I think you may be paying to much... check out the pricing at gojgo.com They do excellent work for very low prices. Also check how the price varies with quantity. Often you can get 5X the number of boards for a 20% increase in total price (excluding shipping). -------------------- > back in 2011 I had 25 extenders of a similar size to the large boards made and the unit cost was USD28.

Today a friend gave me a Datron 4700. It looks like new. It is stored (working) for many years in the cal lab he works. He was allowed to take it home (for me, in return I will repair his SA), He plugged it in, Fail 1 on the display followed by a sound and a smell. I opened it but nothing looks burned. I can not find a service manual, does someone has one ? On the back the label shows no options but if he remembers it well it should have all or at least most options. All slots are filled with pcb's. The "box" in the left upper corner is full and there is a very small pcb next to it. There is not much room left. Just enough to store a small multimeter between the huge transformer and that box. Fred www.pa4tim.nl

Fred, Shorted tantalums most likely. I had several on mine that went bad as quickly as I replaced them. I would start with the inguard supply board. I think the 4708 manual is available for download at KO4BB or xDevs. If not, I can dig up something. I have a set of the manuals. Todd On Thu, Jul 20, 2017 at 10:01 Fred <pa4tim@gmail.com> wrote: > Today a friend gave me a Datron 4700. It looks like new. It is stored > (working) for many years in the cal lab he works. He was allowed to > take it home (for me, in return I will repair his SA), He plugged it in, > Fail 1 on the display followed by a sound and a smell. > I opened it but nothing looks burned. > > I can not find a service manual, does someone has one ? > > On the back the label shows no options but if he remembers it well it > should have all or at least most options. All slots are filled with > pcb's. The "box" in the left upper corner is full and there is a very > small pcb next to it. There is not much room left. Just enough to store > a small multimeter between the huge transformer and that box. > > Fred > www.pa4tim.nl > > _______________________________________________ > volt-nuts mailing list -- volt-nuts@febo.com > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts > and follow the instructions there. >

Hi Tod, I just pulled that board (i think) and found a burned 22uF tantalum. Tantalum caps should have a very long life unless used on the wrong place. I guess this is an example. I do not even stock them, the last bad one I had to replace was in a G&M secutest 2 years ago. ( I repair around 10-20 Secutests a year and that was the only bad tantalum) With what type/value cap did you replace them ? I found the 4708 manual at KO4BB but that is a user manual without schematics. The calibrator should be OK but before I try to start her I always like check things like caps, connectors, solderjoints etc. It really looks like new, not even a scratch or dust. It came with a new looking HP8640 and a new looking HP counter 5248. Both from the same cal lab (part of a company that stayed there) that cal-lab closed about 30 years ago, but all gear stayed where it was (I already had received most of their gear a few years ago). This were the last things because my friend retires. Fred . On 07/20/2017 04:51 PM, Todd Micallef wrote: > Fred, > > Shorted tantalums most likely. I had several on mine that went bad as > quickly as I replaced them. I would start with the inguard supply board. > > I think the 4708 manual is available for download at KO4BB or xDevs. If > not, I can dig up something. I have a set of the manuals. > > Todd > > On Thu, Jul 20, 2017 at 10:01 Fred <pa4tim@gmail.com> wrote: > >> Today a friend gave me a Datron 4700. It looks like new. It is stored >> (working) for many years in the cal lab he works. He was allowed to >> take it home (for me, in return I will repair his SA), He plugged it in, >> Fail 1 on the display followed by a sound and a smell. >> I opened it but nothing looks burned. >> >> I can not find a service manual, does someone has one ? >> >> On the back the label shows no options but if he remembers it well it >> should have all or at least most options. All slots are filled with >> pcb's. The "box" in the left upper corner is full and there is a very >> small pcb next to it. There is not much room left. Just enough to store >> a small multimeter between the huge transformer and that box. >> >> Fred >> www.pa4tim.nl >> >> _______________________________________________ >> volt-nuts mailing list -- volt-nuts@febo.com >> To unsubscribe, go to >> https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts >> and follow the instructions there. >> > _______________________________________________ > volt-nuts mailing list -- volt-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts > and follow the instructions there.

Fred, I used the same values and typically went up to the next higher voltage. I think most ended up as 35v since I bought them in quantity. Some people recommend the OS-CON family as replacements. Many of the failed tantalums fit in a tight space so I just stayed with the original type. Once the in-guard was repaired, I found a few other boards where the tantalums on the same rail also failed so don't be surprised if more start to fail. The 4708 service manual is here https://xdevs.com/doc/Datron/4708/DATRON-4708-CH-SH_c20030307.pdf It is now uploaded to KO4BB. The 4808 service manual will be very close since the 4708 and 4808 share similar designs. The 4708 uses a LTZ1000 as the reference instead of the array of zeners used in the 4000 and the lower spec'd 4700. You will have yourself a good calibrator once it is brought back into service. Be careful around the displays as there is hardly any room between the glass and front panel. Respectfully, Todd On Thu, Jul 20, 2017 at 12:55 PM, Fred <pa4tim@gmail.com> wrote: > Hi Tod, > > I just pulled that board (i think) and found a burned 22uF tantalum. > Tantalum caps should have a very long life unless used on the wrong place. > I guess this is an example. I do not even stock them, the last bad one I > had to replace was in a G&M secutest 2 years ago. ( I repair around 10-20 > Secutests a year and that was the only bad tantalum) > > With what type/value cap did you replace them ? > I found the 4708 manual at KO4BB but that is a user manual without > schematics. > > The calibrator should be OK but before I try to start her I always like > check things like caps, connectors, solderjoints etc. It really looks like > new, not even a scratch or dust. It came with a new looking HP8640 and a > new looking HP counter 5248. Both from the same cal lab (part of a company > that stayed there) that cal-lab closed about 30 years ago, but all gear > stayed where it was (I already had received most of their gear a few years > ago). This were the last things because my friend retires. > > Fred > > . > > On 07/20/2017 04:51 PM, Todd Micallef wrote: > >> Fred, >> >> Shorted tantalums most likely. I had several on mine that went bad as >> quickly as I replaced them. I would start with the inguard supply board. >> >> I think the 4708 manual is available for download at KO4BB or xDevs. If >> not, I can dig up something. I have a set of the manuals. >> >> Todd >> >> On Thu, Jul 20, 2017 at 10:01 Fred <pa4tim@gmail.com> wrote: >> >> Today a friend gave me a Datron 4700. It looks like new. It is stored >>> (working) for many years in the cal lab he works. He was allowed to >>> take it home (for me, in return I will repair his SA), He plugged it in, >>> Fail 1 on the display followed by a sound and a smell. >>> I opened it but nothing looks burned. >>> >>> I can not find a service manual, does someone has one ? >>> >>> On the back the label shows no options but if he remembers it well it >>> should have all or at least most options. All slots are filled with >>> pcb's. The "box" in the left upper corner is full and there is a very >>> small pcb next to it. There is not much room left. Just enough to store >>> a small multimeter between the huge transformer and that box. >>> >>> Fred >>> www.pa4tim.nl >>> >>> _______________________________________________ >>> volt-nuts mailing list -- volt-nuts@febo.com >>> To unsubscribe, go to >>> https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts >>> and follow the instructions there. >>> >>> _______________________________________________ >> volt-nuts mailing list -- volt-nuts@febo.com >> To unsubscribe, go to https://www.febo.com/cgi-bin/m >> ailman/listinfo/volt-nuts >> and follow the instructions there. >> > > _______________________________________________ > volt-nuts mailing list -- volt-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/m > ailman/listinfo/volt-nuts > and follow the instructions there. >

Hi Todd, I will order a bunch en 35 or 50V. Replaced them for now with a smaller value I had. Is only a fixed value LM340 so not very critical. The data sheet states minimal 2u2 at the input and non at the output I found the 4707 manual and upto now the schematics are usable. Seems like I have the AC, ohm and current options. The board I can not find is the HV option. But I do not mind, I already have 3 calibrators that do have 1000V. I have a problem in the +/- 400V rails. They are +115 and -38V. I have no extenders but I use long flexible grabbers. (a wire with banana on one end and a grabber on the other. Lift the board, clip it to a testpoint, push the pcb in and measure. Not optimal but workable. First find out where the 400V is made. Thanks for the help. Fred On 07/21/2017 01:59 AM, Todd Micallef wrote: > Fred, > > I used the same values and typically went up to the next higher voltage. I > think most ended up as 35v since I bought them in quantity. Some people > recommend the OS-CON family as replacements. Many of the failed tantalums > fit in a tight space so I just stayed with the original type. > Once the in-guard was repaired, I found a few other boards where the > tantalums on the same rail also failed so don't be surprised if more start > to fail. > > The 4708 service manual is here > https://xdevs.com/doc/Datron/4708/DATRON-4708-CH-SH_c20030307.pdf > It is now uploaded to KO4BB. The 4808 service manual will be very close > since the 4708 and 4808 share similar designs. > > The 4708 uses a LTZ1000 as the reference instead of the array of zeners > used in the 4000 and the lower spec'd 4700. You will have yourself a good > calibrator once it is brought back into service. Be careful around the > displays as there is hardly any room between the glass and front panel. > > Respectfully, > > Todd > > On Thu, Jul 20, 2017 at 12:55 PM, Fred <pa4tim@gmail.com> wrote: > >> Hi Tod, >> >> I just pulled that board (i think) and found a burned 22uF tantalum. >> Tantalum caps should have a very long life unless used on the wrong place. >> I guess this is an example. I do not even stock them, the last bad one I >> had to replace was in a G&M secutest 2 years ago. ( I repair around 10-20 >> Secutests a year and that was the only bad tantalum) >> >> With what type/value cap did you replace them ? >> I found the 4708 manual at KO4BB but that is a user manual without >> schematics. >> >> The calibrator should be OK but before I try to start her I always like >> check things like caps, connectors, solderjoints etc. It really looks like >> new, not even a scratch or dust. It came with a new looking HP8640 and a >> new looking HP counter 5248. Both from the same cal lab (part of a company >> that stayed there) that cal-lab closed about 30 years ago, but all gear >> stayed where it was (I already had received most of their gear a few years >> ago). This were the last things because my friend retires. >> >> Fred >> >> . >> >> On 07/20/2017 04:51 PM, Todd Micallef wrote: >> >>> Fred, >>> >>> Shorted tantalums most likely. I had several on mine that went bad as >>> quickly as I replaced them. I would start with the inguard supply board. >>> >>> I think the 4708 manual is available for download at KO4BB or xDevs. If >>> not, I can dig up something. I have a set of the manuals. >>> >>> Todd >>> >>> On Thu, Jul 20, 2017 at 10:01 Fred <pa4tim@gmail.com> wrote: >>> >>> Today a friend gave me a Datron 4700. It looks like new. It is stored >>>> (working) for many years in the cal lab he works. He was allowed to >>>> take it home (for me, in return I will repair his SA), He plugged it in, >>>> Fail 1 on the display followed by a sound and a smell. >>>> I opened it but nothing looks burned. >>>> >>>> I can not find a service manual, does someone has one ? >>>> >>>> On the back the label shows no options but if he remembers it well it >>>> should have all or at least most options. All slots are filled with >>>> pcb's. The "box" in the left upper corner is full and there is a very >>>> small pcb next to it. There is not much room left. Just enough to store >>>> a small multimeter between the huge transformer and that box. >>>> >>>> Fred >>>> www.pa4tim.nl >>>> >>>> _______________________________________________ >>>> volt-nuts mailing list -- volt-nuts@febo.com >>>> To unsubscribe, go to >>>> https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts >>>> and follow the instructions there. >>>> >>>> _______________________________________________ >>> volt-nuts mailing list -- volt-nuts@febo.com >>> To unsubscribe, go to https://www.febo.com/cgi-bin/m >>> ailman/listinfo/volt-nuts >>> and follow the instructions there. >>> >> _______________________________________________ >> volt-nuts mailing list -- volt-nuts@febo.com >> To unsubscribe, go to https://www.febo.com/cgi-bin/m >> ailman/listinfo/volt-nuts >> and follow the instructions there. >> > _______________________________________________ > volt-nuts mailing list -- volt-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts > and follow the instructions there.

The 4700 is fixed. The 400V issue was caused by missing -15V, That was caused by a shorted tantalum on the Ohms board. It was less then 0,1 ohm but not even discolored. I was curious about the way they die. So a desoldered about 20 tantalums and measured C, D and leakage current. New ones have a very low D, at 1 kHz well under 0,1. Capacitance did not decrease much like electrolytics do, but D does increase over age. Leakage current is as good as zero, (my best leakage tester has only 1 uA resolution so it can not measure leakage in the nA's) The worst D i found was 0.67. They did not leak, so I think they go from good to short in one step. capacitance does not seem to decrease. In electrolytics this is caused by a decreasing oxidelayer caused by the decreasing electrolyte. I replaced a few by electrolytics as a test. The D factor of the 10uF low ESR panasonic FM caps was better as that of the new 10uF tantalums I had. Most tantalums measured OK, a few had very high D, non of them leaked DC. So I think (based on this to small number test) they get a high D, start to dissipate and as a result of that develop a short. Fred On 07/21/2017 01:59 AM, Todd Micallef wrote: > Fred, > > I used the same values and typically went up to the next higher voltage. I > think most ended up as 35v since I bought them in quantity. Some people > recommend the OS-CON family as replacements. Many of the failed tantalums > fit in a tight space so I just stayed with the original type. > Once the in-guard was repaired, I found a few other boards where the > tantalums on the same rail also failed so don't be surprised if more start > to fail. > > The 4708 service manual is here > https://xdevs.com/doc/Datron/4708/DATRON-4708-CH-SH_c20030307.pdf > It is now uploaded to KO4BB. The 4808 service manual will be very close > since the 4708 and 4808 share similar designs. > > The 4708 uses a LTZ1000 as the reference instead of the array of zeners > used in the 4000 and the lower spec'd 4700. You will have yourself a good > calibrator once it is brought back into service. Be careful around the > displays as there is hardly any room between the glass and front panel. > > Respectfully, > > Todd > > On Thu, Jul 20, 2017 at 12:55 PM, Fred <pa4tim@gmail.com> wrote: > >> Hi Tod, >> >> I just pulled that board (i think) and found a burned 22uF tantalum. >> Tantalum caps should have a very long life unless used on the wrong place. >> I guess this is an example. I do not even stock them, the last bad one I >> had to replace was in a G&M secutest 2 years ago. ( I repair around 10-20 >> Secutests a year and that was the only bad tantalum) >> >> With what type/value cap did you replace them ? >> I found the 4708 manual at KO4BB but that is a user manual without >> schematics. >> >> The calibrator should be OK but before I try to start her I always like >> check things like caps, connectors, solderjoints etc. It really looks like >> new, not even a scratch or dust. It came with a new looking HP8640 and a >> new looking HP counter 5248. Both from the same cal lab (part of a company >> that stayed there) that cal-lab closed about 30 years ago, but all gear >> stayed where it was (I already had received most of their gear a few years >> ago). This were the last things because my friend retires. >> >> Fred >> >> . >> >> On 07/20/2017 04:51 PM, Todd Micallef wrote: >> >>> Fred, >>> >>> Shorted tantalums most likely. I had several on mine that went bad as >>> quickly as I replaced them. I would start with the inguard supply board. >>> >>> I think the 4708 manual is available for download at KO4BB or xDevs. If >>> not, I can dig up something. I have a set of the manuals. >>> >>> Todd >>> >>> On Thu, Jul 20, 2017 at 10:01 Fred <pa4tim@gmail.com> wrote: >>> >>> Today a friend gave me a Datron 4700. It looks like new. It is stored >>>> (working) for many years in the cal lab he works. He was allowed to >>>> take it home (for me, in return I will repair his SA), He plugged it in, >>>> Fail 1 on the display followed by a sound and a smell. >>>> I opened it but nothing looks burned. >>>> >>>> I can not find a service manual, does someone has one ? >>>> >>>> On the back the label shows no options but if he remembers it well it >>>> should have all or at least most options. All slots are filled with >>>> pcb's. The "box" in the left upper corner is full and there is a very >>>> small pcb next to it. There is not much room left. Just enough to store >>>> a small multimeter between the huge transformer and that box. >>>> >>>> Fred >>>> www.pa4tim.nl >>>> >>>> _______________________________________________ >>>> volt-nuts mailing list -- volt-nuts@febo.com >>>> To unsubscribe, go to >>>> https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts >>>> and follow the instructions there. >>>> >>>> _______________________________________________ >>> volt-nuts mailing list -- volt-nuts@febo.com >>> To unsubscribe, go to https://www.febo.com/cgi-bin/m >>> ailman/listinfo/volt-nuts >>> and follow the instructions there. >>> >> _______________________________________________ >> volt-nuts mailing list -- volt-nuts@febo.com >> To unsubscribe, go to https://www.febo.com/cgi-bin/m >> ailman/listinfo/volt-nuts >> and follow the instructions there. >> > _______________________________________________ > volt-nuts mailing list -- volt-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts > and follow the instructions there.