On 9/1/2019 7:46 PM, Billy Gamer wrote:
I have two 465 scopes. Replace PS caps in #1---all voltage problem worsened.
Then the question becomes, 1) what capacitors did you use, 2) could you have replaced them wrongly, 3) were some of the capacitors disguising a problem?? Might be fixable, likely is.
No 2 is dead.
Could it be fixed?
How much lifetime ought devote when Chinese scopes do more with less
investment?
If you look at it by sheer money and time, then none, unless you just need to fix a fuse.? You can always value your time so highly that it's not economical to fix anything.
However, you shouldn't compare an analog scope with a digital scope, and the latest Chinese scopes are not necessarily the same thing as a vintage Tek scope.? Also consider how long it took the Tek scope to "break" and how long it might take the Chinese scope to "break".? Also consider that you can repair the Tek scopes. Unless you can replace SMT chips, including BGA chips, and you can *get* the chips in the first place, you can't do much to fix a Chinese scope (nor some of the later Tek scopes, either, been there, tried that).
Aside from the existential question, it is clear that, at $100 per hour,
putzing around with these old old scopes is economic after three hours,
approximately.
If this is a hobby, then the amount of time you spend on it is your choice, but IMHO, should never be counted in dollars. Hobbies take what time they take, they take what resources they take.? If you have to justify a hobby in either dollars (other than "I don't have it to spend"), then I'd guess the definition of "hobby" needs to be visited. .? If you're out to earn money, then the 100 dollars per hour is your best bet.
But, then, again, there is LOVE for these older machines.... sigh
Which is why they are, for most, a hobby.? Some make it a job, and you'll see that for some, the entire aim of the "I have one, now what" goes immediately to "I have one, I can get $$$ for it".
Harvey
On Sat, Aug 31, 2019 at 7:01 PM Raymond Domp Frank <hewpatek@...>
wrote:
What follows is a longish and sad story.
A few days ago, I was contacted by someone who said he was looking for a
good quality analog 'scope.
Without asking many questions, I showed him one of my 465's and he liked
it. He expressed some concern as to the reliability of these very old
instruments (I think this sample was from 1976/77). I told him that these
old 'scopes were still "more usable than unreliable", that some parts did
tend to fail from old age, especially the dipped tantalum caps but that
diagnosis and repair was straightforward, that I would take care of repair
for some time in the future for free and that I had an ample spare
components supply of all sorts should they be needed.
He was going to use the 'scope mainly for adjusting radio receivers and
was looking forward to the high vertical sensitivity, especially when using
a 1:1 probe. This should have been a warning for me but I limited myself to
explaining why the use of passive 1:1 probes cannot be recommended for some
of his intended use (450 kHz and 10.7 MHz IF) and giving him an example of
the math.
We agreed on a price and he left, happy with his newly acquired classic,
or so I thought.
After a few days, he contacted me, asking for two knobs (A and B trigger
level), since apparently parts had broken off. I told him that I'd send
replacements for free.
Before I could send them, he contacted me, saying that the replacement
knobs were no longer needed since the 'scope had broken down: no beam, no
graticule illumination, no fan sound, and that he had concluded that his
'scope obviously was a total loss. He was sorry to tell me the bad news but
he had very much appreciated my explanations and service and he definitely
wouldn't want any money back. When I offered to repair the 'scope for free,
he added that that wouldn't be possible, since it was now in an underground
dumpster, inaccessible to him. He once again blamed himself for making the
mistake of buying such an old piece of equipment and we "parted as friends".
I still feel for the poor lonely instrument enveloped in darkness...
Raymond
