Author Topic: Racal-Dana 199X Counter - Custom Chip Replacement?  (Read 3594 times)

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Offline edpalmer42

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Racal-Dana 199X Counter - Custom Chip Replacement?
« on: February 22, 2015, 05:07:03 am »
The Racal-Dana 199x series of counters uses a set of custom chips to do their magic.  I have two 1992 counters that have the same fault - one of the custom chips (MCC2) has failed.  I really like these counters, but I'm reluctant to buy another one if it's just going to become a boat anchor after a few years.

Has anyone investigated the replacement of these chips?  Maybe an FPGA?  A plug-in daughterboard?  I don't think there's enough info in the service manual to just design a replacement so some reverse engineering would be required.  The project would be complicated by the ECL interfacing requirements.

Ed
 

Online Andy Watson

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Re: Racal-Dana 199X Counter - Custom Chip Replacement?
« Reply #1 on: February 22, 2015, 05:26:31 am »
Are you sure that it's the custom chips that have failed? I have two 1992/1 and they are still going strong. However, shortly after I obtained the second unit it would throw a fit and latch-up, sometimes reporting random faults. I re-seated all the socketed chips and it's been fine ever since. There are also rumours that Racal manufactured their own PCBs - badly - inspect for bad joints and hair line cracks etc..

I have tried to find information on the custom chips but without success.
 

Online Fraser

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Re: Racal-Dana 199X Counter - Custom Chip Replacement?
« Reply #2 on: February 22, 2015, 09:34:38 am »
I have a complete Racal 199X chassis, lid and front panel. I might be willing to sell it if the price is right.

The unit was fully working but some bright spark decided to replace the faulty push buttons and never completed the task. I bought it for spares in case I ever owned a 199x unit.

Open to reasonable offers for the whole lot or just the PCB's if cheap shipping is desired.

Aurora
Located in the UK
« Last Edit: February 22, 2015, 02:20:26 pm by Aurora »
 

Online KJDS

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Re: Racal-Dana 199X Counter - Custom Chip Replacement?
« Reply #3 on: February 22, 2015, 09:47:56 am »
I probably have the worlds largest collection of Racal counters. At some stage I hope to have the time to revive them

Offline edpalmer42

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Re: Racal-Dana 199X Counter - Custom Chip Replacement?
« Reply #4 on: February 22, 2015, 10:03:55 am »
Are you sure that it's the custom chips that have failed? I have two 1992/1 and they are still going strong. However, shortly after I obtained the second unit it would throw a fit and latch-up, sometimes reporting random faults. I re-seated all the socketed chips and it's been fine ever since. There are also rumours that Racal manufactured their own PCBs - badly - inspect for bad joints and hair line cracks etc..

I have tried to find information on the custom chips but without success.

Yes, unfortunately the MCC2 chip has failed in both.  The chip temperature of 90C is a strong hint!  While looking around for information I found message threads on other boards that talked about the same problem.

I found some info on the MCC2, or rather, the generic chip that was customized to create it.  It was made by AMCC and is part of the Q700 series.  The Q710 part is a 500 gate array that the customer configures and then AMCC manufactures.  The data sheet is widely available, but that's no help without knowing the logical configuration.  Hence, the need for reverse engineering.  The maximum I/O frequency is only 100 MHz which is pretty trivial today.

Ed
 

Online Andy Watson

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Re: Racal-Dana 199X Counter - Custom Chip Replacement?
« Reply #5 on: February 25, 2015, 03:04:37 am »
Information:
Cassidian Test and Services appear to have acquired some remnants of the Racal company. Here is their page of legacy Racal manuals:

http://www.cassidian-ts.com/web/support/racal_legacy.html

The links point to an old site - change the "files-eads" part of the URL to "cassidian" to get the downloads.

The 1992 counter also masquerades as an AN/USM-459A for the military. Here is the manual translated into military/NATO numbers:

http://radionerds.com/images/9/92/TM_11-6625-3232-40.PDF
 

Offline dom0

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Re: Racal-Dana 199X Counter - Custom Chip Replacement?
« Reply #6 on: February 25, 2015, 04:03:45 am »
I don't know anything about these counters except that they're often available here in GER and a good sum of money is paid for them, but if there are custom gate arrays in them I'd expect those to contain fast counters, counter registers and the gate/arm logic. It might be possible to design a replacement just from the schematics. Ideally one would have one working and one faulty unit...
,
 

Offline edpalmer42

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Re: Racal-Dana 199X Counter - Custom Chip Replacement?
« Reply #7 on: February 25, 2015, 05:43:47 am »
Yes, both user and maintenance manuals, including full schematics, have been available online from various sources for some time.  Unfortunately, the custom chips are shown as rectangular blocks.  You can almost imagine a caption "The Magic happens in here!".   :)

Since the schematics are available along with a bit of description regarding the process, I thought it might be possible to reverse engineer the system to replace one or more of the custom chips.  But it doesn't look like anyone has done so.

Ed
 

Offline aroby

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Re: Racal-Dana 199X Counter - Custom Chip Replacement?
« Reply #8 on: February 25, 2015, 03:06:19 pm »
Yes, unfortunately the MCC2 chip has failed in both.  The chip temperature of 90C is a strong hint!  While looking around for information I found message threads on other boards that talked about the same problem.

That is pretty hot.  I ran my counter for about 6 hours today with the lid off.  That chip was showing about 140F (60C).  Still pretty toasty.  I may put heatsinks on mine.

If you decide to ditch it, let me know.  I have two working units, except one of them has a faulty reed relay (parts are unobtainable - some military grade job) and also it never shows a zero reading.  Connect something to it and it works fine.
« Last Edit: February 25, 2015, 03:08:04 pm by aroby »
 

Offline edpalmer42

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Re: Racal-Dana 199X Counter - Custom Chip Replacement?
« Reply #9 on: February 25, 2015, 04:29:37 pm »
Yes, unfortunately the MCC2 chip has failed in both.  The chip temperature of 90C is a strong hint!  While looking around for information I found message threads on other boards that talked about the same problem.

That is pretty hot.  I ran my counter for about 6 hours today with the lid off.  That chip was showing about 140F (60C).  Still pretty toasty.  I may put heatsinks on mine.

If you decide to ditch it, let me know.  I have two working units, except one of them has a faulty reed relay (parts are unobtainable - some military grade job) and also it never shows a zero reading.  Connect something to it and it works fine.

Yes, when mine was working, it was also about 60C.  And, yes, I put a heatsink on mine too.  I don't know if it helped extend the life, but it seemed like the right thing to do.

Regarding the zero reading, it might just be picking up a bit of noise.  Try setting the trigger level to 0.02 volts.  If that gives you a zero reading, I wouldn't worry about it unless you have to look at really low signal levels.

Ed
 


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