Hi All,
Decided to pull out some old equipment I've had stored away here for awhile and try some repairs.
One of which is a Radiometer Copenhagen BKF-10 Automatic distortion analyzer, i got given from ABC radio a year or two ago.
The input Frequency meter works great, and is surprisingly accurate.
However the input/output ratio meter, and distortion meter go all over the place or hard full scale even if nothing is connected..
I've checked all the supply rails i could by testing voltages straight off the regulators.
Everything seems to be in order.
I've re soldered all connections on the mainboard,
I've also pulled out every card and resolded dry solder joins and tested the capacitors.
But still no success 🙁
I'm at a loss of what to look at next, without any knowledge of this system i can't exactly trace faults without a service manual.
If somewhere out there could supply me with one for this unit, i would be forever grateful.
It is a rare bit of kit, but hoping someone out there has service information for it.
Thanks,
Ben.
Decided to pull out some old equipment I've had stored away here for awhile and try some repairs.
One of which is a Radiometer Copenhagen BKF-10 Automatic distortion analyzer, i got given from ABC radio a year or two ago.
The input Frequency meter works great, and is surprisingly accurate.
However the input/output ratio meter, and distortion meter go all over the place or hard full scale even if nothing is connected..
I've checked all the supply rails i could by testing voltages straight off the regulators.
Everything seems to be in order.
I've re soldered all connections on the mainboard,
I've also pulled out every card and resolded dry solder joins and tested the capacitors.
But still no success 🙁
I'm at a loss of what to look at next, without any knowledge of this system i can't exactly trace faults without a service manual.
If somewhere out there could supply me with one for this unit, i would be forever grateful.
It is a rare bit of kit, but hoping someone out there has service information for it.
Thanks,
Ben.
I have the same instrument, but no manuals or documentation what so ever… I would love to get my hands on it, especially a calibration manual or similar.
Now, since I several years back purchased a second hand AP one I have not been using the BKF10 for many years (but it stands proudly in my storage room), so let’s see what I can remember of it.
The main problem I remember was with the connectors on the backplane for the slot in boards, I had constant bad connection there which caused a lot of erratic behaviours, like the meters running wild etc. I was never really able to fully solve that, cleaning as well as contact cleaning spray where only a temporary solution, if the instrument where sitting unused for some time this problem always came back… Then opening it up and pulling all the boards in and out few times (as well as more spray) fixed it, until next time that was.
There is also the same type of connector on the other side of the backplane board which goes to the front panel meters and switches, this connector had the same problem as the others…
Well it could also be one or more of the trimmer potentiometers that where misbehaving, they all look like they had seen better days, but without a proper manual available I did not want to go down that path...
What more I remember is a power transistor breaking on the PSU board; I think it was a BC140 or similar ancient type. But when that happened the instrument was only half alive, not meters going wild and such.
I once made a mistake and put voltage between the two BNC connectors GND… Wrong polarity when connected a power amplifier, that burned a trace which I think was on the backplane itself, but it was so many years ago that I am not sure anymore, so it could have been on one of the slot in boards as well. But regardless I do remember it was easy to spot where it had occurred. When that happened the meters where “running wild”, so if you have not already done that, it might be a good idea to measure that you have low ohm connection between the two BNC GNDs. I also replaced both BNC connectors on mine, they where completely worn out…
I do have a memory of that the generator in this one was a bit unstable and difficult to use; when selecting a frequency or level it took time before it settled. The output level where jumping up and down for a couple of seconds (and it was no small jumps either!) and if now my memory is not totally off, the generator also referenced itself against the input level etc. So it might be a good idea to use this instrument in conjunction with a modern low distortion signal generator, I did just that. But the distortion analyser and frequency counter was all good and straight forward. Of course this with reservation for that the generator in my BKF10 might be faulty...
Well that is what I can add regarding this one, as stated in the start of this post, if you or anyone else where able to find a manual I would be very happy to buy a copy!
Now, since I several years back purchased a second hand AP one I have not been using the BKF10 for many years (but it stands proudly in my storage room), so let’s see what I can remember of it.
The main problem I remember was with the connectors on the backplane for the slot in boards, I had constant bad connection there which caused a lot of erratic behaviours, like the meters running wild etc. I was never really able to fully solve that, cleaning as well as contact cleaning spray where only a temporary solution, if the instrument where sitting unused for some time this problem always came back… Then opening it up and pulling all the boards in and out few times (as well as more spray) fixed it, until next time that was.
There is also the same type of connector on the other side of the backplane board which goes to the front panel meters and switches, this connector had the same problem as the others…
Well it could also be one or more of the trimmer potentiometers that where misbehaving, they all look like they had seen better days, but without a proper manual available I did not want to go down that path...
What more I remember is a power transistor breaking on the PSU board; I think it was a BC140 or similar ancient type. But when that happened the instrument was only half alive, not meters going wild and such.
I once made a mistake and put voltage between the two BNC connectors GND… Wrong polarity when connected a power amplifier, that burned a trace which I think was on the backplane itself, but it was so many years ago that I am not sure anymore, so it could have been on one of the slot in boards as well. But regardless I do remember it was easy to spot where it had occurred. When that happened the meters where “running wild”, so if you have not already done that, it might be a good idea to measure that you have low ohm connection between the two BNC GNDs. I also replaced both BNC connectors on mine, they where completely worn out…
I do have a memory of that the generator in this one was a bit unstable and difficult to use; when selecting a frequency or level it took time before it settled. The output level where jumping up and down for a couple of seconds (and it was no small jumps either!) and if now my memory is not totally off, the generator also referenced itself against the input level etc. So it might be a good idea to use this instrument in conjunction with a modern low distortion signal generator, I did just that. But the distortion analyser and frequency counter was all good and straight forward. Of course this with reservation for that the generator in my BKF10 might be faulty...
Well that is what I can add regarding this one, as stated in the start of this post, if you or anyone else where able to find a manual I would be very happy to buy a copy!
Thanks Bjorn! I had thought it was the card edge connectors too so I re-soldered all the connections and cleaned the sockets but to no avail. I managed to track it to a op amp on the input buffer pcb that was spewing out noise, I will also check the bnc's.
Would be good to get a service manual for it, if I ever track one down I will be sure to share it here.
Thanks, Ben
Would be good to get a service manual for it, if I ever track one down I will be sure to share it here.
Thanks, Ben
I missed this last year. I have a manual for the BKF-10. Its pretty big and clumsy but very complete. I can get it scanned if you guys still need it.
It will be a few weeks before I can scan the whole manual. It's quite large. If there is something specific I can get that piece for you.
Sent from my SGH-M919 using Tapatalk
Sent from my SGH-M919 using Tapatalk
Thx for reply.
First maybe some technical data of these device, i'm considering of buying one of these meters, and maybe calibration procedure. Pictures will be good enough.
Thank you.
First maybe some technical data of these device, i'm considering of buying one of these meters, and maybe calibration procedure. Pictures will be good enough.
Thank you.
I'll try to get something for you. Don't touch it if its not working. There are a lot of complex interactions so sorting it out, especially if not repairs well could be really challenging. Its all analog so actually harder to sort out that say an HP8903. Working, its really neat. Residual around .005%. The sweep is nice and the autotrack works well. max input is something like 20V so not well suited to amps without an external attenuator. Its real target was tape recorders.
Hey Demian.
If you got round to scanning the BKF10 manual I would also very much like to get a copy if at all possible.
Klarskov
If you got round to scanning the BKF10 manual I would also very much like to get a copy if at all possible.
Klarskov
I finally found the manual. I moved in the intervening period and its been a long slow task to recover. Its the original with lots of schematics. Scanning will be time consuming. I'll try to get that started this weekend. If someone needs a specific page let me know.
OK all scanned You can download it here. https://spaces.hightail.com/receive/2b3WW 152 MB so expect a longer download. The manual is 158 pages of text plus schematics that we had to scan in segments. Its all there I hope. Let me know if something is missing or needs to be rescanned.
I was always very impressed with the sophistication of this all analog system that could track and plot amplitude and distortion VS frequency so cleanly.
I was always very impressed with the sophistication of this all analog system that could track and plot amplitude and distortion VS frequency so cleanly.
The uploaded file seems to be gone already.
Any chance for a re-upload, thank you ?
rgds,
/tricomp
Any chance for a re-upload, thank you ?
rgds,
/tricomp
I uploaded the set to K04BB's manual repository: Manuals - KO4BB You will find it under Misc. test equipment.
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