#1

General Discussion / Re: Has anyone modified any ...

Last post by cog7997 - July 15, 2025, 07:43:10 PM

  Just found the following older Post, concerning similar & possible BJT Transistor hfe damage.
( see Comment by Orion  )

https://huntron.com/forum/index.php?topic=377.msg1789#msg1789

... but I still want to Modify my older Huntron for much lower Test Voltage Levels than it currently has !

thanks,

 

#2

General Discussion / Has anyone modified any Hun...

Last post by cog7997 - July 15, 2025, 07:30:17 PM

hi,

Has anyone modified any ( likely Older ) Huntron's to provide Lower Test Voltage Levels ?

( Newer Huntron's seem to have some capability for this ).

I am seeking details about this because  I have a need to explore, in-circuit, components from "underneath" the Turn-On voltage of standard semiconductors, to examine Passive circuit elements,
  As well as to explore some modern and experimental semiconductors having Turn-On voltages in the ranges of, say,  0.2V up to 6.0V (switched steps), and would like to fine tune those with adjustable Pots, etc.

 A third reason is the exploration of 1950's - 1960' semiconductors where the standard (older) Huntron Lo Range Test Voltage level of 10V (7Vrms) is too much and these early semiconductors are "fragile",
 as it were.

  { Forgive me, I only have a Huntron 1005b-S1, and am hoping to modify my unit for the above, and apologize for posting here, ... but this is a general question }.


Refs:
--  Someone has done such a limited Modification (external add-on) to a Huntron 2000:
 Huntron 2000 upgrade > ~ > 2800
  Test O/P  Voltage Level signal reduction modification, via a transformer:
https://www.youtube.com/watch?v=WFDsjMJu6cU


-- Damage to Transistors by Voltage Levels higher than 6V
     ( B-E reverse bias issues, damaging or changing the Transistor's hfe under testing, etc. )

https://audiokarma.org/forums/index.php?threads/huntron-tracker-1000-and-transistor-damage.1032911/

https://huntron.com/sales-support/pdf/independent-study.pdf

thank you

**

#3

Out of Production Hardware / Reduction & Fine tunning of Te...

Last post by cog7997 - July 14, 2025, 09:37:32 AM

hi,

re: Huntron Tracker 1005b-S1
  S/N: 214o3150

How to modify a Huntron 1005b for lower Low-Range Test-Voltage Levels ?

I need lower Test Signal Voltage levels than the Original 10V { 7Vrms } Huntron 1005 Low Range:
to view other passive components in-circuit and to examine Semiconductor Turn On effects from the lower limits, upwards. Also to examine different Semiconductors that have lower Turn On voltages:

The experimental interests are  6V, 5V, 3V and 1.5, 1.3V, 0.6V 0.3V & 0.2V

For in-circuit PCB testing of older 1950's to 1960's transistors where I do not want to damage the transistors in Reverse Bias testing (B-E, etc.) and want to avoid modifying the  hfe of  these older fragile Fabrication process Si & Ge by using a 10V { 7Vrms  is too much ! } voltage level during testing and repairs.
A great number of these old transistors have no modern equivalents for their circuits, one needs to be extremely careful.

For other semiconductor devices, having Turn-On voltages of less than 3V, having multiple materials, Schottky diodes, etc.

-- How to modify the 1005b-S1 ?
How low can the 10k Pot, R11 go,
Or, in different schematics perhaps R6,R7, R8  ?

  so that I can obtain lower Signal Output Voltage Levels,
    than the "Low" range provides.

i.e. Use some switches that will provide several Lower Ranges ( when in the Low Range ) with fixed resistors and pots switching the Normal R11 out of the circuit ?

In one Maintenance manual Section 4.3 & 4.4 ,  R11 is used to adjust the Signal Level.
... what the limits are for R11 ?

Or use a Transformer on the O/P leads of the Huntron
 ( see below YouTube video from India, done on a Huntron 2000 ) ?


https://www.huntron.com/privatesales/technical/1000-21a-maint-info.pdf
  { not sure if this Manual applies directly to my 1005b- S1 Serial Number. }

&

Huntron 2000 to 2800 
Test O/P  Voltage Level signal reduction modification, via transformer:
https://www.youtube.com/watch?v=WFDsjMJu6cU

Damage to Transistors by Voltage Levels higher than 6V ( B-E reverse bias issues damaging hfe, etc. )

https://audiokarma.org/forums/index.php?threads/huntron-tracker-1000-and-transistor-damage.1032911/

https://huntron.com/sales-support/pdf/independent-study.pdf

thank you
**

#4

Technical Support Announcements / July 2025 Huntron Technical Su...

Last post by admin - July 10, 2025, 07:05:41 AM

Huntron Workstation version 4.3.9313 is here and includes workflow enhancing features for both the Huntron Trackers and Probers. Quick Tip #32 & #33, included in this newsletter, highlight these new features. A new whitepaper has also been published discussing the basics of reading a schematic. Learn more at the link below!

Huntron Technical Support Newsletter | July 2025

#5

General Discussion / Re: stuck working on repairing...

Last post by Al1234 - July 05, 2025, 11:45:02 PM

Sorry for the long delay, Took transformer out.
Compaired with a new one. Posted pictures, there is a clear difference between signatures.
If you have any thoughts on this please share and let me know.

I connected power to transformers and measured the secondaries with out load.  It matches with the new transformer.
Next I was going to do a short circuit test. But I need to clean up the desk and set it up.
Or I could just put the new transformer in there and see if it works.

#6

Out of Production Hardware / Re: Tektronix TR-210 Signal Tr...

Last post by Feridun93 - June 28, 2025, 12:31:15 PM

Hello admin, what kind of transformer is this, what kind of sheet metal is used? Is it true that it is an audio transformer? Thank you very much for your interest and help.

#7

General Discussion / Re: stuck working on repairing...

Last post by Al1234 - June 26, 2025, 07:38:00 PM

yap, that is what I was thinking. may be this weekend or in about 10 minutes, LOL

#8

General Discussion / Re: stuck working on repairing...

Last post by CWSmith - June 26, 2025, 05:04:39 PM

A DMM may not show an inductive change because it is a DC signal unlike a Tracker. The signatures pretty much point to a faulty transformer. Last step may be looking at it out of circuit.

#9

General Discussion / Re: stuck working on repairing...

Last post by Al1234 - June 26, 2025, 09:14:40 AM

Thank you for your reply. I tried to respond sooner, but had trouble signing in , my fault
I replaced the pictures with better ones.
There is nothing connected to the secondary from the rest of the board. I removed the rectifier bridge that transformer feeds voltage to.

On yhe primary side, which all the signatures match between the good and the bad board, are 2 zero ohms resister seen in the last picture posted. Resistors, connect to fuse and then a choke and incoming. There is no continuity between secondary and primary of the transfer.
What's interesting is when measuring resistance between the two pens of the secondary, both good and bad board match. it's the same on the primary side, they match. Measurment instrument agilent 34010A.
The only instruments that shows a difference in power off mode testing is my huntron.
Have not done hipot test yet. For that I have to desolder I think.
Nor, have I done any power up measurement yet. Feeding the transformer and measuring the output.
may be a hipot test next.

#10

General Discussion / Re: stuck working on repairing...

Last post by CWSmith - June 24, 2025, 07:52:38 AM

The faulty board signature is showing a lower impedance suggesting that there is a short somewhere possibly the transformer it self. What else is connected to that circuit?