PCS Electronics MAXPRO5015+ v2 User manual

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MAXPRO5015+ v2
High performance FM radio exciter and the perfect pallet driver
Manual

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I M P O R T A N T N O T E
Upon receiving your order inspect the packaging material and unit for apparent damage. Any
damage should be reported immediately so we can make a claim with the shipping company.
Take photos, if you can, they can be used as a proof.
IMPORTANT!: If you want to connect an amplifier to this exciter please first make sure that
output power is set correctly and does not exceed maximum allowable input power of the
amplifier. See appendix for additional tips on driving amplifiers.
Study local regulations and ensure you are operating in compliance.
Never ever operate any exciter/transmitter or amplifier without a properly tuned load/antenna!

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TABLE OF CONTENTS
INTRODUCING THE MAX PRO 5000+ FM EXCITER SERIES (V2.0).................................................... 6
WHAT MAKES THIS FM EXCITER SO GREAT?.................................................................................................... 6
HOW IS MAXPRO5000+ SERIES BETTER THAN MAXPRO3000+ OR MAX PRO4025? .................................... 6
TECHNICAL SPECIFICATIONS: .......................................................................................................................... 7
MAXPRO5000 SERIES + KEY FEATURES......................................................................................................... 7
THANK YOU FOR PURCHASING MAX PRO 5000+ SERIES FM EXCITER ............................................................. 7
MAXPRO50XX+ RF AND LCD BOARD LAYOUT .................................................................................... 8
RF BOARD LAYOUT ........................................................................................................................................ 8
LCD MODULE LAYOUT ................................................................................................................................. 10
RF AND LCD MODULE DRILL TEMPLATE/CUTOUT .......................................................................................... 12
WHAT’S UNDER THE HOOD?.................................................................................................................. 13
BEFORE YOU START................................................................................................................................ 15
ANTENNA..................................................................................................................................................... 15
SO WHAT IS THIS SWR (VSWR) EVERYONE TALKS ABOUT?............................................................................... 16
COAXIAL CABLE ........................................................................................................................................... 16
BNC CONNECTOR......................................................................................................................................... 16
MAINS POWER SUPPLY AND MAINS POWER CABLE .......................................................................................... 16
AUDIO SOURCE WITH MIXER, MICROPHONE ETC ............................................................................................. 17
ENCLOSURE AND COOLING FOR MAX PRO 5000+ SERIES EXCITERS .............................................................. 17
STEREO ENCODER FOR STEREO OPERATION .................................................................................................... 17
WIRING EVERYTHING TOGETHER...................................................................................................... 18
WIRING THINGS UP AND FIRST POWER-UP....................................................................................................... 18
USING THE MAX PRO 50XX+ EXCITER ................................................................................................ 20
LCD CONTROL MODULE................................................................................................................................. 20
LCD CONTROL MODULE MENU SYSTEM .......................................................................................................... 20
CHANGING FREQUENCY ................................................................................................................................ 20
<RF POWER>............................................................................................................................................. 20
<STEREO MODE>..................................................................................................................................... 20
<VIEW SELECT>....................................................................................................................................... 21
<TREBLE> AND <BASS> ........................................................................................................................... 21
COMPRESSOR SETTINGS................................................................................................................................ 21
<LCD CONTRAST>................................................................................................................................... 22
LEFT AND RIGHT CHANNEL VOLUME (ONLY WITH DSP STEREO ENCODERS)..................................................... 22
<PLL STEP>............................................................................................................................................... 23
<FIRMWARE VER> .................................................................................................................................. 23
<CURRENT ALARM> ............................................................................................................................... 23
<TEMP ALARM>....................................................................................................................................... 23
<SWR ALARM>......................................................................................................................................... 23
<U AMP ALARM> ..................................................................................................................................... 23
<BAND SELECT>...................................................................................................................................... 23
<RF AMP CONTROL>............................................................................................................................... 23
<RF POWER ALC> .................................................................................................................................... 23
DESCRIPTION OF WINDOWS CONTROL PROGRAM......................................................................... 24
SETUP .......................................................................................................................................................... 24
FM TX MAIN ............................................................................................................................................... 25
FM TX ALARMS........................................................................................................................................... 27
PI, PTY... .................................................................................................................................................... 28
PS0.............................................................................................................................................................. 29
PS1.............................................................................................................................................................. 30

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PS2.............................................................................................................................................................. 30
TIME, MSG... ............................................................................................................................................. 31
AUTO PS, RT... .......................................................................................................................................... 32
ABOUT ......................................................................................................................................................... 33
COMMON CONTROLS..................................................................................................................................... 34
SCHEDULER.................................................................................................................................................. 35
TROUBLESHOOTING ............................................................................................................................... 37
LIMITING MAXIMUM ADJUSTABLE POWER FOR DRIVING PALLETS ........................................ 40
STEP1 – ESTABLISH NEEDED DRIVE POWER .................................................................................................... 40
STEP2 - SET MAXIMUM OUTPUT POWER TO 4W .............................................................................................. 40
STEP3 – REDUCE 4W DOWN TO THE NEEDED 3.5W WITH ATTENUATOR (OPTIONAL, BUT RECOMMENDED)........ 40
STEP4 – VERIFY PERFORMANCE BEFORE CONNECTING THE PALLET ................................................................. 41
STEP5 – WIRING UP THE PALLET AND FIRST POWER UP.................................................................................... 41
STEP6 – FIRST POWER UP AND SETUP ............................................................................................................. 41
STEP7 – CHECK THE ALC AND SET IT TO PREVENT OVERDRIVING ................................................................... 41
STEP8 – RF POWER ALC (SOFTWARE POWER LIMIT) ................................................................................... 41
APPENDIX A: DIY ANTENNA AND IMPROVEMENT TIPS ................................................................. 42
SIMPLE GP ANTENNA DESIGN........................................................................................................................ 42
SOME MORE IMPROVEMENT TIPS.................................................................................................................... 42
APPENDIX B: CONNECTING STEREO ENCODER............................................................................... 43
APPENDIX C: ADDING AN AMPLIFIER – COMPLETE FM TRANSMITTER BLOCK BY BLOCK 44
APPENDIX D: CONTROLMINI 2.............................................................................................................. 47
APPENDIX E: CONTROLLING OUTPUT POWER - CONTROLMINI 1 .............................................. 49
APPENDIX F: DIGIAMP CONNECTOR PINOUT ................................................................................... 50
APPENDIX G: TELEMETRY CONNECTOR PINOUT............................................................................ 51
APPENDIX H: GENERAL TIPS FOR SETTING UP TRANSMITTERS................................................. 52
TYPICAL FM TRANSMITTER SETUPS .............................................................................................................. 52
TYPICAL FM BROADCASTING ANTENNA SETUPS............................................................................................. 53
WIRING ANTENNAS IN MULTI-BAY CONFIGURATIONS ..................................................................................... 54
APPENDIX I – USING WIRELESS AUDIO LINKS.................................................................................. 55
APPENDIX J – IO BOARD AND PC REMOTE CONTROL .................................................................... 56
SOFTWARE INSTALLATION ............................................................................................................................ 56
CONFIGURING COMMUNICATIONS PORT ......................................................................................................... 57
INSTALLING USB DRIVER (ONLY FOR USB IO BOARD) .................................................................................. 57
CONFIGURING USB DRIVER .......................................................................................................................... 58
APPENDIX K – SETTING UP REMOTE CONTROL VIA ETHERNET................................................. 59
SOFTWARE INSTALLATION ............................................................................................................................ 59
APPENDIX L: COMMUNICATION PROTOCOL EXPLANATION....................................................... 62
APPENDIX L – WARRANTY AND LEGAL INFO ................................................................................... 68
IMPORTANT NOTICE!..................................................................................................................................... 68
WARRANTY AND SERVICING! ........................................................................................................................ 68
LEGAL INFO.................................................................................................................................................. 68
LIMITATION OF LIABILITY ............................................................................................................................. 68

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ALSO AVAILABLE FROM WWW.PCS-ELECTRONICS.COM............................................................. 69
REVISIONS AND ERRATA........................................................................................................................ 70
INDEX........................................................................................................................................................... 70

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Introducing the MAX PRO 5000+ FM exciter series (v2.0)
Next generation of FM exciters with new Qsonic II
VCO/PLL and up to 40W of power
esigned either as a perfect pallet driver or a stand-alone FM exciter, MAX PRO 5000+ series brings up to 40W
of very clean RF power, updated Qsonic II double-speed PLL/VCO subsystem with impressive audio
performance and excellent bass plus several brand new hot features.
What makes this FM exciter so great?
MAX PRO 5015/5025/5040+ displays a number of useful parameters on the LCD display: transmitted power, reflected
power, temperature, voltage, frequency, current consumption, audio modulation level, amplifier voltage, amplifier power and
swr, and amplifier temperature and power consumption. The new Qsonic II VCO/PLL subsystem is protected by a metal
shield for even better performance. Power and all other parameters can be controlled with keys on the LCD module or
remotely via RS232/USB interface. Let us not forget about the power output, 40W is more than enough to drive any big
amplifier out there on the market. Of course this unit is completely no-tune, directly supports our stereo encoders (SE5000
DSP+, SE 2000 and SE3000), and offers impeccable performance 24/7/365. Even as a stand-alone unit this exciter doubles
as an excellent community radio station and can easily cover a small city with suitable antenna.
How is MAXPRO5000+ series better than MAXPRO3000+ or MAX PRO4025?
- MAXPRO5000+ series has slow power ramp-up to ensure safe pallet/amplifier operation
- MAXPRO5000+ series has more output power (40W versus 15/25W)
- MAXPRO5000+ series has output power flat across entire FM band (<0.5dB variation).
- MAXPRO5000+ series has very low spurious output (extremely clean signal without any spurs)
- MAXPRO5000+ series has four maximum power limit jumpers for 2W, 4W, 6W and 8W. Very usefull for driving pallets.
- MAXPRO5000+ series has smaller output power adjustment steps (smoother adjustment).
- MAXPRO5000+ series has additional alarm for amplifier current and amplifier voltage.
- MAXPRO5000+ series is more efficient, it needs less current for the same output power.
Chapter
1
D

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Technical specifications:
- RF output power at 15V DC: 0 to 15W, 0-25 Watts and 0-40W
- Output connector: BNC, 50 Ohms
- Frequency range: 87.5-108MHz
- PLL steps: 50KHz
- Frequency stability: +/- 20Hz, input for TCXO (external high precision clock)
- Spurious/Harmonic rejection: Harmonics: >50dB, Spurious: -90dB
- Power supply: 11-15V/6A or car battery (2.5A max for 15W, 4.5A max for 25W, 6A max for 40W)
- Power connector: 2.1mm power socket, center (+)
- Quartz locked PLL frequency control, ultra stable & clean output
- No expensive test equipment required
- Audio performance: Flat sensitivity across FM band, less than 0.1% distortion, 20Hz-75KHz
- RF output ruggedness: SWR protection
- Polarity protection, temp protection
- Over-current protection
- Pre-emphasis, 50uS, 75uS or none selectable
- Audio Input Impedance: 10Kohm, unbalanced, RCA jack, optional MCX
- Audio Input Level: 0 dB
- S/N ratio: >90 dB
- PC Board Size: Same as MAX PRO 3000+/4025, 100x125mm (see page 11 for drilling template)
- RF monitor output: Yes, solder pads, -30dB
MAXPRO5000 series + key features
- Displays frequency, power, audio level, reflected power, temperature, exciter voltage, amplifier voltage, amplifier current
and exciter current on the LCD.
- Extreme VCO isolation and RF field immunity (our exclusive innovative design)
- SWR and TEMP protection with adjustable sensitivity
- Adjustable software power limit when driving external amplifier
- ALC (Automatic Level Control) system for keeping output power level constant across entire FM band (requires 5000 or
6000 series low pass filter)
- High power (40W typ max)
- True wideband no-tune operation
- Flat audio response, excellent bass
- Directly supports our SE5000 DSP+, SE2000 and SE3000+ stereo encoders via LCD MENU system
- Mains power supply control module available, enables controlling output power by adjusting voltage
- RF control board with directional couplers and SWR protection is available
Thank you for purchasing MAX PRO 5000+ series FM exciter
We hope you will enjoy it as much as we do and remember to tell your friends about it. Please feel free to leave your
comments at our website or post your experience in our forum. From all of us we wish you happy broadcasting!
Your PCS Electronics team

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MAXPRO50XX+ RF and LCD board layout
RF board layout
Fig. 1: MAX PRO 5000 series + RF board layout
Chapter
2

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Ref. Function
A Connect ON/OFF switch here, but you can also just install a jumper. A LED diode can also be connected as
shown on the image, series resistor is on board and is not necessary.
B Output stage bias current. DO NOT change this setting. (Does not exist on new 5015 boards)
C You can connect external TCXO (thermally stabilized reference oscillator). Frequency needs to be 18MHz, TTL.
You will probably have to remove nearby quartz crystal, if you want to use this input.
D Optional ERROR indicator LED can be connected here. This LED is activated when RF output stage is NOT
active. For example, whenever temperature protection is activated, this LED illuminates and RF power is
reduced. This LED is also located on the LCD control module. Important: This LED is also illuminated
whenever you change frequency as the control unit turns RF power off until PLL/VCO tuning is finished. In
such case this does not signal a problem with temperature or SWR.
E Pre-emphasis. Use this jumper to set pre-emphasis. This can either be 50uS (EU and most of the world) or 75uS
(USA). If you plan to connect stereo encoder to the MAXPRO50xx+ board, place the jumper in position None
(top - this disables pre-emphasis).
F Power adjustment jumper. Remove this jumper if you want to control power via LCD module. To set output
power via external control voltage (0-5V) apply voltage to header V (J6).
G Audio input sensitivity adjustment.
H Audio input - coaxial cable or 2-pin header.
I Digiamp connector enables easy control of RF amplifiers and mains power supplies that power them. This greatly
simplifies the process of building FM transmitters. You can read more about this connector in appendix.
@ Internal power meter accuracy adjustment. If the internal power display on the LCD is a bit off you can correct its
accuracy with this trimmer, the range of adjustment is very small.
K RF monitor output. This output contains a small sample of output signal, suitable for monitoring RF signal
quality with instruments such as frequency meter, frequency analyzer or modulation monitor.
L You can connect VUMAX-1 led vu-meter unit here, it will show output power and swr as bar graphs. The 2
remaining bar graphs can be connected to SE5000 DSP+ and will show audio volume.
M Soldering posts for a small 12V fan. Output stage appreciates a bit of air flow, it does not have to be substantial.
As long as the air slowly moves a bit it'll be more than enough so use weakest available FAN. Due to improved
design this fan now spins down completely at low RF power output and our new 40x40x25mm unit is almost
completely inaudible even at highest speed.
N Maxlink connector for easy connection with the SE5000 or SE3000 stereo encoder. This lets you connect and
control both units from the same LCD control units. Our Cyber Max FM+ units use this arrangement. This
connection is now completely solder-free, just plug the connector in and voila, finished. Flat cable that runs
between the units also carries supply voltage for the stereo encoder further reducing required wiring and work.
O LCD control unit, attach your LCD control module here.
P Power supply connector, center is positive. DO NOT use more than 15V.
Q Do not touch unless you understand what this is. Lets you fine-tune the reference frequency. Can be used to set
the unit to any frequency, even though the PLL step is 5KHz. You can for example use this to set the frequency
to 100.001KHz by first using the LCD to set it to 100.000KHz and than using this trimmer to shift it to
100.001.000Hz.
R RF output connection. BNC jack. Use a properly matched FM band antenna. The range and success of your
transmissions will depend primarily upon the quality and position of your antenna so invest your energy and
money into a proper solution. Poor unreliable connections may damage the final transistor.

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S 15W - 2.5A fast, 25W 4A fast and 40W – 6.3A fast fuse. Always replace with this type for continued protection
against short-circuit.
T Telemetry connector. All vital signals are available on this 10-pin connector. You can connect a 10-pin connector
at the back of the transmitter and use them to supervise status of the transmitter.
V External control voltage for power adjustment, only works when jumper J5 (F) is removed. Apply external
control voltage (0-5V).
X External power and swr signal, only use if you are not using digiamp connector (I)
Y Increases sensitivity of external power and SWR meter.
1 Power limit jumper J12, use to limit output power to 2, 4, 6 or 8W (exact value depends on the model)
Table 1: Description of various elements of the MAX PRO 50xx+ FM exciter board
LCD module layout
LCD control module is pretty simple and self-explanatory, but let us have a quick look, note you can disable keys by
soldering over the “Lock Keys” solder bridge:
Fig. 2: LCD module layout, front and back
Fig 3: Installing display board into an enclosure, side view

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Reference Function
1, F UP key
2, G DOWN key
3, H MENU key
4, B POWER indicator LED. Illuminated whenever you turn on the exciter.
5, C ERROR indicator LED. This LED is activated when RF output stage is NOT active. For example,
whenever if temperature protection is activated, this LED illuminates and RF power is reduced.
Important: This LED is also illuminated whenever you change frequency as the control unit turns RF
power off until adjustments are finished and VCO is locked. In such case this does not signal a problem
with temperature or SWR.
6,7 Mounting screws, M2.5 metric screw is to be used here.
8 LCD module, with backlight
A 14-pin connector for flat cable going to the RF board
D Microcontroller with software
E Connections to the IO board (RS232 or USB)
Table 2: Description of various elements of the LCD display module

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RF and LCD module drill template/cutout
LCD control module is pretty simple and self-explanatory, but let us have a quick look;
Fig. 4: LCD module cutout and holes, all measurements in mm
Fig. 5: RF module drill template, all measurements in mm, all holes are for M3 metric screws. Board is 10mm above the enclosure due to heatsink running
under the entire length of the board. The pink hole is exclusive to MAX PRO 50XX and MAXPRO4025+, it does not exist in MAXPRO3000+. The other
holes are identical to those in MAXPRO3000+.

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What’s under the hood?
The block diagram of the MAXPRO5000+ series exciter is shown below. It is simplified as the actual block diagram would
be too complex for this manual. Only the basic building blocks of the exciter are shown and briefly explained one by one.
Fig. 6: Block diagram of the MAXPRO5000+ series FM exciter
Chapter
3

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Reference Function
1 Pre-emphasis is standard part of FM audio broadcasting. It helps minimize noise in received audio.
2 VCO/PLL system generates transmitter frequency and makes sure it is stable.
3 Buffer amplifies VCO signal to 1-2W.
4 Output stage additionally amplifies signal to full 15W.
5 Output filter with power and SWR meter ensures clean signal and provides signals for the power/SWR
meter.
6 The microcontroller is a small computer which coordinates all of the functions of the transmitter.
7 LCD module makes it possible to monitor and set many of the parameters of this product.
8 Power/SWR meter selection circuitry, this is handled via software (LCD selection) in MAXPRO50xx+.
You have to enter menu system and select whether you want to measure internal or external power/swr.
9 Output power control circuitry controls output power.
10 The microcontroller also provides control signal for a small fan which can be used to cool the unit.
MAXLINK This is a 6-pin connector, designed for easy connectivity with stereo encoders. You can read more about
stereo encoders at the back of this document.
DIGIAMP This is a 14-pin connector, designed for controlling RF amplifiers. You can read more about connecting
and controlling amplifiers at the back of this document.
Table 3: Description of various blocks of the MAX PRO 5000+ series block diagram

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Before you start
It is recommended that you read this section before you power your unit up for the first time. Let us clear up some basics
you should know about. You will also find some useful tips in our guides and forum at http://www.pcs-electronics.com.
Here is what you need to get your TV transmitter on the air:
Antenna
Preferred type of antenna is affected by several factors, but mostly by desired radiation pattern, space available and your
budget. If you are located in the middle of the area you want to cover you'll need an omni-directional antenna which
transmits equally in all directions. If you are located at the edge of your desired coverage area you can beam the signal into
the target area with a directional antenna. Directional antennas are also practical for point-to-point communications.
Another thing to consider is that directional antennas usually have much higher gain than omni-directional antennas since
the power which is radiated in all directions with omni antenna is concentrated mainly into one direction with directional
antenna. Antennas with more gain thus have narrower beam. A compromise is usually made depending on budget and
space available, higher gain antennas are often bigger and often more expensive.
Once you’ve chosen and installed your antenna there is another thing to consider. You can read more about it in the next
section (So what is this SWR everyone talks about). Before powering up your transmitter on the air you should tune your
antenna to get minimal SWR. This is typically done by adjusting the position of the antenna and any adjustable pieces. Aim
for 2:1 or less. Use low power into the antenna when tuning it up and making adjustments. If you were using full power and
a bit of the antenna came off in your hand the VSWR could be so bad as to blow the final transistor. For the same reason
check the DC continuity of the antenna with an ohmmeter before plugging it in, to be sure it's what it's meant to be, either a
short circuit or an open one, depending on the antenna type. For instructions regarding construction of antennas please see
our website: http://www.pcs-electronics.com (guides section - antennas).
Antenna is a crucial part of the system so take special care. It is usually a good idea to place antenna away from your
transmitter, power supply and audio system. Also any transmitter should be in a metal case which shields circuitry from the
radiation of the antenna. If you cannot meet these requirements, you could experience feedback and other RF problems. We
cannot guarantee proper operation of any transmitter/amplifier unless suitable antenna system is used and transmitters are in
ventilated metal enclosure! This applies to any transmitter. Interestingly, strong RF field can make CD players and other
digital devices go bezerk. Try placing antenna next to yours and see what happens. Most of the modern audio gear is not RF
shielded – reducing costs is unfortunately the mantra today. This is why keeping antenna away from audio gear is a good
idea.
If you are going to place your antenna outside, on your roof, please take care of the grounding. This should be done to
prevent lightning hazard and should be done by a company specializing in lightning protection. You can read more about
lightning protection in the book recommended below or many of the websites (Google up “lightning protection ham radio”
for example) .
I hope this basic introduction will not scare you too much, it should be sufficient for the time being although we encourage
you to explore this exciting subject further with the help of a book such as the ARRL Antenna Book:
http://www.amazon.com/exec/obidos/ASIN/0872598047/mightyspiraterad
Chapter
4

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So what is this swr (vswr) everyone talks about?
SWR is a measure of how well two devices are impedance matched to each other. Typical radio/TV transmission equipment
is designed for 50 ohm load impedance, so we usually use 50 ohm cables and build or buy antennas that are specified for 50
ohm. While most cables have flat impedance over frequency (they measure 50 ohm at all frequencies you are likely to use)
the same is not true of the antennas.
A 1.0:1 VSWR is a perfect match. That means the load impedance is exactly 50 ohms. A 2.0:1 VSWR is obtained when the
load impedance is either 25 ohms or 100 ohms.
Because most transmitters will deliver full power with a load VSWR of up to 2.0:1, this value is usually considered the limit
for acceptable operation. Many prefer to keep their VSWR below that however, but for all practical purposes, it is
unnecessary to spend time or money trying to get much below a VSWR of 1.5:1. The benefits will be hard to measure and
even harder to notice.
On the other hand, coaxial cable losses increase rapidly, for a given frequency of operation, when the antenna VSWR
exceeds 2.0:1. This can even, in some extreme cases, result in the coaxial cable burning, even when running 100 W. Using a
higher grade of cable will definitely improve things, but even high quality coaxial cable becomes very lossy when VSWR
exceeds 3.0:1 at higher HF frequencies (or VHF and higher).
Coaxial cable
Coaxial cable is an electrical cable consisting of a round, insulated conducting wire surrounded by a round, conducting
sheath, usually surrounded by a final insulating layer. The cable is designed to carry a high-frequency or broadband signal,
usually at radio frequencies. Coaxial Cabling is a two conductor closed transmission medium that is often used for the
transmission of RF energy. It yields excellent performance at high frequencies and superior EMI control/shielding when
compared to other types of copper cabling. Coaxial cabling is commonly found in broadcast and networking systems. Most
coaxial cables have a characteristic impedance of either 50 or 75 ohms. The RF industry uses standard type-names for coaxial
cables. The U.S military uses the RG-# or RG-#/U format (probably for "radio grade, universal", but other interpretations
exist).
The common RG-58 from Radio Shack is NOT the best you can do and can eat a lot of your effective power out! Use it
only for short runs. BELDEN makes terrific coaxial cable in various qualities and with very low loss (measured in
dB’s…decibels). 3 dB loss = 1/4 of your signal strength - either lost or gained. Watch out for the correct impedance; RG58,
RG213, H-500 and H-155 have 50 Ohms, RG-59 and RG-6 have 75 Ohms. Most antennas and transmitters including ours
are 50 ohm. Check our website for good coax. Don't buy more than you need to make the long run to your antenna and
don't make up a few "jumpers" to go between your exciter, VSWR meter and your antenna as all you'll do is create higher
SWR and more line losses. H-155 or H500 are good choices! RG-142 with Teflon is recommended for wiring inside
cabinets, for baluns, Wilkinson couplers and everywhere where resistance to heat is required as insulation won’t melt during
soldering or operation.
BNC connector
A connector comes between coaxial cable and your transmitter. It’s a standard VHF RF connector for low power
applications, just like the one used for older Ethernet networks. You might get it along with your antenna. Try to find a good
quality BNC connector as PC type usually uses cheap plastic instead of Teflon. The good ones are usually easily recognized
by higher prices. Another reliable method is a test with soldering iron; Teflon won’t melt while plastic will. BNC to N or
BNC to SO239 converters are available and will make it possible to connect N or PL259 (CB type or UHF) connector
directly.
Mains power supply and mains power cable
Do not underestimate the importance of mains power supply, despite abundance of all kinds of cheap units available today
they unfortunately do not always meet requirements. What you need is a well stabilized DC 15V mains power supply that
can supply at least 5 amps of continuous current without overheating, introducing buzzing, dropping the voltage down to
12V or lower (a classic case) or acting up in other way. Whenever in doubt please buy our mains power supply. One final
note, our units are set for 15V and if you use less this may lower your output power a bit. The lower the supply voltage the
lower the power. You can compensate for this by slightly increasing output stage bias current.
If you ordered and received our mains power supply (which is recommended) you’ll notice the mains cable is not included,
but can be obtained in any radio/computer/hardware shop at the cost of about 1 US$. It is the type used in your PC for

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17
mains power. Since these cables vary from country to country and we had trouble getting the exact type locally we decided
against including them, especially since finding them is so easy locally.
Audio source with mixer, microphone etc
You need some kind of audio source to drive your transmitter. This will typically be either a computer (just plug the cable
into your sound card outputs, a mixer and a variety of audio sources, such as a microphone, CD player, DAT player, tape
deck, gramophone, MP3 player etc.
Enclosure and cooling for MAX PRO 5000+ series exciters
Use metal (preferably aluminum) for your enclosures and allow some free space for future add-ons (stereo encoders etc.) and
heat dissipation, also make ventilation holes at the top and/or back of the enclosure. Fix the PCB and heat-sink with all
screws tightly. Read again, ALL screws. Make sure they make a good contact with the metal enclosure and if there is paint
remember to remove it under the distancers. Use metal distancers, not plastic. Flat cable should be wired away RF sections
or if you are not sure where that is move it away from the board in general. A fan is needed, 40x40x25mm will run quietly,
you can connect it to the provided pads which also regulate fan speed according to output power. Make sure you tightly
screw the rf board to the enclosure as this is how the output transistor dissipates its heat! Since 40W is quite a lot of
power it is important that you follow these guidelines. If you still experience instability, make sure there are metal shields
between compartments in your enclosure. You can also sand off the black anodizing off the heatsink where the heatsink
meets the enclosure and board to ensure better contact. Anodizing creates isolating layer. You can remove that also for the
top heatsink where it meets the board.
Stereo encoder for stereo operation
If you want to transmit in stereo, you also need a stereo encoder. The cool thing about MAXPRO50XX+ is that it directly
supports SE3000 AN+, SE2000 or SE5000 DSP+ stereo encoder. This makes it possible to set all audio parameters easily
via LCD control module. SE5000 DSP+ comes with excellent DSP filters and 19KHz notch. When using other units look
for good stereo separation, 19KHz notch filters, a limiter and balanced inputs, if possible. Balanced inputs are an instant cure
for most noise problems and this is why all professional installations usually take advantage of balanced inputs. Of course
you can use any stereo encoder out there.

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18
Wiring everything together
Wiring things up and first power-up
Wiring the MAXPRO50xx+ is easy, just make sure you read the previous chapter and setup enclosure, antenna and coaxial
cable correctly. Than proceed with the following:
- Install MAXPRO5015/25/40+ in a suitable enclosure and provide a small cooling fan which will blow across the board. If
you have stereo encoder, you can install it in the same enclosure, but a metal separating/shielding wall is needed.
- Connect LCD module via flat cable
- Set the power limit jumper (J12) into the lowest position (2W), this will prevent any damage due to high SWR.
- If you don’t have artificial load (dummy load) erect antenna tower and install antenna securely. Make sure your antenna is
well away from any metal objects. Ensure your antenna tower is grounded securely. Connect one end of your 50ohm coaxial
cable to the antenna. If you have SWR analyzer you can now verify SWR of your antenna. If your antenna is already tuned
connect the other end of coaxial cable to the antenna connector (BNC) at the back of the transmitter. If you have
SWR/POWER meter, you can wire that inline between antenna and transmitter as well. Make sure the SWR meter supports
the frequency band required (87-108MHz).
- Ensure all connectors are firmly secured and antenna is mounted securely.
- While making sure power switch is off connect mains power cable into the mains power supply and connect mains power
supply into the back of the exciter.
- Inspect all cables quickly again and make sure everything is secure.
- Turn on a radio receiver and set it to your intended transmitter frequency.
- Flip the POWER switch and wait for the unit to turn on. Enter the menu system by pressing the bottom key (Menu)
repeatedly and look for the <RF power> menu item. Now set desired output power with the UP/DOWN keys. For tuning
and testing use around 25-50% of full power. Press Menu again to exit back to main display. Now you can use the
UP/DOWN keys to set the desired frequency of operation. Wait a few seconds for the red LED diode to turn off. Your
radio should now mute since you did not connect any audio sources yet.
- You can now connect audio sources of choice and verify audio performance. You should not sound louder than other
stations, in fact unless you have an expensive high performance software or hardware sound processor you should sound
quieter than other stations. Remember, if you’re using stereo encoder you do not need pre-emphasis so set it to none.
- Observe SWR and output power. If everything seems ok you can enter <RF power> menu again and increase power to
full. Remove or reposition the power limit jumper (J12) if more power is desired.
Chapter
5

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19
Fig. 7: Setting up MAX PRO 50XX+

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20
Using the MAX PRO 50XX+ exciter
Lcd control module
Basically there are three push-buttons available for the menu system; UP, DOWN and MENU. By pushing UP or
DOWN you get a shift of frequency in corresponding direction. Hold any of these keys for a few seconds and the jumps
will increase to 500 KHz. The new frequency is saved automatically. The third button (MENU) gives you an option to
select and setup many of the options and DSP functions of this unit. Note that for most users setting frequency and power
are the two important/useful settings, leave the rest alone at default.
Lcd control module menu system
The UP and DOWN keys are used to change parameter values. In normal mode the LCD simply shows the frequency and
power or whatever view you select. Menu key can be used to enter the menu mode, repeatedly pressing this key brings up
the following menus: <RF POWER>, <STEREO MODE>, <VIEW SELECT>, <TREBLE>, <BASS>,
<COMPRESSION>, <THRESHOLD>, <ATTACK>, <DECAY>, <INTEGRATION>, <LCD CONTRAST>,
<RIGHT CH VOL>, <LEFT CH VOL>, <PLL STEP>, <FIRMWARE VER>, <CURRENT ALARM>, <TEMP
ALARM>, <SWR ALARM>, <U AMP ALARM>, <BAND SELECT>, <RF AMP CONTROL> and <RF POWER
ALC>. Pressing the UP or DOWN key selects the desired parameter and allows you to modify its value. Another press on
the MENU key and you’re back to the normal mode. Note that all these settings except power and frequency are already set
as they should be so changing them should not be necessary and is not recommended.
Changing frequency
Simply press the UP/DOWN button to change frequency. Depending on PLL STEP setting your frequency will go down in
50/100/200KHz steps. If you keep pressing a key for a while the PLL STEP switches to fast tuning mode and jumps in
500KHz steps.
Note: UP/DOWN keys change frequency also when you have set a view type which does not show frequency, such as
UPTIME.
<RF POWER>
This setting allows you to set output power. Select desired power with the UP/DOWN keys and press MENU key to exit
the menu system and return to normal operation. Selected power is displayed on the LCD as a line of bars. Think of this
setting as an accelerator (gas) pedal in your car. Think of the power in watts that is shown on the LCD as the speed meter in
your car. Depending on the road going uphill or downhill speed meter will show different values even if your accelerator
pedal is fixed in the same position. If you go downhill your speed will be greater with same amount of gas pedal. Likewise
here your supply voltage can affect the actual output power slightly.
<STEREO MODE>
You can set your transmitter to MONO or STEREO here. This only works when you connect stereo encoder to the MAX
PRO 50xx+ with MAXLINK cable (6-pin flat cable).
Chapter
6