VHF90's and me!

[pwdrive]

Yes, the ultimate dry joint.

Lawrence.

[Skywave]

That's a bit of an understatement, Lawrence! There was no trace of any solder at all on that 'joint'. But such mistakes can all too easily occur. You're in the middle of a complex task and a 'non-maskable interrupt' arises - such as a call to dinner from the domestic engineering department. So, feeling ravenous, you drop everything (well, almost everything ) and dash off. Of course, when you do return later, it's a case of "Err, now let me see . . . where was I? Ah yes, I remember: I finished that bit."

Al.

[pwdrive]

Used to get them on new stock stuff.

Lawrence.

[Skywave]

Rob's experience does prompt me to state what I've said many times before: as fixers of electronic equipment, there is a strong tendency to neglect the test equipment that Nature has given us and to dive straight in with the test equipment. Yes, by all means take sensible precautions with a piece of unknown kit prior to applying power, e.g. isolation transformer; lamp limiter, etc. And then, having powered the item up, making voltage (and possibly waveform) measurements. But prior to any of that, give the item a good 'visual': the things to look for are too many to list and are well-known to experienced fixers. And using your nose to detect any indications of burnt materials or dampness is a good idea. Then when the item is powered up for the first time, is anything running obviously too hot (e.g. the heat-sinks of power transistors)? Are all the valve filaments glowing? Are there any untoward sounds heard - such as cracking or popping? Advance the A.F. gain control: any sounds heard? Give the item a few gentle taps and knocks: any untoward sounds heard?

A lot of 'history' about an item can be gleaned before power is first applied by using eyes, nose, ears and sense of touch - and doing that first can save a lot of headaches later.

Al.

[Bushbaby]

I think Al is totally right about using our senses to look for faults. I had 3 long stints on working with that VHF90 and thought that I had introduced an error in my rewiring etc.

Regards

Rob

[Joe]

".... so perhaps I must have cut it in error"

I'm glad you're not a Surgeon

Alan

   

[Bushbaby]

Thanks Joe,
I'm thinking of starting on the Ekco A23s

Regards

Rob