31-07-2011, 10:06 PM
Quote: Rob t (tiv48): "A good meter and a signal gen of some kind are more important (than an oscilloscope, for repair of 'ordinary' vintage radios)".
I wouldn't say that those items are more important - but at the same time, I wouldn't say that they are less important either. Those three items of test kit should just about cover 99% of all the faults you will ever meet in repairing domestic vintage radios; they frequently are used together, in effect forming a 'test kit suite'. (Incidentally, to that list, I would also add a frequency counter).
However, along with that list of kit, the accuracy of the calibrations of those items, the knowledge of how to use each item meaningfully and the ability to fully comprehend the information that they reveal to you must all be considered. As I said earlier, the concept of 'trust' is deeply embedded in the usage of any item of test kit. For example . . . if, having spent many hours chasing that impossible fault that defies all the known laws of Physics, you subsequently discover that your test kit was 'telling you fibs', (read: calibrations seriously out), you'd have been better off not having had that item of test kit in the first place and simply relying of experience and judgement alone - which is not always the best method. As I have found on many an occasion, when a well-known fault symptom becomes manifest, the temptation to dive right in and change components X, Y and Z is very strong - and is often sucessful. But one fateful day, that strategy doesn't work. And you're sitting there with a funny expression on your face. Time to break out the tried, tested and proven test kit.
Which neatly brings me back to where I came in.
I wouldn't say that those items are more important - but at the same time, I wouldn't say that they are less important either. Those three items of test kit should just about cover 99% of all the faults you will ever meet in repairing domestic vintage radios; they frequently are used together, in effect forming a 'test kit suite'. (Incidentally, to that list, I would also add a frequency counter).
However, along with that list of kit, the accuracy of the calibrations of those items, the knowledge of how to use each item meaningfully and the ability to fully comprehend the information that they reveal to you must all be considered. As I said earlier, the concept of 'trust' is deeply embedded in the usage of any item of test kit. For example . . . if, having spent many hours chasing that impossible fault that defies all the known laws of Physics, you subsequently discover that your test kit was 'telling you fibs', (read: calibrations seriously out), you'd have been better off not having had that item of test kit in the first place and simply relying of experience and judgement alone - which is not always the best method. As I have found on many an occasion, when a well-known fault symptom becomes manifest, the temptation to dive right in and change components X, Y and Z is very strong - and is often sucessful. But one fateful day, that strategy doesn't work. And you're sitting there with a funny expression on your face. Time to break out the tried, tested and proven test kit.
Which neatly brings me back to where I came in.
