Huntron Tracker 1000, looking for some advice on repair please.

Thread Starter

vintaronica

Joined Jan 24, 2021
3
Hello Everyone

I have acquired a Huntron Tracker, curve tracer. There appears to be no continuity detected when the leads are shorted, as the tracer line should go vertical with the probes shorted and it doesn't. I have the unit apart, and conducted several basic continuity checks on the board where the probes connect and there isn't any faults in terms of continuity from the board to the leads. I have had a scope on the leads, and there is a 60khz frequency signal present on the hot lead, so there certainly is function there; but other than that i'm still faced with a Tracker that wont respond.

I have downloaded the service manual; and am about to go through the troubleshooting stages; I have even got a 3kv AVO for the job; but it's still a bit cold out in the shed at the moment so i'm reluctant to go out there for hours troubleshooting in a damp cold shed for now. (i do have a heater but even with it running it's flipping cold)

So I guess in the interim between the cold and the weather warming up.. the reason for the post is to ask if anyone knows these units; and is there any common "KNOWN" faults with these units that could fast-track me to sorting this issue; I originally thought it might be part of the oscillator circuit that drives the tube, but when I select between high, med, and low the tube responds exactly as it should in the operation manual; with the line going diagonal on the other settings, so the driver circuit for the display is working fine, other than this I am now faced with the very real prospect of checking every component in the unit which could take me weeks, or even months.

It would be nice to have it working, I am a hobbyist audio electronics tinkerer/bodgeineer (see what i did there..lol) and to have this unit working on my bench will really help; its a shame I haven't got a Tracker to diagnose this tracker.
 

MrChips

Joined Oct 2, 2009
30,714
I am of the same opinion as spook but nevertheless I am sure it gives one a good feeling to get old things working again.
The nice thing about antique equipment is that many times they are still serviceable if you have the schematics unlike modern equipment in our current throw away society that we live in.

Give me chance to dig up the circuit schematics.
 

MrChips

Joined Oct 2, 2009
30,714
You don't have to go checking every component. That is not the most productive way of going about trouble shooting.
You need to look at it from a functional perspective.
What does the machine do and what does it not do?
What sections of the unit would cause those symptoms?

From what you have described it would appear to be related to the input vertical amplifiers.
The first thing I would do is get some electronic contact cleaner and spray in on the option switches (High, Medium, Low) and work the switches vigourously while the cleaner has not yet evaporated. IPA (isopropyl alcohol)) dispensed from a syringe needle works too. Do not use an oil lubricant such as WD40.
 

Thread Starter

vintaronica

Joined Jan 24, 2021
3
Thank you Mr Chips for your reply. I do have IPA alcohol, and syringes. Can you please explain to me why you think that cleaning the switches might get the unit to respond? When I select the switches, the display changes which to me indicates function.

Secondly the input vertical amplifiers; could you please elaborate on that for me. I have the full service manual, and its very in-depth with regards to the setup and tuning of those trim pots, are you saying it might just need adjusting and cleaning or is it a possibility that the amplifier controller for the vertical scan is popped.
 

MrChips

Joined Oct 2, 2009
30,714
Thank you Mr Chips for your reply. I do have IPA alcohol, and syringes. Can you please explain to me why you think that cleaning the switches might get the unit to respond? When I select the switches, the display changes which to me indicates function.

Secondly the input vertical amplifiers; could you please elaborate on that for me. I have the full service manual, and its very in-depth with regards to the setup and tuning of those trim pots, are you saying it might just need adjusting and cleaning or is it a possibility that the amplifier controller for the vertical scan is popped.
You say that you get a diagonal line with certain settings. This indicates to me that the CRT is receiving both X and Y deflection signals. Hence I would be looking at the Y-input amplifier stages.

From what I can glean from the Instruction Manual you are supposed to get a different picture when HIGH, MED, LOW settings are selected. I know from experience that for equipment sitting idle for years the first problem to develop is tarnished contacts on sliding switches.

Don't attempt to adjust anything yet at this point until you get the initial problem resolved.
 

Thread Starter

vintaronica

Joined Jan 24, 2021
3
Ok Mr Chips

I will try your suggestion this weekend. And whilst I am at it I better check the signal fuse; been reading through the troubleshooting guide and fuse F1 can blow if someone's been using the unit on a cap that's not been discharged for example. Only just noticed that, and apparently that's quite a common failure.
 

bklein

Joined May 13, 2010
1
Check supplies first, then looks like should be 80 Hz at TP1. Check F1. Check K1. Check U6. I had one of these for years but never used it. Worth a lot on eBay so I sold it.
 

nsaspook

Joined Aug 27, 2009
13,087
Great to have a museum piece but IMO useless for most hobbyist level troubleshooting.
Where a Huntron Tracker, curve tracer is useful. Checking rows of identical circuits for one bad component. Here we're looking for bad Zener diodes.
PXL_20220116_211956896.jpg
Good trace, Zener good
PXL_20220116_212003183.jpg
Circuit testing
PXL_20220116_212030434.jpg
Bad trace, Zener shorted
 
Top