Looking for PDP-8 G603 "Memory Selector Matrix" boards (or dec T-2052 transformers)

[Pete Lancashire]

Using a t-2052 build up a test fixture, a pulse generator and​ a
oscilloscope and if have access to one a high bandwidth current probe. Use
the 2052s you have, record the curves etc and then make up some test
transformers.

-Pete component engineer in a former life.

On Apr 13, 2017 3:36 PM, "Vincent Slyngstad via cctalk" <
cctalk at classiccmp.org> wrote:

> I realize it's a long shot, but does anyone have:
>>
>
> - Any spare T-2052s (or know of a source)
>> - Any idea what the T-2052 *was* so I can try to replace them.  I haven't
>> found much detail as of yet.
>>
>
> Good news on this front!
>
> I had previously obtained a data sheet for the T2037, a similar
> transformer.
>
> I extracted 4 each T2037 and T2052 from a broken G228, and today I was
> able to get measurements off of them:
>
> T2037:
> A: 230uH, 170 mohm primary, 42.9uH 100 mohm secondary
> B: 220/170, 41.6/100
> C: 232/170, 43.8/60
> D: 231/170, 43/80
>
> These are consistent with 16 turns and 7 turns of #33 wire, wound on an
> FT37-77 toroid per the instructions on the data sheet, and also with the
> 220 uH /43 uH 20% specs that appear there.
>
> Here are the T2052 measurements:
> A: 597/320, 597/320
> B: 530/270, 530/270
> C: 34/1040, 24/680
> D: 551/280, 551/280
>
> Ignoring "C", which is quite likely broken in some way, these are
> consistent with a 25 turn 1:1 transformer.  I'm not sure what they are
> wound with, as #33 wire should give a lower DC resistance.
> (#34 is closer.  It's also possible that they changed cores, but I suspect
> that they are also wound on FT37-77 cores.)
>
> It's possible that a fairly standard modern 1:1 pulse transformer could be
> substituted.  The 78615/2JC, for instance is 500uH, 1:1 if you ignore the
> center tap pins.
>
>    Vince
>