[WT-support] DXDoubler issues resolved by replacing parallel card.

[Bob Wilson, N6TV]

GW4BVE did a great job diagnosing why the DX Doubler at MW0EDX just would
not work.  All the issues were caused by low voltage output from a Startech
PCI parallel card.  Details below.

73,
Bob, N6TV
---------- Forwarded message ----------
From: John Clifford
Date: Sun, Nov 9, 2014 at 5:29 AM
Subject: Fwd: M0EDX Wintest-DXDoubler Issues

Hello again Bob

Anton now has the DxDoubler interfaced to Wintest and working correctly.
He purchased a new parallel card which had more drive voltage and that
solved the problem.   For your information these are the card details:

Old card
Startech PEX1P.   Logic high outputs are about 3.1v unterminated and will
not drive the DXDoubler.

New card
Sunix PAR6408A.  Logic high outputs are about 4v unterminated and drive the
DxDoubler perfectly.

Basically if the parallel card is using 3.3v logic levels the DxDoubler
will not work or at best be unreliable.   This is due to the voltage levels
required to drive the HCF4049UBE chip used in the DxDoubler.

All working now.  Thanks for your help.

73 John GW4BVE
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