run for 10 seconds" A coworker was telling me about requirements for oscillators in fire control radars attached to gatling guns - Now there's a vibe sensitivity requirement. So, as Bob pointed out, most oscillators go into applications that have idiosyncratic requirements and a cost or delivery schedule requirement pushing against the overall performance requirement. Not everyone wants a 1kg ultra stable oscillator from APL with a 3 year delivery time. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Opening an Isotemp OCXO
Hi Well, the first issue would be the one that started this thread…. what’s the supply and pinout. Yes, you can tear a couple open and work that out. Next step would be to verify that the other couple hundred in the batch all are the same pinout and supply. Assuming that you have all the same parts, next up would be making the test fixtures for the units. It does not need to be super complex, but you need a way to solidly connect to the part. If the leads have been cut off, this is a bit more complex than if you have full length leads. Most processes age the units first. That would involve putting all hundred pieces on power and looking at each of them with a counter every couple of minutes for a month or two. Based on that data you could get a pretty good idea of what the aging will run. You also will weed out some percentage of the units that didn’t survive whatever process got them to you. After stabilization, They would go into temperature test. Likely something like a dozen or two per run. Since you don’t know the top end, I’d do a search for that first. I’d then do a search for the low end. Based on data from a few runs (several dozen parts) you should have some idea of the upper and lower temp limits. A formal temp run over that range would be next. I’d probably do 5 degree steps. That way if you are off on the endpoint guess you might be able to see the correct end points. You would test the whole batch of units and then look at the data. My guess is that you would re-guess the end points and re-test the batch at that point. Assuming you know the correct load and EFC from the original tear down, they would move on to some sort of bench check. If not, you would need to work that out. On the bench check, I’d run each one over the (assumed) EFC range at something like 0.1V steps. Here if your range is off, the data probably is still ok. That should give you a proper EFC setting for each one. Since they have been aged and TC’d at this point, the EFC center point should be pretty good. After that, things like phase noise and ADEV would be on the list. Same thing, run them all and see what they do. Make some decisions and toss out the outliers. So, yes it can be done. Because of the tear down process early on and the data redundancy needed, you have to get a pretty good sized group of units. The risk is that you get a group of parts with a common (to that batch) defect. They *were* headed to the garbage dump and went to eBay instead …. Lots of Fun Bob > On Oct 28, 2016, at 4:09 PM, Bob Stewart wrote: > > Hi Bob, > Can't the OCXOs be characterized pretty closely by someone with the right > tools and staff? I don't have a big sample to speak from, but the Trimbles I > use only have a couple of ceramic coated pieces, and those can be exposed > down to the die by hand and then characterized, can't they? Granted, that's > beyond my capabilities, but given the right tools and employees... > > Bob > > From: Bob Camp > To: pe...@reilley.com; Discussion of precise time and frequency measurement > > Sent: Friday, October 28, 2016 2:46 PM > Subject: Re: [time-nuts] Opening an Isotemp OCXO > > Hi > > Roughly 99.9% of all OCXO’s made go to large OEM customers. The percentage may > actually be a bit higher than that. There are relatively few markets that > “catalog” OCXO’s > sell into. > > Inevitably the first thing that an OEM wants is some form of customization. A > specific > supply voltage, a certain output format, a wider (or narrower) EFC range … > there > are lots of possibilities. For every OCXO that goes into production for these > guys, > five or ten other designs are done (all equally custom) that never see the > light of day > past the samples. > > The spec’s that these parts are built to are negotiated between the supplier > and the OEM. > In some cases they are the property of the OEM and the spec is their control > drawing on > the part. In other cases the drawing is done by the supplier for that OEM and > is property > of the supplier. > > The OEM often has competitors. They would *love* to get access to the OEM’s > control > drawings to see how the systems are designed. The supplier has competitors. > They > would love to get access to the suppliers drawings so they can make cheap > knock off > parts to those drawings. In both cases, the drawings (in general) have very > real value. > > The net result of this is that both suppliers and OEM’s put fairly fancy > rules in place about > passing out drawings. More or less anything up to and including being boiled > in oil is > (if legal in the jurisdiction) fair recourse under most of these rules. > Needless to say > people learn pretty quick that you get fired for this sor
Re: [time-nuts] Opening an Isotemp OCXO
I do not think the designer was considering noise at all because tying the inputs together would not do anything useful. Emitter resistance is inversely proportional to emitter current (26/mA) but putting them in parallel lowers the current through each emitter so the total emitter resistance stays the same. Supply current is separate for each TTL gate so by using a single 8-input part, total power it is about half that of a dual 4-input part and a quarter of a quad 2-input part depending on the exact operating conditions. Unused *outputs* should be high for lowest power. 74S30 Single 8-Input 5mA 10mA 74S20 Dual 4-Input 8mA 18mA 74S00 Quad 2-Input 16mA 36mA One clever design I ran across used the 7420 dual 4-input NAND pinout but wired the inputs which are pin compatible so the 7400 quad 2-input pinout would also work. This allows using a 74x00, 74x20, or 74S120 dual 4-input NAND buffer but it draws even more power. 74S120 Dual 4-Input 18mA 44mA On Fri, 28 Oct 2016 13:31:38 -0400, you wrote: >I wounder if originally the designer was hoping to use all 8 wire or'd >inputs to lower the input referred noise during midscale transition. Then >backed out later for some reason. > >On Fri, Oct 28, 2016 at 1:03 PM, Scott Stobbe >wrote: > >> Could also be a quirk about the 74S30 that gives it better phase noise >> over a basic buffer. >> >> >> On Friday, 28 October 2016, jimlux wrote: >> >>> On 10/28/16 9:13 AM, Scott Stobbe wrote: >>> The OCXO82-59 datasheet lists 12V supply, 5V clock out, could also be a blown regulator in your ocxo, if it is indeed a 12v model. There you go..the design could use a 74S30 as a driver - it's fast, >>> fairly good drive, but runs off 5V. If the regulator is shorted, and you >>> put 12V on it, it will cook. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Opening an Isotemp OCXO
>From experience, I can tell you that you can't always depend on the seller >when it comes to how to feed your new OCXO. For instance, the seller of the >Trimble 65256 insisted that it took 12V. So, that's what I used, and all the >magic smoke came tumbling out. Bob From: Peter Reilley To: Discussion of precise time and frequency measurement Sent: Friday, October 28, 2016 2:10 PM Subject: Re: [time-nuts] Opening an Isotemp OCXO The reason that there was 12 volts on the unit was because I put it there. I should have tried 5 volts first but the only datasheet that I could find said 12 volts. All the eBay units that look the same say 12 volts. Pete. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Opening an Isotemp OCXO
It looks like that is the only device that could be damaged by 12 volts. Can you find a replacement and try running at 5 volts? - Original Message - From: "Peter Reilley" To: "Discussion of precise time and frequency measurement" Sent: Friday, October 28, 2016 3:10 PM Subject: Re: [time-nuts] Opening an Isotemp OCXO The reason that there was 12 volts on the unit was because I put it there. I should have tried 5 volts first but the only datasheet that I could find said 12 volts. All the eBay units that look the same say 12 volts. Pete. On 10/28/2016 12:53 PM, paul swed wrote: I confirmed the pin out matches a 74s30 also. An S30 is TTL. Great pix to look at. So 12 V on a 5 V chip is indeed a smoker. Find out why there was 12 V. OK crazy talk I see a 1K resistor next to the VCC chip. Would anyone be crazy enough to use a dropping resistor from 12 V to get 5?? Really bad engineering and I don't actually believe they would. But if true a open 74s30 would indeed show 12 V on pin 14. Good luck. Paul WB8TSL On Fri, Oct 28, 2016 at 12:48 PM, jimlux wrote: On 10/28/16 9:13 AM, Scott Stobbe wrote: The OCXO82-59 datasheet lists 12V supply, 5V clock out, could also be a blown regulator in your ocxo, if it is indeed a 12v model. There you go..the design could use a 74S30 as a driver - it's fast, fairly good drive, but runs off 5V. If the regulator is shorted, and you put 12V on it, it will cook. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/m ailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Opening an Isotemp OCXO
Hi Bob, Can't the OCXOs be characterized pretty closely by someone with the right tools and staff? I don't have a big sample to speak from, but the Trimbles I use only have a couple of ceramic coated pieces, and those can be exposed down to the die by hand and then characterized, can't they? Granted, that's beyond my capabilities, but given the right tools and employees... Bob From: Bob Camp To: pe...@reilley.com; Discussion of precise time and frequency measurement Sent: Friday, October 28, 2016 2:46 PM Subject: Re: [time-nuts] Opening an Isotemp OCXO Hi Roughly 99.9% of all OCXO’s made go to large OEM customers. The percentage may actually be a bit higher than that. There are relatively few markets that “catalog” OCXO’s sell into. Inevitably the first thing that an OEM wants is some form of customization. A specific supply voltage, a certain output format, a wider (or narrower) EFC range … there are lots of possibilities. For every OCXO that goes into production for these guys, five or ten other designs are done (all equally custom) that never see the light of day past the samples. The spec’s that these parts are built to are negotiated between the supplier and the OEM. In some cases they are the property of the OEM and the spec is their control drawing on the part. In other cases the drawing is done by the supplier for that OEM and is property of the supplier. The OEM often has competitors. They would *love* to get access to the OEM’s control drawings to see how the systems are designed. The supplier has competitors. They would love to get access to the suppliers drawings so they can make cheap knock off parts to those drawings. In both cases, the drawings (in general) have very real value. The net result of this is that both suppliers and OEM’s put fairly fancy rules in place about passing out drawings. More or less anything up to and including being boiled in oil is (if legal in the jurisdiction) fair recourse under most of these rules. Needless to say people learn pretty quick that you get fired for this sort of thing. The net result is that the drawings for most OCXO’s simply do not exist in the public domain. They do (or did) exist in some form somewhere. Getting at public copies of them is highly unlikely. Going by “similar looking” drawings is not a real good idea …. Bob ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Opening an Isotemp OCXO
Man O man I am loosing track here. The s30 makes it a ttl part. So 12 V would have smoked it. Seems like an easy fix for that piece at least. Regards Paul WB8TSL On Fri, Oct 28, 2016 at 3:28 PM, Peter Reilley wrote: > That seems the most reasonable thing to do. > > Pete > > > On 10/28/2016 3:20 PM, Tom Miller wrote: > >> It looks like that is the only device that could be damaged by 12 volts. >> Can you find a replacement and try running at 5 volts? >> >> >> - Original Message - From: "Peter Reilley" < >> preilley_...@comcast.net> >> To: "Discussion of precise time and frequency measurement" < >> time-nuts@febo.com> >> Sent: Friday, October 28, 2016 3:10 PM >> Subject: Re: [time-nuts] Opening an Isotemp OCXO >> >> >> The reason that there was 12 volts on the unit was because I put it >>> there. I should >>> have tried 5 volts first but the only datasheet that I could find said >>> 12 volts. >>> All the eBay units that look the same say 12 volts. >>> >>> Pete. >>> >>> On 10/28/2016 12:53 PM, paul swed wrote: >>> >>>> I confirmed the pin out matches a 74s30 also. An S30 is TTL. Great pix >>>> to >>>> look at. >>>> So 12 V on a 5 V chip is indeed a smoker. Find out why there was 12 V. >>>> OK crazy talk I see a 1K resistor next to the VCC chip. Would anyone be >>>> crazy enough to use a dropping resistor from 12 V to get 5?? Really bad >>>> engineering and I don't actually believe they would. But if true a open >>>> 74s30 would indeed show 12 V on pin 14. >>>> Good luck. >>>> Paul >>>> WB8TSL >>>> >>>> On Fri, Oct 28, 2016 at 12:48 PM, jimlux wrote: >>>> >>>> On 10/28/16 9:13 AM, Scott Stobbe wrote: >>>>> >>>>> The OCXO82-59 datasheet lists 12V supply, 5V clock out, could also be a >>>>>> blown regulator in your ocxo, if it is indeed a 12v model. >>>>>> >>>>>> There you go..the design could use a 74S30 as a driver - it's fast, >>>>>> >>>>> fairly good drive, but runs off 5V. If the regulator is shorted, and >>>>> you >>>>> put 12V on it, it will cook. >>>>> >>>>> >>>>> ___ >>>>> time-nuts mailing list -- time-nuts@febo.com >>>>> To unsubscribe, go to https://www.febo.com/cgi-bin/m >>>>> ailman/listinfo/time-nuts >>>>> and follow the instructions there. >>>>> >>>>> ___ >>>> time-nuts mailing list -- time-nuts@febo.com >>>> To unsubscribe, go to https://www.febo.com/cgi-bin/m >>>> ailman/listinfo/time-nuts >>>> and follow the instructions there. >>>> >>>> >>> ___ >>> time-nuts mailing list -- time-nuts@febo.com >>> To unsubscribe, go to https://www.febo.com/cgi-bin/m >>> ailman/listinfo/time-nuts >>> and follow the instructions there. >>> >> >> >> > ___ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/m > ailman/listinfo/time-nuts > and follow the instructions there. > ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Opening an Isotemp OCXO
Hi Roughly 99.9% of all OCXO’s made go to large OEM customers. The percentage may actually be a bit higher than that. There are relatively few markets that “catalog” OCXO’s sell into. Inevitably the first thing that an OEM wants is some form of customization. A specific supply voltage, a certain output format, a wider (or narrower) EFC range … there are lots of possibilities. For every OCXO that goes into production for these guys, five or ten other designs are done (all equally custom) that never see the light of day past the samples. The spec’s that these parts are built to are negotiated between the supplier and the OEM. In some cases they are the property of the OEM and the spec is their control drawing on the part. In other cases the drawing is done by the supplier for that OEM and is property of the supplier. The OEM often has competitors. They would *love* to get access to the OEM’s control drawings to see how the systems are designed. The supplier has competitors. They would love to get access to the suppliers drawings so they can make cheap knock off parts to those drawings. In both cases, the drawings (in general) have very real value. The net result of this is that both suppliers and OEM’s put fairly fancy rules in place about passing out drawings. More or less anything up to and including being boiled in oil is (if legal in the jurisdiction) fair recourse under most of these rules. Needless to say people learn pretty quick that you get fired for this sort of thing. The net result is that the drawings for most OCXO’s simply do not exist in the public domain. They do (or did) exist in some form somewhere. Getting at public copies of them is highly unlikely. Going by “similar looking” drawings is not a real good idea …. Bob > On Oct 28, 2016, at 3:14 PM, Peter Reilley wrote: > > I don't know, I looked for a name and could not find one. > Sometimes there is no substitute for a big block of copper when soldering. > I pick them up at flea markets, no one wants them. I have a few. > > Pete. > > On 10/28/2016 12:27 PM, Adrian Godwin wrote: >> That's one sweet soldering iron. Is it an American Beauty ? >> >> > > ___ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Opening an Isotemp OCXO
That seems the most reasonable thing to do. Pete On 10/28/2016 3:20 PM, Tom Miller wrote: It looks like that is the only device that could be damaged by 12 volts. Can you find a replacement and try running at 5 volts? - Original Message - From: "Peter Reilley" To: "Discussion of precise time and frequency measurement" Sent: Friday, October 28, 2016 3:10 PM Subject: Re: [time-nuts] Opening an Isotemp OCXO The reason that there was 12 volts on the unit was because I put it there. I should have tried 5 volts first but the only datasheet that I could find said 12 volts. All the eBay units that look the same say 12 volts. Pete. On 10/28/2016 12:53 PM, paul swed wrote: I confirmed the pin out matches a 74s30 also. An S30 is TTL. Great pix to look at. So 12 V on a 5 V chip is indeed a smoker. Find out why there was 12 V. OK crazy talk I see a 1K resistor next to the VCC chip. Would anyone be crazy enough to use a dropping resistor from 12 V to get 5?? Really bad engineering and I don't actually believe they would. But if true a open 74s30 would indeed show 12 V on pin 14. Good luck. Paul WB8TSL On Fri, Oct 28, 2016 at 12:48 PM, jimlux wrote: On 10/28/16 9:13 AM, Scott Stobbe wrote: The OCXO82-59 datasheet lists 12V supply, 5V clock out, could also be a blown regulator in your ocxo, if it is indeed a 12v model. There you go..the design could use a 74S30 as a driver - it's fast, fairly good drive, but runs off 5V. If the regulator is shorted, and you put 12V on it, it will cook. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/m ailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Opening an Isotemp OCXO
The data sheet for the device only mentions 12V. Other data sheets (eg the 131) mention 5V and 12V, but don't indicate how to specify one or the other. Gerry Sweeny's article at http://gerrysweeney.com/diy-hpagilent-53131a-010-high-stability-timebase-option/ mentions a part number suffix that distinguishes two choices but this doesn't appear in the main datasheet. Other writers here have in the past mentioned that the suffix has no predefined meaning and is used only to distinguish design variants internally. It appears that Isotemp do offer a choice of voltage options but don't like to document it publicly. Tom Miller's strategy seems the safest if using a surplus device. On Fri, Oct 28, 2016 at 8:10 PM, Peter Reilley wrote: > The reason that there was 12 volts on the unit was because I put it > there. I should > have tried 5 volts first but the only datasheet that I could find said 12 > volts. > All the eBay units that look the same say 12 volts. > > Pete. > > > On 10/28/2016 12:53 PM, paul swed wrote: > >> I confirmed the pin out matches a 74s30 also. An S30 is TTL. Great pix to >> look at. >> So 12 V on a 5 V chip is indeed a smoker. Find out why there was 12 V. >> OK crazy talk I see a 1K resistor next to the VCC chip. Would anyone be >> crazy enough to use a dropping resistor from 12 V to get 5?? Really bad >> engineering and I don't actually believe they would. But if true a open >> 74s30 would indeed show 12 V on pin 14. >> Good luck. >> Paul >> WB8TSL >> >> On Fri, Oct 28, 2016 at 12:48 PM, jimlux wrote: >> >> On 10/28/16 9:13 AM, Scott Stobbe wrote: >>> >>> The OCXO82-59 datasheet lists 12V supply, 5V clock out, could also be a blown regulator in your ocxo, if it is indeed a 12v model. There you go..the design could use a 74S30 as a driver - it's fast, >>> fairly good drive, but runs off 5V. If the regulator is shorted, and you >>> put 12V on it, it will cook. >>> >>> >>> ___ >>> time-nuts mailing list -- time-nuts@febo.com >>> To unsubscribe, go to https://www.febo.com/cgi-bin/m >>> ailman/listinfo/time-nuts >>> and follow the instructions there. >>> >>> ___ >> time-nuts mailing list -- time-nuts@febo.com >> To unsubscribe, go to https://www.febo.com/cgi-bin/m >> ailman/listinfo/time-nuts >> and follow the instructions there. >> >> > ___ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/m > ailman/listinfo/time-nuts > and follow the instructions there. > ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Opening an Isotemp OCXO
I don't know, I looked for a name and could not find one. Sometimes there is no substitute for a big block of copper when soldering. I pick them up at flea markets, no one wants them. I have a few. Pete. On 10/28/2016 12:27 PM, Adrian Godwin wrote: That's one sweet soldering iron. Is it an American Beauty ? ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Opening an Isotemp OCXO
The reason that there was 12 volts on the unit was because I put it there. I should have tried 5 volts first but the only datasheet that I could find said 12 volts. All the eBay units that look the same say 12 volts. Pete. On 10/28/2016 12:53 PM, paul swed wrote: I confirmed the pin out matches a 74s30 also. An S30 is TTL. Great pix to look at. So 12 V on a 5 V chip is indeed a smoker. Find out why there was 12 V. OK crazy talk I see a 1K resistor next to the VCC chip. Would anyone be crazy enough to use a dropping resistor from 12 V to get 5?? Really bad engineering and I don't actually believe they would. But if true a open 74s30 would indeed show 12 V on pin 14. Good luck. Paul WB8TSL On Fri, Oct 28, 2016 at 12:48 PM, jimlux wrote: On 10/28/16 9:13 AM, Scott Stobbe wrote: The OCXO82-59 datasheet lists 12V supply, 5V clock out, could also be a blown regulator in your ocxo, if it is indeed a 12v model. There you go..the design could use a 74S30 as a driver - it's fast, fairly good drive, but runs off 5V. If the regulator is shorted, and you put 12V on it, it will cook. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/m ailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Opening an Isotemp OCXO
There is no regulator in the unit. The power pin is connected directly to the S30 chip. Pete. On 10/28/2016 1:31 PM, J. L. Trantham wrote: Have you measured the voltage on the 'power' pin for the chip with 12 V applied to the OCXO (or 5 V applied)? Is there a 5 V regulator on the board? Joe -Original Message- From: Peter Reilley [mailto:preilley_...@comcast.net] Sent: Friday, October 28, 2016 9:11 AM To: J. L. Trantham Subject: Re: [time-nuts] Opening an Isotemp OCXO Thanks for the link. I did not find any S30 chips that would run off 12 volts. Could the whole OCXO be a 5 volt unit? Pete. On 10/28/2016 9:53 AM, J. L. Trantham wrote: Peter, Thanks for the update. No time to spend right now but I found this by googling 'TI S30 SOIC chip' http://www.ti.com/packaging/docs/partlookup.tsp#divline Hope it helps. Joe -Original Message- From: Peter Reilley [mailto:preilley_...@comcast.net] Sent: Friday, October 28, 2016 8:24 AM To: J. L. Trantham Subject: Re: [time-nuts] Opening an Isotemp OCXO I did finally get it open. I used a very large old style soldering iron and .003 inch steel shim stock. I would melt the solder on the straight seams and insert small pieces of the shim. Solder does not stick well to steel so the shim kept the soldered seam open. I used a soldering iron rather than a torch because I can control the temperature. I could not use the shim at the corners. After all the straight seams were separated I could pull each corner using a screw in the mounting hole and melt the solder at the corner. Slowly working my way around, corner by corner, I got it opened. I did not damage anything so I should be able to close it up after I fix it. Looking around with my scope it seems that the output driver chip is bad as I expected. It is a TI 14 pin surface mount DIP. It says S30 on it which if it is a 74S30 it is an 8 input positive NAND gate. The board layout confirms this as the 10 MHz signal is connected to pin 2 and all other inputs are tied high. Pin 8 is connected to the output. The chip is run off 12 volts so it must be CMOS. But I cannot find any chip like that that will run off 12 volts. Any suggestions for a replacement? Also, using an 8 input NAND chip for a driver seems an odd choice. When I put 12 volts on the unit the S30 chip gets really hot. After I removed the chip the unit seems to work OK. The current jumps between about .1 amp to .9 amps. It seems like the temperature regulator is an on/off type controller. The device on eBay, item 261920574725, looks exactly like what I have. I have placed a bunch of pictures in my dropbox. https://www.dropbox.com/sh/52e9d1rva9kpb3w/AABmbIj1aK7Zk2J9SNMmu-JAa?d l=0 Pete. On 10/18/2016 10:57 AM, J. L. Trantham wrote: Pete, I'm not familiar with your OCXO but I found one shown on 'theBay' (item 261920574725) and it appeared to have an option for 'mounting screws', four of them, on the bottom. Interestingly, the 'link' to the datasheet for that unit did not show threads for mounting screws. If your unit has that option, I would suggest placing four long screws, mounting the item in a vise, use a small torch (I've used a hand held propane torch turned down very low to open a number of units from 5061A's) around the bottom of the case while gripping the top with an appropriate sized Channel Lock plier and lifting off the top. If you can repair the OCXO, it should be easy to reassemble the unit with solder. TheBay unit looks like it has a screw cover (which likely has a rubber gasket) for mechanical adjustment of the frequency. I'd remove that before applying the torch. :^). If you get it open, I'd love to see some pictures of the insides. Good luck and hope this helps. Joe -Original Message- From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Peter Reilley Sent: Tuesday, October 18, 2016 8:11 AM To: time-nuts@febo.com Subject: [time-nuts] Opening an Isotemp OCXO I bought an Isotemp OCXO82-59 with a frequency of 10 MHz for a $3 at the MIT flea market. As expected it was dead. It heats up as expected but looking at the output with a scope there is nothing. However looking at the output with a spectrum analyzer I can see a faint 10 MHz signal. It seems that the oscillator is running but the output circuitry is dead. Reasonable assumption? Anyway, has anyone had any luck unsoldering the tin case without destroying it? Pete. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Opening an Isotemp OCXO
There is no regulator chip in the unit. I am thinking that this must be a 5 volt unit. Pete. On 10/28/2016 12:42 PM, Dan Rae wrote: On 10/28/2016 9:09 AM, Peter Reilley wrote: The only document that I could find said 12 volt. Pete. The 82 series came in a lot of flavors. I have one 82-49 which is definitely 12V ( draws 0.12A when warm and maybe 0.3 when cold) and has a 5V pp square wave output at 10 MHz. It also has a Vref output and an EFC input. What is odd about this one is that it came to me from a TRW swap meet scrap dealer who bought stuff from Cubic Communications in San Diego and it had a "Reject" tag from them. Probably because it was supposed to be a 5 MHz unit as marked, so presumably had the wrong crystal fitted by Isotemp. Other versions of the 82 series (-10) were fitted to Racal Receivers like the RA6790/GM. Screw adjustment on the side and 5 MHz output. Are you sure yours shouldn't have a 5V supply on that output IC? Could be why it died if there is an internal regulator that failed putting the full supply voltage on the IC? Dan ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Opening an Isotemp OCXO
When I have an unknown OCXO, I put a scope on the output and connect a bench power supply to the DC inputs. I bring up the voltage until the RF out hits a stable level. That is where the internal regulator starts regulating. Then set it to the nearest normal power supply voltage, +5, +12, +15, +24, +28 volts. Some OCXOs will have separate inputs for the oscillator and the oven. Example- an HP OCXO has a +15 regulated input that is switched for the oscillator and a +24 volt input for the oven that is on always. I usually try the same voltage as the oscillator first and watch the current as the oven warms up. If it takes too long to heat up, try a little higher voltage. Some units have a separate ground return for the oscillator and oven so you need to watch that. Good luck and thanks for the report. Regards, Tom - Original Message - From: "Peter Reilley" To: "Discussion of precise time and frequency measurement" Sent: Friday, October 28, 2016 12:09 PM Subject: Re: [time-nuts] Opening an Isotemp OCXO The only document that I could find said 12 volt. Pete. On 10/28/2016 11:49 AM, Poul-Henning Kamp wrote: In message <10a3ea7d-37f0-51bc-2470-35645d767...@comcast.net>, Peter Reilley writes: The chip is run off 12 volts so it must be CMOS. Or the OCXO is not a 12V model ? ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Opening an Isotemp OCXO
I wounder if originally the designer was hoping to use all 8 wire or'd inputs to lower the input referred noise during midscale transition. Then backed out later for some reason. On Fri, Oct 28, 2016 at 1:03 PM, Scott Stobbe wrote: > Could also be a quirk about the 74S30 that gives it better phase noise > over a basic buffer. > > > On Friday, 28 October 2016, jimlux wrote: > >> On 10/28/16 9:13 AM, Scott Stobbe wrote: >> >>> The OCXO82-59 datasheet lists 12V supply, 5V clock out, could also be a >>> blown regulator in your ocxo, if it is indeed a 12v model. >>> >>> There you go..the design could use a 74S30 as a driver - it's fast, >> fairly good drive, but runs off 5V. If the regulator is shorted, and you >> put 12V on it, it will cook. >> >> ___ >> time-nuts mailing list -- time-nuts@febo.com >> To unsubscribe, go to https://www.febo.com/cgi-bin/m >> ailman/listinfo/time-nuts >> and follow the instructions there. >> > ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Opening an Isotemp OCXO
The 1k resistor doesn't seem to feed the 'S30'. It looks as though pin 14 (Vcc) goes via that thick track to the +12 input. On Fri, Oct 28, 2016 at 5:46 PM, jimlux wrote: > On 10/28/16 8:31 AM, Peter Reilley wrote: > > Looking around with my scope it seems that the output driver chip is bad >> as I expected. It is a TI 14 pin surface mount DIP. It says S30 on it >> which if it is a 74S30 it is an 8 input positive NAND gate. The board >> layout confirms this as the 10 MHz signal is connected to pin 2 and all >> other inputs are tied high. Pin 8 is connected to the output. >> >> The chip is run off 12 volts so it must be CMOS. But I cannot find any >> chip like that that will run off 12 volts. Any suggestions for a >> replacement? >> >> Also, using an 8 input NAND chip for a driver seems an odd choice. >> >> > could it be some sort of 74C series? if it's intended to run off 12V, a > lot of the CMOS parts can run at almost any Vdd (a virtue of 4000 series > CMOS - 15V power, no problem) > > Maybe they got a good price on the 8 input NAND parts? > > If unused pins are tied high, it's unlikely that they are outputs - most > parts are either a totem pole or open collector output, neither one of > which would like being tied high. > > > > > ___ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/m > ailman/listinfo/time-nuts > and follow the instructions there. > ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Opening an Isotemp OCXO
Could also be a quirk about the 74S30 that gives it better phase noise over a basic buffer. On Friday, 28 October 2016, jimlux wrote: > On 10/28/16 9:13 AM, Scott Stobbe wrote: > >> The OCXO82-59 datasheet lists 12V supply, 5V clock out, could also be a >> blown regulator in your ocxo, if it is indeed a 12v model. >> >> There you go..the design could use a 74S30 as a driver - it's fast, > fairly good drive, but runs off 5V. If the regulator is shorted, and you > put 12V on it, it will cook. > > ___ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/m > ailman/listinfo/time-nuts > and follow the instructions there. > ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Opening an Isotemp OCXO
On 10/28/16 8:31 AM, Peter Reilley wrote: Looking around with my scope it seems that the output driver chip is bad as I expected. It is a TI 14 pin surface mount DIP. It says S30 on it which if it is a 74S30 it is an 8 input positive NAND gate. The board layout confirms this as the 10 MHz signal is connected to pin 2 and all other inputs are tied high. Pin 8 is connected to the output. The chip is run off 12 volts so it must be CMOS. But I cannot find any chip like that that will run off 12 volts. Any suggestions for a replacement? Also, using an 8 input NAND chip for a driver seems an odd choice. could it be some sort of 74C series? if it's intended to run off 12V, a lot of the CMOS parts can run at almost any Vdd (a virtue of 4000 series CMOS - 15V power, no problem) Maybe they got a good price on the 8 input NAND parts? If unused pins are tied high, it's unlikely that they are outputs - most parts are either a totem pole or open collector output, neither one of which would like being tied high. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Opening an Isotemp OCXO
I confirmed the pin out matches a 74s30 also. An S30 is TTL. Great pix to look at. So 12 V on a 5 V chip is indeed a smoker. Find out why there was 12 V. OK crazy talk I see a 1K resistor next to the VCC chip. Would anyone be crazy enough to use a dropping resistor from 12 V to get 5?? Really bad engineering and I don't actually believe they would. But if true a open 74s30 would indeed show 12 V on pin 14. Good luck. Paul WB8TSL On Fri, Oct 28, 2016 at 12:48 PM, jimlux wrote: > On 10/28/16 9:13 AM, Scott Stobbe wrote: > >> The OCXO82-59 datasheet lists 12V supply, 5V clock out, could also be a >> blown regulator in your ocxo, if it is indeed a 12v model. >> >> There you go..the design could use a 74S30 as a driver - it's fast, > fairly good drive, but runs off 5V. If the regulator is shorted, and you > put 12V on it, it will cook. > > > ___ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/m > ailman/listinfo/time-nuts > and follow the instructions there. > ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Opening an Isotemp OCXO
On 10/28/16 9:13 AM, Scott Stobbe wrote: The OCXO82-59 datasheet lists 12V supply, 5V clock out, could also be a blown regulator in your ocxo, if it is indeed a 12v model. There you go..the design could use a 74S30 as a driver - it's fast, fairly good drive, but runs off 5V. If the regulator is shorted, and you put 12V on it, it will cook. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Opening an Isotemp OCXO
On 10/28/2016 9:09 AM, Peter Reilley wrote: The only document that I could find said 12 volt. Pete. The 82 series came in a lot of flavors. I have one 82-49 which is definitely 12V ( draws 0.12A when warm and maybe 0.3 when cold) and has a 5V pp square wave output at 10 MHz. It also has a Vref output and an EFC input. What is odd about this one is that it came to me from a TRW swap meet scrap dealer who bought stuff from Cubic Communications in San Diego and it had a "Reject" tag from them. Probably because it was supposed to be a 5 MHz unit as marked, so presumably had the wrong crystal fitted by Isotemp. Other versions of the 82 series (-10) were fitted to Racal Receivers like the RA6790/GM. Screw adjustment on the side and 5 MHz output. Are you sure yours shouldn't have a 5V supply on that output IC? Could be why it died if there is an internal regulator that failed putting the full supply voltage on the IC? Dan ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Opening an Isotemp OCXO
Here is the TI document on "Case Marking." It may not be a 74S30. http://www.ti.com/lit/an/snoa039c/snoa039c.pdf --- Graham == On Fri, Oct 28, 2016 at 11:27 AM, Adrian Godwin wrote: > That's one sweet soldering iron. Is it an American Beauty ? > > > On Fri, Oct 28, 2016 at 4:31 PM, Peter Reilley > wrote: > > > I did finally get it open. I used a very large old style soldering > > iron and .003 inch steel shim stock. I would melt the solder on the > > straight seams and insert small pieces of the shim. Solder does not > > stick well to steel so the shim kept the soldered seam open. > > I used a soldering iron rather than a torch because I can control the > > temperature. > > > > I could not use the shim at the corners. After all the straight seams > > were separated I could pull each corner using a screw in the mounting > > hole and melt the solder at the corner. Slowly working my way around, > > corner by corner, I got it opened. I did not damage anything so I > > should be able to close it up after I fix it. > > > > Looking around with my scope it seems that the output driver chip is bad > > as I expected. It is a TI 14 pin surface mount DIP. It says S30 on it > > which if it is a 74S30 it is an 8 input positive NAND gate. The board > > layout confirms this as the 10 MHz signal is connected to pin 2 and all > > other inputs are tied high. Pin 8 is connected to the output. > > > > The chip is run off 12 volts so it must be CMOS. But I cannot find any > > chip like that that will run off 12 volts. Any suggestions for a > > replacement? > > > > Also, using an 8 input NAND chip for a driver seems an odd choice. > > > > When I put 12 volts on the unit the S30 chip gets really hot. After I > > removed the chip the unit seems to work OK. The current jumps between > > about .1 amp to .9 amps. It seems like the temperature regulator is > > an on/off type controller. > > > > The device on eBay, item 261920574725, looks exactly like what I have. > > > > I have placed a bunch of pictures in my dropbox. > > https://www.dropbox.com/sh/52e9d1rva9kpb3w/ > AABmbIj1aK7Zk2J9SNMmu-JAa?dl=0 > > > > Pete. > > > > > > > > > > On 10/18/2016 10:57 AM, J. L. Trantham wrote: > > > >> Pete, > >> > >> I'm not familiar with your OCXO but I found one shown on 'theBay' (item > >> 261920574725) and it appeared to have an option for 'mounting screws', > four > >> of them, on the bottom. Interestingly, the 'link' to the datasheet for > >> that unit did not show threads for mounting screws. > >> > >> If your unit has that option, I would suggest placing four long screws, > >> mounting the item in a vise, use a small torch (I've used a hand held > >> propane torch turned down very low to open a number of units from > 5061A's) > >> around the bottom of the case while gripping the top with an appropriate > >> sized Channel Lock plier and lifting off the top. > >> > >> If you can repair the OCXO, it should be easy to reassemble the unit > with > >> solder. > >> > >> TheBay unit looks like it has a screw cover (which likely has a rubber > >> gasket) for mechanical adjustment of the frequency. I'd remove that > before > >> applying the torch. :^). > >> > >> If you get it open, I'd love to see some pictures of the insides. > >> > >> Good luck and hope this helps. > >> > >> Joe > >> > >> > >> > >> -Original Message- > >> From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Peter > >> Reilley > >> Sent: Tuesday, October 18, 2016 8:11 AM > >> To: time-nuts@febo.com > >> Subject: [time-nuts] Opening an Isotemp OCXO > >> > >> I bought an Isotemp OCXO82-59 with a frequency of 10 MHz for a $3 at the > >> MIT flea market. > >> As expected it was dead. It heats up as expected but looking at the > >> output with a scope there > >> is nothing. However looking at the output with a spectrum analyzer I > >> can see a faint 10 MHz > >> signal. It seems that the oscillator is running but the output > >> circuitry is dead. Reasonable > >> assumption? > >> > >> Anyway, has anyone had any luck unsoldering the tin case without > >> destroying it? > >> > >> Pete. > >> > >> ___
Re: [time-nuts] Opening an Isotemp OCXO
That's one sweet soldering iron. Is it an American Beauty ? On Fri, Oct 28, 2016 at 4:31 PM, Peter Reilley wrote: > I did finally get it open. I used a very large old style soldering > iron and .003 inch steel shim stock. I would melt the solder on the > straight seams and insert small pieces of the shim. Solder does not > stick well to steel so the shim kept the soldered seam open. > I used a soldering iron rather than a torch because I can control the > temperature. > > I could not use the shim at the corners. After all the straight seams > were separated I could pull each corner using a screw in the mounting > hole and melt the solder at the corner. Slowly working my way around, > corner by corner, I got it opened. I did not damage anything so I > should be able to close it up after I fix it. > > Looking around with my scope it seems that the output driver chip is bad > as I expected. It is a TI 14 pin surface mount DIP. It says S30 on it > which if it is a 74S30 it is an 8 input positive NAND gate. The board > layout confirms this as the 10 MHz signal is connected to pin 2 and all > other inputs are tied high. Pin 8 is connected to the output. > > The chip is run off 12 volts so it must be CMOS. But I cannot find any > chip like that that will run off 12 volts. Any suggestions for a > replacement? > > Also, using an 8 input NAND chip for a driver seems an odd choice. > > When I put 12 volts on the unit the S30 chip gets really hot. After I > removed the chip the unit seems to work OK. The current jumps between > about .1 amp to .9 amps. It seems like the temperature regulator is > an on/off type controller. > > The device on eBay, item 261920574725, looks exactly like what I have. > > I have placed a bunch of pictures in my dropbox. > https://www.dropbox.com/sh/52e9d1rva9kpb3w/AABmbIj1aK7Zk2J9SNMmu-JAa?dl=0 > > Pete. > > > > > On 10/18/2016 10:57 AM, J. L. Trantham wrote: > >> Pete, >> >> I'm not familiar with your OCXO but I found one shown on 'theBay' (item >> 261920574725) and it appeared to have an option for 'mounting screws', four >> of them, on the bottom. Interestingly, the 'link' to the datasheet for >> that unit did not show threads for mounting screws. >> >> If your unit has that option, I would suggest placing four long screws, >> mounting the item in a vise, use a small torch (I've used a hand held >> propane torch turned down very low to open a number of units from 5061A's) >> around the bottom of the case while gripping the top with an appropriate >> sized Channel Lock plier and lifting off the top. >> >> If you can repair the OCXO, it should be easy to reassemble the unit with >> solder. >> >> TheBay unit looks like it has a screw cover (which likely has a rubber >> gasket) for mechanical adjustment of the frequency. I'd remove that before >> applying the torch. :^). >> >> If you get it open, I'd love to see some pictures of the insides. >> >> Good luck and hope this helps. >> >> Joe >> >> >> >> -Original Message- >> From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Peter >> Reilley >> Sent: Tuesday, October 18, 2016 8:11 AM >> To: time-nuts@febo.com >> Subject: [time-nuts] Opening an Isotemp OCXO >> >> I bought an Isotemp OCXO82-59 with a frequency of 10 MHz for a $3 at the >> MIT flea market. >> As expected it was dead. It heats up as expected but looking at the >> output with a scope there >> is nothing. However looking at the output with a spectrum analyzer I >> can see a faint 10 MHz >> signal. It seems that the oscillator is running but the output >> circuitry is dead. Reasonable >> assumption? >> >> Anyway, has anyone had any luck unsoldering the tin case without >> destroying it? >> >> Pete. >> >> ___ >> time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to >> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >> and follow the instructions there. >> >> >> > ___ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/m > ailman/listinfo/time-nuts > and follow the instructions there. > ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Opening an Isotemp OCXO
The OCXO82-59 datasheet lists 12V supply, 5V clock out, could also be a blown regulator in your ocxo, if it is indeed a 12v model. On Friday, 28 October 2016, Poul-Henning Kamp wrote: > > In message <10a3ea7d-37f0-51bc-2470-35645d767...@comcast.net > >, Peter Reilley writes: > > >The chip is run off 12 volts so it must be CMOS. > > Or the OCXO is not a 12V model ? > > > -- > Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 > p...@freebsd.org | TCP/IP since RFC 956 > FreeBSD committer | BSD since 4.3-tahoe > Never attribute to malice what can adequately be explained by incompetence. > ___ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/ > mailman/listinfo/time-nuts > and follow the instructions there. > ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Opening an Isotemp OCXO
The only document that I could find said 12 volt. Pete. On 10/28/2016 11:49 AM, Poul-Henning Kamp wrote: In message <10a3ea7d-37f0-51bc-2470-35645d767...@comcast.net>, Peter Reilley writes: The chip is run off 12 volts so it must be CMOS. Or the OCXO is not a 12V model ? ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Opening an Isotemp OCXO
In message <10a3ea7d-37f0-51bc-2470-35645d767...@comcast.net>, Peter Reilley writes: >The chip is run off 12 volts so it must be CMOS. Or the OCXO is not a 12V model ? -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Opening an Isotemp OCXO
I did finally get it open. I used a very large old style soldering iron and .003 inch steel shim stock. I would melt the solder on the straight seams and insert small pieces of the shim. Solder does not stick well to steel so the shim kept the soldered seam open. I used a soldering iron rather than a torch because I can control the temperature. I could not use the shim at the corners. After all the straight seams were separated I could pull each corner using a screw in the mounting hole and melt the solder at the corner. Slowly working my way around, corner by corner, I got it opened. I did not damage anything so I should be able to close it up after I fix it. Looking around with my scope it seems that the output driver chip is bad as I expected. It is a TI 14 pin surface mount DIP. It says S30 on it which if it is a 74S30 it is an 8 input positive NAND gate. The board layout confirms this as the 10 MHz signal is connected to pin 2 and all other inputs are tied high. Pin 8 is connected to the output. The chip is run off 12 volts so it must be CMOS. But I cannot find any chip like that that will run off 12 volts. Any suggestions for a replacement? Also, using an 8 input NAND chip for a driver seems an odd choice. When I put 12 volts on the unit the S30 chip gets really hot. After I removed the chip the unit seems to work OK. The current jumps between about .1 amp to .9 amps. It seems like the temperature regulator is an on/off type controller. The device on eBay, item 261920574725, looks exactly like what I have. I have placed a bunch of pictures in my dropbox. https://www.dropbox.com/sh/52e9d1rva9kpb3w/AABmbIj1aK7Zk2J9SNMmu-JAa?dl=0 Pete. On 10/18/2016 10:57 AM, J. L. Trantham wrote: Pete, I'm not familiar with your OCXO but I found one shown on 'theBay' (item 261920574725) and it appeared to have an option for 'mounting screws', four of them, on the bottom. Interestingly, the 'link' to the datasheet for that unit did not show threads for mounting screws. If your unit has that option, I would suggest placing four long screws, mounting the item in a vise, use a small torch (I've used a hand held propane torch turned down very low to open a number of units from 5061A's) around the bottom of the case while gripping the top with an appropriate sized Channel Lock plier and lifting off the top. If you can repair the OCXO, it should be easy to reassemble the unit with solder. TheBay unit looks like it has a screw cover (which likely has a rubber gasket) for mechanical adjustment of the frequency. I'd remove that before applying the torch. :^). If you get it open, I'd love to see some pictures of the insides. Good luck and hope this helps. Joe -Original Message- From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Peter Reilley Sent: Tuesday, October 18, 2016 8:11 AM To: time-nuts@febo.com Subject: [time-nuts] Opening an Isotemp OCXO I bought an Isotemp OCXO82-59 with a frequency of 10 MHz for a $3 at the MIT flea market. As expected it was dead. It heats up as expected but looking at the output with a scope there is nothing. However looking at the output with a spectrum analyzer I can see a faint 10 MHz signal. It seems that the oscillator is running but the output circuitry is dead. Reasonable assumption? Anyway, has anyone had any luck unsoldering the tin case without destroying it? Pete. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Opening an Isotemp OCXO
I got one open without too much much trouble with a propane torch. Work fast, use gravity and have something pointy to pry with as you go. -ch 73 de ai6kg On Oct 18, 2016 6:14 AM, "Peter Reilley" wrote: > I bought an Isotemp OCXO82-59 with a frequency of 10 MHz for a $3 at the > MIT flea market. > As expected it was dead. It heats up as expected but looking at the > output with a scope there > is nothing. However looking at the output with a spectrum analyzer I can > see a faint 10 MHz > signal. It seems that the oscillator is running but the output circuitry > is dead. Reasonable > assumption? > > Anyway, has anyone had any luck unsoldering the tin case without > destroying it? > > Pete. > > ___ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/m > ailman/listinfo/time-nuts > and follow the instructions there. > ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Opening an Isotemp OCXO
Pete, I'm not familiar with your OCXO but I found one shown on 'theBay' (item 261920574725) and it appeared to have an option for 'mounting screws', four of them, on the bottom. Interestingly, the 'link' to the datasheet for that unit did not show threads for mounting screws. If your unit has that option, I would suggest placing four long screws, mounting the item in a vise, use a small torch (I've used a hand held propane torch turned down very low to open a number of units from 5061A's) around the bottom of the case while gripping the top with an appropriate sized Channel Lock plier and lifting off the top. If you can repair the OCXO, it should be easy to reassemble the unit with solder. TheBay unit looks like it has a screw cover (which likely has a rubber gasket) for mechanical adjustment of the frequency. I'd remove that before applying the torch. :^). If you get it open, I'd love to see some pictures of the insides. Good luck and hope this helps. Joe -Original Message- From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Peter Reilley Sent: Tuesday, October 18, 2016 8:11 AM To: time-nuts@febo.com Subject: [time-nuts] Opening an Isotemp OCXO I bought an Isotemp OCXO82-59 with a frequency of 10 MHz for a $3 at the MIT flea market. As expected it was dead. It heats up as expected but looking at the output with a scope there is nothing. However looking at the output with a spectrum analyzer I can see a faint 10 MHz signal. It seems that the oscillator is running but the output circuitry is dead. Reasonable assumption? Anyway, has anyone had any luck unsoldering the tin case without destroying it? Pete. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Opening an Isotemp OCXO
Pete Another MIT-er. Well the only way I have handled them is with a small torch. Clamp the unit. Heat the solder and it will flow down to the low point and tend to drip out. Stick a small xacto knife in to break any remaining solder loose. Not super pretty but all of it can be cleaned up usually and then re-soldered. Hey its dead whats to loose? Regards Paul WB8TSL On Tue, Oct 18, 2016 at 9:11 AM, Peter Reilley wrote: > I bought an Isotemp OCXO82-59 with a frequency of 10 MHz for a $3 at the > MIT flea market. > As expected it was dead. It heats up as expected but looking at the > output with a scope there > is nothing. However looking at the output with a spectrum analyzer I can > see a faint 10 MHz > signal. It seems that the oscillator is running but the output circuitry > is dead. Reasonable > assumption? > > Anyway, has anyone had any luck unsoldering the tin case without > destroying it? > > Pete. > > ___ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/m > ailman/listinfo/time-nuts > and follow the instructions there. > ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
[time-nuts] Opening an Isotemp OCXO
I bought an Isotemp OCXO82-59 with a frequency of 10 MHz for a $3 at the MIT flea market. As expected it was dead. It heats up as expected but looking at the output with a scope there is nothing. However looking at the output with a spectrum analyzer I can see a faint 10 MHz signal. It seems that the oscillator is running but the output circuitry is dead. Reasonable assumption? Anyway, has anyone had any luck unsoldering the tin case without destroying it? Pete. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.