interfaces for use with ale

8/3/2019 Interfaces for Use With ALE

1/12

Interfaces for Use with ALE (Computer to Radio)The following information is provided as an aid in constructing, using, and understanding computer-to-radio hardware control, for usewith PCALE, other ALE software, or external ALE hardware controllers. The same interfaces may be applied to most digital modesand other computer programs for interface with computer control of radios. Unlike some other types of ham radio software though,most external ALE controllers, including PCALE, only send commands to the radio via the serial port, and do not receive commandsback from the radio via the serial port.

The good old standard RS-232 serial port is used by the computer ALE controller to send control signals to the radio. On older desktop computers designed in the 1980s through the 1990s, the RS-232 serial port used a DB25 (male 25 pin connector). The DB9connector (male 9 pin connector) was found on computers designed after about 1997. Most modern computers have a USB port anddon't have an RS-232 serial port, so a USB-to-Serial Adapter must be added as an external accessory plugged into the USB port. A
http://hflink.com/interface/#simple


2/12

USB-to-Serial Adapter is a commercially available device containing a small circuit built into the enclosure of a DB9 male plug, witha USB connector on the other end. It requires a software driver to be loaded and run on the computer, so the computer can recognize itas a "virtual" RS-232 serial port. The COM PORT number is often randomly assigned every time the USB to Serial Adapter is

plugged into the computer, so be aware of this as a setup issue when dealing with fixed port numbers in the software. The COM PORTnumber may be discovered by using the Control Panel>System>Hardware>Ports or similar menu in the main control software of Windows.

4 pins of the serial port connector are used for the ALE controller interface:

TXD [Transmit Data] DB9 pin 3 - For the frequency control of the radio. Known as the CAT transmit data, this goes low and highrapidly at the serial port baud rate during the transfer of frequency information data from the computer to the radio. [Pin 6 of DB25]

RTS [Ready To Send] DB9 pin 7 - For the PTT (Push To Talk), goes high to transmit. It is also known as the Hardware PTT line in

ALE jargon. [Pin 4 of DB25]

DTR [Data Terminal Ready] DB9 pin 4 - For the Speaker Mute, goes high to mute the speaker, and commonly controls a relay in thestation's external speaker line. This un-mutes by closing the speaker line relay contact whenever an incoming ALE call is received, toalert the operator and provide easy monitoring of traffic on the channel. [Pin 3 of DB25]

GND [Common Ground] DB9 pin 5 - Connected to the computer's logic ground and the chassis and earth ground of a desktopcomputer, this is the common ground reference for the TXD, RTS, and DTR signals on the RS-232 serial bus . It is connected to pin 5on a DB9 connector. [Pin 7 of DB25]

See DB9 Pinout

The control signal voltage on the RS-232 pins is not standard , and the design spec can vary quite a bit by manufacturer and model.Modern computers are often in the range of about +/-3V to +/-12V, depending upon how much resistive load you put on them. USB toSerial dongles generally run about +/-3V to about +/-8V, and they can source (drive) about 5 milliamperes to 10 milliamperes of current into a load. Logic LOW (0) is a negative voltage (or ground) and Logic HIGH (1) is a positive voltage . To determine thevoltage level on any particular serial port, it is easy to simply measure one of the pins with a voltmeter.
http://en.wikipedia.org/wiki/RS-232http://en.wikipedia.org/wiki/RS-232http://hflink.com/interface/#DB9pinouthttp://en.wikipedia.org/wiki/RS-232http://en.wikipedia.org/wiki/RS-232http://hflink.com/interface/#DB9pinouthttp://en.wikipedia.org/wiki/RS-232


3/12

An effective interface takes the nominal range of the above signals from the RS-232 serial port, and converts to the proper polarityand logic levels of the radio. Also, some interfaces provide RF isolation and/or AC-DC isolation between the computer and thetransceiver. This isolation prevents noise from the computer from being conducted into the receiver audio, transmit audio, or the

antenna. It also prevents transmitter power starting at the antenna from being conducted to the computer and causing RF feedback andother problems on transmit audio.

A Simple ALE Control Interface for use with PCALE or MARSALE

PCALE APPROVED This circuit is made from a bare minimum of commonly available parts and provides about 1k ohm of RF and Ground isolation. Itcontains circuits for: CAT control of Icom radios, PTT, and Speaker Muting.
http://hflink.com/pcale/


4/12

Click on schematic to zoom:


5/12
http://hflink.com/hardware/ALE_INTERFACE_ICOM_1.jpg


6/12

IMPLE ALE INTERFACE - PATS LISTJ1 DB9 CONNCTOR FEMALE J2 MINISTEREO PLUG J3 MINI STEREO PLG K1 RELAY SPDT, WITH 12VDC COILQ1 2N2222 oPN2222 or Similar NPN TransistorQ2 2N2222 or

PN2222 or Similar NPN Transistor Q3 2N2222 orPN2222 or Similar NPN Transistor R11K RESISTOR, 1/4 Watt or 1/2 WattR2 1K RESISTOR, 1/4 Watt or 1/8 Watt R3 1K RESISTOR, 1/4 Watt or 1/8 Watt R4 1

K RESISTOR, /4 Watt or 1/8 Watt S1 SPEAKERSW1 SPSTOGGLE SWITCHMSC WIREMISC CABLEMISC E

Simple Icom C-IV Adapter for use with PCALEThis simple RS-232 to C-IV adapter can be built inside the shell of a DB-9 connector. It requires no power, and it works

with all Icom radios for use with PCALE. Remember, it is only a one-way C-IV, you will be able to send CAT data from the


7/12

computer to the transceiver, but the transceiver will not be able to send data back to the computer.

Isolated ALE Interface: Audio, CAT, Hardware PTT, Speaker Mute

PCALE APPROVED

The following interface circuit provides RF, DC, and AC isolation between the signals of computer and the radio, andbetween the grounds of the computer and the radio. It is recommended for use with PCALE and other ALE controllers.The interface has all features needed for ALE, including:
http://hflink.com/pcale/http://hflink.com/interface/SIMPLE_ICOM_CIV_ADAPTER_ALE_1.jpg


8/12

1. Audio transformer isolation2. Opto isolation of the computer control signals3. Speaker muting (operator alerting / channel monitoring when called by other stations4. Transmit inhibit switch to prevent undesired computer processes from transmitting5. CAT control of Icom radios.

Click on the schematic to zoom:
http://hflink.com/interface/ISOLATED_ALE_INTERFACE_ICOM_1.jpg


9/12

Parts for the Isolated ALE InterfaceLike the previously described Simple ALE Interface, this Isolated ALE Interface is made from common parts, whilekeeping total parts count to a bare minimum. New parts for this circuit may be acquired at some local electronic partsstores (where they still exist) or via online electronic parts stores such as Digikey or Jameco . Homebrewers areencouraged to recycle parts from old equipment... many of these parts may be found in the junkbox, or scavenged fromold consumer computer peripherals, telephones, radios, or telephone answering machines. Links to download thedatasheets / and spec sheets PDF files for the optocouplers, relays, and transformers are in the Parts List .

For part substitution, most of the parts and part values are not critical, and a lot of leeway for the homebrewer is providedin the design. For example, almost any of the common 6-pin opto coupler ICs may be substituted in the circuit. Thetransformers may be substituted with almost any small audio transformer, various impedances (100 ohms, up to 50kohms or so) and even a speaker transformer from an old transistor radio... but 1:1 transformers with impedances of about

600 ohms or 10k ohms will probably work best (such as a telephone modem transformer). The relay may be almost anylow power 12VDC coil relay that has Double Throw. The power to run the relay is taken from the transceiver's switched13.8VDC output, normally found on the transceiver's rear panel accessory connector, or it may be taken from the main13.8VDC supply (through a 1 amp fuse). Alternatively, a relay with a different coil voltage may be substituted with anappropriate DC supply to match the coil voltage of the relay... or an appropriate value and power of resistor may beinserted in series with the relay coil to substitute a low voltage coil, such as 5V coil, running on a 12V supply.

Isolated ALE Interface - Parts List

C1 1000PF CERAMIC, 50VDCC2 10UF 16VDCC3 1000PF CERAMIC, 50VDCC4 10UF 16VDCC5 10UF 16VDCD1 1N4004 OR SIMILAR DIODEJ1 MINI STEREO PLUG MALE, 3.5MMJ2 MINI STEREO PLUG MALE, 3.5MM
http://digikey.com/http://jameco.com/http://hflink.com/interface/#isolatedpartslisthttp://digikey.com/http://jameco.com/http://hflink.com/interface/#isolatedpartslist


10/12

J3 MINI STEREO PLUG MALE, 3.5MMJ4 DB9 CONNECTOR FEMALE CABLE CONNECTOR, WITH SHELLJ5 MINI STEREO PLUG MALE, 3.5MMK1 RELAY SPDT 12VDC COIL ( TAKAMISAWA SY-12-K , OMROM G5V-1-12VDC, OR SIMILAR)R1 1K RESISTOR 1/8WR2 1K RESISTOR 1/8WR3 10K POTENTIOMETER 1/8W, PCB MOUNT, TRIMMERR4 4.7K RESISTOR 1/8WR5 4.7K RESISTOR 1/8WR6 10K POTENTIOMETER 1/8W, PCB MOUNT, TRIMMERR7 4.7K RESISTOR 1/8WR8 1K RESISTOR 1/8WR9 1K RESISTOR 1/8WR10 1K RESISTOR 1/8WSP1 SPEAKER 4 TO 16 OHMS, 4WATTS, WITH ENCLOSURESW1 SPST SWITCH ON/OFF, TOGGLET1 AUDIO TRANSFORMER 1:1 ( TAMURA TTC-5023 , TRIAD TY-141P , OR SIMILAR)T2 AUDIO TRANSFORMER 1:1 (TAMURA TTC-5023, TRIAD TY-141P, OR SIMILAR)U1 OPTOCOUPLER 4N25, H11A1, OR SIMILARU2 OPTOCOUPLER 4N25, H11A1, OR SIMILARU3 OPTOCOUPLER 4N25, H11A1, OR SIMILARW1 COAXIAL CABLE RG-174W2 COAXIAL CABLE RG-174W3 COAXIAL CABLE RG-174W4 COAXIAL CABLE RG-174MISC WIRES

MISC CABLESMISC TRANSCEIVER REAR PANEL ACCESSORY CONNECTORS

A Single Transistor PTT Interface CircuitThe following interface circuit is a very simple circuit only for PTT keying of the transmitter to transmit. No bells, nowhistles. Bare minimum. It is useful not only for ALE (without automatic CAT scanning) but it can be used for almost any
http://hflink.com/interface/Takamisawa_SY_Series_relays.pdfhttp://hflink.com/interface/Tamura_modem_transformer_TTC5023.pdfhttp://hflink.com/interface/Triad_audio_transformer_%20TY141P.pdfhttp://hflink.com/interface/Triad_audio_transformer_%20TY141P.pdfhttp://hflink.com/interface/Optocouplers_4N35_series_or_H11_series.pdfhttp://hflink.com/interface/Takamisawa_SY_Series_relays.pdfhttp://hflink.com/interface/Tamura_modem_transformer_TTC5023.pdfhttp://hflink.com/interface/Triad_audio_transformer_%20TY141P.pdfhttp://hflink.com/interface/Optocouplers_4N35_series_or_H11_series.pdf


11/12

digital mode or computer control of a Push-To-Talk of most modern transceivers. It does not provide RF or groundisolation, but has protection and RFI filtering to prevent any RF feedback from keeping the transmitter keyed or causing itto be keyed due to high RF fields. The circuit may be also applied to other pins of the RS-232 to provide logic levelconversion from the +/- voltage of the RS-232 via open collector output, to the input of radios or other types of controlsystems that require a corresponding logic signal to ground. The collector output may also be used to drive a morse CWkeying input. Or, it may drive a relay, by connecting one side of the relay coil to a grounded power supply, and the otherside of the relay coil to the open collector of this circuit.Click on the schematic to zoom:

Note: R2 and D1 (protection circuit), and C1 (RF filter) may be deleted if not required.
http://hflink.com/interface/PTT_TRANSISTOR.jpg


12/12

DB9 Connector RS-232 Pinout

interfaces for use with ale

Documents