[Boatanchors] SDR unit

[Jim Haynes]

On Fri, 21 Mar 2014, Robert Nickels wrote:

> On 3/21/2014 6:47 PM, Jim Wilhite wrote:
>>  Sadly we live in a throw away world where only manufacturers can afford
>>  the equipment to repair individual boards.
>
This reminded me of the time when I first heard of an integrated circuit,
sometime in the 1950s.  My immediate thought was, "why would you want to 
do that?  How would you replace a bad transistor or other part?"  Well
now we have ICs with many millions of transistors, and if one goes bad you
throw away the whole thing.  Because even if you could get the lid off
the package there is no way you could go in and replace one little part
of it.  If they were not made that way you would not have a personal
computer; you might be time-sharing on a huge machine located in some
computer center.  So with radio equipment we have to accept a certain
amount of manufacturing technology to get the performance we do.  If
you had to build a radio out of 14-pin ICs in sockets you would't be able
to build what you can buy today.

So if you want to mess with individual circuit elements you can still
use boatanchors, or build more modern stuff out of parts.  There was an
item in the last IEEE Spectrum about a company that makes a kit where
you can build the functional equivalent of a 555 timer IC out of parts.
I don't think you'd want to build more than one of them.

Jim W6JVE