Scopex 4D10a - UK Vintage Radio Repair and Restoration Discussion Forum

Burnt wire · 8th Jul 2020, 10:36 pm

Hi there all,
I've just got a Scopex 4D10a and I didnt get any probes with it, so I purchased some probes and I'm damned if I can find out how to do the compensation on the scope ! If any one can give some info I'd appreciate it. they have 1x and 10x switch.

PETERg0rsq · 8th Jul 2020, 11:41 pm

Pretty sure there is no option for probe compensation on this scope.

Channels can be compensated internally, but reference is made to do it with a Scope calibrator connected directly to the chanel inputs.

If you are after a manual, look for one for a Racal 9386, as they are the same scope.

If you can't find it on the web, I can send a pdf copy.

ajgriff · 9th Jul 2020, 8:13 am

Most probes have their own compensation adjustment. Look for a small screw on the probe body.

Alan

David G4EBT · 9th Jul 2020, 8:41 am

Maybe I’m missing something, but as Alan says, every scope probe I’ve had has a small screw to tweak to adjust the compensation.

As often as not the probes have come with instructions and some included a small screwdriver.

Some info re the necessity for compensation here:

https://www.electronics-notes.com/ar...mpensation.php

Neutrino · 9th Jul 2020, 8:41 am

The photos show:
• Probe Compensation Instructions
• Trimmer tool pointing to the trimmer
• Scopex 4D10A with probe having been adjusted (Note the excellent book propping up the scope!)
Most scopes have a probe adjust output that provides a square wave but the Scopex 4D10A doesn’t. I use my Aneng AN8008 which is reviewed here:
https://www.vintage-radio.net/forum/...d.php?t=138122
David

Ambientnoise · 9th Jul 2020, 10:18 am

If you’ve bought x1 probes (as opposed to x10 or x100), they almost certainly will not have an adjustment on the probe.

ajgriff · 9th Jul 2020, 10:25 am

If they are switchable x1/x10 probes as stated they should have compensation adjustment.

Alan

DonaldStott · 9th Jul 2020, 3:11 pm

My probes have an adjustable x1/x10 slider switch:-

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ajgriff · 9th Jul 2020, 3:38 pm

..... and the compensation adjustment screw can be seen just next to the switch.

Alan

Burnt wire · 9th Jul 2020, 6:35 pm

Thanks for the input, I've found out the Scopex has its probes hooked up to an external square wave generator to adjust compensation. So I have managed to find one and when it arrives I'll be able to sort it out..

8th Jul 2020, 10:36 pm	#1
Burnt wire Tetrode Join Date: Mar 2018 Location: Plymouth, Devonshire, UK. Posts: 56	Scopex 4D10a Hi there all, I've just got a Scopex 4D10a and I didnt get any probes with it, so I purchased some probes and I'm damned if I can find out how to do the compensation on the scope ! If any one can give some info I'd appreciate it. they have 1x and 10x switch.

8th Jul 2020, 11:41 pm	#2
PETERg0rsq Heptode Join Date: Jun 2009 Location: St Helens, Lancashire, UK. Posts: 641	Re: Scopex 4D10a Pretty sure there is no option for probe compensation on this scope. Channels can be compensated internally, but reference is made to do it with a Scope calibrator connected directly to the chanel inputs. If you are after a manual, look for one for a Racal 9386, as they are the same scope. If you can't find it on the web, I can send a pdf copy. __________________ SPECIALIST.....Knows everything about nothing EXPERT..........Knows nothing about everything

9th Jul 2020, 8:13 am	#3
ajgriff Nonode Join Date: May 2004 Location: Halifax, West Yorkshire, UK. Posts: 2,587	Re: Scopex 4D10a Most probes have their own compensation adjustment. Look for a small screw on the probe body. Alan

9th Jul 2020, 8:41 am	#4
David G4EBT Dekatron Join Date: Feb 2003 Location: Cottingham, East Yorkshire, UK. Posts: 5,760	Re: Scopex 4D10a Maybe I’m missing something, but as Alan says, every scope probe I’ve had has a small screw to tweak to adjust the compensation. As often as not the probes have come with instructions and some included a small screwdriver. Some info re the necessity for compensation here: https://www.electronics-notes.com/ar...mpensation.php __________________ David. BVWS Member. G-QRP Club member 1339.

9th Jul 2020, 8:41 am	#5
Neutrino Pentode Join Date: Oct 2016 Location: Maldon, Essex, UK. Posts: 182	Re: Scopex 4D10a The photos show: • Probe Compensation Instructions • Trimmer tool pointing to the trimmer • Scopex 4D10A with probe having been adjusted (Note the excellent book propping up the scope!) Most scopes have a probe adjust output that provides a square wave but the Scopex 4D10A doesn’t. I use my Aneng AN8008 which is reviewed here: https://www.vintage-radio.net/forum/...d.php?t=138122 David Attached Thumbnails

9th Jul 2020, 10:18 am	#6
Ambientnoise Heptode Join Date: Feb 2006 Location: Marlborough, Wiltshire, UK. Posts: 915	Re: Scopex 4D10a If you’ve bought x1 probes (as opposed to x10 or x100), they almost certainly will not have an adjustment on the probe.

9th Jul 2020, 10:25 am	#7
ajgriff Nonode Join Date: May 2004 Location: Halifax, West Yorkshire, UK. Posts: 2,587	Re: Scopex 4D10a If they are switchable x1/x10 probes as stated they should have compensation adjustment. Alan

9th Jul 2020, 3:11 pm	#8
DonaldStott Octode Join Date: Aug 2015 Location: Glasgow, UK. Posts: 1,842	Re: Scopex 4D10a My probes have an adjustable x1/x10 slider switch:- __________________ BVWS Member

9th Jul 2020, 3:38 pm	#9
ajgriff Nonode Join Date: May 2004 Location: Halifax, West Yorkshire, UK. Posts: 2,587	Re: Scopex 4D10a ..... and the compensation adjustment screw can be seen just next to the switch. Alan

9th Jul 2020, 6:35 pm	#10
Burnt wire Tetrode Join Date: Mar 2018 Location: Plymouth, Devonshire, UK. Posts: 56	Re: Scopex 4D10a Thanks for the input, I've found out the Scopex has its probes hooked up to an external square wave generator to adjust compensation. So I have managed to find one and when it arrives I'll be able to sort it out..