How To Start Guide

Setting up a radio station

This page deals with the problems of setting up a radio station. Our transmitters and MAXPRO FM kits will be used as an example, although others could be used as well. We will assume here that you want to setup a FM radio station, AM will be covered at the bottom of this document in a similar short guide.

First, you need to establish what kind of an area you need to cover.

1.) What range will my transmitter have, how much power do I need?
Propagation of radio signals is limited by laws of physics. Range is thus determined and limited by several factors:

a) Optical visibility. This can sometimes be up to 40 miles, if you are looking out from a mountain top.

b) Interference from other stations on the same or close-by frequency. Receivers are not ideal and some are even becoming more crappy in this modern age of crappy Chinese dollar radios. Such receivers have difficulty discerning your signal while there are other strong signals close by.

c) Transmission power. Even if optical visibility is 20 miles, 1W probably won’t get you more than a mile. If 1000 Watt ERP is used, it’s very likely that at least 20 miles of range will be achieved. This is because 1000 Watt ERP is ample power to propagate a strong signal 20 miles. If 10000 Watts of power is used, it is very likely that signal will only propagate just over 20 miles. This is because the range is limited as described in point a) above (optical visibility). To increase range it would be necessary to move antenna much higher to a mountain top which would increase optical visibility.

Assuming the antenna has a clear view, the frequency is clear and an average (poor) quality portable receiver is used, typical transmission power vs range figures are as follows:

Power watts ERPRange miles (Km)
1Wapproximately 1-2 (1.5-3km)
5W approximately 3-4 (4-5km)
15Wapproximately 6 (10km)
30Wapproximately 9 (15km)
100Wapproximately 15 (24km)
400Wapproximately 30 (45km)
1000W approximately 30-50 (45-55km)
>2000W approximately 35-75 (45-100km) solid coverage
Range for FM band transmitters

It is not possible to have hundreds of miles of range on FM broadcast band (87.5MHz to 108MHz), even if terrain is perfectly flat and you have your antenna on the top of the mountain and you’re using many KW of power. It is occasionally possible due to special atmospheric conditions, such as inversion etc. Such special conditions happen rarely and only last for a very short time so it is not possible to rely upon them in any way. In order to cover so many square miles it is necessary to setup a grid of transmitters and link them via wireless audio links, making sure they do not transmit at the same frequency as they could interfere. Have you ever heard FM station from another country? Sometimes you can, when atmospheric conditions make this possible. However it is rare and usually does not last long.

Finally, for absolute novice, there is no difference in range between transmitters of different manufacturers, provided they’re operating at the same power level. The difference can show in audio quality, reliability, life span and spurious emissions. There are no secret designs or techniques to reach further with the same amount of power out there.


2. What are the building blocks of a radio station, what do I need to setup a radio station
We have provided a number of prepared complete packages for you, containing everything you need to start broadcasting immediately and explaining what is included in the package. These complete packages can be found here. It is recommended that you check them out even if you do not intend on purchasing any of them, just to get some feel of what you need. Check also the options below as there are some basic studio packages as well.

Here is a quick list of things you need to start your own radio station:

A.) FM radio Transmitter
This can be any of our FM transmitters, depending on your budget and your target range. If you just want to cover your property (house, apartment, yard), think about PCI MAX. This transmitter is a PC card, you can insert it into your PC (just like any other computer board) and it turns your PC into a FM radio station. This unit is another small solution with excellent audio connectivity, even AES/EBU digital inputs.

If you’re looking to setup drive-in cinema FM radio or small community station, these packages are perfect. 100W will satisfy most small community radio stations, college radio stations, drive-in cinemas, village setups, tunnel radios or small transponders. If you need more power, consider stronger units, we have 200W, 400W, 600W, 1000W, 2000W and 3000W FM transmitters available.

Yet cheaper are our FM KITs . They are just the FM exciter and most require a stereo encoder to produce stereo signal, but we now offer also a solution with on-board RDS and stereo. They also require a bit more knowledge to mount into a case, wire audio and other connections and operate. A novice is advised to check our boxed units instead.

B.) Antenna
Our packages mentioned above come with an antenna included. PCI MAX comes with a very rudimentary short-range small handy antenna. All other transmitters require a proper antenna and as a consequence provide vastly superior range. There are two major antenna groups, the directional (transmit most of the power in one direction and thus provide substantial gain) and omni-directional (transmit in all directions more less equally, with lower gain). You need to be careful about several things:
– Antenna needs to be placed as high as possible, preferably on a roof or a highly elevated tower.
– Keep your coaxial cable as short as possible, but still make sure antenna is at least a few meters away from the transmitters and other audio equipment.
– Choose a good location. A mountain top is just about perfect
– Keep your antenna away from audio gear and computer/power supply/transmitter. Also well away from TV or other antennas, cable TV coax and other installations.
– A good antenna system is a much better investment than an amplifier. It will not waste electricity. If you build it well and maintain it it can run for decades with very low maintenance costs.

Multi-bay system with multiple dipole antennas
One way to increase range and gain of the antenna system is to place several dipoles one above the other. Quadrupling number of dipoles doubles your range. So going from 2 dipoles to 8 dipoles doubles your range. Same goes from going from 1 to 4 dipoles. These dipoles can either be vertical or circular.

Multi-bay dipole antenna system


Also check our antenna guide for info. You can buy our FM antennas here.

C.) Coaxial cable
It carries the energy from your transmitter to the antenna. The exact type needed depends on the length of cable, power level and your budget. Short cable and low-power installations are happy with RG-58 or H-155, for longer runs and higher power levels use a better cable such as H-2000 flex or Cellflex 1/2″ or 7/8″. You can check specs and buy coaxial cable here.

D.) Power supply
Some transmitters require external power supply, others don’t. Make sure to check the specs of your chosen transmitter and include mains power supply in your order, where necessary. If you’re low on your budget, build your own. But today this almost never saves any money.

E.) Audio equipment
This can be a limiter – compressor, mixing tables, cd players or even a PC. Most professional radio stations today use PC as audio source. Check our guide for Audio Equipment here.

F.) Radio Etiquette; act responsibly on the air!
Remember, people out there will be listening. There might be children out there so act responsibly.


3.) CYBERMAXFM+ SE V3 15W installation example for community radio or drive-in cinema

Here we will show you a typical small radio station. Simply scale-up power or substitute another antenna/transmitter for your particular application. 15W FM transmitter is used and a simple FM Dipole antenna. They can all be purchased in a package here.

Drive-in cinema FM transmitter

This package is based on our CyberMaxFM+ SE V3  rack mounted FM transmitter series for demanding broadcasters operating in the 87.5 to 108MHz band. It contains our reliable FM transmitter with optional DSP stereo and RDS, an antenna, coaxial cable and all connectors. A perfect FM transmitter for a regular licensed radio station, drive-in cinema, church, medium size radio station, campus radio or a religious radio. Very suitable for portable or improvised installations and small radio stations, advertising (housing, shops), special occasions, drive-in cinema wireless sound distribution, translation, tourism…. Protected with Temp and SWR protection. It can also serve to drive an amplifier of any power.

Here is a guide to setting up FM transmitter for drive-in cinema.

ADVANTAGES
– Frequency and power fully adjustable via LCD (from zero to max for given model)
– Excellent audio quality and stereo separation (V3 with SE8000 DSP+)
– Improved DSP compressor for high dynamic range handling (much improved in V3)
– New Expander mode especially for movies (boosts quiet sections)
– USB audio input for direct connection to PC or laptop
– XLR and RCA audio inputs
– Optional Ethernet IP audio streaming and remote control
– Optional RDS available
– High quality ESD protected RF hardened balanced inputs
– Enough power for up to 10km of range with good antenna and location on a mountain top
– Includes coaxial cable, mains power supply and antenna!

DISADVANTAGES
– Hardly any

RANGE
It is never easy to predict range. It basically depends a lot on your antenna location, soil conductivity, antenna height and other factors. You can expect anywhere from 1Km to 10Km range, perhaps less in extremely unfavorable conditions and possibly even 20Km in extremely favorable conditions. Check the top of this page to get more info.

WHAT ELSE YOU (MIGHT) NEED AND WASN’T INCLUDED?
SWR meter or even better AA-230 antenna analyzer to tune your antenna (optional).
CD players, mixer, microphone, a PC…


4.) CYBERMAXFM+ SE V3 1000W installation example for medium size radio station

Here we will show you a typical 1KW radio station. Simply scale-up power or substitute another antenna/transmitter for your particular application. 1000W FM transmitter is used and a simple 4-bay FM antenna made out of 4 vertical dipoles. They can all be purchased in a package here.

Wiring instructions for FM transmitter
Drive-in cinema FM transmitter

This package is based on our CyberMaxFM+ SE V3  rack mounted FM transmitter series for demanding broadcasters operating in the 87.5 to 108MHz band. It contains our reliable FM transmitter with optional DSP stereo and RDS, an antenna, coaxial cable and all connectors. A perfect FM transmitter for a regular licensed radio station, campus radio or a religious radio. Very suitable for small to medium towns with range from 30 to 80km depending on antenna system location. 4-bay antenna ensures 6dBd gain making this 1000W FM transmitter radiate ERP of 4000W.

ADVANTAGES
– Frequency and power fully adjustable via LCD (from zero to max for given model)
– Excellent audio quality and stereo separation (V3 with SE8000 DSP+)
– Improved DSP compressor for high dynamic range handling (much improved in V3)
– New Expander mode especially for movies (boosts quiet sections)
– USB audio input for direct connection to PC or laptop
– XLR and RCA audio inputs
– Optional Ethernet IP audio streaming and remote control
– Optional RDS available
– High quality ESD protected RF hardened balanced inputs
– Enough power for up to 100km of range with good antenna and location on a mountain top
– Includes coaxial cable, mains power supply and antenna!

DISADVANTAGES
– Hardly any

RANGE
It is never easy to predict range. It basically depends a lot on your antenna location, soil conductivity, antenna height and other factors. You can expect anywhere from 30Km to 100Km range, perhaps less in extremely unfavourable conditions and possibly even >100Km in extremely favourable conditions.

WHAT ELSE YOU (MIGHT) NEED AND WASN’T INCLUDED?
SWR meter or even better AA-230 antenna analyzer to tune your antenna (optional).
CD players, mixer, microphone, a PC…
DSP audio processor is recommended for top performance
– Wireless audio link from studio to transmitter may be needed if studio and transmitter aren’t at the same location.


5.) BUILDING A TRANSMITTER FROM KITS, MODULES

One of the first steps when building your own FM transmitter from modules will be the choice of exciter module. Below are a few typical scenarios that will help you decide.

Small community stations in remote areas, far from urban centers
STMAX3015+ works best for these since it comes with built-in stereo encoder and RDS. This reduces both cost and complexity. It can also be easily programmed via LCD without the need for PC to set the RDS parameters. You can mount one of these on the top of these amplifier modules, this will form a complete Stereo RDS FM transmitter. Audio quality is pretty good. Spurious level is not suitable for professional setups as DDS digital modulator creates some in-band artefacts about -50dBc down. If you’re looking for a simple solution where those issues are not a factor (remote rural area) do get one of these, you will not be disappointed.

Small community stations that require spurious levels to be >65dBc
If your signal needs to be clean but 15W is all you need, MAXPRO2015+ works best. You will also need a separate stereo encoder or audio processor with MPX output. The added benefit is that you can now also use MPX STL wireless link. MAXPRO2015+ can be used as a simple pallet amplifier driver.

Large stations that require spurious levels to be >65dBc
MAXPRO8015+ works best. You will also need a separate stereo encoder or audio processor with MPX output. You can also use MPX STL wireless link. It is equipped with DIGIAMP I interface and also supports MAXLINK II so when interfacing with SE8000 you don’t need to solder at all. Any of these can drive any amplifier up to 10KW and more.

Here is a quick comparison chart between different types of our FM exciters:

NameSTR-1000STMAX3000+ seriesMAXPRO2015+MAXPRO8015+ SBMAXPRO8015+ STR
Available todayAvailable in June 2020YesYesYesYes
Frequency range87,5-108 MHz (76-90MHz on request)87,5-108 MHz (76-90MHz on request)87,5-108 MHz (54-68 and 76-90MHz on request)87,5-108 MHz (54-68 and 76-90MHz on request)87,5-108 MHz (54-68 and 76-90MHz on request)
Output power100mW15W/25W/35W/50W/100W15W15W, 25W15W, 25W, 50W, 100W
Supply voltage12-15V12-15V (48V for 100W)12-15V12-15V12-15V
PLL step size100 kHz (down to 1KHz on request)100 kHz (down to 1KHz on request)100 kHz (down to 50KHz on request)100 kHz (50KHz possible)100 kHz (50KHz possible)
Antenna connectorBNCBNCBNCBNCMXC or SMA
Modulation typeOn-board 2xRCA, 2x XLR, USB and AES/EBUL/R input (2xRCA), with new ucoming input board also XLR, USB and AES/EBUStandard MPX inputStandard MPXStandard MPX, RCA, XLR inputs
VCO typeDDS digitalDDS digitalStandard VCO + PLLLow noise VCO + PLLLow noise VCO + PLL
Spurious output~-50dBc~-50dBc<-65dBc<-83dBc<-85dBc
Built-in stereo encoderYesYesNo, requires SE2000, SE5000 or SE8000 (SE7000 not supported)No, requires SE2000, SE5000, SE8000 DSP+ recommended!Yes, high quality DSP
MAXLINK supportYesYesYes, MAXLINKIYes, MAXLINKIINot needed
Built-in RDSYesYesNo, requires externalSame as 8015+Plug-in available
What kind of STL link can be usedSplit audio channels onlySplit audio channels onlyMPX or regular split audio channels (with stereo encoder)MPX or regular split audio channels (with stereo encoder)MPX or regular split audio channels
Digiamp supportNoYesNo, but it has input for external power and swrYesYes
RDS controlDirectly from LCD display or via PC applicationDirectly from LCD display or via PC applicationVia PC aplication, requires RDS encoderVia PC aplication, requires RDS encoderVia PC aplication, requires RDS encoder
PC remote controlCyberNanoFM+ programCyberNanoFM+ programCyberMaxFM+ programCyberMaxFM+ programCyberMaxFM+ V60 program (more advanced than 8015SB)
Support for new large 4×16 LCDYesYesNoYesYes, new type with 16-lead cable
Super Bass:YesYesNoYesYes
Suitable for:Low cost Stereo + RDS solution, all functions including RDS adjustable from LCD display. For remote areas.Low cost Stereo + RDS solution, all functions including RDS adjustable from LCD display. For remote areas.Low cost solution with a clean signalVery clean signal for pro solutions, requires Stereo/RDS encoderVery clean signal for pro solutions, very practical all on single board

What are the benefits of DSP stereo encoder?
Very shart input filters with a deep 19KHz notch, advanced signal processing with compressor and limiter, all adjustable via LCD display


What is RDS?
Radio Data System, basically it displays station name and sometimes song name and similar information on a compatible radio receiver. Very popular in Europe, less so in the US. Requires connection to a PC at the time of programming, but retains settings even when powered off. Serial programming cable for COM port is included.

PLL step size:
No legal radio stations exist outside 200KHz steps so 100KHz is more than enough for a PLL step size. Many car receivers have 200KHz step size.

RDS:
Radio data system, displays radio station name on the display of receiver

DIGIAMP support:
When building a larger transmitter which consists from exciter module, amplifier module and output filter, this interface simply plugs into our filter to provide a host of signals to the exciter. Exciter can display those on the LCD. These include power, swr, temperature, amplifier voltage and others.

Here is a quick comparison chart between different types of our stereo encoders:

NameSE2000 D+SE5000 DSP+SE7000 DSP+SE8000 DSP+
Available todayYesYesYesYes
Supply voltage12-15V12-15V12-15V12-15V
Balanced inputsYesYesYesYes
USB audio inputYesNoYesYes
DSP processorNoYesYesYes
Signal noisevery goodvery goodexcellentexceptional
Stereo separationgoodgoodexceptionalexceptional
RDS plugin boardavailableavailableavailableavailable
IO boardNoNoYes, USB + RS232 + optional Ethernetneeds IO board
On board XLR connectorNoNoYes, with IORDS5000Yes
Support for LCDNoYesYesYes
AES/EBU:NoNoNoPlug-in
Suitable for:Small transmittersSmall/medium transmitterspro solutions pro solutions

What is a PCI MAX card?
PCI MAX is a computer card, you install it into your PC just like a network or any other card. It contains a small FM stereo PLL controlled transmitter with optional RDS capability. It makes it possible to transmit sound from your PC to any radio receiver in your appartment or further away and can even form a small comunity radio station. A simple windows program lets you set the frequency, power and other parameters.

If we want a big radio station with considerable range, is a PCI MAX 3000+ a good way to go about this?
Not really, PCI MAX cards were not designed for that kind of application. It is better to have a stand-alone solution, such as our Cyber Max series. You can still feed any of our Cyber Max series transmitters with audio from your computer.

If I use filters I can put my antenna right next to my neighbor’s TV antenna without any problems right?
Wrong! The low pass filters only attenuate harmonics. If harmonics are not the cause of your problem (they almost never are – our exciters are very clean!) removing them won’t help. What causes 99% of all radio interference problems? Too strong local fundamental signal! A high power fundamental signal in CLOSE PROXIMITY to ANY type of receiving equipment (TV, radio, telephone, PA system etc.) will blow right past any tuner or filtering on this equipment and enter the amplifier stage along with the intended signal where it will cause interference. This type of interference is called “fundamental overload”. All the harmonic filters in the world won’t help in this very common situation. What will help? Increase the standoff distance (vertical, horizontal or both) between your antenna and what you are interfering with. This is one of the many reasons high power FM radio station antennas are located on high towers. A 100 KW radio station would cause a lot of RFI even though the harmonic levels meet FCC requirements.

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