M2 Antenna Systems S2 Operating Instructions Manual

M2 Antenna Systems, Inc.

Model No: S2

Sequencer

Operating Instructions

OVERVIEW

INSTALLATION

SPECIFICATIONS

MODEL NUMBER ........................................... EME SEQUENCER S2

POWER REQUIREMENTS. ............................ 86-264VAC / 1AMP

HOT SWITCH SECURITY ............................... DPDT Relay / Latching

ENCLOSURE SIZE ......................................... W=6.25”/ H=2.25” / D=8”

COLOR ........................................................... Black Anodized

RELAY CONTROL OUTPUTS ........................ (4) RX Selectable / (4) TX Selectable

No Jumper = Open Circuit (No State)
A to B Jumper = Ground (On TX)
B to C Jumper = +13VDC (On TX)

SEQUENCER DELAY ..................................... With Jumper = ~80 Milliseconds

Without Jumper = ~120 Milliseconds

CONTROLS .................................................... Power Switch / Preamp Switch / Polarity Switch

PLEASE READ BEFORE USE AND SAVE

M2 Antenna Systems, Inc. 4402 N. Selland Ave. Fresno, CA 93722

Tel: [phone] Fax: [phone] Web: www.m2inc.com

©2015 M2 Antenna Systems Incoporated

06/01/15

Rev.00

TROUBLESHOOTING

ADDENDUM

WARRANTY

FRONT & REAR PANEL OVERVIEW

I / O (POWER)

This button controls AC power to the Sequencer unit.

I / O (PREAMP)

This button controls +12VDC to control a mast mounted preamp.

V & H (POLARITY SWITCH)

This switch controls the Vertical or Horizontal Polarization to a mast mounted 24-28VDC coaxial relay.

T (PREAMP TEST SWITCH)

If an M2 preamp is used, the Noise Test feature can be operated by the “T” push button on the front panel. Noise
Test provides an approximate 10 db increase in receiver noise to verify the preamp is operating correctly.

NUMBERED SEQUENCE INDICATORS 1-4

Sequence indicators will light when the proper sequence is achieved during keying.

AC IN

The supplied (3) prong AC cord plugs into this socket. Connect to a reliable 110 VAC source. The Main AC input

and switching power supply have been designed to filter and adjust for incoming AC from (86-264 VAC).

TERMINAL STRIP

The (10) position terminal strip, serves as your multi-conductor cable interface to a tower mounted relay / preamp
system. A ground connection on terminal (10) has been provided for shielded cables.

DISCONNECT THE AC POWER CORD WHEN CONNECTING CABLE LEADS.

XCVR INPUTS (TRANSCEIVER)

In order for the S2 Sequencer to determine the difference between Transmit or Receive, it is necessary to supply
a “Keyed” state from your Transceiver. We have supplied both a “+2-12VDC” input and a “To Ground” input.
Check your Transceiver manual for the proper connections. Most modern Tranceiver’s “Key to Ground.”

EME S2 SEQUENCER SYSTEM OVERVIEW

S2 EME SEQUENCER THEORY

If you have ever blown up your new GasFET preamp or hard-to-find coaxial relay, or are just plain worried about It, this

transmit / receive Time Delay Generator/Sequencer is the answer.

The S2 Sequencers’ primary application is for VHF/UHF transverter, amplifier and antenna switching. But it can be used
in any amplifier antenna scheme. An enable signal to the sequencer will produce sequential output commands to a RX
relay, a TR relay, an amplifier and a transverter automatically, plus a polarity change lockout.

WHY USE A SEQUENCER ?

In stations using transverters, extra power amplifiers and external antenna mounted TR relays, several problems may
arise. When the exciter is switched into transmit by the PTT or VOX line, it immediately puts out a ground (or in some
cases a positive voltage) command for relay control and RF signal. If a control signal is supplied to the transverter,
amplifier and antenna relays simultaneously, RF can be applied as the relay contacts bounce. In most cases, RF will be
applied before a relay can make full closer. This can easily arc contacts on DC and RF relays and cause permanent
damage. In addition, if the TR relay is not fully closed before RF from the power amplifier is applied, excessive RF may
leak into the receive side of the relay. The likely result...preamplifier failure. The TR (Transmit/Receive) time-delay
generator supplies commands, one after another, going into transmit and going back to receive from transmit, to turn on
all station relays in the right order, eliminating the problems just described.

HERE’S HOW IT WORKS

Assume we’re in receive and are going to transmit. A customer selectable (+2 to +12VDC) or ground command to one of
the relays turns it off. This allows a capacitor to charge through a resistor raising the voltage applied to all positive inputs
through the IC. The ladder network on all negative inputs sets the threshold point of each comparator at a successively
higher level. As the capacitor charges up, each comparator will sequentially change output states. The outputs drive
transistors which are “off” in the receive mode. Drive from the gates turns these transistors “on.” This causes the

collectors of the transistors to go low, allowing the base-to-emitter junctions to be forward-biased through the (4) LED’s

to turn on the relays in sequential order. The LED’s serve as a built-in indicators to check performance and sequencing
of the generators. This is convenient if any state changes are made.

WHY OUR SEQUENCER IS DIFFERENT

M2 Inc. has looked at many sequencer concepts and has determined the biggest problem...hot switch (During Transmit)
security. W e have integrated a security relay into the sequencer that DISABLES the front panel vertical / horizontal po-
larization switch when the sequencer is keyed. This security relay will save costly repairs or replacements to your high
quality RF power relays.