Re: Mullard Valve Tester Card Project
 

Mine's the same as this one.:thumbsup:

rgds
Colin

Re: Mullard Valve Tester Card Project
 

It seems that it was the E7600/3.
So does anyone have an E7600/2 or E7600/5+ ???

Re: Mullard Valve Tester Card Project
 

Hi Gents, It's the first one I've seen with a hinged cover for the instructions, mine is the slide out type.
PS scans in post today George.


Ed

Re: Mullard Valve Tester Card Project
 

Mine is an E7600/4 model with horizontal buttons and having recently spent hours checking tolerance and replacing parts I now know it is an exact match to the Operating Manual Issue 4 (1958). It came with a test card index dated January 1966. Perhaps 5% of the 720 cards that came with it have the 'series' letters A or B under the Mullard logo.

Re: Mullard Valve Tester Card Project
 

In addition to finding all the cards we must also endeavour to find the latest revisions of the cards, especially as there were some pretty bad errors in the original versions. To this end I have now built a list of which cards submitted so far were revised.
So I am now asking everyone to check through your cards again, this time looking for revised cards.
And don't forget that we still have plenty of cards to find in any revision!
Details on http://home.btconnect.com/gmb/mullard.htm

Re: Mullard Valve Tester Card Project
 

There has been some confusion about how to recognise a revision letter so I have updated the web page with an illustration.

Re: Mullard Valve Tester Card Project
 

I'll second that George, I've had one of these testers for 20 years and only just spotted the rev letter!!

Ed

Re: Mullard Valve Tester Card Project
 

I've got a HSV Tester in my northern location which came with two heavy metal trays full of cards. I will try and list them for you next time I'm at home but it may be two or three months. I've often wondered how many there are given the number of actual valve types that were produced over the years-cheers.

Re: Mullard Valve Tester Card Project
 

Hi GMB

I have recently bought an E7600/4. The cards that came with it contained about 70% of those on your "Revisions" list. I have scanned them to JPEG. You have a PM.

Re: Mullard Valve Tester Card Project
 

Thanks to ukcol for finding the first revision "C" card.
We have started to reach the point of diminishing returns with this project as far as missing cards goes, but not for revisions yet.
We still need more of the military card sets to be checked as this is where we will most likely find the missing cards.

Re: Mullard Valve Tester Card Project
 

It has been mentioned that some mistakes were made by Mullard when they produced the cards which can damage the valve being tested and/or the tester. Having just restored a 7600/4 to working order I have identified one such mistake. In the first box of valves I was testing I came across a PY32 which is a half wave rectifier with an octal base designed for television. The Mullard card index lists the test cards as 967 AB but when I pulled out the cards there were 3, that is 967 ABC. To have 3 cards is usually the pattern for a full wave rectifier. Card A marked ELECTRODE (to test for shorts) and cards A and B one for each anode to check emission. Cards A and B worked fine and the valve tested OK, but when I tried card B, I switched off quickly when I was greeted with the very unhealthy sound of a lot of current flowing. So if you have a set of 967 cards, throw card C away and change the number of cards mark on cards A and B to 2.

Re: Mullard Valve Tester Card Project
 

Hi Gents, this sounds like a MUllard "TRAP" if you obey the instructions and only use A&B all is OK, BUT presented with 3 cards the tester is likely to try to use all 3 with the results mentioned. I assume A,B,C cards are used to test a full wave rect with a different type number as well. These testers were often used by unskilled people in shops so I'm not surorised it caused problems.
This is probably the foundation of the warning about a rouge card that started in the 50's.
A worthwhile mod, that I carried out on my tester was to add fuses in all the HT transformer output windings (about 10 in all). These will then pop with a problem like this and prevent damage to an irriplaceable transformer.
The main trip and fuses will not always blow under these conditions.

Ed

Re: Mullard Valve Tester Card Project
 

The 967 example shows how important it is to get the correct revision of the cards, hence I now publish a list of known revisions. It is perhaps a pity that Mullard didn't think to duplicate 967B as 967C so as to ensure that the old cards were thrown away! The mistake seems to be down to this single diode having 2 pins for the one anode. You can see how this could have been mistaken for being a double diode. During tests of double valves the unwanted sections are often grounded out to avoid interference effects. The difficulty with this error is that it only becomes apparent when the valve is in the socket since the short-out flows though the valve base.

Re: Mullard Valve Tester Card Project
 

George further to your recent pm, a quick trip north home reveals my Mullard VT as a 600/3. An even quicker run through the two tins of cards [with the help of my teen daughter] didn't reveal any of the special later items but from the missing list that you posted I appear to HAVE-

550 667ABC 715 721B 722 723 724 725 726ABC 727ABC 728 730AB 733AB 738 739 742ABC 744AB 745AB 746AB 747AB 749ABC 765 805 806 809 810 820 821 826 829 832 835 841AB 844AB 846 849ABC 851 852 855 856ABC 858ABC 863AB 864 866 868 869 870 871AB 872 873ABC 874 875 876AB 879AB 880AB 882AB 883 884AB 889ABCD 890 894 895 897 901 904AB 914AB 915 916 917 928 948 952 953 954 955 956 961AB 962 964 968AB 969AB 970 971 972 973 974 979 984 985 986ABC 987 989 990AB 991 993 994 995 1003 1004 1005AB 1007AB 1008 1009ABC 1010 1011 1012 1014 1016AB 1017 1021

Hope This might be of interest.

Dave Walsh Sussex

Re: Mullard Valve Tester Card Project
 

If anyone else has some cards to add to the database then please note that I will be available at Harpenden on the 5th to photograph your cards.

Re: Mullard Valve Tester Card Project
 

Hi,
I am in the middle of going through six (don't ask) boxes of cards. I seem to have a few "A" revisions but so far none of your missing cards. I can't go to Harpenden sadly but will get in touch when I'm finished. Cheers,
Kneale

Re: Mullard Valve Tester Card Project
 

I am presuming that people know Alan Nunneley will do card copies [it says up to 10] on www.mullion-cove.com but of course there is a charge as it's his business. 6 tins is a lot. I was glad that my daughter helped me with two!

Re: Mullard Valve Tester Card Project
 

The project had a good day at Harpenden with 11 new cards sets and 57 revisions found!

It has now become clear why the card sets vary so much - the deal was that you got your new tester with a standard card set plus 100 cards of your choice.

We now have 88.6% of known-to-exist card sets - so still looking for 125 sets and wondering why 103 were not issued.

For those who are waiting to check their cards, http://home.btconnect.com/gmb/mullard.htm is now updated.

Re: Mullard Valve Tester Card Project
 

This French guy need a copy of the Operating Instructions in French. Does anybody know if these exist?
http://retro-forum.com/viewtopic.php?t=9069
Gordon.

Re: Mullard Valve Tester Card Project
 

Ed has sent me this picture of the pre-war Mullard tester, has anyone got a better picture (or even has an actual tester)?