Picture of Mullard MW41/1 Gun - UK Vintage Radio Repair and Restoration Discussion Forum

Duke_Nukem · 1st Feb 2006, 2:16 pm

Don't suppose anyone has a set with the Mullard MW41/1 metal cone CRT ? If so any chance of a couple of photo's of the electron gun assembly so as I can compare it against the English Electric version I have ?

TTFN,
Jon

Heatercathodeshort · 1st Feb 2006, 8:54 pm

Hello Jon,
I hope this picture will be of some use. I took it a few moments ago of the MW41-1 gun in my Ferguson 989T. It is completely without emission!
I think the Mullard tube is infact made by Mullard as the gun assembly matches that of the MW36-24 series. The early English Electric ones were .6amp heaters, a rating Mullard never used for tubes manufactured after 1948. If you need a better pic I will see what I can do............
Regards JOHN.

Duke_Nukem · 2nd Feb 2006, 9:22 am

Thanks John,

Can't quite make out enough detail though. I've attached the EE version, does the Mullard one look remotely similar ?

Someone mentioned in passing that they wouldn't be at all suprised if the Mullard one was a re-badged EE tube. Pure speculation, but it seems odd that a) Mullard bought out thier 41/1 so quickly after EE, b) EE quickly changed from 0.6A to 0.3A heater, c) hey surely Mullard would have been well aware that rectangular CRT's were only about a year away so why would they have invested in designing their own metal cone tube, and 4) A 16" tube was the largest reasonably available and only used in the more top end sets so Mullard would have needed a larger tube for their regular customers but just not many.

Pure conjecture I grant you, but looking at the gun assemblies of the 0.3A tubes might be a clue.

TTFN,
Jon

PS : Blimey these metal tubes are light !

Heatercathodeshort · 2nd Feb 2006, 3:38 pm

Hello again Jon,
The metal cone tubes have always been odd and I have no doubt that they originated from the U.S.A. In this country the sets that use them appear to date from 1951 and most makers had a go at using this tube in at least one model even if they were married to Mazda for their thermionic supplies. Mullard produced another odd one, the rectangular MW43-43, a 17" version released just before the introduction of the all glass MW 43-64 in 1952/53. E.E. also produced a hideous 21" ROUND metal cone tube they used in one of the most vile looking sets ever produced. I repaired one in the 60's and it was HORRIBLE. The two pictures of the guns appear to be different, maybe Mullard ordered the shell and neck assembly and equiped it with their own screen and gun assembly. The MW41-1 does give a super bright picture with a fantastic grey scale. Hoping this information may be of interest.
Regards JOHN.

Duke_Nukem · 2nd Feb 2006, 5:01 pm

Hi John,

Yes, thats interesting. And yes, the metal cone did indeed appear in the states first.

After less than a year, EE changed from advertising the tube for commercial sets and totally aimed it at the amateur builder. Amateur builder + several square meters of metal at 16KV =

.

Not heard mention of a 21" EE tube and did I read correctly that there was a MW43-43 with a rectangular metal cone

The only other one I know of was a 21" monster used in a HMV set (the 1820?) - no idea who made it (could very well have been EE).

TTFN,
Jon

FERNSEH · 2nd Feb 2006, 5:24 pm

Hi,
The HMV 1820 did indeed employ a 21" metal cone CRT. I can't recall the type number but it was of EMI manufacture, it had a tetrode gun and had an all glass 7 pin base.
As a replacement EMI supplied the all glass rectangular MW53/20 as a replacement.
As for English Electric, the model 1650 was fitted with an EE metal cone tube, type T900. This tube had a narrow deflection angle, 55 degrees.

The American CRT 16GP4 is similar to the MW41/1 but has a 0.6 amp heater.

DFWB.

Heatercathodeshort · 2nd Feb 2006, 9:18 pm

Hello again Jon,
Yes you got it right the first time. There was indeed a RECTANGULAR Mullard MW43-43 crt released in this country but I have never seen a set with it fitted. The 21" E.E. set mentioned is the C45/46 if my memory serves me right. [Frantic search for makers manual...] The 21" circular metal cone tube was the T909. It was HUGE as these pictures from the E.E. manual, that I have just unearthed in the last few moments shows! It was replaced by the MW53-20 all glass type when it failed. Ferguson also supplied a modification kit to replace the MW41-1 metal cone crt with the 17" MW43-64/69 in their models 989T and 990T.
The main thing tube makers were concerned about were the angles and pressure points associated with glass stress with rectangular tubes. The rectangular tubes were not 'blown' in the usual manner but were constructed from seperate pieces of 'moulded glass welded together. It was not until the makers were completely happy about this new form of construction that the 'big picture' rectangular tubes could safely replace the old circular construction. Happy days! Regards JOHN.

FERNSEH · 4th Feb 2006, 2:07 am

While on the subject of metal cone CRTs, the daddy of them all has to be the round 30" CRT fitted into the American DuMont Royal Sovereign TV set.
The tube is designated 30BP4. Check out the ETF website for pictures:
www.earlytelevision.org

Another large screen CRT was the Rauland Corporation 27QP4. This was a 27" rectangular 90 degree CRT. The gun assembly has an electrostatic focusing system. A picture of the tube appeared in the March 1952 Radio-Electronics magazine. An American publication. The tube has the look of a metal cone type.

DFWB.

1st Feb 2006, 2:16 pm	#1
Duke_Nukem Octode Join Date: Jan 2003 Location: Birmingham, West Midlands, UK. Posts: 1,268	Picture of Mullard MW41/1 Gun Don't suppose anyone has a set with the Mullard MW41/1 metal cone CRT ? If so any chance of a couple of photo's of the electron gun assembly so as I can compare it against the English Electric version I have ? TTFN, Jon

1st Feb 2006, 8:54 pm	#2
Heatercathodeshort Dekatron Join Date: Jun 2005 Location: Warnham, West Sussex. 10 miles south of DORKING. Posts: 9,147	Re: Picture of Mullard MW41/1 Gun Hello Jon, I hope this picture will be of some use. I took it a few moments ago of the MW41-1 gun in my Ferguson 989T. It is completely without emission! I think the Mullard tube is infact made by Mullard as the gun assembly matches that of the MW36-24 series. The early English Electric ones were .6amp heaters, a rating Mullard never used for tubes manufactured after 1948. If you need a better pic I will see what I can do............ Regards JOHN. Attached Thumbnails

2nd Feb 2006, 9:22 am	#3
Duke_Nukem Octode Join Date: Jan 2003 Location: Birmingham, West Midlands, UK. Posts: 1,268	Re: Picture of Mullard MW41/1 Gun Thanks John, Can't quite make out enough detail though. I've attached the EE version, does the Mullard one look remotely similar ? Someone mentioned in passing that they wouldn't be at all suprised if the Mullard one was a re-badged EE tube. Pure speculation, but it seems odd that a) Mullard bought out thier 41/1 so quickly after EE, b) EE quickly changed from 0.6A to 0.3A heater, c) hey surely Mullard would have been well aware that rectangular CRT's were only about a year away so why would they have invested in designing their own metal cone tube, and 4) A 16" tube was the largest reasonably available and only used in the more top end sets so Mullard would have needed a larger tube for their regular customers but just not many. Pure conjecture I grant you, but looking at the gun assemblies of the 0.3A tubes might be a clue. TTFN, Jon PS : Blimey these metal tubes are light ! Attached Thumbnails

2nd Feb 2006, 3:38 pm	#4
Heatercathodeshort Dekatron Join Date: Jun 2005 Location: Warnham, West Sussex. 10 miles south of DORKING. Posts: 9,147	Re: Picture of Mullard MW41/1 Gun Hello again Jon, The metal cone tubes have always been odd and I have no doubt that they originated from the U.S.A. In this country the sets that use them appear to date from 1951 and most makers had a go at using this tube in at least one model even if they were married to Mazda for their thermionic supplies. Mullard produced another odd one, the rectangular MW43-43, a 17" version released just before the introduction of the all glass MW 43-64 in 1952/53. E.E. also produced a hideous 21" ROUND metal cone tube they used in one of the most vile looking sets ever produced. I repaired one in the 60's and it was HORRIBLE. The two pictures of the guns appear to be different, maybe Mullard ordered the shell and neck assembly and equiped it with their own screen and gun assembly. The MW41-1 does give a super bright picture with a fantastic grey scale. Hoping this information may be of interest. Regards JOHN.

2nd Feb 2006, 5:01 pm	#5
Duke_Nukem Octode Join Date: Jan 2003 Location: Birmingham, West Midlands, UK. Posts: 1,268	Re: Picture of Mullard MW41/1 Gun Hi John, Yes, thats interesting. And yes, the metal cone did indeed appear in the states first. After less than a year, EE changed from advertising the tube for commercial sets and totally aimed it at the amateur builder. Amateur builder + several square meters of metal at 16KV = . Not heard mention of a 21" EE tube and did I read correctly that there was a MW43-43 with a rectangular metal cone The only other one I know of was a 21" monster used in a HMV set (the 1820?) - no idea who made it (could very well have been EE). TTFN, Jon

2nd Feb 2006, 5:24 pm	#6
FERNSEH Dekatron Join Date: Mar 2005 Location: Gateshead, Tyne and Wear, UK. Posts: 7,444	Re: Picture of Mullard MW41/1 Gun Hi, The HMV 1820 did indeed employ a 21" metal cone CRT. I can't recall the type number but it was of EMI manufacture, it had a tetrode gun and had an all glass 7 pin base. As a replacement EMI supplied the all glass rectangular MW53/20 as a replacement. As for English Electric, the model 1650 was fitted with an EE metal cone tube, type T900. This tube had a narrow deflection angle, 55 degrees. The American CRT 16GP4 is similar to the MW41/1 but has a 0.6 amp heater. DFWB.

2nd Feb 2006, 9:18 pm	#7
Heatercathodeshort Dekatron Join Date: Jun 2005 Location: Warnham, West Sussex. 10 miles south of DORKING. Posts: 9,147	Re: Picture of Mullard MW41/1 Gun Hello again Jon, Yes you got it right the first time. There was indeed a RECTANGULAR Mullard MW43-43 crt released in this country but I have never seen a set with it fitted. The 21" E.E. set mentioned is the C45/46 if my memory serves me right. [Frantic search for makers manual...] The 21" circular metal cone tube was the T909. It was HUGE as these pictures from the E.E. manual, that I have just unearthed in the last few moments shows! It was replaced by the MW53-20 all glass type when it failed. Ferguson also supplied a modification kit to replace the MW41-1 metal cone crt with the 17" MW43-64/69 in their models 989T and 990T. The main thing tube makers were concerned about were the angles and pressure points associated with glass stress with rectangular tubes. The rectangular tubes were not 'blown' in the usual manner but were constructed from seperate pieces of 'moulded glass welded together. It was not until the makers were completely happy about this new form of construction that the 'big picture' rectangular tubes could safely replace the old circular construction. Happy days! Regards JOHN. Attached Thumbnails

4th Feb 2006, 2:07 am	#8
FERNSEH Dekatron Join Date: Mar 2005 Location: Gateshead, Tyne and Wear, UK. Posts: 7,444	Re: Picture of Mullard MW41/1 Gun While on the subject of metal cone CRTs, the daddy of them all has to be the round 30" CRT fitted into the American DuMont Royal Sovereign TV set. The tube is designated 30BP4. Check out the ETF website for pictures: www.earlytelevision.org Another large screen CRT was the Rauland Corporation 27QP4. This was a 27" rectangular 90 degree CRT. The gun assembly has an electrostatic focusing system. A picture of the tube appeared in the March 1952 Radio-Electronics magazine. An American publication. The tube has the look of a metal cone type. DFWB.