UK Vintage Radio Repair and Restoration Powered By Google Custom Search Vintage Radio and TV Service Data

Go Back   UK Vintage Radio Repair and Restoration Discussion Forum > Specific Vintage Equipment > Vintage Television and Video

Notices

Vintage Television and Video Vintage television and video equipment, programmes, VCRs etc.

Closed Thread
 
Thread Tools
Old 26th Mar 2017, 5:01 pm   #1
1100 man
Octode
 
1100 man's Avatar
 
Join Date: Apr 2016
Location: Ventnor, Isle of Wight, & Great Dunmow, Essex, UK.
Posts: 1,377
Default Mazda vs Mullard CRT's

Good afternoon,
Having read most of the TV threads over the last year, there seems to be a general consensus, especially among the people who were in the trade in the '50's, that Mazda tubes have shorter lives than Mullard. Was this the case back in the '50's and 60's or is it a more recent thing?
Presumably, Mazda used different manufacturing techniques to Mullard but was there any difference in performance when they were new? Were they cheaper for set makers to use?
Was it a case that set makers were not driving them correctly?
I assume both manufacturers introduced tube types at the time which showed rapid failure and were a bit of an embarrassment?
I must say, all of the 405 sets that have come my way recently have had Mazda tubes and they have all read zero emission and have needed a tickle on the rejuvinator!
I would be interested to hear peoples' experiences who were in the trade back then.
Cheers Nick
1100 man is offline  
Old 26th Mar 2017, 5:08 pm   #2
Nuvistor
Dekatron
 
Nuvistor's Avatar
 
Join Date: Aug 2013
Location: Wigan, Greater Manchester, UK.
Posts: 9,427
Default Re: Mazda vs Mullard CRT's

I was never a fan of Mazda B/W CRT's, but only have experience of the 60's and 70's wide angle tubes. The Mazda CRT's did seem to have a brighter picture when new but low emmision and the really annoying fault of the O/C cathode. The Mullard ones seems to last a good few years.
Mullard did have problems in the 50's with the heater shorting giving low emmision but cannot say I remember them
I always quoted Mullard for new replacements and we had a company that supplied reguns if the customer wanted that type.
Frank
Nuvistor is online now  
Old 26th Mar 2017, 5:54 pm   #3
Freya
Octode
 
Freya's Avatar
 
Join Date: Jan 2009
Location: Falmouth, Cornwall, UK.
Posts: 1,987
Default Re: Mazda vs Mullard CRT's

In my experience of my owns sets with Mazda tubes in Ekco televisions, 2 out of 20 CRT`s to be faulty with little or no emission, at least 3 are soft with an impaired vacuum. This is just my particular case using Ekco televisions as the basis.
The five sets that I do have that have Mullard tubes, 2 have heater related shorts and need transformers.
This does not really paint any constructive argument for or against.
__________________
Stephen
_________"It`s only an old telly" ___
Freya is offline  
Old 26th Mar 2017, 6:10 pm   #4
Heatercathodeshort
Dekatron
 
Heatercathodeshort's Avatar
 
Join Date: Jun 2005
Location: Warnham, West Sussex. 10 miles south of DORKING.
Posts: 9,145
Default Re: Mazda vs Mullard CRT's

The early Mazda 2volt triodes suffered very badly from intermittent heater/cathode shorts. CRM 91/92/121/151 etc.
This was easily cured with a low capacity isolation transformer that cost around a £1.

Unfortunately they also suffered a short life often going low emission after just two years or even less. Of course many had a long life which points to a quality control problem and I suspect impurities during the evacuating stage, screen impurities or problems with the getter material were not purged at evacuation.

This fault went on for far too long and as the leading manufacturers employed mostly Mazda tubes I'm amazed they did not create a stink about it. It is noted in 'Murphy Service News' That in 1952 dealers were complaining about the short life. Murphy stated that they were aware of the problem as was Ediswan and they were assured that something would be done about it in 'the near future..' The problem was never completely rectified.

The first Mazda tetrodes were even worse. [CRM141/CRM142/CRM171 types went flat just after the then 6 month guarantee expired resulting in thousands of customers tv's sitting on service dept shelves awaiting expensive replacements. At one period Mazda were producing more replacements than tubes for the set makers.

Another infuriating fault was an O/C cathode connection presumably caused due to poor spot welding while assembling the gun assembly. Nothing could be done to repair this.

My mate that owned a high quality rebuilding company told me that the best combination was a Mazda screen and a Mullard gun. Mazda certainly had the edge on Mullard picture wise. Aluminising was carried out by Mazda from 1952 across the range and this certainly improved the brightness and contrast. The first rectangular 17" CRM171 gave a fantastic picture but was one of the first to lose it's emission fast!

The later CRM172 used in the Murphy V310 and a large range of Ekco receivers faired much better as did the CRM93 9" [EKCO TMB272] and the CRM124 [Murphy V230] The rectangular 14" tubes also enjoyed a good life. The first 19" Mazda tube the CME1901 was a complete disaster. Flat after 12 months or an O/C cathode.

Unfortunately the O/C cathode came to light again with the 'Gold Star' series in the mid 60's. I changed large numbers of these in Thorn 900/950 models for this unnecessary manufacturing fault.

The manufacturers appeared to put up with this state of affairs as they were signed up with Mazda. Most had problems with Mazda HT rectifiers and boost rectifiers and modified their receivers to accept Mullard/Cossor types.

Defiant being connected with the Co-Op requested that their receivers were fitted with British company produced valves and tubes in British factories. Plessey had no connections or ties with any particular valve or CRT manufacturer so supplied their TV chassis with Mazda tubes and valves for the Defiant receivers.

The strange thing is Mullard valves and tubes were produced in British factories by British workers but the actual company was of course part of the Philips organization based at Eindhoven in the Netherlands.

Little did the Co-op realize that they were not giving their customers the best deal by insisting on Mazda valves and particularly CRTs.

Mazda certainly did make some outstanding valves. RF triodes and pentodes were unsurpassed and they made an excellent range of output valves that to this day have very long lives and were highly respected. You can't get it all right all the time but the faults encountered should have been jumped upon and rectified at the earliest moment.

I've often wondered if the Mazda tube factory at Ponders End Brimsdown being so close to the huge King George's reservoir had anything to do with the impurity problem, maybe condensation, air impurities etc. CRT manufacture was and still is a very specialized subject.

As to price, Mazda CRTs were certainly not cheap being a pound or two dearer than the Mullard contemporary.

Mullard were not entirely innocent. They had quite a serious problem with partially shorted heaters on all tube types from the MW31-74 to the AW43-80. Being in a series chain they only dropped around 4v giving a very poor picture.
They also had quite a number of red label MW43-69 tubes develop an O/C heater. I replaced quite a number in the Ferguson 306T. There was no outside cause for this and the fault was quite well known.
Hope this explains a bit of your query. John.
Heatercathodeshort is offline  
Old 26th Mar 2017, 6:39 pm   #5
DangerMan
Heptode
 
Join Date: Jul 2009
Location: Stoke-on-Trent, Staffordshire, UK.
Posts: 719
Default Re: Mazda vs Mullard CRT's

A lot of Mazda's problems have been attributed to the line pumping system used at Brimsdown where the crt's allegedly did not spend enough time in the baking process.
This was eventually fixed and it seems the plant later pumped a lot of Mullard tubes under sub-contract, with no ill effect on their longevity.
DangerMan is offline  
Old 26th Mar 2017, 10:35 pm   #6
1100 man
Octode
 
1100 man's Avatar
 
Join Date: Apr 2016
Location: Ventnor, Isle of Wight, & Great Dunmow, Essex, UK.
Posts: 1,377
Default Re: Mazda vs Mullard CRT's

Quote:
Originally Posted by Heatercathodeshort View Post
This fault went on for far too long and as the leading manufacturers employed mostly Mazda tubes I'm amazed they did not create a stink about it.
The first Mazda tetrodes were even worse. [CRM141/CRM142/CRM171 types went flat just after the then 6 month guarantee expired resulting in thousands of customers tv's sitting on service dept shelves awaiting expensive replacements. At one period Mazda were producing more replacements than tubes for the set makers.
Sadly, that seemed to typify the British way of doing things at that time. The situation was the same with car production at BMC. With no foreign competition, the attitude seemed to be "you should be jolly grateful we allow you to have crt's at all"!
We had so much to learn from the Japanese!!
That was a really interesting insight, John and was exactly the sort of thing I was looking for- many thanks.
With the CRM141 etc, failing in large numbers after 6 months, did Mazda rigidly stick to their 6 month guarantee? I don't think you could get away with that now!
Cheers Nick
1100 man is offline  
Old 27th Mar 2017, 12:18 am   #7
McMurdo
Dekatron
 
McMurdo's Avatar
 
Join Date: Jun 2009
Location: Staffordshire Moorlands, UK.
Posts: 5,263
Default Re: Mazda vs Mullard CRT's

I'm sure most new tvs, particularly in the early colour era came with seperate warranties for the set and the CRT.
__________________
Kevin
McMurdo is offline  
Old 27th Mar 2017, 9:14 am   #8
Nuvistor
Dekatron
 
Nuvistor's Avatar
 
Join Date: Aug 2013
Location: Wigan, Greater Manchester, UK.
Posts: 9,427
Default Re: Mazda vs Mullard CRT's

The set, valves and CRT had seperate guarantees, 3 months, 12 months and 1 year. It's possible that some B/W CRT's had 2 year guarantees in the late 60's, something in the back of my mind but cannot be sure. Colour CRT's came with a 12 month guarantee extendable for about £7 by 3 years for a total of 4.
The set and CRT had separate cards to be completed and returned.

The consumer legislation (approx 1971) put the onus on the retailer and the guarantee was usually for 12 months for the whole item but the colour CRT could still be extended to 4 years, payed to the CRT maker.

My comments early were about B/W CRT's , I replaced quite a few Mullard colour CRT's under 4 years old mainly low emmision.
Frank
Nuvistor is online now  
Old 27th Mar 2017, 9:35 am   #9
HurtyAC
Tetrode
 
HurtyAC's Avatar
 
Join Date: May 2009
Location: Ware, Hertfordshire, UK.
Posts: 75
Default Re: Mazda vs Mullard CRT's

Hi All, My experience with Mazda verses Mullard tubes in early Colour sets (1967-80) across the A56/66/67-120X range. The Mullard tubes would on average do 4 to 7 years no problem but you would see the familiar soft out of focus gun (usually blue) on a Mazda tube after 2 years! That is my experience. You could buy ex-rental sets at £65 with "tested tube" and £45 with "untested tube" meaning it was duff. It cost £1 an inch to have a colour tube re-gunned (Ralph Stevenson Tubes Longridge) so made sense to buy the "duff tube" sets as they looked like new with a re-built tube fitted and sold straight off! The last tube I had re-built by Mr Stevenson was in a Thorn 2000, which my Dad used, in 1980. He used this set until he passed on in 1990 but the tube is still going strong. Mr Stevenson used to pump the tubes heated.

Adrian
Attached Thumbnails
Click image for larger version

Name:	DSC00080.JPG
Views:	352
Size:	62.3 KB
ID:	139895  
HurtyAC is offline  
Old 27th Mar 2017, 9:47 am   #10
Nuvistor
Dekatron
 
Nuvistor's Avatar
 
Join Date: Aug 2013
Location: Wigan, Greater Manchester, UK.
Posts: 9,427
Default Re: Mazda vs Mullard CRT's

Interesting about the Mazda Colour CRT's, I had little experience of them. The sets we sold used mainly Mullard, I think some ITT sets used ones made on the continent. There were a few Mullard colour CRT's I saw made in Japan, they seemed to fail early.
Wish I had known about Ralph Stevenson Tubes Longridge, we tried a few rebuilders and never found one I was really happy with. I always found Mullard rebuilt colour CRT's they supplied under the 4 year guarantee as good as a new one, something I didn't find with third party reguns.
Frank
Nuvistor is online now  
Old 27th Mar 2017, 8:05 pm   #11
Heatercathodeshort
Dekatron
 
Heatercathodeshort's Avatar
 
Join Date: Jun 2005
Location: Warnham, West Sussex. 10 miles south of DORKING.
Posts: 9,145
Default Re: Mazda vs Mullard CRT's

Most early tubes only carried a 6 month guarantee and this was rigidly applied. Customers receivers were awaiting tubes on dealer's racks. They still had to pay the payments and find the money for the replacement tube. All a very sad state of affairs.
'Setmakers' state that Mazda pumped tubes for Mullard but I would be very interested to find out which types they pumped.

Mullard 110 degree tubes types AW43-88 AW43-89 AW53-88 AW53-89 and the first 19" and 23" tubes AW47-90/91 were indestructible and all will be found in 100% condition even today. The 20/24" types were a poor comparison often loosing their sparkle after a couple of years sometimes not noticed by the customer. I wonder if these were pumped by Mazda.

My theory concerning impurities may be backed up by the fact that I have experienced many totally flat Mazda tubes still retaining hard black getters.
All water under the bridge and the failures certainly gave us an income and employed many people in the service industry. Regards, John.
Heatercathodeshort is offline  
Old 27th Mar 2017, 8:24 pm   #12
G6Tanuki
Dekatron
 
G6Tanuki's Avatar
 
Join Date: Apr 2012
Location: Wiltshire, UK.
Posts: 13,953
Default Re: Mazda vs Mullard CRT's

There's a comment in "The Setmakers" that in the immediate post-WWII era some TVs were shipped with tubes made by "Cathodeon", a second-line producer of the Mullard/Philips/Pye stable - and that dealers would receive TVs fitted with either Mullard or Cathodeon tubes depending on whether someone in the manufacturing-chain perceived the dealer to be an upmarket or downmarket one.
G6Tanuki is offline  
Old 28th Mar 2017, 8:25 pm   #13
McMurdo
Dekatron
 
McMurdo's Avatar
 
Join Date: Jun 2009
Location: Staffordshire Moorlands, UK.
Posts: 5,263
Default Re: Mazda vs Mullard CRT's

Yes the setmakers has a mine of information on the valve/tube makers with lovely anecdotes like that.
Cathodeon still trades but is now owned by german company Heraeus. They make high end technical glassware, tubes and lamps for military, medical and industrial use.

At the risk of drifting OT, tv engineers may recognize these crystals branded CCL. They were made by Cathodeon.
Attached Thumbnails
Click image for larger version

Name:	ccl.jpg
Views:	172
Size:	5.2 KB
ID:	139996  
__________________
Kevin

Last edited by McMurdo; 28th Mar 2017 at 8:32 pm.
McMurdo is offline  
Old 29th Mar 2017, 1:30 am   #14
Maarten
Dekatron
 
Join Date: Dec 2007
Location: Haarlem, Netherlands
Posts: 4,185
Default Re: Mazda vs Mullard CRT's

Very interesting, I think Heraeus also bought some of the tube manufacturing machinery from CRT B.V., another former Philips plant.

Also, on http://www.pyemuseum.org/divisions/i...cacl_intro.php it says CCL fell around 1989, but the crystal you show has a date code that looks like 9614 or 9814.
Maarten is offline  
Old 29th Mar 2017, 8:55 am   #15
Peter.N.
Dekatron
 
Join Date: Jul 2008
Location: Charmouth, Dorset, UK.
Posts: 3,601
Default Re: Mazda vs Mullard CRT's

This was especially the case in the '50s when we had Mazda tubes going low emmision or soft under guarantee, the Ekco T161 seems to be the main culprit, in our experience anyway.

Peter
Peter.N. is offline  
Old 2nd Apr 2017, 8:08 pm   #16
Heatercathodeshort
Dekatron
 
Heatercathodeshort's Avatar
 
Join Date: Jun 2005
Location: Warnham, West Sussex. 10 miles south of DORKING.
Posts: 9,145
Default Re: Mazda vs Mullard CRT's

Murphy radio began to supply their own low capacity isolation transformer in 1952. They were 15/-[75p]. They sold out overnight and a much bigger batch had to be produced.
Not sure when the splendid Radiospares CRT transformer range was introduced to cater for all the differing CRT heater voltages. They produced around 5 different types and were wound with a 20% boost tag to be used when the emission failed which it eventually did! It was all a very long time ago and who would have thought back then that we would still have the aftermath of the Mazda saga 65 years on..John.
Heatercathodeshort is offline  
Old 2nd Apr 2017, 8:46 pm   #17
1100 man
Octode
 
1100 man's Avatar
 
Join Date: Apr 2016
Location: Ventnor, Isle of Wight, & Great Dunmow, Essex, UK.
Posts: 1,377
Default Re: Mazda vs Mullard CRT's

Quote:
Originally Posted by Heatercathodeshort View Post
Most early tubes only carried a 6 month guarantee and this was rigidly applied. Customers receivers were awaiting tubes on dealer's racks. They still had to pay the payments and find the money for the replacement tube. All a very sad state of affairs.
It never ceases to amaze me how shabbily the British consumer was treated back in those days!
The idea that you had to shell out for a new tube after 6 months after already paying a hefty price for the set is quite amazing. I am sure these days the manufacturer would be deemed to be responsible- thank goodness for consumer rights!
It is no wonder that so many people rented just to save all the aggravation. My parents decided to buy a TV in 1964 rather than rent. Their choice was a Sobell DST1000 (hence my quest for one as it was the set from my childhood) I still have the sales leaflet with Mum's shorthand scrawl noting how much it would be to convert it to UHF!!
Consequently, we still had the thing in 1981 when most other people had had colour for years
I don't know if it would have had a Mazda or Mullard tube, but when I got it in 1981 after it was replaced with a G11 for the royal wedding, the emission was still pretty good.
Many thanks for the input, everyone- its fascinating to hear experiences from people who were actually there at the time!
Cheers Nick
1100 man is offline  
Old 2nd Apr 2017, 10:58 pm   #18
dazzlevision
Dekatron
 
Join Date: Sep 2003
Location: Near Swindon, North Wiltshire, UK.
Posts: 3,595
Default Re: Mazda vs Mullard CRT's

Quote:
I don't know if it would have had a Mazda or Mullard tube, but when I got it in 1981 after it was replaced with a G11 for the royal wedding, the emission was still pretty good.
It would have been a Mullard AW47-91, if it was the original.
dazzlevision is offline  
Old 4th Apr 2017, 5:57 am   #19
Heatercathodeshort
Dekatron
 
Heatercathodeshort's Avatar
 
Join Date: Jun 2005
Location: Warnham, West Sussex. 10 miles south of DORKING.
Posts: 9,145
Default Re: Mazda vs Mullard CRT's

Mullard AW47-91. Almost indestructible! From the AW43-88 [1959] to the end of the 23" tubes around 1968, this was Mullard's most brilliant period. It's very rare even today to see a flat one. John.
Heatercathodeshort is offline  
Old 5th Apr 2017, 9:39 am   #20
Focus Diode
Octode
 
Focus Diode's Avatar
 
Join Date: Jan 2006
Location: Borough of Gateshead, UK.
Posts: 1,420
Default Re: Mazda vs Mullard CRT's

The Mazda Rimband III 19" and 23" CRTs seem to have faired better than earlier types, but they weren't in production for long as the 20" and 24" types quickly replaced them.
Focus Diode is offline  
Closed Thread

Thread Tools



All times are GMT +1. The time now is 11:48 pm.


All information and advice on this forum is subject to the WARNING AND DISCLAIMER located at https://www.vintage-radio.net/rules.html.
Failure to heed this warning may result in death or serious injury to yourself and/or others.


Powered by vBulletin®
Copyright ©2000 - 2024, vBulletin Solutions, Inc.
Copyright ©2002 - 2023, Paul Stenning.