LF: Re: Softrock SDR RX/TX on LF

[M0FMT <m0fmt@yahoo.co.uk>]

1a. Re: 500 kHz RXTX Ensemble operation
Posted by: "Parks, Tony" kb9yig@fivedash.com kb9yig
    Date: Mon Sep 3, 2012 7:01 am ((PDT))

Good Morning All,

The clk/16 circuit board layout for the low-cost add-on circuit board to
provided for LF operation of the RXTX Ensemble transceiver was completed
this past weekend.

The board is small, 1.0 inches x0.625 inches, and mounts two 74AC74 devices
to provide for a clock division of 16 on the clock signal coming from the
Si570 via T1. Other components included on the board are three capacitors
and four resistors. Two of the resistors need to be mounted on the add-on
board with their leads extending below the board to mate up with the
R12/R14 hole pattern on the RXTX board for power and signal connections
between the two boards.

With an overall division of 64 on the Si570 output frequency to the QSD/QSE
quadrature clocks the Si570 will be at about 8.7 MHz for 136 kHz operation
and about 32 MHz for 500 kHz operation.

Prototype clk/16 circuit boards will go on order Tuesday and boards should
be back by early this coming week. What remains now is to get the details
worked out for the LPF/BPF changes on the RXTX board for the two LF
frequency options.

I am still planing on building up two test samples of the RXTX Ensemble
transceiver, one for the 136 kHz case and one for the 500 kHz case. These
two test samples will be sent at no charge to people who are interested in
evaluating RXTX LF operation.

Thanks for your interest in the project.

73,
Tony KB9YIG

 

Think this is a candidate for this group to get involved with?

 

73 es GL Pete M0FMT IO91UX