Tips for Technicians - Mallory Capacitors
May 1967 Electronics World
I know I keep saying this,
but it keeps being true so I say it again: The basics of electricity and electronics have not changed in the last
50 or more years, so there articles from vintage issues of electronics magazines are as applicable today as they
were back then. If you are just getting into the field of electronics, valuable information can be found here to
supplement your learning process. In fact, I have seen examples in some of these articles where I re-learned
something long-ago forgotten, and some of the stuff is rarely, if ever, seen in contemporary writings. Regardless,
making yourself aware of the work done by pioneers in the industry is always valuable because it gives you a sense
of approaches taken that have led to success, and sometimes failure on the way to eventual success.
[Table of Contents]
People old and young
enjoy waxing nostalgic about and learning some of the history of early electronics. Electronics World was published
from May 1959 through December 1971.
As time permits, I will be glad to scan articles for you. All copyrights (if any) are hereby
Electronics World articles.
Tips for Technicians
Capacitor stability at bargain prices
Any capacitor changes its microfarad value when temperature varies. And some capacitors change more than
others. In some circuits, capacitance drift with temperature can cause real problems.
at circuits where you have fractional microfarad values of paper, film, ceramic or mica capacitors. During warm-up
from room temperature to 65° C ambient, a capacitor with a temperature coefficient of, for example, 500 parts per
million per degree C will increase capacitance value by 2%. This change is enough to cause troublesome drift in
tuned circuits, where inductance also increases with temperature. It can knock the accuracy of a timing circuit
off, or mess up the performance of a differentiator network. For these applications, we have a new kind of
capacitor that beats anything we've seen in the stability race. It's the new Mallory Polystyrene Capacitor.
They're made of stretched polystyrene film and high purity aluminum foil. The assembly is fused into one piece,
with the polystyrene forming a solid case of clear plastic that you can look through and see the foil. Their
temperature coefficient is less than 150 parts per million per degree C, which is about half that of polyester
film capacitors. And the coefficient is negative; capacitance goes down when temperature goes up, compensating for
the upward drift of inductance elements in tuned circuits.
Want more? Mallory Polystyrene Capacitors have
the lowest dielectric loss ... only a small fraction of that of other film capacitors. Their insulation resistance
is way above that of mica, film or paper capacitors. And the best part of the whole deal is that they're really
low in price!
There's something new from Mallory, too, in stable electrolytic capacitors. It's the
molded-case MTA, which has temperature stability that beats most metal case types. It has shown up so well on life
test that manufacturers are using it in instruments and computers. And while it's priced down with cardboard-case
tubulars, it beats them every way on quality.
You can get these stable Mallory capacitors, and everything
else you need for service or experimenting, from your nearby Mallory Distributor. Ask him for a copy of our 1967
General Catalog, or write to Mallory Distributor Products Company, a division of P. R. Mallory & Co. Inc.,
Indianapolis, Indiana 46206.
DON'T FORGET TO ASK 'EM - "What else needs fixing?"