[wxsig] Beta kits

[William Beals]

John:

Thanks for sending out the beta kits.

For the Beta folk:

Do not install
 X1 32.768KHz crystal
 C10, C11: 20pf capacitors
 R6: 330K resistor
 R7: 10M resistor

You will receive a 32MHz crystal oscillator from John shortly.  The best
place for this crystal oscillator is to "dead bug" it on the back side of
the main T238+ board underneath the CPU.  Note the locations of pins 7, 8,
and 14.  Pin 1 is idendified by both a dot on the top of the package and a
less rounded corner on the package flange.  Be careful on noting the pins,
as you will be dealing with an upside-down chip, so the pin ordering will be
reversed too.

Using any convenient SHIELDED wire make the following connections:
Oscillator pin  7 (GND) to C1, pin closest to J1.
Oscillator pin 14 (VCC) to C1, pin farthest from J1.
Oscillator pin  8 (CLK) to U2, pin 5.

The purpose of this rework is use an external oscillator instead of the MCUs
built-in oscillator.  That oscillator requires an additional VCO filter I
did not include and the easiest solution is to just go back to an
oscillator.  Production boards will have the oscillator support in the
layout.

will

-----Original Message-----
From: wxsig-bounces at lists.tapr.org
[mailto:wxsig-bounces at lists.tapr.org]On Behalf Of John Koster
Sent: Monday, July 19, 2004 2:57 PM
To: TAPR WX Special Interest Group
Subject: [wxsig] Beta kits


Today I shipped 5 beta kits to those who responded to Will's announcement
(quite some time ago, I'm afraid) of the 'lottery' winners.

I won't go into details, but a mountain of personal issues delayed my
shipping of them.

They went out UPS ground from Texas, so figure accordingly.  (the one to
Canada actually goes out tomorrow via air mail)

The kits are supposed to be complete except for the 32MHz oscillator which
I will ship shortly.  Will please announce which part to leave off the
board, since I didn't pull them back out of the kits.

John Koster, W9DDD
<w9ddd at tapr.org>




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