Midian Electronics BTD-1A, Manual

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3
HARDWARE INSTALLATION
Be certain to follow standard anti-static procedures when handling any of Midian’s products.
P1-1 – Green – Transpond Out – Provides a low output (200mA) approximately 2 seconds after the horn output.
P1-2 – Red - +5.5 – 15 VDC – Connect to switched B+ in the radio.
P1-3 – Brown – Repeater Output: Provides a low output when decode occurs. This output floats when carrier is
removed. See P1-7 positive and negative squelch inputs.
P1-4 – Black – Ground – Connect to the nearest ground point.
P1-5 – Blue – Alert Tone Output (Lo Z) – Provides a tone output (2400Hz) for approximately 2 seconds upon
decoding.
P1-6 – Orange – Audio Input – Connect to an unsquelched audio point in the receiver. Usually the discriminator
or volume control high. Note: The input audio level is adjusted by changing the value of R4. See gain chart on
schematic.
P1-7 – Yellow – Positive or Negative Squelch Input – With JU5 installed, connect to a point in the receiver
squelch circuit that is high when a carrier is present and low when the carrier is missing. With JU6 installed,
connect to a point in the receiver that is low when a carrier is present and high when the carrier is missing.
Repeater knock down will occur when the carrier is removed.
P1-8 – Green/White – Squelch Output – Connect to the radio squelch circuit to mute the radio until decode
occurs. Provides a high output until decode, then a float is present with JU3 installed. With JU4 installed a low
output is provided via D9 from U2C Pin 14.
P1-9 – White – Call Light Output – Provides a latched low output (200mA).
P1-10 – Gray/White – Horn Output – Provides a low (200mA) output for approximately 4 seconds after decode.
P1-11 – Gray – Monitor 2 Input – Remove JU2. Connect grey/white lead to a point in the radio that is normally
low and goes high or to a float when PTT is pressed. A return to a low when PTT is released will reset the
squelch outputs.
P1-12 – Orange/White – Monitor 1 Input – Connect to a point in the radio that goes high when PTT is pressed.
The squelch outputs will not be reset when the PTT is released.
P1-13 – Violet – Alert Tone Output (Hi Z) – Provides a tone output (2400Hz) for approximately 2 seconds upon
decoding.