Brought to you by PCS Electronics, www.pcs-electronics.com
9
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 MAX 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.
