Maker Pro
Maker Pro

Wartime Minicsope oscilloscope , any info/sources ?

N

N_Cook

Jan 1, 1970
0
http://home.graffiti.net/diverse:graffiti.net/miniscope9.jpg

Made for ultra portability fits in an 8x11x 2.5 inch case when the thyratron
and vibrator are removed from the chassis and stowed near the hinge. What
war time use was there for such a small 'scope, with in-the-field 12V supply
capability?
War finish presumably means the off white enamel rather than black crackle
finish.
Plate on the brown casing lid
Miniscope
Miniature C/R oscilloscope
Pattern No 58259

Stencilled labels on the case are
R.L. 4
and No 1

Presumably somewhere would have info on the pattern number.
Even using "-dr who" googling does not find anything on Miniscope or that
pattern number, plenty on the 6K25 thyratron but nothing on 9 pin VR91,
10E/92 voltage regulator? or 9 pin CRT
VCR 522, 10E/787, Design Inspected CRT 4
(shattered probably when the shoulder carrying strap broke and corner brace
broke off and split occured in the "suitcase" )
no other valves,
also Masteradio G650 12V vibrator, military trident symbol in a couple of
places , after an A on the VR91 and before a Z on the CRT
side panels missing, someone has crudely bodged in pot .


http://home.graffiti.net/diverse:graffiti.net/miniscope1.jpg
http://home.graffiti.net/diverse:graffiti.net/miniscope2.jpg
http://home.graffiti.net/diverse:graffiti.net/miniscope3.jpg
http://home.graffiti.net/diverse:graffiti.net/miniscope4.jpg
specs etc on hinge-down, prop-up plate
http://home.graffiti.net/diverse:graffiti.net/miniscope5.jpg
http://home.graffiti.net/diverse:graffiti.net/miniscope7.jpg
 
J

Jeffrey D Angus

Jan 1, 1970
0
N_Cook said:
Made for ultra portability fits in an 8x11x 2.5 inch case

Well that's certainly a clever bit of kit.

Keep us posted if you find out anything about it.

Jeff
 
E

engineer

Jan 1, 1970
0
What a neat piece of history! Never seen one before so can't add any info.
Pity about the broken CRT - is it replaceable? Also, I love the words "time
base" on the label - takes me back to those days of yesteryear!

BTW, the VR91/EF50 is an RF pentode - I once had an old TRF, one channel TV
(Pye 19T) that used several of them in the RF strip. One of my first
"serious" tube(valve) proejcts was to build an ITV converter from scrap WW2
parts to convert circa 180 MHz ITV to the circa 42.5 MHz (vision) and 41.5
MHz (sound) antenna input of the Pye 19T (I forget the actual frequencies.)
Cheers,
Roger
 
N

N_Cook

Jan 1, 1970
0
engineer said:
What a neat piece of history! Never seen one before so can't add any info.
Pity about the broken CRT - is it replaceable? Also, I love the words "time
base" on the label - takes me back to those days of yesteryear!

BTW, the VR91/EF50 is an RF pentode - I once had an old TRF, one channel TV
(Pye 19T) that used several of them in the RF strip. One of my first
"serious" tube(valve) proejcts was to build an ITV converter from scrap WW2
parts to convert circa 180 MHz ITV to the circa 42.5 MHz (vision) and 41.5
MHz (sound) antenna input of the Pye 19T (I forget the actual frequencies.)
Cheers,
Roger


I picked it up at a "silent key" disposal at a carboot sale. Inheritors had
no knowldege about it. The valves etc may not be what was originally in
there of course.
 
A

Arfa Daily

Jan 1, 1970
0
N_Cook said:
http://home.graffiti.net/diverse:graffiti.net/miniscope9.jpg

Made for ultra portability fits in an 8x11x 2.5 inch case when the
thyratron
and vibrator are removed from the chassis and stowed near the hinge. What
war time use was there for such a small 'scope, with in-the-field 12V
supply
capability?
War finish presumably means the off white enamel rather than black crackle
finish.
Plate on the brown casing lid
Miniscope
Miniature C/R oscilloscope
Pattern No 58259

Stencilled labels on the case are
R.L. 4
and No 1

Presumably somewhere would have info on the pattern number.
Even using "-dr who" googling does not find anything on Miniscope or that
pattern number, plenty on the 6K25 thyratron but nothing on 9 pin VR91,
10E/92 voltage regulator? or 9 pin CRT
VCR 522, 10E/787, Design Inspected CRT 4
(shattered probably when the shoulder carrying strap broke and corner
brace
broke off and split occured in the "suitcase" )
no other valves,
also Masteradio G650 12V vibrator, military trident symbol in a couple of
places , after an A on the VR91 and before a Z on the CRT
side panels missing, someone has crudely bodged in pot .


http://home.graffiti.net/diverse:graffiti.net/miniscope1.jpg
http://home.graffiti.net/diverse:graffiti.net/miniscope2.jpg
http://home.graffiti.net/diverse:graffiti.net/miniscope3.jpg
http://home.graffiti.net/diverse:graffiti.net/miniscope4.jpg
specs etc on hinge-down, prop-up plate
http://home.graffiti.net/diverse:graffiti.net/miniscope5.jpg
http://home.graffiti.net/diverse:graffiti.net/miniscope7.jpg

VR91 / EF50 was used in many wartime radios and early radar units (PPI and
pulse position). I owned a '1392 ex RAF vhf control tower receiver for many
years, and that was full of them.

Arfa
 
N

N_Cook

Jan 1, 1970
0
Arfa Daily said:
VR91 / EF50 was used in many wartime radios and early radar units (PPI and
pulse position). I owned a '1392 ex RAF vhf control tower receiver for many
years, and that was full of them.

Arfa

I downloaded the GEC schematic from
http://www.thevalvepage.com/download/download.php?file=miniscope.pdf&dir=gec
but substantially different, except 4V and 6.3V heaters agree with
VCR 522
and VR91.
Looks as though I'll have to get/derive the
CRT VCR 722/ CV1522 or related E4103/B/4 / CV320 / CV967 / CV335 pinout and
maybe de-topologize for the schematic.
But I'd really like to find out what sort of use it was put to, most likely
tech
museum or forum to try ?
Very large print , 1 inch high letters "R.L.4" = radio location unit 4 ?
 
N

N_Cook

Jan 1, 1970
0
Of course a broken CRT makes it easy to determine pinning.
As broke unpowered the heater is still there, all 4 X,Y plates exposed and
A3 so just leaves A2 and grid undetermined without destroying the envelope
more.
155mm long, 1.5 in diam, and 7 out of 9 pins agrees with GEC 4103/B/4 with
1.1KV pda and 4V heater.
And I have the pinning for the 6K25 and pentode.
I may scan in the board edges, as is with added valve pin labels , and
multi-photo before undoing and trying to unravel the schematic while trying
to find out about its likely in service use.
 
H

hr(bob) [email protected]

Jan 1, 1970
0
Of course a broken CRT makes it easy to determine pinning.
As broke unpowered the heater is still there, all 4 X,Y plates exposed and
A3 so just leaves A2 and grid undetermined without destroying the envelope
more.
155mm long, 1.5 in diam, and 7 out of 9 pins agrees with GEC 4103/B/4 with
1.1KV pda and 4V heater.
And I have the pinning for the 6K25 and pentode.
I may scan in the board edges, as is with added valve pin labels , and
multi-photo before undoing and trying to unravel the schematic while trying
to find out about its likely in service use.

Would someone at the, if I remember from a visit to London 10 years
ago, British War Museum be able to help you?
 
N

N_Cook

Jan 1, 1970
0
Of course a broken CRT makes it easy to determine pinning.
As broke unpowered the heater is still there, all 4 X,Y plates exposed and
A3 so just leaves A2 and grid undetermined without destroying the envelope
more.
155mm long, 1.5 in diam, and 7 out of 9 pins agrees with GEC 4103/B/4 with
1.1KV pda and 4V heater.
And I have the pinning for the 6K25 and pentode.
I may scan in the board edges, as is with added valve pin labels , and
multi-photo before undoing and trying to unravel the schematic while trying
to find out about its likely in service use.
onhttp://home.graffiti.net/diverse:graffiti.net/

Would someone at the, if I remember from a visit to London 10 years
ago, British War Museum be able to help you?

******

I'd thought of contacting Kew ,PRO, national archives, but the Imperial War
Museum makes sense as well.
I'm a bit concerned with the use of the word pattern before the number 53259
in that it may relate to the "samsonite" case rather than scope although
etched on to the metal plate refering to C/R oscilloscope, I will take
another pic later . Perhaps there is a GEC archive somewhere other than Kew
and the war museum.
 
N

N_Cook

Jan 1, 1970
0
Of course a broken CRT makes it easy to determine pinning.
As broke unpowered the heater is still there, all 4 X,Y plates exposed and
A3 so just leaves A2 and grid undetermined without destroying the envelope
more.
155mm long, 1.5 in diam, and 7 out of 9 pins agrees with GEC 4103/B/4 with
1.1KV pda and 4V heater.
And I have the pinning for the 6K25 and pentode.
I may scan in the board edges, as is with added valve pin labels , and
multi-photo before undoing and trying to unravel the schematic while trying
to find out about its likely in service use.
onhttp://home.graffiti.net/diverse:graffiti.net/

Would someone at the, if I remember from a visit to London 10 years
ago, British War Museum be able to help you?

*****

GEC/Marconi archives site
http://www.marconicalling.com/front.htm
seems to be defunct

I will try contacting
http://www.theiet.org/about/libarc/index.cfm
and am aware of a very active retired members branch around Portsmouth
http://www.theiet.org/local/uk/south/solent/rm-section.cfm
who may be able to help as I seem to remember GEC had a site in Pompey
 
T

terry

Jan 1, 1970
0
VR91 / EF50 was used in many wartime radios and early radar units (PPI and
pulse position). I owned a '1392 ex RAF vhf control tower receiver for many
years, and that was full of them.

Arfa- Hide quoted text -

- Show quoted text -

VR91/EF50 High gain pentode. Many of them were painted red. Some were
manufactured in the USA for Britain (I have one marked Sylvania').
They have a special 9 pin base. AIUI tube was based on a Dutch Philips
design.
Had always assumed they were a non-variable mu RF or IF pentode, which
were also used in some early mid-war aircraft radar receiver plug-in
units labelled RF24 through RF27 available on the surplus market after
WWII. But in a discussion some years ago on a group such as this, one
poster found the characteristics and pointed out that the tube did not
have a sharp control grid cut-off.
Cheers for 2009
 
N

N_Cook

Jan 1, 1970
0
Mike said:
Assuming that it's military, I think the "R" would stand for Radio.
The "L" would stand for Laboratory (test & calibration).

http://www.hypertools.com/nomenclature.html


I have to disagree. No laboratory equipment would be made deliberately too
small, requiring the removal of parts before placing in a protective
housing.
This was made to be ultra-portable, the smallest possible carrying case for
discretion, airbourne use, or covert reason, I would suggest. Routine
military equiptment is not made for the effete to carry around. Come to
think of it wartime airbourne radios etc were not made deliberately light or
compact.

Drawing out the preliminary circuit topology is half complete, i will place
on the page
http://home.graffiti.net/diverse:graffiti.net/miniscope.htm
when nearer complete, before unravelling for the intermediary schematic.
 
Top