Hi All,
I thought that I would add some photos from the mini workshop where Kevin Hoyland and I worked on 3 CRB testers - and acheived a result of 3 out 3 working (100% success). What we found was that the Hunts Waxies were all found to be at least 150% of tolerance (high). In good practice, we (mostlt Kevin I would add), replaced each cap one at time and could see the tester improve stage by stage.
The choice caps used were some old NOS Mullard 'mustards' which, although old, when tested with a DMM where found to be spot on with respect to there values so I can see why they are held in such high esteem (and still expensive).
We also found that a cap purchased from Just Radios was found to be 130% of tolerance which we agreed was rather worrying having purchased a stock of these but this could be a one off.
There is a strange looking 1uF Hunts cap that looks like a cork and covered in a rubberised coating. It was found that when replaced with an equivalent 'mustard', the tester wouldn't work!! However, in using a 0.47uF, the testers would all work perfectly - probably the best that they have worked in about 50 years.
I must add that the testers repaired were all latter models - all over 3000 serial numbers. We have yet to get the early testers working as these have a differing layout. Its hoped that we can achieve this at our next 'workshop'.
We both had a great weekend with the 3 testers repaired and all of the purchases from the Golborne swap meet.
I thought that I would add some photos from the mini workshop where Kevin Hoyland and I worked on 3 CRB testers - and acheived a result of 3 out 3 working (100% success). What we found was that the Hunts Waxies were all found to be at least 150% of tolerance (high). In good practice, we (mostlt Kevin I would add), replaced each cap one at time and could see the tester improve stage by stage.
The choice caps used were some old NOS Mullard 'mustards' which, although old, when tested with a DMM where found to be spot on with respect to there values so I can see why they are held in such high esteem (and still expensive).
We also found that a cap purchased from Just Radios was found to be 130% of tolerance which we agreed was rather worrying having purchased a stock of these but this could be a one off.
There is a strange looking 1uF Hunts cap that looks like a cork and covered in a rubberised coating. It was found that when replaced with an equivalent 'mustard', the tester wouldn't work!! However, in using a 0.47uF, the testers would all work perfectly - probably the best that they have worked in about 50 years.
I must add that the testers repaired were all latter models - all over 3000 serial numbers. We have yet to get the early testers working as these have a differing layout. Its hoped that we can achieve this at our next 'workshop'.
We both had a great weekend with the 3 testers repaired and all of the purchases from the Golborne swap meet.
if all else fails...read the instructions!
