MICOR type noise squelch board - by Masters Communications

Custom Products from Masters Communications

MICOR (Type) Analog Noise Squelch Board
For Two-Way Radio Applications

Model MS-50

Click Here for schematic, installation, and set-up instructions.

Ordering instructions on bottom of page.

The MS-50 is a professional, yet affordable, add on analog noise squelch detection system on a small printed circuit board.

This board can be added to any radio or repeater that has a suitable discriminator connection.

This board is mostly through-hole construction to allow repair or modification by the common technician.

It is used to create a quality noise squelch logic to be interfaced with a standard repeater controller or radio interface with AllStar.

It doesn't mute or control the audio in any way.

This board uses some common IC's and other discrete components to provide operation similar to the Motorola MICOR squelch chip.

Kit - complete with preinstalled surface mount components - $50.00 each.
Assembled and Tested - $85.00 each.

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First-Class shipping available to most locations worldwide, calculated at checkout.
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Photo of actual size MS-50 module.
(Click image to enlarge)

Description:
The MS-50 provides MICOR (Type) noise squelch detection and logic on a small printed circuit board. The board uses discrete and common integrated circuitry to emulate the operation of the famous Motorola M6709 "MICOR" squelch chip.

There are three differently colored LEDs for status. One is blue, it indicates a valid carrier squelch detection. The second is green which also indicates a valid carrier squelch detection, but it also verifies the transistor logic circuitry is operating properly. The third is yellow, and helps to set the squelch at threshold. This LED can be disabled.

About the inputs and outputs.
There are only three necessary connections for input; discriminator audio, power, and ground.

The logic outputs for COS are not totem pole, however, both active high and active low outputs are available.

Why do we need this board?
Not all radios have easy access to quality COS signal. Some repeater hardware may not include a conventional squelch control or may require reprogramming just to change the squelch setting or CTCSS tone. Some radios simply have inferior noise squelches. DSP in AllStar applications is good, but nothing beats a MICOR type noise squelch.

The board has a precision vertical multi-turn potentiometer for the squelch control.

Features:

Power Source: +12 to +16 VDC recommended, must be constant, not switched. Maximum voltage is 24 VDC.

Onboard regulation + 9.6V for the noise squelch circuitry and logic.

Squelch control is 25 turn vertical type.

Current draw, about 47 mA standby, (75 mA unsquelched - 2 LEDs lit), depending on logic load.

Active high and low logic is sourced from 9.6 VDC. Pull-up and pull-down resistors are included.

Small size - can fit inside many radios.

Add a quality squelch to that radio whose logic signals are hard to get to.

Great for AllStar - app_rpt or connecting up your favorite repeater controller!

Simple to hook up and set up.

90 day Limited Warranty. Repair available for units out of, or not covered under warranty (my determination).

Mounts with double-sided foam tape or stand-offs (not included).

Hookup is made with a 6 position polarized female Molex header connector and pins (both included).

Kit comes with pc board and all necessary thru-hole components. Surface mount ICs are preinstalled.

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Shipping amount is calculated at checkout for shipping to most locations Worldwide.

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Click Here for schematic, installation, and set-up instructions.

Email Kevin Custer for ordering information, order by check, and/or quantity pricing of this exciting product.

Product of Kevin Custer - Masters Communications, all rights reserved.
Specifications may change without notice.
Images are property of Kevin Custer - W3KKC
Board layout by Kevin Custer
HTML June 6, 2019, Kevin Custer - All Rights Reserved!

	Power Source: +12 to +16 VDC recommended, must be constant, not switched. Maximum voltage is 24 VDC.
	Onboard regulation + 9.6V for the noise squelch circuitry and logic.
	Squelch control is 25 turn vertical type.
	Current draw, about 47 mA standby, (75 mA unsquelched - 2 LEDs lit), depending on logic load.
	Active high and low logic is sourced from 9.6 VDC. Pull-up and pull-down resistors are included.
	Small size - can fit inside many radios.
	Add a quality squelch to that radio whose logic signals are hard to get to.
	Great for AllStar - app_rpt or connecting up your favorite repeater controller!
	Simple to hook up and set up.
	90 day Limited Warranty. Repair available for units out of, or not covered under warranty (my determination).
	Mounts with double-sided foam tape or stand-offs (not included).
	Hookup is made with a 6 position polarized female Molex header connector and pins (both included).
	Kit comes with pc board and all necessary thru-hole components. Surface mount ICs are preinstalled.