Print Date 08/04/14 Page 9 of 34 S79005-00MA-05
1.3 TECHNICAL SPECIFICATIONS
The S7900 range of FM Transmitters is designed to meet or exceed ETSI Standards:-
EN 301 489-01 : ERM/EMC for Radio Equipment, Part 1, Common Technical Requirements.
EN 301 489-11 : ERM/EMC for Radio Equipment, Part 11, Specific Conditions for FM Transmitters.
EN 302 018-02 : ERM (Spectral Occupancy) for the FM Radio Broadcast Services.
EN 60215:1989 : Safety Requirements for Radio Transmitting Equipment
Note that the following figures do not include any which principally depend on the Exciter/Drive being
used (e.g. frequency stability). The figures given below may also be affected by the Exciter/Drive’s
performance. In both cases the Exciter/Drive’s own manual should be consulted.
RF Interface Ports
50
Ω
nominal
Input Drive Power
RF Input from Exciter/Drive supplied :-
8-10W (13W absolute maximum)
Output Power Level With any load with a return loss
≥
14dB (1.5:1 VSWR) any angle.
(though see note below in ‘Output Power shutdown’ section)
Note two independent settings available for selection.
Adjustable at least 200W to 500W (Power Low setting)
Adjustable at least 300W to 500W (Power High setting)
Output Power
Variation
Not more than
±
1dB under all specified operating conditions.
Output Power
Shutdown
Output power is automatically reduced or shutdown to ensure that any load
with return loss
<
10dB including open and short circuits, does not cause any
damage to the transmitter.
The return loss level at which shutdown starts can be increased by an
internal adjustment (see section 2.3.3). This level is normally set at the
factory to be 16dB, the level at which excess reverse power first produces a
warning indication.
Output Reverse
Intermodulation
Reverse intermodulation products will be better than or equal to –10dB,
relative to the interfering incident signal, this being offset over the range
±
300kHz to
±
20MHz (but remaining within 87.5MHz to 108MHz).
Frequency Range
87.5 -108MHz
Spurious Emissions In the range 9kHz to 1000MHz : -
Better than or equal to –75dBc
Out of Band
(Adjacent Channel)
Emissions
Better than or equal to –110dBc/Hz, at
±
200kHz offsets, and 145dBc/Hz at
±
2MHz. When measured in a 1kHz bandwidth, the limit figures become –
80dBc at
±
200kHz offsets and –115dBc at
±
2MHz.
Incidental
Amplitude
Modulation
Synchronous (AM due to FM) :-
Not greater than 2% with a peak deviation of
±
40kHz at a modulation
frequency of 500Hz.
Asynchronous (residual AM due to hum and noise with no FM modulation) :-
Not greater than 1% when measured unweighted in a 20Hz to 20kHz
bandwidth.
