Re: [time-nuts] 5MHz ocxo- Opening Solder sealed cans
Paul Flinders wrote: On 28/07/2012 22:38, John Miles wrote: I can't guarantee anything, but I'd be surprised if Fluxclene didn't do the trick: http://www.electrolube.com/docs/cleaningmain.asp?id=13 Thanks I'll give it a try. Also try some naptha (sold as lighter fluid, or as a product called Goof-Off.) goof-off doesn't seem to be available easily in the UK - naptha might be worth a go. That said I did try a label removal solvent which I've found useful on other general gunk (the pro-power one) and that didn't touch it. Fluxclene is also excellent for removing glue residue left by labels, etc. Mike ___ 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] 5MHz ocxo- Opening Solder sealed cans
On 29/07/12 07:21, Mike Millen wrote: Fluxclene is also excellent for removing glue residue left by labels, etc. Yes, I saw your previous message and certainly plan to try it (might try some lighter fluid first). In fact was going to order it from link you posted until I hit the £12 postage fee - Farnell stock it at only fractionally above the Electrolube site - £16.80 vs £16.51 for the 1L size and also sell the smaller sizes in one off quantities. Postage is then free as long as I spend the £20 minimum order value - so once I've accumulated a few more bits to buy from them I'll get some. ___ 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] 5MHz ocxo- Opening Solder sealed cans
Paul Flinders wrote: On 29/07/12 07:21, Mike Millen wrote: Fluxclene is also excellent for removing glue residue left by labels, etc. Yes, I saw your previous message and certainly plan to try it (might try some lighter fluid first). In fact was going to order it from link you posted until I hit the £12 postage fee - Farnell stock it at only fractionally above the Electrolube site - £16.80 vs £16.51 for the 1L size and also sell the smaller sizes in one off quantities. Postage is then free as long as I spend the £20 minimum order value - so once I've accumulated a few more bits to buy from them I'll get some. Even if my hunch is wrong it doesn't dissolve the foam remains it won't be money wasted; I find it one of the most useful ( most used) items in the workshop cupboard. Mike ___ 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] 5MHz ocxo- Opening Solder sealed cans
Silver solder has a higher melting temperature so make sure you adjust your soldering iron to the right temperature otherwise you will just make another cold joint. Also wick all the old solder before making a new joint with different solder. Didier KO4BB Ron Ward n6idl...@comcast.net wrote: Hi: I have been looking at the poor quality solder joints on the oscillator. If you have a steady hand and a small tipped soldering with silver baring (about 2% silver) solder, I would re-solder the connections. Many of them do not look properly wetted and cold. Some of the heat from removing the top may have re-soldered a problem connection. Ron -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Paul Flinders Sent: Thursday, July 26, 2012 2:59 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] 5MHz ocxo- Opening Solder sealed cans On 26/07/12 20:49, Tom Miller wrote: Pick up a few sticks of ChipQuik and mix it in with a good iron. Then, you may do just what you say. It should melt below about 95°C. A good hot air heat gun would most likely do the trick. Maybe use some solder wick first to lower the amount of tin/lead solder. Then add the chipquik. You might also just solder a tab on the bottom then you could clamp the top in a leather jawed vise. Hit it with a hot air gun while pulling on the base tab. Well, a few exploratory attempts confirmed my initial suspicion that I don't have a soldering iron big enough for the job - the largest I have is 60W or so, and the hot air gun didn't touch it even set to 480deg C So, I reached for the next larger source of heat which is a small blowtorch I have, set a small flame and ran it round the whole seam then pulled the top off with a gloved hand. Things did get a bit warm but only for a short while. The first thing I encountered was some insulating foam - this was rather sticky. Not sure whether it had gone like that over time or due to my heating the whole thing a bit too much. On three sides the foam was separated from the case by what looks like some thin SRBP. This had blistered a bit so obviously things were a bit hot just there but the foam was much the same whether protected by the SRBP so I'm wondering whether this has just disintegrated over time. Pulling/washing the foam off reveals three PCBs and a further enclosed metal case with the crystal. A TIP21 bolted to this acts as the heating element. Originally there had been some cable ties anchoring the crystal enclosure but these were brittle - presumably from the heat of the oven. Hooking the unit up to 12V and an oscilloscope shows that it has survived the encounter with the blow torch and produces a nice 5MHz sine wave at 2.5V p-p (into 10Meg ohm). Irritatingly it doesn't really want to misbehave - presumably because whatever didn't like the heat is now cooler with the insulating foam removed. The inner metal case gets too hot to touch but the thermostat seems to be working because the current drawn drops from about 380mA to 240 or so. It should probably be lower but, again, without the usual amount of insulation it's likely to draw more keeping the oven up to temperature. So, as it doesn't want to misbehave, I'm not totally clear which way to go. The output does drop to about 1.8V p-p when the oven is fully warm which might be related to the original fault. I suppose the fact that the fault has gone away eliminates the oven assembly or crystal itself as the source of the problem. Photos for comments or curiosity. The black stuff all over the PCBs is the remains of the foam. http://www.wild-pc.co.uk/images/P1020364.jpg http://www.wild-pc.co.uk/images/P1020367.jpg http://www.wild-pc.co.uk/images/P1020368.jpg http://www.wild-pc.co.uk/images/P1020369.jpg http://www.wild-pc.co.uk/images/P1020370.jpg ___ 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. -- Sent from my Motorola Droid Razr phone with K-9 Mail. Please excuse my brevity. ___ 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] 5MHz ocxo- Opening Solder sealed cans
On 27/07/12 03:17, Tom Miller wrote: I agree with Ron. Clean the board up real good then do an inspection. Talking of which does anyone have any suggestions as to with what? I've tried IPA, ethanol, acetone and even some of the tiny amount of 1,1,1 trichloroethane I have left (yes, I know it's banned). Nothing so far has had much impact on the remains of the foam or the remains of the sticky tape (the yellow residue on some of the components in the photos). I'm running out of ideas as to what might clean it off without damaging the board. ___ 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] 5MHz ocxo- Opening Solder sealed cans
Paul Flinders wrote: On 27/07/12 03:17, Tom Miller wrote: I agree with Ron. Clean the board up real good then do an inspection. Talking of which does anyone have any suggestions as to with what? I've tried IPA, ethanol, acetone and even some of the tiny amount of 1,1,1 trichloroethane I have left (yes, I know it's banned). Nothing so far has had much impact on the remains of the foam or the remains of the sticky tape (the yellow residue on some of the components in the photos). I'm running out of ideas as to what might clean it off without damaging the board. I can't guarantee anything, but I'd be surprised if Fluxclene didn't do the trick: http://www.electrolube.com/docs/cleaningmain.asp?id=13 Mike ___ 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] 5MHz ocxo- Opening Solder sealed cans
On 28/07/12 21:13, Mike Millen wrote: Paul Flinders wrote: On 27/07/12 03:17, Tom Miller wrote: I agree with Ron. Clean the board up real good then do an inspection. Talking of which does anyone have any suggestions as to with what? I've tried IPA, ethanol, acetone and even some of the tiny amount of 1,1,1 trichloroethane I have left (yes, I know it's banned). Nothing so far has had much impact on the remains of the foam or the remains of the sticky tape (the yellow residue on some of the components in the photos). I'm running out of ideas as to what might clean it off without damaging the board. I can't guarantee anything, but I'd be surprised if Fluxclene didn't do the trick: http://www.electrolube.com/docs/cleaningmain.asp?id=13 Thanks I'll give it a try. ___ 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] 5MHz ocxo- Opening Solder sealed cans
I can't guarantee anything, but I'd be surprised if Fluxclene didn't do the trick: http://www.electrolube.com/docs/cleaningmain.asp?id=13 Thanks I'll give it a try. Also try some naptha (sold as lighter fluid, or as a product called Goof-Off.) -- john, KE5FX Miles Design LLC ___ 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] 5MHz ocxo- Opening Solder sealed cans
On 28/07/2012 22:38, John Miles wrote: I can't guarantee anything, but I'd be surprised if Fluxclene didn't do the trick: http://www.electrolube.com/docs/cleaningmain.asp?id=13 Thanks I'll give it a try. Also try some naptha (sold as lighter fluid, or as a product called Goof-Off.) goof-off doesn't seem to be available easily in the UK - naptha might be worth a go. That said I did try a label removal solvent which I've found useful on other general gunk (the pro-power one) and that didn't touch it. ___ 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] 5MHz ocxo- Opening Solder sealed cans
On 27/07/12 03:17, Tom Miller wrote: I agree with Ron. Clean the board up real good then do an inspection. With a microscope if you can get your hands on one. Look for cracked SMT parts. The high heat from the oven could very well stress the parts causing a failure. Flux the board up and hit all the connections with a small iron. When you melt the solder on each end of a part, if one is broken, it will then show up. Thanks for the tips. On further reflection I think that the foam probably has disintegrated over time (mostly). The pattern of what is melted/stuck to components is wrong for an exogenous heat source. I might have to play around with solvents as IPA didn't have much effect on the really stuck down stuff. I agree it's likely to be a dry joint or cracked SM part so the plan of a thorough clean and visual inspection is a good one - I don't have access to a microscope but do have a couple of decent hand lenses. I suspect careful use of the heat gun and freezer spray will help as well. I'm going to be away for a week so will pick this up again when I get back. I'll update the list with any progress. ___ 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] 5MHz ocxo- Opening Solder sealed cans
Ron Ward sayeth: Hi: I have been looking at the poor quality solder joints on the oscillator. If you have a steady hand and a small tipped soldering with silver baring (about 2% silver) solder, I would re-solder the connections. Many of them do not look properly wetted and cold. Some of the heat from removing the top may have re-soldered a problem connection. I wondered whether that was possible but I don't think the inside got anywhere near reflow temperatures - the only heat damage was that bit of SRBP like stuff and the foam behind that looked much the same as everywhere else. It probably did get above 100deg C for a while. I'll give it a thorough clean and have a close look at all the joints and SMT components when I have chance. ___ 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] 5MHz ocxo- Opening Solder sealed cans
Hi Standard approach: 1) Secure the top of the part (the cover) in a vise. You need something between the cover and metal jaws to keep it from wicking the heat. Leather works, so do plastic inserts. Keep the jaws as far away from the base as practical. 2) Fire up what ever you have for a major soldering job. Big old tube era soldering irons are the weapon of choice for many. Others use torches. If it's an old electric iron, let it heat for at least 30 minutes. 3) Start working around the lip of the base with the iron. As you heat, the solder will start to run. Wick it out with your favorite brand of wicking material (coax braid also works). You probably will need to make two loops around the part to get the bulk of the solder off. 4) Continue with heat, and use a knife blade to separate the base from the cover. It's a little bit at a time thing. Some parts will go fast, others not so fast. You slowly walk the two parts apart. On the part you have, you may need to spread the base open a bit to get the cover to move easily. First time out, it can take a while to get it done. After you have done a few hundred, it's easier. Bob -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Demian Martin Sent: Wednesday, July 25, 2012 6:47 PM To: time-nuts@febo.com Subject: [time-nuts] 5MHz ocxo- Opening Solder sealed cans Bob: Perhaps you can describe how to do this. I can't see a way that would not make a huge mess (big torch) or not ever get there (big soldering iron). I would really like to be able to get inside of some of these without making them all into trash. Demian _ Date: Wed, 25 Jul 2012 18:10:55 -0400 From: Bob Camp li...@rtty.us To: Discussion of precise time and frequency measurement time-nuts@febo.com Subject: Re: [time-nuts] 5MHz ocxo Message-ID: a99eee8d-e120-48cf-84d6-d3434b754...@rtty.us Content-Type: text/plain; charset=windows-1252 Hi That's just a basic solder sealed package. It should be pretty easy to pop open. You'll use up a bit of solder wick doing it? 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. ___ 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] 5MHz ocxo- Opening Solder sealed cans
Hi Bob, Did you look at his pictures of the oscillator? I think the base will need to be secured and the top pulled off. This is different from most of the OCXOs I have seen. Regards, Tom - Original Message - From: Bob Camp li...@rtty.us To: 'Discussion of precise time and frequency measurement' time-nuts@febo.com Sent: Thursday, July 26, 2012 12:05 PM Subject: Re: [time-nuts] 5MHz ocxo- Opening Solder sealed cans Hi Standard approach: 1) Secure the top of the part (the cover) in a vise. You need something between the cover and metal jaws to keep it from wicking the heat. Leather works, so do plastic inserts. Keep the jaws as far away from the base as practical. 2) Fire up what ever you have for a major soldering job. Big old tube era soldering irons are the weapon of choice for many. Others use torches. If it's an old electric iron, let it heat for at least 30 minutes. 3) Start working around the lip of the base with the iron. As you heat, the solder will start to run. Wick it out with your favorite brand of wicking material (coax braid also works). You probably will need to make two loops around the part to get the bulk of the solder off. 4) Continue with heat, and use a knife blade to separate the base from the cover. It's a little bit at a time thing. Some parts will go fast, others not so fast. You slowly walk the two parts apart. On the part you have, you may need to spread the base open a bit to get the cover to move easily. First time out, it can take a while to get it done. After you have done a few hundred, it's easier. Bob -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Demian Martin Sent: Wednesday, July 25, 2012 6:47 PM To: time-nuts@febo.com Subject: [time-nuts] 5MHz ocxo- Opening Solder sealed cans Bob: Perhaps you can describe how to do this. I can't see a way that would not make a huge mess (big torch) or not ever get there (big soldering iron). I would really like to be able to get inside of some of these without making them all into trash. Demian _ Date: Wed, 25 Jul 2012 18:10:55 -0400 From: Bob Camp li...@rtty.us To: Discussion of precise time and frequency measurement time-nuts@febo.com Subject: Re: [time-nuts] 5MHz ocxo Message-ID: a99eee8d-e120-48cf-84d6-d3434b754...@rtty.us Content-Type: text/plain; charset=windows-1252 Hi That's just a basic solder sealed package. It should be pretty easy to pop open. You'll use up a bit of solder wick doing it? 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. ___ 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] 5MHz ocxo- Opening Solder sealed cans
Hi Yes, it's a base that goes outside the cover rather than a base that fits inside the cover. Since the cover is the big part it's the only practical thing to grab onto. The base with the pins coming through it is tough to pull on without getting yourself into trouble. Bob -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Tom Miller Sent: Thursday, July 26, 2012 12:49 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] 5MHz ocxo- Opening Solder sealed cans Hi Bob, Did you look at his pictures of the oscillator? I think the base will need to be secured and the top pulled off. This is different from most of the OCXOs I have seen. Regards, Tom - Original Message - From: Bob Camp li...@rtty.us To: 'Discussion of precise time and frequency measurement' time-nuts@febo.com Sent: Thursday, July 26, 2012 12:05 PM Subject: Re: [time-nuts] 5MHz ocxo- Opening Solder sealed cans Hi Standard approach: 1) Secure the top of the part (the cover) in a vise. You need something between the cover and metal jaws to keep it from wicking the heat. Leather works, so do plastic inserts. Keep the jaws as far away from the base as practical. 2) Fire up what ever you have for a major soldering job. Big old tube era soldering irons are the weapon of choice for many. Others use torches. If it's an old electric iron, let it heat for at least 30 minutes. 3) Start working around the lip of the base with the iron. As you heat, the solder will start to run. Wick it out with your favorite brand of wicking material (coax braid also works). You probably will need to make two loops around the part to get the bulk of the solder off. 4) Continue with heat, and use a knife blade to separate the base from the cover. It's a little bit at a time thing. Some parts will go fast, others not so fast. You slowly walk the two parts apart. On the part you have, you may need to spread the base open a bit to get the cover to move easily. First time out, it can take a while to get it done. After you have done a few hundred, it's easier. Bob -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Demian Martin Sent: Wednesday, July 25, 2012 6:47 PM To: time-nuts@febo.com Subject: [time-nuts] 5MHz ocxo- Opening Solder sealed cans Bob: Perhaps you can describe how to do this. I can't see a way that would not make a huge mess (big torch) or not ever get there (big soldering iron). I would really like to be able to get inside of some of these without making them all into trash. Demian _ Date: Wed, 25 Jul 2012 18:10:55 -0400 From: Bob Camp li...@rtty.us To: Discussion of precise time and frequency measurement time-nuts@febo.com Subject: Re: [time-nuts] 5MHz ocxo Message-ID: a99eee8d-e120-48cf-84d6-d3434b754...@rtty.us Content-Type: text/plain; charset=windows-1252 Hi That's just a basic solder sealed package. It should be pretty easy to pop open. You'll use up a bit of solder wick doing it? 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. ___ 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] 5MHz ocxo- Opening Solder sealed cans
On 26/07/12 17:49, Tom Miller wrote: Hi Bob, Did you look at his pictures of the oscillator? I think the base will need to be secured and the top pulled off. This is different from most of the OCXOs I have seen. I'm somewhat tempted to try putting the bottom in the vice, heating the whole seam with a hot air gun and trying to pull the case off (with a heavy leather glove on one hand). We're having what we laughably call summer in the UK - it's not hot in any absolute sense (mid-high 20's Celsius) but the humidity after several week's rain makes it *feel* as though I just have to get the case a few degrees above ambient and the solder will melt with ease :-) ___ 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] 5MHz ocxo- Opening Solder sealed cans
Pick up a few sticks of ChipQuik and mix it in with a good iron. Then, you may do just what you say. It should melt below about 95°C. A good hot air heat gun would most likely do the trick. Maybe use some solder wick first to lower the amount of tin/lead solder. Then add the chipquik. You might also just solder a tab on the bottom then you could clamp the top in a leather jawed vise. Hit it with a hot air gun while pulling on the base tab. Tom - Original Message - From: Paul Flinders p...@flinders.org To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Thursday, July 26, 2012 2:20 PM Subject: Re: [time-nuts] 5MHz ocxo- Opening Solder sealed cans On 26/07/12 17:49, Tom Miller wrote: Hi Bob, Did you look at his pictures of the oscillator? I think the base will need to be secured and the top pulled off. This is different from most of the OCXOs I have seen. I'm somewhat tempted to try putting the bottom in the vice, heating the whole seam with a hot air gun and trying to pull the case off (with a heavy leather glove on one hand). We're having what we laughably call summer in the UK - it's not hot in any absolute sense (mid-high 20's Celsius) but the humidity after several week's rain makes it *feel* as though I just have to get the case a few degrees above ambient and the solder will melt with ease :-) ___ 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] 5MHz ocxo- Opening Solder sealed cans
On 26/07/12 20:49, Tom Miller wrote: Pick up a few sticks of ChipQuik and mix it in with a good iron. Then, you may do just what you say. It should melt below about 95°C. A good hot air heat gun would most likely do the trick. Maybe use some solder wick first to lower the amount of tin/lead solder. Then add the chipquik. You might also just solder a tab on the bottom then you could clamp the top in a leather jawed vise. Hit it with a hot air gun while pulling on the base tab. Well, a few exploratory attempts confirmed my initial suspicion that I don't have a soldering iron big enough for the job - the largest I have is 60W or so, and the hot air gun didn't touch it even set to 480deg C So, I reached for the next larger source of heat which is a small blowtorch I have, set a small flame and ran it round the whole seam then pulled the top off with a gloved hand. Things did get a bit warm but only for a short while. The first thing I encountered was some insulating foam - this was rather sticky. Not sure whether it had gone like that over time or due to my heating the whole thing a bit too much. On three sides the foam was separated from the case by what looks like some thin SRBP. This had blistered a bit so obviously things were a bit hot just there but the foam was much the same whether protected by the SRBP so I'm wondering whether this has just disintegrated over time. Pulling/washing the foam off reveals three PCBs and a further enclosed metal case with the crystal. A TIP21 bolted to this acts as the heating element. Originally there had been some cable ties anchoring the crystal enclosure but these were brittle - presumably from the heat of the oven. Hooking the unit up to 12V and an oscilloscope shows that it has survived the encounter with the blow torch and produces a nice 5MHz sine wave at 2.5V p-p (into 10Meg ohm). Irritatingly it doesn't really want to misbehave - presumably because whatever didn't like the heat is now cooler with the insulating foam removed. The inner metal case gets too hot to touch but the thermostat seems to be working because the current drawn drops from about 380mA to 240 or so. It should probably be lower but, again, without the usual amount of insulation it's likely to draw more keeping the oven up to temperature. So, as it doesn't want to misbehave, I'm not totally clear which way to go. The output does drop to about 1.8V p-p when the oven is fully warm which might be related to the original fault. I suppose the fact that the fault has gone away eliminates the oven assembly or crystal itself as the source of the problem. Photos for comments or curiosity. The black stuff all over the PCBs is the remains of the foam. http://www.wild-pc.co.uk/images/P1020364.jpg http://www.wild-pc.co.uk/images/P1020367.jpg http://www.wild-pc.co.uk/images/P1020368.jpg http://www.wild-pc.co.uk/images/P1020369.jpg http://www.wild-pc.co.uk/images/P1020370.jpg ___ 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] 5MHz ocxo- Opening Solder sealed cans
OK I get to add 10 cents here. Yes indeed various foam stuff goes to heck after many years and can indeed become this strange goo-ie stuff. Or it gets all flakey. Well the good news is stuff seems to work and that can be frustrating. So I would suggest the very deep dive and look at all of the solder joints. Variable caps absolutely go to heck. Had to change one on an RB that fixed the exciter. Good luck Paul WB8TSL On Thu, Jul 26, 2012 at 5:58 PM, Paul Flinders p...@flinders.org wrote: On 26/07/12 20:49, Tom Miller wrote: Pick up a few sticks of ChipQuik and mix it in with a good iron. Then, you may do just what you say. It should melt below about 95°C. A good hot air heat gun would most likely do the trick. Maybe use some solder wick first to lower the amount of tin/lead solder. Then add the chipquik. You might also just solder a tab on the bottom then you could clamp the top in a leather jawed vise. Hit it with a hot air gun while pulling on the base tab. Well, a few exploratory attempts confirmed my initial suspicion that I don't have a soldering iron big enough for the job - the largest I have is 60W or so, and the hot air gun didn't touch it even set to 480deg C So, I reached for the next larger source of heat which is a small blowtorch I have, set a small flame and ran it round the whole seam then pulled the top off with a gloved hand. Things did get a bit warm but only for a short while. The first thing I encountered was some insulating foam - this was rather sticky. Not sure whether it had gone like that over time or due to my heating the whole thing a bit too much. On three sides the foam was separated from the case by what looks like some thin SRBP. This had blistered a bit so obviously things were a bit hot just there but the foam was much the same whether protected by the SRBP so I'm wondering whether this has just disintegrated over time. Pulling/washing the foam off reveals three PCBs and a further enclosed metal case with the crystal. A TIP21 bolted to this acts as the heating element. Originally there had been some cable ties anchoring the crystal enclosure but these were brittle - presumably from the heat of the oven. Hooking the unit up to 12V and an oscilloscope shows that it has survived the encounter with the blow torch and produces a nice 5MHz sine wave at 2.5V p-p (into 10Meg ohm). Irritatingly it doesn't really want to misbehave - presumably because whatever didn't like the heat is now cooler with the insulating foam removed. The inner metal case gets too hot to touch but the thermostat seems to be working because the current drawn drops from about 380mA to 240 or so. It should probably be lower but, again, without the usual amount of insulation it's likely to draw more keeping the oven up to temperature. So, as it doesn't want to misbehave, I'm not totally clear which way to go. The output does drop to about 1.8V p-p when the oven is fully warm which might be related to the original fault. I suppose the fact that the fault has gone away eliminates the oven assembly or crystal itself as the source of the problem. Photos for comments or curiosity. The black stuff all over the PCBs is the remains of the foam. http://www.wild-pc.co.uk/**images/P1020364.jpghttp://www.wild-pc.co.uk/images/P1020364.jpg http://www.wild-pc.co.uk/**images/P1020367.jpghttp://www.wild-pc.co.uk/images/P1020367.jpg http://www.wild-pc.co.uk/**images/P1020368.jpghttp://www.wild-pc.co.uk/images/P1020368.jpg http://www.wild-pc.co.uk/**images/P1020369.jpghttp://www.wild-pc.co.uk/images/P1020369.jpg http://www.wild-pc.co.uk/**images/P1020370.jpghttp://www.wild-pc.co.uk/images/P1020370.jpg __**_ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/** mailman/listinfo/time-nutshttps://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] 5MHz ocxo- Opening Solder sealed cans
Hi: I have been looking at the poor quality solder joints on the oscillator. If you have a steady hand and a small tipped soldering with silver baring (about 2% silver) solder, I would re-solder the connections. Many of them do not look properly wetted and cold. Some of the heat from removing the top may have re-soldered a problem connection. Ron -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Paul Flinders Sent: Thursday, July 26, 2012 2:59 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] 5MHz ocxo- Opening Solder sealed cans On 26/07/12 20:49, Tom Miller wrote: Pick up a few sticks of ChipQuik and mix it in with a good iron. Then, you may do just what you say. It should melt below about 95°C. A good hot air heat gun would most likely do the trick. Maybe use some solder wick first to lower the amount of tin/lead solder. Then add the chipquik. You might also just solder a tab on the bottom then you could clamp the top in a leather jawed vise. Hit it with a hot air gun while pulling on the base tab. Well, a few exploratory attempts confirmed my initial suspicion that I don't have a soldering iron big enough for the job - the largest I have is 60W or so, and the hot air gun didn't touch it even set to 480deg C So, I reached for the next larger source of heat which is a small blowtorch I have, set a small flame and ran it round the whole seam then pulled the top off with a gloved hand. Things did get a bit warm but only for a short while. The first thing I encountered was some insulating foam - this was rather sticky. Not sure whether it had gone like that over time or due to my heating the whole thing a bit too much. On three sides the foam was separated from the case by what looks like some thin SRBP. This had blistered a bit so obviously things were a bit hot just there but the foam was much the same whether protected by the SRBP so I'm wondering whether this has just disintegrated over time. Pulling/washing the foam off reveals three PCBs and a further enclosed metal case with the crystal. A TIP21 bolted to this acts as the heating element. Originally there had been some cable ties anchoring the crystal enclosure but these were brittle - presumably from the heat of the oven. Hooking the unit up to 12V and an oscilloscope shows that it has survived the encounter with the blow torch and produces a nice 5MHz sine wave at 2.5V p-p (into 10Meg ohm). Irritatingly it doesn't really want to misbehave - presumably because whatever didn't like the heat is now cooler with the insulating foam removed. The inner metal case gets too hot to touch but the thermostat seems to be working because the current drawn drops from about 380mA to 240 or so. It should probably be lower but, again, without the usual amount of insulation it's likely to draw more keeping the oven up to temperature. So, as it doesn't want to misbehave, I'm not totally clear which way to go. The output does drop to about 1.8V p-p when the oven is fully warm which might be related to the original fault. I suppose the fact that the fault has gone away eliminates the oven assembly or crystal itself as the source of the problem. Photos for comments or curiosity. The black stuff all over the PCBs is the remains of the foam. http://www.wild-pc.co.uk/images/P1020364.jpg http://www.wild-pc.co.uk/images/P1020367.jpg http://www.wild-pc.co.uk/images/P1020368.jpg http://www.wild-pc.co.uk/images/P1020369.jpg http://www.wild-pc.co.uk/images/P1020370.jpg ___ 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] 5MHz ocxo- Opening Solder sealed cans
I agree with Ron. Clean the board up real good then do an inspection. With a microscope if you can get your hands on one. Look for cracked SMT parts. The high heat from the oven could very well stress the parts causing a failure. Flux the board up and hit all the connections with a small iron. When you melt the solder on each end of a part, if one is broken, it will then show up. Tom - Original Message - From: Ron Ward n6idl...@comcast.net To: 'Discussion of precise time and frequency measurement' time-nuts@febo.com Sent: Thursday, July 26, 2012 9:54 PM Subject: Re: [time-nuts] 5MHz ocxo- Opening Solder sealed cans Hi: I have been looking at the poor quality solder joints on the oscillator. If you have a steady hand and a small tipped soldering with silver baring (about 2% silver) solder, I would re-solder the connections. Many of them do not look properly wetted and cold. Some of the heat from removing the top may have re-soldered a problem connection. Ron -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Paul Flinders Sent: Thursday, July 26, 2012 2:59 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] 5MHz ocxo- Opening Solder sealed cans On 26/07/12 20:49, Tom Miller wrote: Pick up a few sticks of ChipQuik and mix it in with a good iron. Then, you may do just what you say. It should melt below about 95°C. A good hot air heat gun would most likely do the trick. Maybe use some solder wick first to lower the amount of tin/lead solder. Then add the chipquik. You might also just solder a tab on the bottom then you could clamp the top in a leather jawed vise. Hit it with a hot air gun while pulling on the base tab. Well, a few exploratory attempts confirmed my initial suspicion that I don't have a soldering iron big enough for the job - the largest I have is 60W or so, and the hot air gun didn't touch it even set to 480deg C So, I reached for the next larger source of heat which is a small blowtorch I have, set a small flame and ran it round the whole seam then pulled the top off with a gloved hand. Things did get a bit warm but only for a short while. The first thing I encountered was some insulating foam - this was rather sticky. Not sure whether it had gone like that over time or due to my heating the whole thing a bit too much. On three sides the foam was separated from the case by what looks like some thin SRBP. This had blistered a bit so obviously things were a bit hot just there but the foam was much the same whether protected by the SRBP so I'm wondering whether this has just disintegrated over time. Pulling/washing the foam off reveals three PCBs and a further enclosed metal case with the crystal. A TIP21 bolted to this acts as the heating element. Originally there had been some cable ties anchoring the crystal enclosure but these were brittle - presumably from the heat of the oven. Hooking the unit up to 12V and an oscilloscope shows that it has survived the encounter with the blow torch and produces a nice 5MHz sine wave at 2.5V p-p (into 10Meg ohm). Irritatingly it doesn't really want to misbehave - presumably because whatever didn't like the heat is now cooler with the insulating foam removed. The inner metal case gets too hot to touch but the thermostat seems to be working because the current drawn drops from about 380mA to 240 or so. It should probably be lower but, again, without the usual amount of insulation it's likely to draw more keeping the oven up to temperature. So, as it doesn't want to misbehave, I'm not totally clear which way to go. The output does drop to about 1.8V p-p when the oven is fully warm which might be related to the original fault. I suppose the fact that the fault has gone away eliminates the oven assembly or crystal itself as the source of the problem. Photos for comments or curiosity. The black stuff all over the PCBs is the remains of the foam. http://www.wild-pc.co.uk/images/P1020364.jpg http://www.wild-pc.co.uk/images/P1020367.jpg http://www.wild-pc.co.uk/images/P1020368.jpg http://www.wild-pc.co.uk/images/P1020369.jpg http://www.wild-pc.co.uk/images/P1020370.jpg ___ 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] 5MHz ocxo- Opening Solder sealed cans
How about using a commercial type Hot Plate. I have one that can be set to temp. I use it for cleaning SMD devices off PC boards. 73, Dick, W1KSZ -Original Message- From: Demian Martin demian...@yahoo.com Sent: Jul 25, 2012 3:47 PM To: time-nuts@febo.com Subject: [time-nuts] 5MHz ocxo- Opening Solder sealed cans Bob: Perhaps you can describe how to do this. I can't see a way that would not make a huge mess (big torch) or not ever get there (big soldering iron). I would really like to be able to get inside of some of these without making them all into trash. Demian _ Date: Wed, 25 Jul 2012 18:10:55 -0400 From: Bob Camp li...@rtty.us To: Discussion of precise time and frequency measurement time-nuts@febo.com Subject: Re: [time-nuts] 5MHz ocxo Message-ID: a99eee8d-e120-48cf-84d6-d3434b754...@rtty.us Content-Type: text/plain; charset=windows-1252 Hi That's just a basic solder sealed package. It should be pretty easy to pop open. You'll use up a bit of solder wick doing it? 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. ___ 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] 5MHz ocxo- Opening Solder sealed cans
You might try to use some chip-quik alloy. It greatly lowers the melting point of the solder. http://www.chipquikinc.com/ Their flux is very good also. - Original Message - From: Richard W. Solomon w1...@earthlink.net To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Wednesday, July 25, 2012 7:28 PM Subject: Re: [time-nuts] 5MHz ocxo- Opening Solder sealed cans How about using a commercial type Hot Plate. I have one that can be set to temp. I use it for cleaning SMD devices off PC boards. 73, Dick, W1KSZ -Original Message- From: Demian Martin demian...@yahoo.com Sent: Jul 25, 2012 3:47 PM To: time-nuts@febo.com Subject: [time-nuts] 5MHz ocxo- Opening Solder sealed cans Bob: Perhaps you can describe how to do this. I can't see a way that would not make a huge mess (big torch) or not ever get there (big soldering iron). I would really like to be able to get inside of some of these without making them all into trash. Demian _ Date: Wed, 25 Jul 2012 18:10:55 -0400 From: Bob Camp li...@rtty.us To: Discussion of precise time and frequency measurement time-nuts@febo.com Subject: Re: [time-nuts] 5MHz ocxo Message-ID: a99eee8d-e120-48cf-84d6-d3434b754...@rtty.us Content-Type: text/plain; charset=windows-1252 Hi That's just a basic solder sealed package. It should be pretty easy to pop open. You'll use up a bit of solder wick doing it? 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. ___ 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.
