Advance Instruments TC8 - Only counts

[pwarren]

Hi folks,

I've been given some test gear recently, a Tektronix 466, which I think I've mostly worked out, it needs a calibration, but I'll get that done later, and an Advance Instruments Timer Counter TC8.  I'm told it's a frequency counter, but I can only seem to get it to count events, so I get an increasing count that does eventually roll over. I made a video and stuck it on Youtube of the output I've been able to get:


I don't really know what all the knobs and buttons do, so I may have it in the wrong mode. I've also not been able to find any sort of manual online for it so I'm struggling a bit!

Any help would be much appreciated!

[Rerouter]

I cannot help with much, but look for a timebase / gate knob, (usually in decades of 10) as my own tectronics plugin counter has a similar setting,

[pwarren]

Thanks Reroute, it does have a row of gate buttons with ?s, ms and s (see picture attachment), but pressing those buttons sometimes does things, and sometimes doesn't

Sometimes changing the buttons stops the count, other times the only effect is to move the decimal indicating light, other times it speeds up the count a lot.

I'm thinking that perhaps all the buttons and knobs need a good clean, it had been sitting in a shed full of spiders and ants! From a search, it looks like de-oxit is the stuff to use to clean the contacts so I'll see if I can find a retailer and have a go at that.

If I open up the case, I don't really know what to look for to see if any components are busted, anything to watch out for or test with a multimeter?

[bance]

Hey,

I've got the TC9B which is very similar to your counter, mine doesn't work yet....
I found a manual for it here:-
http://www.collection.archivist.info/searchv13.php?searchstr=Advance

There does appear to be a copy of the TC8 manual but it hasn't been scanned, or is not available for download, but don't worry mine was the same. Just email the archivist and he'll get back to you,
they don't charge for the manuals, just make a donation so the resource can survive!

PS your manual is in the sixth section down, right at the very top.

HTH Steve.

[pwarren]

Ah, thanks Bance,

I had dismissed that website prematurely before without fully reading the front page! So, Dave's scanned in the manual for me, and that's clarified a lot of things. It seems that It's a faulty unit, mostly with the timebase module, or possibly the time reference, I'll check that out on the scope tonight.

Have had a quick go with de-oxit, with no improvement as yet, but I could only find a pen locally, which doesn't get the goop where it needs to go! Still random behaviour when pressing the buttons.

[bance]

Yes the way the site is set up is a bit strange, but I was surprised at how quickly Dave responded...

My unit had a faulty Pass transistor in the power supply, which I changed, that gave me a display, but it still wouldn't count. I found that there is an intermittent fault on the voltage attenuator switch,
but it's a PITA to get to it so I've set it aside for the moment.

I think I'll have another go at it soon....

Steve.

[pwarren]

Well, the 10MHz reference crystal does put out a signal, see picture.  It looks Ok, but is not exactly aligned, which could be either the scope, or the counter, both are very old, not used for ages pieces

But I'm wondering if it's just going to be easier to buy a slightly more modern counter. I'm going to be using it to assist in building amateur radios, and I've a lot to learn before I'm comfortable diagnosing and fixing the counter!

[bance]

It would be easier, definitely, but you might learn a heck of a lot by trying to fix it.

The people on this forum are great, and I'm sure you'd get a lot of support from them.

Since you got the counter for free you don't have a lot to loose by giving it a go, except time maybe.

Have a look at the trouble shooting section in the manual, it should give an idea of where to start.

HTH Steve.

PS. maybe edit the title of the post/ make a new post to reflect what you're trying to do!

[pwarren]

Well, I know it's been a while, but I've learned enough now to diagnose it properly, and found that the fault is in at least IC11 and probably all the way through to IC17, the decade count ICs.

They're 69-959-79 Fairchlid 24095 ICs, which I've not been able to find out anything about

So, I've got myself a slightly newer, reasonably cheap 50MHz counter which will do for a while!

And wow, I didn't realise I posted this nearly 2 years ago! I've certainly increased my knowledge a little since then!

[Chelle]

Hi, I found this post because I've just bought the same model counter and looking for a manual and diagrams for it.
The link for the manual above does not work any longer, anyone have a copy?