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



--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/

VR91 would seem a pentode
http://www.radiomuseum.org/tubes/tube_vr91.html

CRTm some info
www.radiomuseum.org/tubes/tube_vcr522.html


--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/

N_Cook wrote:
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

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_Cook" wrote in message
...

VR91 would seem a pentode
http://www.radiomuseum.org/tubes/tube_vr91.html

CRTm some info
www.radiomuseum.org/tubes/tube_vcr522.html


--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/

On Thu, 1 Jan 2009 16:10:05 -0000, "N_Cook" wrote:


VR91 would seem a pentode

equivalent EF50 (often red coating) was used a lot in early TRF televisions.

Bit of info on the 6K25 - probably used for a timebase:-
http://www.domino405.co.uk/documents...V71_Series.pdf

--
Geo

engineer wrote in message
...
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_Cook" wrote in message
...

VR91 would seem a pentode
http://www.radiomuseum.org/tubes/tube_vr91.html

CRTm some info
www.radiomuseum.org/tubes/tube_vcr522.html


--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/






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.

--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/

Mike wrote in message
news


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.

Looks like a "Malvern" variant from this page:
http://www.thevalvepage.com/testeq/scope.htm


Thanks for that
I've used or repaired nearly all those on bottom 3 rows and a few of the
earlier

http://www.thevalvepage.com/testeq/g.../miniscope.htm
GEC one looks very similar externally, especially the prop plate
The chassis dimensions are similar, this one 8 x 6.5 x 2.25 inches but
valves and internals are look earlier.

--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/

"N_Cook" wrote in message
...
http://home.graffiti.net/diverse:gra...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:gra...miniscope1.jpg
http://home.graffiti.net/diverse:gra...miniscope2.jpg
http://home.graffiti.net/diverse:gra...miniscope3.jpg
http://home.graffiti.net/diverse:gra...miniscope4.jpg
specs etc on hinge-down, prop-up plate
http://home.graffiti.net/diverse:gra...miniscope5.jpg
http://home.graffiti.net/diverse:gra...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

Arfa Daily wrote in message
...

"N_Cook" wrote in message
...
http://home.graffiti.net/diverse:gra...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:gra...miniscope1.jpg
http://home.graffiti.net/diverse:gra...miniscope2.jpg
http://home.graffiti.net/diverse:gra...miniscope3.jpg
http://home.graffiti.net/diverse:gra...miniscope4.jpg
specs etc on hinge-down, prop-up plate
http://home.graffiti.net/diverse:gra...miniscope5.jpg
http://home.graffiti.net/diverse:gra...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



I downloaded the GEC schematic from
http://www.thevalvepage.com/download...pe.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 ?

--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/

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.


--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/

On Jan 1, 4:08*pm, "N_Cook" wrote:
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.

--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list 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?

hr(bob) wrote in message
...
On Jan 1, 4:08 pm, "N_Cook" wrote:
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.

--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list
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.



--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/

hr(bob) wrote in message
...
On Jan 1, 4:08 pm, "N_Cook" wrote:
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.

--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list
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...rm-section.cfm
who may be able to help as I seem to remember GEC had a site in Pompey


--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/

I've put a page together on
http://home.graffiti.net/diverse:gra.../miniscope.htm
with a pic of the case top with the "R.L.4" stencil

and will add to when I've found out any more


--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/

In article ,
"N_Cook" wrote:

http://home.graffiti.net/diverse:gra...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.

I don't know if you found this page or not, but it may be of help.
There's a claim to a service manual for (some model of) the GEC
miniscope, among other details. I have no idea if it's the same basic
design or not, but they do look at least related.

http://www.thevalvepage.com/testeq/g.../miniscope.htm

Presumably it's the civilian finish for the one on that page, what with
fancier knobs and such.

--
Andrew Erickson

"He is no fool who gives what he cannot keep to gain that which he cannot
lose." -- Jim Elliot

CUTE, I want one!!! I sold my Jackson 1" 'scope a few years ago and regret
it.

John H.

On Jan 1, 4:22*pm, "Arfa Daily" wrote:
"N_Cook" wrote in message

...





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

Mike wrote in message
...
On Fri, 2 Jan 2009 12:25:35 -0000, "N_Cook" wrote:

I've put a page together on
http://home.graffiti.net/diverse:gra.../miniscope.htm
with a pic of the case top with the "R.L.4" stencil

and will add to when I've found out any more

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:gra.../miniscope.htm
when nearer complete, before unravelling for the intermediary schematic.

--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/

Solomon K. wrote in message
...
On Fri, 2 Jan 2009 23:07:57 -0500, "HagstAr"
wrote:

CUTE, I want one!!! I sold my Jackson 1" 'scope a few years ago and
regret
it.

John H.

You can bid on one now. Starting at £49.99


http://cgi.ebay.co.uk/GEC-Miniscope-...temZ1603075191
37QQcmdZViewItemQQimsxZ20090101?IMSfp=TL0901011120 02r15921


"Condition unknown, NOT been powered up" very wise
Anyone know of an E4103/B/4 or compatible CRT around the UK ?
I quite often see similar at radio rallies.


--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/

Solomon K. wrote in message
...
On Fri, 2 Jan 2009 23:07:57 -0500, "HagstAr"
wrote:

CUTE, I want one!!! I sold my Jackson 1" 'scope a few years ago and
regret
it.

John H.

You can bid on one now. Starting at £49.99


http://cgi.ebay.co.uk/GEC-Miniscope-...temZ1603075191
37QQcmdZViewItemQQimsxZ20090101?IMSfp=TL0901011120 02r15921


"Condition unknown, NOT been powered up" very wise
Anyone know of an E4103/B/4 or compatible CRT around the UK ?
I quite often see similar at radio rallies.


--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/

On Jan 3, 9:02*am, "N_Cook" wrote:

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 pagehttp://home.graffiti.net/diverse:graffiti.net/miniscope.htm
when nearer complete, before unravelling for the intermediary schematic.

I agree with you Nigel. The fact it runs on 12VDC [the GEC Miniscope
does not] would indicate it was for mobile or field use where where
'mains' power was unavailable. I was thinking the RL might be 'radio
location' where it could be used for timing compaison or phasing check
as ground mobile. The transit case and the external vibrator smack of
a 'modified' unit for temporary applications. I get the impression
that the GEC uses a horizontal multivibator so the thyratron may also
be a mod for some special requirement. Since it looks to be able to
operate from mains and aircraft power as well, the application was
likely broadly used. Also could be for adjusting or troubleshooting
high speed data circuits [teletype].

Neil S.

nesesu wrote in message
...
On Jan 3, 9:02 am, "N_Cook" wrote:

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 pagehttp://home.graffiti.net/diverse:graffiti.net/miniscope.htm
when nearer complete, before unravelling for the intermediary schematic.

I agree with you Nigel. The fact it runs on 12VDC [the GEC Miniscope
does not] would indicate it was for mobile or field use where where
'mains' power was unavailable. I was thinking the RL might be 'radio
location' where it could be used for timing compaison or phasing check
as ground mobile. The transit case and the external vibrator smack of
a 'modified' unit for temporary applications. I get the impression
that the GEC uses a horizontal multivibator so the thyratron may also
be a mod for some special requirement. Since it looks to be able to
operate from mains and aircraft power as well, the application was
likely broadly used. Also could be for adjusting or troubleshooting
high speed data circuits [teletype].

Neil S.


******

There was no original probes just some home-brew croc-lead things from the
60s or 70s , of much the same date as the bodged pot.
I will test the 6K25 and the VR91 as EF50 settings, heaters are ok

--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/

An email response from the guy at the valvepage site

Yes that GEC is internally quite different to mine, and the use of bigger
valves suggests an earlier design.

The catch on that case looks very un-military-like as it and the case look
so fragile.

Maybe the crt broke when the chap in the aircraft got fed up and threw the
darn thing out of the aircraft - the shaped controls on mine are still
fiddly, yet the controls on the front of yours would I think be impossible
to use with gloves on !

Also, where on earth do the valves go ? There doesn't seem to be any space,
and I also can't spot any ht rectifier.

I've seen quite a few of the GEC scopes like mine but not encountered any
like yours before so I can't really add any information. Perhaps you could
let me know if you find out more. Also, could I scrounge a couple of pics
for my website ? Just a small pic of the front and one of the side, just
enough so if a visitor sees my page they'll think "that looks just like
mine" and they can then follow a link to your page.


--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/

"Solomon K." wrote in message
...


You can bid on one now. Starting at £49.99

AH, but I'm in Vermont, USA. No shipping offered to here, and shipping is
quite pricey anyway. Thanks though!

John H.

I found 2 unlabelled black painted glass Si diodes of the 70s , not original
for the added reason that 2 solder points were to wires and not tag board
tags. Se rectifiers been around since earlier than 1933 but where was there
space for any. Even if the vibrator was originally synchronous type , would
it be possible to use such a vibrator to rectifierless feed mains in , via
the transformer to such a vibrator, to allow 12V and 180/230V ac use?
The mains cable seems to go to the output side of the vibrator, with no
mechanical interlock to lockout other than someone remembering to unplug the
vibrastor, or does it matter ?.
For the 4 pin vibrator, that came with it, gum on Masteradio label is bad
and original un-re-badged label under is
Mallory G650
Indianapolis Ind
Made in USA

Anyone have specs for the G650 ? or even whether synchronous types could be
in only 4 pin format


--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/

On Sun, 4 Jan 2009 13:35:57 -0000, "N_Cook" wrote:

Mallory G650

The only reference I found was a google cached page which include this info on a
PSU:-

"The Power Supply Unit is running from a 6 V car battery using a Vibrator or
from the mains at 110, 150 or 220 Vca 50 Hz.
The Vibrator is of the "nonsycronous" 4 pins type (B MKII or Mallory 650)
The mains voltage value can be changed by a switching system on the front.
A valve 6X5G is used like rectifier.
When the set is to be used on the mains, the vibrator must be removed to prevent
burning up. "



--
Geo

Geo wrote in message
...
On Sun, 4 Jan 2009 13:35:57 -0000, "N_Cook" wrote:

Mallory G650

The only reference I found was a google cached page which include this
info on a
PSU:-

"The Power Supply Unit is running from a 6 V car battery using a Vibrator
or
from the mains at 110, 150 or 220 Vca 50 Hz.
The Vibrator is of the "nonsycronous" 4 pins type (B MKII or Mallory 650)
The mains voltage value can be changed by a switching system on the front.
A valve 6X5G is used like rectifier.
When the set is to be used on the mains, the vibrator must be removed to
prevent
burning up. "



--
Geo

What i suspected. I happened to have rebuilt the contacts of a synchronous
one last year and that was 7 pins. At the moment I'm bogged down with
confusing cap colour codes.


--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/

On Jan 4, 8:01*am, "N_Cook" wrote:
Geo wrote in message

...





On Sun, 4 Jan 2009 13:35:57 -0000, "N_Cook" wrote:

Mallory G650

The only reference I found was a google cached page which include this
info on a
PSU:-

"The Power Supply Unit is running from a 6 V car battery using a Vibrator
or
from the mains at 110, 150 or 220 Vca 50 Hz.
The Vibrator is of the "nonsycronous" 4 pins type (B MKII or Mallory 650)
The mains voltage value can be changed by a switching system on the front.

This is the preliminary node map for the scope
http://home.graffiti.net/diverse:gra..._node_map2.jpg
Scanner does not like full A4 useage.
Letters E, K and C along the top

2 tag boards running vertical, numbered from bottom S (16) and R (16) then P
(11) and Q (11),
colours match major component pinning numbers to node numbers.
ground lines not added and some components around the front panel pots,
switches and 2 3.5 mm i/p sockets (feintly marked as worn off , maybe read
INVERT and GAIN not readable on the earlier pics) not transcribed. Some
unplaced loose wires
and 2 caps covered in laquered cloth so left in place as unknown values and
puffy cap values are assumed , ignoring the green and yellow "multiplier"
dots that are probably temp or tolerance values.
polarised caps marked with a - .
QQ is unkown function as knob missing and other Q pot functions as letters
on the knobs, as found.
There are bound to be still more errors, I've just noticed the 22K resistor
apparently going to doubley N/C K6, maybe used as a tag.
M & VIB wiring and power select shorting plug arrangement is probably much
like the valvepage schematic including the vib, for the later miniscope.
Power cable wiring Y,R,B is the same in both cases
Next intermediary schematic is placing the valves etc into the optimum
coloured nodes and un-knotting to a certain extent.
Nothing powered up so far, a few volts from variac may resolve a few
problems, and valves not tested yet.
Primary of M is probably ok , selecting 230V is 129 ohm and 180V is 75 ohm

The socket for the vib is badly fixed , one bolt is skew as it interferes
with something else on the chassis. So maybe not original vib type but I
don't see how a synchronous type could have made it Si diode rectifierless.
What were the smallest Se rectifiers available in the 1940s for this sort of
application ?

page devoted to this project
http://home.graffiti.net/diverse:gra.../miniscope.htm


--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/

Anyone care to decode the knob legends
Vc,Vf,F,C,A,S

Vc was on the 6 way timebase switch, I am assuming it was moved from the
least used or easiest to turn without a knob
Gueses S for Sync, A for attenuation, F for Fine, C for Coarse , Vf for
focus but Vc ?


--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/

On Tue, 6 Jan 2009 17:47:55 -0000, "N_Cook" wrote:

Anyone care to decode the knob legends
Vc,Vf,F,C,A,S

Vc was on the 6 way timebase switch, I am assuming it was moved from the
least used or easiest to turn without a knob
Gueses S for Sync, A for attenuation, F for Fine, C for Coarse , Vf for
focus but Vc ?

Vc is cathode voltage - probably the brilliance control
Agree Vf for focus.
F could be (timebase) Frequency?

--
Geo

I have a CV320 tube that has a pale green screen and might possibly work
as a replacement for your tube. I have not checked the filament for
continuity, but the tube 'looks' fine...

John :-#)#
Vancouver, Canada.

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



--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/







--
(Please post followups or tech inquiries to the newsgroup)
John's Jukes Ltd. 2343 Main St., Vancouver, BC, Canada V5T 3C9
Call (604)872-5757 or Fax 872-2010 (Pinballs, Jukes, Video Games)
www.flippers.com
"Old pinballers never die, they just flip out."

John Robertson wrote in message
news:fpacl.5304$Db2.2903@edtnps83...
I have a CV320 tube that has a pale green screen and might possibly work
as a replacement for your tube. I have not checked the filament for
continuity, but the tube 'looks' fine...

John :-#)#
Vancouver, Canada.

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



--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/







--
(Please post followups or tech inquiries to the newsgroup)
John's Jukes Ltd. 2343 Main St., Vancouver, BC, Canada V5T 3C9
Call (604)872-5757 or Fax 872-2010 (Pinballs, Jukes, Video Games)
www.flippers.com
"Old pinballers never die, they just flip out."



I would be interested, different pinning, no problem, otherwise much the
same specs
http://www.r-type.org/exhib/aaa0831.htm

is your valid email address really spam and then the things sharks and
pinball m/cs have .com


--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/