FlexRadio Systems SDR-1000 Troubleshooting Manual

SDR-1000/SDR-Console Troubleshooting Guide
This guide is intended as a companion to the SDR-1000 Hardware Manual and the SDR-
Console Installation and Quick Start Guide. It addresses common installation and
configuration problems and their possible solutions. Please read the appropriate sections
of the above referenced manuals for more detail on these topics.
Relays Don't Click When SDR-Console Software Loads
Operational Description: The SDR-1000 uses a set of four 8-bit latches for controlling
the relays and DDS. When the unit is powered on, these latches are in an unknown state.
The SDR-Console should be loaded after powering on the radio for the first time. This
will reset all of the relays and the DDS to a known state. Pull down the bottom of the
SDRConsole form to reveal a Reset button that can be used after software is loaded.

Probable Causes:

1. Parallel cable does not have 25 conductors – The cable must be a 25 conductor
straight through cable with a DB-25P on each end. Some cables may have 25 pin
connectors but less than 25 conductors. The cable should be the shortest available
and in no case longer than 6 feet in length. Caution: most flat cables do not
work in this application.
2. Parallel port base address not set properly – For the radio to function, the base
address must be correctly set on the Setup Options/General tab under PIO Base
Address. The base address may be located by finding the first (lowest)
hexadecimal number under Setting column on the Resources tab under the Printer
Port (LPT?) Properties, which may be found in the Windows Device Manager.
3. Shorts caused by metal spacers or washers – Do not use metal spacers or washers
between the boards. They can short one of the power supplies to ground.
However, you can safely use metal screws on top of the BPF board to screw into
the nylon spacers below. You should place a set of four nylon washer and 3/8"
nylon spacer combinations between the BPF and TRX boards, and between the
TRX and PIO boards respectively.
4. Power supply does not handle sufficient current – The SDR-1000 can pull as
much as 1.25A before reset and will normally draw 600-700mA in receive mode.
Place a current meter in line with the power supply to see that it is drawing the
600-700mA after reset. This is a good general indicator to tell if the radio is
working properly.

Relays Reset but Operation is Intermittent

Operational Description: See the previous Operation Description. Capacitive loading
on the parallel port cable as well and insufficient drive from the parallel port itself can
adversely affect reliability of the signals that control the SDR-1000 latches. This can
cause the DDS to tune to random frequencies and/or the relays to operate erratically.
FlexRadio Systems 2003
TM
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