No, I'm not an electronic engineer or repair technician. In fact my work is
far removed from technology. Something I cherish even more is to be able to
think for myself rationally and clearly, unencumbered by orthodoxy. My
interest in electronics started in my teens. In those days, I built my
audio amplifiers using vacuum valves. (See, I'm still using "condensers"
instead of "capacitors". g) The book I mentioned earlier in electronics
was an eye opener showing me the mysteries and delights in circuit designs.
The book is probably forgotten by most now though at the time, end of 70's,
it was very popular. The author later took the chair at MIT. There was
rumour of a 2nd edition in the Practical Electronics in the 90's, but it
never materialised.
Thanks for the history, but that only revealed the poor quality in design
where the other components could not stand the strain and eventually failed.
Yes, I do remember reading something like that in the Wireless World. This
must be 20 years ago. Or, was it a Mullard/Ferguson chassis? Anyway, I
have come to the conclusion, actually about the same time, that big names
meant nothing. Poor design is time and again the villain, and provided that
is controlled, as, for example, in TV where the design is now mature, an
electronic equipment from a small company can be as good as, if not better
than, one from a big one. Not accepting this fact is sticking the head into
sand, and giving away good money at the same time.
Bee.
--
[I have found my Shangri-La in ntlworld.]
wrote in message
...
In sci.electronics.repair Bee wrote:
You have just illuminated my point! Philips had a poorly design chassis
some time ago. JVC is promoting itself but using a model from a little
Exactly 1, yes, and then the trouble with the power switches. This goes
only to show that even large manufacturers (who are forced to cut cost!)
make this mistake. No-name brands, however, do it all the time. About
the power switches: after Philips discovered this problem, they used
another brand. About the Onwa capacitors: if they ever discovered this
problem, it took them 5 to 10 years. By that time the industry standard
for power supply design was alltogether different, so they never
redesigned the thing or selected better quality electrolytics. Instead,
the just abandoned the design in favour of another standard application
note.
known manufacturer. Big names do not guarantee quality or differ little
from the small guys. Consumers are doped and are willing to pay over the
odds for the big names.
That's not what I said. Although large manufacturers are under great
pressure by people who want something but don't want to pay for it, they
still can throw more money and experience at the design, choice of
components and manufacturing.
Good point. You mentioned the leakage of electrolytic condensers due to
poor
design. Now we are back to the quality of circuit design. I hope you
agree
And the quality of components (given the poor design, a good capacitor
would have lasted much longer). Two other examples: The Vestel 11AK16
chassis blowing Philips TDA8351 IC's rather often, while the same IC
lasts much longer in a Philips TV. This is mostly attributed to lack of
experience in design. Luckily they did abandon this design after a short
while. In favour of the design used in the next example ;-)
Next example: The Vestel 11AK19 chassis blowing the Philips E/W output
stage. This is contributed to a poorly made E/W correction coil, of
which the turns can short after some usage. No design problem here, only
cutting costs.
Note that the semiconductors used were exactly the same, illustrating
the point that while the exact same key components are used, this does
_not_ mean automatically that the same overall quality is achieved.
with me, as reverend_roger has, that good circuit design has no
exclusivity.
The example you cited is simply sheer incompetence, sadly it can inflicts
While the Onwa design was consistently incompetent, the components used
could have lasted a few years longer if they had been of better quality.
big names as well as small, expensive models as well as cheapos. So, it
follows, and I hope you also agree with me, that these days given a good
design, an inexpensive TV is just as reliable and long lasting as an
expensive model .
Nope. You are jumping to conclusions, missing my point. Because of
cheep-ass people, larger brands have indeed lost quality, but are mostly
still better than no-name stuff. A good illustration is the JVC example.
First, they decided there is no profit in making 14" sets anymore, so
they use Onwa chassis. Any repairman can tell you they do indeed have a
higher faillure rate. Now they decide, there is no profit in making 4:3
sets anymore, so they let Vestel make them. Quality goes down here as
well. So, if a set can be made more cheaply, thus increasing profit for
JVC, why not let Vestel make all of them? That's because despite
everything, people expect some amount of new techniques and quality in
a still expensive TV set. See my point?
About another name brand: In a Grundig technical publication of the
early eighties, they stated that they purposely overrated every
component by at least 50% and created a good airflow in their new TV
chassis series. Indeed, I have a 1983 Grundig TV set here, still playing
as new with only a few minor repairs needed over the years.
Having typed all this, I notice you ignored some of my comments and
questions, and conclude you indeed have no background in electronics,
making this discussion rather abstract and not as usefull.as one would
hope.
---
Met vriendelijke groet,
Maarten Bakker.
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