In article , () wrote:

On Fri, 26 Jan 2018 17:32:28 -0600
wrote:
In article , () wrote:

On Fri, 26 Jan 2018 06:32:11 -0600
wrote:
In article , ()
wrote:
That sounds highly unlikely. You can still buy chips designed in the
70s if you so desi

https://www.digikey.co.uk/catalog/en...roup/z80/15507

But you can't create the circuit boards and assemble them at
affordable costs.
Which is what I said.

so the chances of whatever microcontroller the radios used being
unavailable is pretty slim. Plus the analogue radio components and
op-amps will always be available until someone invents usable
optotronics. More than likely the cost of redesigning the board for
SMDs was more than railtrack was prepared to pay.

So you know more than a multi-national radio manufacturing company?
It's a true story, as told to me by our salesman to Railtrack at the
time.

Told to you by a salesman? Oh well, it MUST be true then.

He was an engineer who maintained the company's relationship with the
railway. We made all the NRN radios in the 1980s and 1990s (at least all
those I've seen in cabs on depot visits in recent years). I worked there
for over 25 years so knew a lot about how the kit was manufactured.

You'll know then which components were impossible to source. Feel free to
fill us in on which ones they were.

As I've said more than once it wasn't a components problem. It's that the
boards were unmanufacturable at any affordable price. They needed
redesigning for modern components and assembly methods which meant starting
the approval process all over again from scratch.

--
Colin Rosenstiel