Farnell DTC12 Oscilloscope - UK Vintage Radio Repair and Restoration Discussion Forum

ex 2 Base · 9th Jun 2018, 9:11 am

I was recently given a Farnell Oscilloscope DTC 12. What are your thoughts on the DTC12 good/bad limitations ?

evingar · 9th Jun 2018, 9:50 am

Pretty low bandwidth (12 MHz) by modern standards.
On the positive side, it looks "fixable" and full service data is available

:-

http://rtellason.com/manuals/Farnell...illoscopes.pdf

9th Jun 2018, 1:48 pm

Looks a fine 'scope for radio work, easy to use too.

turretslug · 9th Jun 2018, 2:29 pm

Should be a very useful diagnostic tool for many vintage hobbyist things- whenever 'scopes come into a discussion amongst tech folk, there's inevitably an element of willie-waving going on- "mine's got quad-trace, 400MHz bandwidth, delay, hold-off, digital capture, I don't know how anyone gets by with anything less, blah, yawn...."- but for a great deal of audio and much radio work, seeing a more-or-less sync'ed wavy line of about the right size says a lot and aids quick trouble-shooting progression. Sounds a good, workaday device.

I see it has mains-derived EHT- that's an obvious caveat when digging around inside and whether a 'scope has mains- or HF-inverter derived EHT, the fine windings on compact cores are an Achille's heel- when storing a 'scope for any length of time be kind and find it a dry spot next to a radiator if you can and at the least keep it under a bin-bag or similar- dust attracts humidity creates corrosion breeds more dust... If it's obviously a previous garage/shed store item, be patient and give it a few days in the warm before rushing to power it.

MotorBikeLes · 9th Jun 2018, 9:46 pm

I seem to recall Peter Waugh telling me this was the Scopex 4D10(A?) but with smaller graduations (perhaps 0.8cm/div instead of 1cm/div) thereby making it effectively a higher bandwidth scope. (bandwidth Xs gain is fairly constant for a given amplifier, in this case Y-amplifier).
Les.

Goldie99 · 9th Jun 2018, 10:01 pm

I've been using a DTC12-5 now & again for several years, and the only problems I've had with it have been dirty contacts related (various switch wafer contacts). Be careful if you need to do any work on it - there are Beryllium Oxide based insulators under some of the transistors, that should ideally be left alone if poss.

Yes, it's very basic, only 12MHz, and years out of calibration, but it's been fine for most of the vintage SS audio amps I tend to work on. I'll probably 'upgrade' to a 20MHz Hameg (or similar) when I come across a convenient one, but until then, it's suited my purposes admirably well - especially for the extortionate sum of £16 that I paid for it, including P&P !!

Alan

9th Jun 2018, 9:11 am	#1
ex 2 Base Heptode Join Date: Nov 2009 Location: Scarborough, North Yorkshire, UK. Posts: 510	Farnell DTC12 Oscilloscope I was recently given a Farnell Oscilloscope DTC 12. What are your thoughts on the DTC12 good/bad limitations ?

9th Jun 2018, 9:50 am	#2
evingar Octode Join Date: Oct 2003 Location: Newbury, Berkshire, UK. Posts: 1,770	Re: Oscilloscope Pretty low bandwidth (12 MHz) by modern standards. On the positive side, it looks "fixable" and full service data is available :- http://rtellason.com/manuals/Farnell...illoscopes.pdf __________________ Chris

9th Jun 2018, 1:48 pm	#3
Guest Guest Posts: n/a	Re: Oscilloscope Looks a fine 'scope for radio work, easy to use too.

9th Jun 2018, 2:29 pm	#4
turretslug Dekatron Join Date: Nov 2011 Location: Surrey, UK. Posts: 4,396	Re: Farnell DTC12 Oscilloscope Should be a very useful diagnostic tool for many vintage hobbyist things- whenever 'scopes come into a discussion amongst tech folk, there's inevitably an element of willie-waving going on- "mine's got quad-trace, 400MHz bandwidth, delay, hold-off, digital capture, I don't know how anyone gets by with anything less, blah, yawn...."- but for a great deal of audio and much radio work, seeing a more-or-less sync'ed wavy line of about the right size says a lot and aids quick trouble-shooting progression. Sounds a good, workaday device. I see it has mains-derived EHT- that's an obvious caveat when digging around inside and whether a 'scope has mains- or HF-inverter derived EHT, the fine windings on compact cores are an Achille's heel- when storing a 'scope for any length of time be kind and find it a dry spot next to a radiator if you can and at the least keep it under a bin-bag or similar- dust attracts humidity creates corrosion breeds more dust... If it's obviously a previous garage/shed store item, be patient and give it a few days in the warm before rushing to power it.

9th Jun 2018, 9:46 pm	#5
MotorBikeLes Nonode Join Date: Dec 2012 Location: Kirk Michael, Isle of Man Posts: 2,350	Re: Farnell DTC12 Oscilloscope I seem to recall Peter Waugh telling me this was the Scopex 4D10(A?) but with smaller graduations (perhaps 0.8cm/div instead of 1cm/div) thereby making it effectively a higher bandwidth scope. (bandwidth Xs gain is fairly constant for a given amplifier, in this case Y-amplifier). Les.

9th Jun 2018, 10:01 pm	#6
Goldie99 Heptode Join Date: Jul 2014 Location: Boston, Lincolnshire, UK. Posts: 995	Re: Farnell DTC12 Oscilloscope I've been using a DTC12-5 now & again for several years, and the only problems I've had with it have been dirty contacts related (various switch wafer contacts). Be careful if you need to do any work on it - there are Beryllium Oxide based insulators under some of the transistors, that should ideally be left alone if poss. Yes, it's very basic, only 12MHz, and years out of calibration, but it's been fine for most of the vintage SS audio amps I tend to work on. I'll probably 'upgrade' to a 20MHz Hameg (or similar) when I come across a convenient one, but until then, it's suited my purposes admirably well - especially for the extortionate sum of £16 that I paid for it, including P&P !! Alan