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
...
Hi Hank,


Thanks for the tips, got the line from 60 deg to 45 degrees by tweaking
another pot...

The correct angle for the LOW setting should be whatever gives you a
line that goes from the lower left corner to the upper right corner of
the screen.

I tested a 30 volt zener and got a good Z but just got as small blip on
one
leg of the z on a 56 volt zener

That sounds correct. Nothing about the Huntron is absolute, only
relative.

I measured the voltage on the probes, 60 Hz, hi: 40.5 volts, med 20.4
volts,
and lo is 6.6 volt.

The actual voltages will be somewhat higher. The Huntron is a very high
impedance source.

Since these are rms, and peak to peak would be 2.8 higher,,
Does Huntron caution about testing any devices because of the voltage?

Huntron is very specific to say that the Tracker CANNOT harm any solid
state device, or other component. I would be worried about some of the
older Mosfets like the 3N128 which have no protection diodes built
in. But in a properly designed circuit, the circuit elements would
protect even a Mosfet.

With a short all 3 levels show a vertical line but with an open high and
medium present a horizontal line while low presents a 45 degree line.
Do
you know the reason for this?

The early Huntron Trackers used parts that presented a fair amount of
series resistance to the measurement circuit. This series resistance
wasn't visible in the High and Med positions, but in the Low, it would
have made a diagonal line on short circuit. The folks at Huntron must
have felt that it was more important to make a short circuit always
appear as a vertical line than it was to make an open always appear as
a horizontal line, so they added circuitry that allowed them to rotate
the display in the LOW position to make a short appear as a vertical
line.

In later Huntrons, they figured out how to null out this impedance and
those units always have a short vertical, and an open horizontal.

-Chuck

hank
I posted a personal reply as well as to the groups as I figured others
might
be interested.

I wish you wouldn't!

I check email a lot more often than newsgroups. I don't usually
notice that you have done this until after I have composed and sent
a response to your email. Then when I read the same question in the
newsgroup, and have to reply there as well. A lot of bother.

If you want the reply on the newsgroup, please don't send an email!

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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