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1 Increasing No. of Stations
Increasing the Number of Stations
The FM Radcap PCIe is factory-configured for 6, 12, 18, 24 or 32 stations but
needs licensing on your PC hardware. For an additional charge, the number of
stations can be increased in the field by entering the appropriate expansion
key on this page. Contact Sonifex to obtain an expansion key, quoting the
card’s Hardware ID and the number of stations you require.
The number of stations can also be reduced if the full capabilities of the card
are not required. This can be used to reduce the processing overhead if, for
example, only twenty-six stations are needed on a thirty-two station card.
The number of stations specified must be even, with odd numbers being
rounded up.
The card can be configured to operate in stereo, mono or paired-mono
modes. Paired-mono mode combines two stations together as the left and
right sides of a two-channel audio stream. Which mode is best will depend
on the application software being used.
The audio de-emphasis may also be set to either 50us or 75us. In Australia,
New Zealand & Europe 50us is used, while in the USA & Canada it is 75us.
RDS decoding can be enabled, but be aware that this adds some host CPU
overhead.
Once the configuration has changed it may take up to a minute for Windows
to reconfigure itself – be patient, it hasn’t crashed! If multiple cards are
installed in the PC, each card can be configured independently (for example
one card could be set to stereo while the other is set to mono or paired-
mono).
Windows XP and Server 2003 limit the total number of audio input devices
to 32. Please be aware of this limit, particularly if there are other audio input
devices present in the PC. Paired-mono mode can be useful to work around
this limit in some cases, as it halves the number of audio input devices
needed to represent the card. There is no device limit in Windows Vista,
Windows 7, Windows 8, Server 2008, Server 2008-R2 or Server 2012.
Mono Recording Bug (Windows Vista, 7, 8, Server
2008, 2008-R2, 2012)
When making a mono recording from any stereo input, the audio engine on
these versions of Windows will provide only the left channel rather than the
expected left-plus-right mix. To circumvent this, set any stations to mono
mode (using the Tuner application or the Radcap API), or alternatively
configure the whole card as Mono.
Setting Station Frequencies
A utility program called Tuner is supplied on the driver disc/download.
This can be used to set the frequency of each station and also to monitor
each station through the PC’s standard sound card or motherboard sound
port. Note that this application can also be used with the AM Radcap and
the older-style two-channel FM Radcap cards, replacing the AmTune and
FMTune applications previously supplied. A minimum screen resolution of
1024x768 is recommended for use with this application.
To run the program, insert the driver CD, or go to the download directory
and run \AM & FM Radcap\Tuner.exe. To set the frequency of a station,
click on the Set button for that station, type in the frequency (in MHz) and
click on OK. For FM stations, it is also possible to force mono reception or
additionally reduce the audio bandwidth.
To monitor a station, click on the Monitor button for that station. Note that
there is a delay of about one second in the audio heard via this monitor,
due to the audio buffering used. Stereo reception is indicated by a blue
backlight in the stereo indicator (this is inoperative when the card is
configured as mono or paired-mono).
If RDS decoding is enabled, the RDS indicator will light when the decoder
is locked, and the transmitted Program Service Name will be displayed on
the surrounding box. When the station being monitored is broadcasting
Radiotext, the text is shown at the top of the main window, along with the
transmitted date/time information if this is available.
