FM Broadcast Transmitters
A basic maxim of electronic equipment purchasing is: the true and total cost of a cheaper product may not be reflected in its selling price. FRB manufactures FM broadcast transmitters using the KISS (Keep it Simple Sam) principle. We over design our transmitters where it matters but do not add unnecessary features. Our transmitters are designed to operate 24/7 and meet the demands of less than ideal operating environments, such as those found in developing countries – high temperatures, humidity, dust, etc.
FRB FM Transmitter design features:
Heavy duty aluminum and steel 19 inch rack enclosures
External heat sink
with cooling fan(s). No dust, dirt insects, etc. are drawn into the enclosure as is the
case with most other manufactures who place the heatsink inside the
enclosure. Although the external heatsink requires a larger
enclosure, such placement allows for both natural convection and
forced air cooling. This virtually eliminates the issue of hot spots on the final amplifier heatsink
which will degrade both performance and longevity. Cleaning dust
from the heat sink is simple, unclip the fan assembly and wipe the
dust off. Further, external placement of the heatsink prevents other
components inside the enclosure from overheating.
Easy servicing. All of the active components with the exception of the power supply are mounted on a rear panel which can be easily accessed for servicing if required. Many manufacturers offer hard to service transmitters by cramming everything into the smallest enclosure possible. This creates cooling issues as well.
Over rated power supply. Unlike many manufacturers, we use power supplies rated for a current draw of 15 to 20 percent over the nominal current draw of the transmitter. By not operating the power supply close to its maximum rating, the longevity of the transmitter is increased.
Final amplifiers are not set for the maximum power possible. For example, our 1000 watt transmitter uses a final amplifier rated for 1200 watts. Operating at a reduced power prolongs the longevity of the transmitter.
Frequency control and audio circuits are comprised of discrete components not FM transmitter ICs – an almost universal component in most Chinese manufactured FM transmitters. FRB transmitters employ a true discrete IC (ADF4116) PLL (Phase Lock Loop) circuit combined with a low phase noise, fully shielded VCO (MiniCircuits POS-150) for frequency control and synthesis.
Standalone stereo generator, not an FM transmitter IC which has very poor separation and noise performance. If the stereo option is selected, FRB provides a discrete FM stereo generator. This assures broadcast audio quality for the transmitted signal.
No overly complicated transmitter operations. Many manufactures attempt to cram every sort of function into a limited LCD front panel display controller. Adhering to our KISS principle, FRB transmitters use either a simple 8 position DIP switch to set the frequency. Located inside the transmitter case, this prevents tampering with the frequency once it has been set. An LCD display with limited control options will be available as well.
