1
Safety feature
Important! One safety design feature of the SDR-4+ receiver is that when it or the PC
is powered down all the bandpass relays are powered off shorting the bandpass
filters to ground to provide extra isolation and protection to the PC. This can also
happen when changing the SDR program. When first powered up the relays remain
in a safe condition until the receiver is tuned past a bandpass filter change point i.e.
4, 8, or 16 MHz.
After powering up the receiver or changing the SDR program, step the frequency up
or down by 10 MHz or change the operating band and the desired filter will switch in.
You can then select the required frequency of operation.
3
WARNING!
The SDR-4+ receiver has been carefully designed to meet CE and FCC
specifications and also provide protection to your computer from static
electricity and electrical pulses. The receiver is designed to be powered only
from the USB connection on the PC. If the receiver is modified by the user
this voids the CE and FCC certifications and may damage the receiver or
user's PC.
No warranty claims will be accepted if the receiver case has been
opened.
The receiver has been designed to isolate the antenna from the computer.
Connection to the antenna should be made only via the BNC connector or by
the 2mm connectors. External antenna earths or grounds should only be
connected to the BNC connector.
The receiver case is connected to the computer ground and should be
isolated from any antenna connection.
