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The Daniels MT-2 UHF receiver module
By David VanHorn   KC6ETE
 

The Daniels MT-2 UHF receiver module:

Input section: Six section helical filter, with bipolar transistor preamplifier.

Local oscillator: TCXO with two section helical filter, feeding the first IF at 21.4 MHz, and second IF at 455 kHz.

I got my crystals from West crystals:
West Crystal, 10-2550 Acland Rd Kelowna BC V1X 7L4
(250) 765-4833 Fax: (250) 765-3308
wcrystal@shaw.ca   http://www.westcrystal.com/index2.html

West Crystals no longer manufactures this product, and ICM has not been able to temp-comp the Daniels modules.

The crystals are carried in TCXO modules, a small green ice-cube like case, with gold pins, a single gold screw on the top, and an adjustment hole. If you don't have this module, you are in a bit of trouble. The actual oscillator is on the receiver board, but the module contains several thermistors, and a varactor, and will prove to be difficult to duplicate.

In terms of connections, this module is practically identical to the VHF receiver module, but I will present the connection data again, so that each document is complete and stands on its own.

This module needs only 9.5VDC to operate.

It provides a 0-5V received signal strength indicator (RSSI) output, a 3V nominal AFC output, and several options for audio output.

Squelch is internally adjustable. Squelch hysteresis can be externally disabled, and squelch can be turned off externally.

Audio outputs normally available are:
Discriminator (non de-emphasized)
De-emphasised audio, filtered, for CTCSS detection

Optional audio outputs:
5W speaker audio
600 ohm balanced audio (simple to install if you want to)

Control signals are all low true, so you ground KEY to transmit, and COR goes low to indicate presence of a signal.

All the input pins have EMI filter network. These networks consist of a series inductor and 330pF cap to ground.

The rear panel connector is a DIN standard connector, with three columns of even numbered pins, numbered from 1 to 32. The three columns are labeled on the connector, "D", "B", and "Z", at the top. The pins are numbered on the right side, but only the rightmost digit shows, so you see this:

D B Z
OOO
OOO
OOO
OOO
OOO
OOO
OOO
OOO
OOO
OOO
OOO
OOO
OOO
OOO
OOO
OOO
Row Number
2
4
6
8
0 (should be 10)
2 (should be 12)
4 (should be 14)
6 (should be 16)
8 (should be 18)
0 (should be 20)
2 (should be 22)
4 (should be 24)
6 (should be 26)
8 (should be 28)
0 (should be 30)
32

Receiver modules:
The "D" column is not connected. I would not say that it is safe to make connections to those pins though, just that the manual does not list any connections to them. "No connection" and "DONT CONNECT" aren't the same thing.

The receiver connections are as follows:

FunctionPin(s)Comment
GroundB30, Z30, B32, Z32 
+9.5V inB6, Z6 
B-SystemB16,Z16Jumper inside the RX connects this point with B6,Z6
6.0Vdc outZ4 
COR normalB12,Z12Goes to ground when signal present
COR IsolatedB16,Z16Optional opto-isolated COR, + on B16, - on Z16
Squelch Hysteresis controlZ28Ground to remove hysteresis
AFC voltageZ24Should be 3.0V for on-frequency input signal
CTCSS audioB14Disc output before any processing or squelch
Balanced audioB26 to Z26Optional 600 ohm balanced output, if you have this,
you'll see a quarter-sized transformer on the PCB
Aux speaker audioB4 
De-Emphasized audioB22  
Flat audioB20 
Squelch override inputZ14Ground to open the squelch
Carrier strengthB240-5 volts
Mute inputB28Asserting this mute signal low will prevent the COR
output from happening

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Text copyright © 2005 by David VanHorn   KC6ETE
Hand-coded HTML © Copyright 2005 Mike Morris WA6ILQ
This page last updated 06-Jun-2013

The information presented in and on these conversion pages is © Copyrighted 1995 - (date of last update) by Kevin Custer W3KKC and multiple originating authors.