FIXED ....Huntron 1005B-1S low range setup problems

Started by driftboat, January 14, 2016, 04:10:07 PM

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I recently picked up a Huntron Tracker:
(on the tag) HRT 1005-1S  Serial 214 04203
Maintenance Manual Download from here:

This one seems to be a hybrid compared to the manual.  The front page photo is of a single input.  This one has the dual input.   The schematic on page 20 and 21 does show the 555 timer for the dual input.  The oscillator circuit is different than the one of a "single can" type.  The oscillator has its own small circuit board with an output of 4.2v RMS at 80Hz (different from the normal 10V 80Hz ones).
On page 35 there is a diagram of the component layout with various voltage test points. On the upper portion of the diagram IC-1 measured 1.3mv and IC-2  1.1mv.  All the others in the upper section R24, R21 and R23 measured good.  I did not measure any for the CRT as it seems to be functioning properly.
In the lower portion of the diagram, Transformer T1 measured 4.2 RMS at 80Hz. The output of the bridge (D-1 thru D-4) had 12V but the input was 12V RMS, not 8.8V.  My digital voltmeter must not like square wave on R38, Q3 and Q4, no readings taken.
The output of the test terminal are shown on page 5, peak to peak voltages of 120, 40 and 18. 
The measured voltage 126,41,14 PP.

Now to the Problem..... The setup procedures on page 16 work perfectly on steps 1 thru 25 (High and Med ranges)

Page 17...
Step 27. Short the output and adjust LOW range vertical phase (R1) for no vertical tilt.  The trace on the CRT was approx. 1/4" tall and in a backward "s" type trace. By adjusting R1, the trace became a straight vertical trace about 1/2" long.
Step 28. Open the output and adjust LOW range horizontal gain (R9) so the trace looks like figure 12. All that the adjustment did is increase the length of trace without any deflection as shown on figure 12.

Long and windy but that is what I've got going.

Thanks, Lou

Finally got around to do some trouble shooting on my tracker.  Found a bad resistor, R6 10 ohm in the LOW range circuit.  Did the setup/adjustment, everything seems to be OK now.


Hi Driftboat,
The manual you have is for an older model. Maybe this manual will be more useful:

It sounds like your Tracker may have been "upgraded" to the solid state oscillator at some point.
Hope this helps.
The most important troubleshooting tool is your eyes.


Thanks Admin for the manual.  It seems to be the same one that I'm using, but it has the Switcher Control Board schematic which mine did not have.