Dead Zone on MUTE IN DefeatDecrease Hold Time
As supplied, MUTEINis intended for use as amomentaryThe hold time can be decreased fromthe factory preset of
cough button or privacy function (mute when necessary).0.4 seconds to 0.3 seconds. (Less than 0.3 seconds is not rec-
However,iftheMUTEINisintendedto beused sothat thetalk-ommended.)
er must unmute microphones to enable speech pickup (un-Procedure:Install a 2 M resistor at jumpers X903.
mute when needed), this modification is needed. This re-
moves the muted channel from the MaxBus which eliminates
?dead zones.? A dead zone is an area in which a microphoneRemote Control of Link Global/Local, Off-Attenua-
picksupatalkerthroughamutedmicrophoneandothermicro-tion, Last Mic Lock-on, and Automatic/Manual DIP
phones do not activate for that talker.Switches
Procedure:Short jumper X115. Repeat these steps for allIf desired, these functions can each be remotely con-
channels needing modification.trolled with an SPST switch.
Procedure:
Change MUTE IN to Inhibit1. Solder a wire in the pc board jumper hole adjacent to the
As supplied, a channel will mute when its MUTE IN termi-desired function (printed on the pc board). Thesejumpers
nal is grounded. The mute function can be changed to ?Inhibit?are located just behind DIP switch SW902.
by an internal modification for each channel. After the modifi-2. Solder a wire in the pc board jumper hole marked ?GND?
cation, a logic ?Low? at the MUTE IN terminal prevents that
near switch SW902.
channel fromgating on if it is off, but allows it to remain on if it is
already on. IMPORTANT:To prevent high-frequency oscilla-3. Set the desired DIP switch(es) to the Up position.
tion,neverconnectachannel?sGATEOUTtoitsown MUTEIN4. Run the jumper wires to the desired remote location and
unless the ?Inhibit? modification has been made.solder them to an SPST toggle switch. The wires can exit
Procedure:Short jumper X111. Repeat these steps for allthe AMS8100 chassis above the DIP switches. Shorting
channels needing modification.any wire to the Ground wire will set the function(s) to the
corresponding switch ?down? position.
Change OVERRIDE IN to MUTE IN for Use with Fili-
buster ModeRemote Volume Control of Channels
This modification should only be performed with theUsing an external VCA(Voltage Controlled Amplifier), the
ChangeMUTEINtoInhibitmodification described above.level of a channel, the aux, or the master can be remote con-
trolled via a DC voltage. An example of an external VCA is the
Procedure:Short jumper X113. Remove resistors R1046ST-VCA1 from Radio Design Labs. They can be reached by
andR1058.Repeatthesestepsforallchannelsneedingmodi-
phone at 1--800--281--2683, or on the Internet at
fication.www.rdlnet.com.
For channel control ? Perform DirectOuttoPost-Fader
Change Off-Attenuation LevelSend/Returnmodification. Connect thetip ofa 1/4-in.connec-
This modification changes the off-attenuation level fromtor to the line input of the VCA, and the sleeve to the ground of
-15 dB to a selected value. Select from the following resistorthe VCA. Connect the ring to the line output of the VCA. Plug
values.the 1/4-in. connector to the Direct Out jack of the AMS8100.
The channel?s level control should be set at 5.
Off-Attenuation LevelResistor ValueFor Aux In control ? Connect the external source to the
10 dB18 k
VCA line input. Connect the VCA line output to the tip and
20 dB50 ksleeve of the AMS8100 Aux input. The Aux control should be
30 dB150 ksetat5.
Procedure:Remove resistors R9088 and R9145. InstallFor Master control ? Connect AMS8100 Line output to
new resistor at jumper points X904 and X908.theVCAlineinput. ConnecttheVCAlineoutputto theexternal
device (amplifier, tape recorder, etc.). Set Master control at 5.
Increase Hold Time
Using Multiple Gates to Drive a Single Relay
In place of the DIP switch SW902 option of 1.0-secondWhen using muliple gates to drive a single relay, the relay
hold time, the hold time can be increased to 1.5 seconds.may fail to release when gate out changes state.
(More than 1.5 seconds is not recommended.)
Procedure:Usingasolderingiron,removetwo30kresi-
Procedure:Install a 470k resistor across jumper pointssitors from the circuit path.
X902. Move DIP switch down to 1.0-second position.
For example, if Gate Out #7 is in parallel with other Gate
Outs to drive one relay, remove resistors R9026 and R9027.
Or, if Gate Out #1 is in parallel to drive one relay, remove resis-
tors R9039 and R9041. Do the same for any Gate Out used in
parallel with any other gate out.
Thismodificationshouldnotbenecessaryifarelayiscon-
trolled by only one Gate Out.
Eng h --22lis |
ACEC
