Hi Hank,

Your machine is working just fine.

The newer 1005's have an 80 Hz inverter built in because they were
designed for a more international environment where 50Hz or 60Hz
power was possible. They chose 80Hz to avoid most of the annoying
beat frequencies that would result if they chose 60Hz and the unit
was running on 50Hz or 60Hz power.

Huntron's use of opamps in the later units had nothing to do with
improving the sensitivity of the Tracker. It was all about making
the unit easier to manufacture.

When transistor circuits get designed by marginal engineers, they
often end up with stage gains being so close to the transistor's
maximum gain that the transistors need to be selected for proper
operation in the circuit. That ends up being a manufacturer's
nightmare! National's 2N4401's might work 90% of the time, but
Fairchild's only work 10% of the time. This datecode is fine, but
that one is a bust...soon manufacturing is looking for an engineer's
head to put on a pole.

So by using opamps with their massive amounts of gain, and using lots
of negative feedback, a gain stage can be made more cheaply and easily.
Gain becomes dependent only on the tolerance of the feedback resistors.

-Chuck

OBTW, Huntron didn't give any specs on what value of capacitor, or
inductor, or resistor would give this or that display. It is all
relative, all approximate. This is a short, that is an open, and see
this angley thing, that is somewhere between a short and an open...

Where the Tracker really shines is when looking at transistor junctions.
They all give nice identifiable waveforms. Most Trackers are used for
making comparisons between the various points on a bad board and the
same points on a good board.


Henry Kolesnik wrote:
My last test was inductance and all I got was a straight vertical line till
I tested an 8.6 mH toroid, and it has to be on low. Both high and medium
show a short. On low it can barely detect a 4 mH toroid, it a vertical
ellipse with very little space between the lines. Anything in the specs on
the inductance limits for each range? How about capacitance?
I notice that newer units with prefix serial numbers have a couple of op
amps and a high freq oscillator so they must have more range and be more
sensistive than my unit with no op amps that I can see and the frequency is
60 cps.
Again tnx for going to all the trouble, it is appreciated.

hank wd5jfr
As far a the 3 ranges go, I can see them being usefull
"Chuck Harris" wrote in message
...

In article , Chuck Harris
writes:

When transistor circuits get designed by marginal engineers, they
often end up with stage gains being so close to the transistor's
maximum gain that the transistors need to be selected for proper
operation in the circuit. That ends up being a manufacturer's
nightmare! National's 2N4401's might work 90% of the time, but
Fairchild's only work 10% of the time. This datecode is fine, but
that one is a bust...soon manufacturing is looking for an engineer's
head to put on a pole.

At Bell Labs I heard the story of an early transistorized circuit that was in
mass production for years by Western Electric. Suddenly, one year the new
units started giving trouble. Turns out the designer had assumed a *maximum*
gain per transistor. The transistor plant had finally improved the gain of
that type to where the original circuit would no longer work!

Generally, the more negative feedback you put into a transistor or tube stage,
the less finicky it is about how "hot" a device you plug in. --Mike K.

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