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post #736 of 3525
Fantastic mate, I wondered who 21 is! Can you take a plain shot of the tube you show above. if there is printing on both sides then two shots one of each side. Also the box as I will be able to tell from that. I think I know what they are but plain photo's will help a great deal.. Even though that arty shot is amazing!
post #737 of 3525
So woodcans.

I just took a picture of my Mullard 3S4 along side my Brimar 1T4


I need a clearer picture of your tube to say wether it is Brimar or Mullard. Mine show it is a government spec tube though not military, B shows it has UK government approval and D is the Mullard Mitcham factory code.
Edited by ianmedium - 7/3/13 at 6:53pm
post #738 of 3525

Ian, here are my pics:

 

 

post #739 of 3525

Well, mil-spec Mullards I wil take any day of the week. Thank you for your help Ian!

post #740 of 3525
Great! Yours are Mitcham made Mullards and were made in January 1956 so nice early ones!
CV designates Military though I think the K means perhaps no active (I am guessing here as the descriptions I will print below show K as made to specification K1001 or K1006, If it had been J it would be mil spec , not sure what the difference is as they have military markings!

Now here is the interesting thing.. Your Mullards and my Mullards are almost Identical, Mine were made in November 1955 just before yours.. Were cousins !biggrin.gif
Here is a bit of a write up of the codes


Military valves have different markings to commercial valves. Most have a CV number (CV = common valve) It is best explained with an example. I recently sold some E88CC or 6922 with the following markings CV2492 KB/AD ZF. Decoded this means:

CV2492 is saying this is an E88CC or 6922 or any other equivalvent - ie a high class 6DJ8 or ECC88.

K is saying this valve has been made to specification K1001 or K1006 if it had been a J it would have meant it was made to a JAN or MIL spec.

B is saying the qualification approval was given by a UK authority, if it had been a U it would be US or a D for Australia or an X for DERAD Air approval.

AD is the factory identification code in this case Brimar rochester plant. There are several pages of codes and some of those you might look out for as well respected makers of valves are D Mullards Mitcham, DA Mullard Blackburn, DB Mullard Salford, DC Mullard Whytleafe, DE Mullard Fleetwood, DF Mullard Waddon, DH Phillips France, L MOV pre 1951, Q English electric, QB Marconi, QC marconi, R Ferranti, Z MO Hammersmith, ZA MOV Gateshead, ZB MOV Perivale, ZC MOV springvale, ZD MOV Dover.

ZF is the date code which was 1968 June. . The first letter representing the year starting at A for 1945 and second the month so AA would be 1945 January, AB is 1945 February and NF 1956 June and so on with I and O not being used.

There is another system of date marking used from about 1965 onwards and that consisted of four digits, the first two being the year and the last two being the week so 6407 would be February 1964. The date code was the date the code was put on the valve so if there may be an earlier manufacturers code on the valve as well.

If you have found this useful please vote YES below as this will enable more people to see it and encourage me to write more guides on valves. If there is something incorrect please email me and tell me so i can put it right.
post #741 of 3525
the interesting thing is my Phillips are actually made in the same Mitcham Mullard factory this time in 1952!
Glad I could help mate.
post #742 of 3525

one day, one parcel:

 

post #743 of 3525

Woohooo... That's look awesome GG... beerchug.gif

post #744 of 3525
post #745 of 3525
Quote:
Originally Posted by ianmedium View Post

Fantastic mate, I wondered who 21 is! Can you take a plain shot of the tube you show above. if there is printing on both sides then two shots one of each side. Also the box as I will be able to tell from that. I think I know what they are but plain photo's will help a great deal.. Even though that arty shot is amazing!

 

So lets only hope that i am number 20 !!!!!!

post #746 of 3525
Quote:
Originally Posted by GermanGuy View Post

So lets only hope that i am number 20 !!!!!!

 

Cheers for that GG... beerchug.gif

post #747 of 3525
I now realize thanks to Boringer that it was 20 through 22 not 20 and 22!

GG, that plating kit looks daunting to someone like me, I can't wait to see the results!
post #748 of 3525

 

Quote:
Originally Posted by GermanGuy View Post

 

So lets only hope that i am number 20 !!!!!!

 

 

Thanks for the link, GG, much appreciated. I went ahead and grabbed two pairs.

 

I hope you are as well. Really looking forward to your plating project.

post #749 of 3525

Thats from Robert whom i purchased my Tungsram's and Sylvania's from (remember one was marked Sylvania, the other Ken Rad but they were both from the same batch Sylvania) If these sound as good as the Sylvania's your in for a treat.. These were headed for the US Signal corps and looking at the Box what is really interesting is that these were some of the first off the line in Kentucky after GE acquired them in 1945..

Just looking at the description, for those who have ordered make sure your ask for same batch Ken Rad's, the way the description is you may end up with what I did which is a mix. No bad thing as they sound great but if you want these exact tubes make sure you ask Robert for them!
post #750 of 3525

I ordered 6x dl92 ken rad tubes , so maybe some sorting is nessesary !

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