Anyone Recognise this scope? - UK Vintage Radio Repair and Restoration Discussion Forum

davegsm82 · 9th Dec 2010, 6:26 pm

A long time ago, I bought this DIY scope from someone, I cant even remember how I came to buy it but I did.

I beleive its a 'Heathkit', possibly, something to do with a self-teach course I've seen in old Practical wireless or Practical Electronics mags.

It consists (electrically) of a Mullard D7-5 or D7-31 tube (cant remember which, I have both) and there are only 2 valves used as well as a silicon bridge rectifier. I beleive the valves are possibly EF80's or ECF80's, I have a box with 2 of each with the scope.

I'd like to find the original schematics or build instructions, then possibly I will re-build it to this spec or find another more accomodating design, ultimately with more valves and features.

Here are the pictures anyway...

Stockden · 9th Dec 2010, 7:06 pm

Not Heathkit (at least not in the sense of being produced by Heath/Daystrom) but certainly looking like one that appeared in ads for one of the postal radio/electronics courses in the 60's & 70's. Unfortunately I don't have any information on it.

Hugh

ParcGwyn · 9th Dec 2010, 8:12 pm

It certainly looks like the one in the attached advertisment. If anyone has a copy of the circuit diagram they can post I would like to see it.

If you are interested in just building a simple scope see my website below.

Dave
GW7ONS
http://www.parcgwyn.talktalk.net

davegsm82 · 10th Dec 2010, 12:35 am

Hi Dave.

Thats the Very advert I was thinking about! It does look a lot like that one if not identical.

I think I searched a long time ago for the 'school' at the bottom of the advert, to no avail.

I'd love it if someone actually has the schematic for it, I hate it sitting there just being a box of bits. Its not that I need a scope either, I have a couple of Tectronix TDS range LCD scopes, but I just love the glow of my analogue valve ones as much.

Thanks, Dave.

MichaelR · 10th Dec 2010, 4:01 am

I can confirm that the scope is exactly that shown in the advert. I actually purchased that course and built the scope in 1969 when I was a wee lad.

It was not cheap and I must say not a very useful scope , good enough as a monitor , I think it only had a bandwidth of about 1 MHZ ( could be wrong ). However you have got to remember that in those days scopes were very expensive and very few amateurs had acess to them privately.

Regards
Mike

davegsm82 · 11th Dec 2010, 1:07 am

Hi Mike,

Its a longshot, but you don't still have the documentation for it do you?

Thanks, Dave.

MichaelR · 11th Dec 2010, 1:13 am

Hi Dave,

I am afraid I do not , I remember it was published by the British National Radio School, I would post a request for it because I bet somebody has got it.

Mike

Staigen · 16th Jan 2011, 3:13 pm

Hi Dave,

I found this out on the internet some while ago, i am sure it is the right schematic.

//Staigen

MichaelR · 16th Jan 2011, 4:54 pm

Well done, that is definitely the scope I built. Be careful with the Y plates It is easy to get a shock off those sockets.

Mike

Staigen · 16th Jan 2011, 6:25 pm

What are the Y outputs for? And wich tubes are used(I mean the pentodes)? Let me guess, its EF80:s or EF184:s. Also, can anyone explain to me how the T/B oscillator works? I have seen this type of osillator in many DIY scopes!

//Staigen

Tractorfan · 17th Jan 2011, 10:28 pm

Hi,
Wasn't there a company called "Philip Harris" that sold 'scope kits? I may have had one before we moved here. No idea what became of it.
Cheers, Pete

Ray Cooper · 17th Jan 2011, 11:10 pm

Quote:

Originally Posted by Staigen

...can anyone explain to me how the T/B oscillator works? I have seen this type of osillator in many DIY scopes!

It sees to be a circuit called either a Miller Transitron, or Phantastron. These are a crafty bit of circuitry and were very widely used in WWII radar gear. A Google on either of the above names should tell you all you want to know.

Bumblebee · 18th Jan 2011, 12:59 am

Quote:

Originally Posted by Staigen

I found this out on the internet some while ago, i am sure it is the right schematic.

I put this Circuit diagram on here last week for Dave last week. I have one of these that I bulit in 1978.
Mark (Bumblebee)

Staigen · 18th Jan 2011, 8:36 am

Ok, I belive it was right here I found it then.

I would also like to build this scope, but I dont have a DG7-31 CRT, only a DG7-32. Someone that have one for sale?

//Staigen

Ed_Dinning · 18th Jan 2011, 8:50 pm

Hi Staigen, see if you can find the datasheet for the tubes and you may find they are interchangeable, or only require a minor mod the the voltage chain across the tube.

Happy building, Ed

Ray Cooper · 18th Jan 2011, 11:53 pm

Datasheets for these tubes available here:

http://frank.pocnet.net/sheetsD1.html

ParcGwyn · 19th Jan 2011, 7:31 pm

The DG7-31 was designed for the x-plates to be driven asymmetrically whilst the DG7-32 was designed for symmetric operation. An alternative to the DG7-31 is a DG7-6 although you may have to adjust a few voltages.

Regards

Dave
GW7ONS
www.parcgwyn.talktalk.net

Staigen · 21st Jan 2011, 10:37 pm

Hi, sorry I havent replied earlier.

Quote:

Datasheets for these tubes available here:

http://frank.pocnet.net/sheetsD1.html

I allready have those datasheets, and more on the DG7-32/01, and now I also have on DG7-31, DG731/01 and DG7-32.
Frank's tube datasheets I have known for several years, too.
I belive I can build it with the DG7-32/01 that I already have, and will start a new thread when i do, with pictures and all, that is going to be fun.

Quote:

The DG7-31 was designed for the x-plates to be driven asymmetrically whilst the DG7-32 was designed for symmetric operation

I allready know that, but thanks anyway.

Quote:

An alternative to the DG7-31 is a DG7-6

I dont have a DG7-6.

//Staigen

glowinganode · 14th Jan 2012, 2:14 pm

Do you still need a crt?
Rob.

9th Dec 2010, 6:26 pm	#1
davegsm82 Heptode Join Date: Jan 2004 Location: Blyth, Northumberland, UK. Posts: 858	Anyone Recognise this scope? A long time ago, I bought this DIY scope from someone, I cant even remember how I came to buy it but I did. I beleive its a 'Heathkit', possibly, something to do with a self-teach course I've seen in old Practical wireless or Practical Electronics mags. It consists (electrically) of a Mullard D7-5 or D7-31 tube (cant remember which, I have both) and there are only 2 valves used as well as a silicon bridge rectifier. I beleive the valves are possibly EF80's or ECF80's, I have a box with 2 of each with the scope. I'd like to find the original schematics or build instructions, then possibly I will re-build it to this spec or find another more accomodating design, ultimately with more valves and features. Here are the pictures anyway... Attached Thumbnails

9th Dec 2010, 7:06 pm	#2
Stockden Heptode Join Date: Mar 2008 Location: Forest of Dean, Gloucestershire, UK. Posts: 648	Re: Anyone Recognise this scope? Not Heathkit (at least not in the sense of being produced by Heath/Daystrom) but certainly looking like one that appeared in ads for one of the postal radio/electronics courses in the 60's & 70's. Unfortunately I don't have any information on it. Hugh Last edited by Stockden; 9th Dec 2010 at 7:06 pm. Reason: clarification

9th Dec 2010, 8:12 pm	#3
ParcGwyn Hexode Join Date: Jun 2005 Location: Aberystwyth, Wales, UK. Posts: 358	Re: Anyone Recognise this scope? It certainly looks like the one in the attached advertisment. If anyone has a copy of the circuit diagram they can post I would like to see it. If you are interested in just building a simple scope see my website below. Dave GW7ONS http://www.parcgwyn.talktalk.net Attached Thumbnails Last edited by ParcGwyn; 9th Dec 2010 at 8:36 pm. Reason: adding more info

10th Dec 2010, 12:35 am	#4
davegsm82 Heptode Join Date: Jan 2004 Location: Blyth, Northumberland, UK. Posts: 858	Re: Anyone Recognise this scope? Hi Dave. Thats the Very advert I was thinking about! It does look a lot like that one if not identical. I think I searched a long time ago for the 'school' at the bottom of the advert, to no avail. I'd love it if someone actually has the schematic for it, I hate it sitting there just being a box of bits. Its not that I need a scope either, I have a couple of Tectronix TDS range LCD scopes, but I just love the glow of my analogue valve ones as much. Thanks, Dave.

10th Dec 2010, 4:01 am	#5
MichaelR Retired Dormant Member Join Date: Mar 2006 Location: Sheffield, South Yorkshire, UK. Posts: 1,587	Re: Anyone Recognise this scope? I can confirm that the scope is exactly that shown in the advert. I actually purchased that course and built the scope in 1969 when I was a wee lad. It was not cheap and I must say not a very useful scope , good enough as a monitor , I think it only had a bandwidth of about 1 MHZ ( could be wrong ). However you have got to remember that in those days scopes were very expensive and very few amateurs had acess to them privately. Regards Mike

11th Dec 2010, 1:07 am	#6
davegsm82 Heptode Join Date: Jan 2004 Location: Blyth, Northumberland, UK. Posts: 858	Re: Anyone Recognise this scope? Hi Mike, Its a longshot, but you don't still have the documentation for it do you? Thanks, Dave.

11th Dec 2010, 1:13 am	#7
MichaelR Retired Dormant Member Join Date: Mar 2006 Location: Sheffield, South Yorkshire, UK. Posts: 1,587	Re: Anyone Recognise this scope? Hi Dave, I am afraid I do not , I remember it was published by the British National Radio School, I would post a request for it because I bet somebody has got it. Mike

16th Jan 2011, 4:54 pm	#9
MichaelR Retired Dormant Member Join Date: Mar 2006 Location: Sheffield, South Yorkshire, UK. Posts: 1,587	Re: Anyone Recognise this scope? Well done, that is definitely the scope I built. Be careful with the Y plates It is easy to get a shock off those sockets. Mike

16th Jan 2011, 6:25 pm	#10
Staigen Retired Dormant Member Join Date: Jan 2011 Location: Timmersdala, Vastra Gotaland, Sweden. Posts: 13	Re: Anyone Recognise this scope? What are the Y outputs for? And wich tubes are used(I mean the pentodes)? Let me guess, its EF80:s or EF184:s. Also, can anyone explain to me how the T/B oscillator works? I have seen this type of osillator in many DIY scopes! //Staigen

17th Jan 2011, 10:28 pm	#11
Tractorfan Dekatron Join Date: Mar 2008 Location: St. Frajou, l'Isle en Dodon, Haute Garonne, France.(Previously: Ellesmere Port, Cheshire, UK.) Posts: 3,184	Re: Anyone Recognise this scope? Hi, Wasn't there a company called "Philip Harris" that sold 'scope kits? I may have had one before we moved here. No idea what became of it. Cheers, Pete __________________ "Hello?, Yes, I'm on the train, I might lose the signal soon as we're just going into a tunn..."

18th Jan 2011, 8:36 am	#14
Staigen Retired Dormant Member Join Date: Jan 2011 Location: Timmersdala, Vastra Gotaland, Sweden. Posts: 13	Re: Anyone Recognise this scope? Ok, I belive it was right here I found it then. I would also like to build this scope, but I dont have a DG7-31 CRT, only a DG7-32. Someone that have one for sale? //Staigen Last edited by Brian R Pateman; 18th Jan 2011 at 1:32 pm. Reason: Quote fixed.

18th Jan 2011, 8:50 pm	#15
Ed_Dinning Dekatron Join Date: Jan 2004 Location: Newcastle upon Tyne, Tyne & Wear, UK. Posts: 8,196	Re: Anyone Recognise this scope? Hi Staigen, see if you can find the datasheet for the tubes and you may find they are interchangeable, or only require a minor mod the the voltage chain across the tube. Happy building, Ed

18th Jan 2011, 11:53 pm	#16
Ray Cooper Retired Dormant Member Join Date: Jan 2007 Location: Porthmadog, Gwynedd, UK. Posts: 199	Re: Anyone Recognise this scope? Datasheets for these tubes available here: http://frank.pocnet.net/sheetsD1.html

19th Jan 2011, 7:31 pm	#17
ParcGwyn Hexode Join Date: Jun 2005 Location: Aberystwyth, Wales, UK. Posts: 358	Re: Anyone Recognise this scope? The DG7-31 was designed for the x-plates to be driven asymmetrically whilst the DG7-32 was designed for symmetric operation. An alternative to the DG7-31 is a DG7-6 although you may have to adjust a few voltages. Regards Dave GW7ONS www.parcgwyn.talktalk.net

14th Jan 2012, 2:14 pm	#19
glowinganode Octode Join Date: Apr 2009 Location: Aylesbury, Buckinghamshire, UK. Posts: 1,522	Re: Anyone Recognise this scope? Do you still need a crt? Rob. __________________ We have done so much, for so long, with so little, we are now qualified to do anything with nothing.