Hi Lyle,
Two of the bus switches in the pack of four are used to enable the quadrature clocks to the control lines of a two switch QSD circuit. The two switches are used to mute the RX function by stopping the QSD with its switches open. (I am looking forward to adding a third board in the stack for a transmit function and want a quick way to kill the I and Q signals to the sound card.)
73,
Tony KB9YIG
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----- Original Message -----
From: "Lyle Johnson" <kk7p@...>
To: <softrock40@...>
Sent: Tuesday, October 18, 2005 10:01 PM
Subject: Re: [softrock40] SoftRock v5.0 schematic
Your comments would be appreciated.
I'm a little mystified by the switch control logic in the mixer.
The FST3126 data sheet indicates the control inputs are pins 1, 4, 10
and 13 and that these need logic level drive.
The logic level drive outputs from the LT1719 comparators are applied to
pins 6 and 8 which are analog ports., with the logic inputs tied to
analog signal lines.
Or, I may be reading the data sheet incorrectly
73,
Lyle KK7P
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