Microlog AIR-1 User manual

RADIO INTERFACE
CARTRIDGE FOR THE
COMMODORE:
□ VIC-20 □ ‘64’
□ with AMTOR
Compete termina with
software in permanent ROM
for Sending and Receiving
RTTY and MORSE Code.
MICROLOG
© MICROLOG CORPORATION 1985

TYPICAL
"TRANSCEIVER
key EXT.
o n #
5 PKR.
MIC
PTT
HAND KEY
OR
I KEYfK
(ALL CABLES SHOULD BE SHIELDED iR<q56CETG.

REVISIONS
LTR DESCRIPTION DATE APPROVED
U 5 -b
rttv7cw
CONTROL IN
NOTES
1.) Unless specified,
all resistors are i watt,
5% tolerance, resistance
values in ohms.
.) Unless specified,
all capacitor values are
in microgarads (yF).
3.) All capicitors 1yF
and above are tantalum
electrolytic.
4.) All .001 F capaci
tors are ceramic, rated
1 KV.
5.) PROM signal names —
are same as VIC- 0/C-64
computer signal names.
6.) D-10, Q-7, R-34, J
J-1, J-3, U~8, & 5- used
only on C-64 version.
• 2-NZ22Z /A A /B E U5ED
I N p / c e O F M RSA05
MICROLOG , .
CORPORATION (a-M)
AIR-V- VIC-20/C-64
RADIO INTERFACE CIRCUITS

VIC-20 J 1 C-64
GND
+5V
+5V
GND
CD0
C01
CD 2
CD3
CD4
CD5
CDfe
CD7
BLK3
BLK5
+5V
GND
GND
CAj#
CA1
c a e
CA3
CA4
CAS
CAb
CAT
CA8
CA9
CA10
CA11
CA12
i/02
i/£3
GND
i
10
11
13
LA
15
18
B
D
- f
K
M
N
U
_V_
12
16
I f
19
"25“
21
22
W
¥
z/<U
US PlMlfi
GND EX ROM
1/03
BLK5
CD7
CDfe
CD5
CD4
CD3
CD2
CD1
CD0
GND
GND
ROM H
CA1
CA11
CA10
CA9
CA8
CAT
CAb
CA5
CA4
CA3
CA2
CA1
CA2S
GND
REVISIONS
LTR DESCRIPTION DATE APPROVED
+ 6 V
fsk/cw- 2
CD0-i DI(B|T0)
CD2
CWfcrTY CTRL IN - ,
1
TX DATA FROM-L a j M
/fr c o mp u te r p F /77
RX RTTy OUT
C O 0
RX CW OUT
CD 1
CAI2T
CA6"
CA5'
CA4
CA3
CA2~
CA I "
CA^-121
CD0
_Z
CD I
CD2. 2
2
44
U 7
fSAME. FOR. U 0)
7 6 4
PROM
27
£ cas
gcA9
_rv.
2fi_
26-
CAI
CAltf
VIC- Q
~ BLK3 HpW
iJormal /
------ O
CD 7
CDfc
CD5
CD4
CD3
c-fc-q
USES 5-2 U6
20
22
J
PIN B
/77
/77 ^ 7
COMPUTER
"EXPAMSION)v
Port
TOLERANCES UNLESS
OTHERWISE SPECIFIED
FRACTIONS DEC ANGLES
m . 2/3/84
MICROLOG CORPORATION
M R-1: VIC-20 C-64
CATAe ADDRESS INTERFACE CIRCUIT
B
DRAWING NO.
DO NOT SCALE DRAWING
©BISHOP GRAPHICS. INC.
REORDER NO. 20621

AIR-1 BREEZES
Your Comments Welcome
Battery operation of the VIC-20: Add a 2 OHM, 10 watt resistor is series
with a 12-volt battery connected to the two pin "9 VAC" power jack on the
VIC for portable/emergency operation. (Direct 12-volt connection causes
excessive power dissapation in the VIC's regulator .
Some of the ICOM IC720's require a 22 OHM | watt resistor in series with
the mike PTT line on the AIR-1 to prevent a "transmit hang-up" condition.
(Radio will not go back to receive after transmission .
To prevent RFI/Cabling problems, use "braided" shield cables. Not foil
or spiral wrapped for ail Gozinta's and Gozouta's on the AIR-1. Several
passes through a toroid will limit radiation from the shield if necessary.
More battery operation: The newer ViC's are using externa, +5V power
supplies instead of just supplying 9 VAC. This is the same power supply
arrangement as the "64" with a 7-pin "DIN" power input connector. Unless
you want to run the DATASET, you'll only need to supply +5VDC. Use an
LM323 on a big heatsink directly off the 12 volts.
The FSK input on the ICOM 720 requires 22 KOHM pull-up resistor from
pin 6 to pin 9 on the 24-pin motex connector. Also, the pin 4 fixes audio
is too low to drive the AIR-1 in receive; use the speaker output.
Some early YAESU FT101's (A,B,E,EE will not key in CW to full power out
put unless R-28 (2.2 KOHM is reduced to about 330 CHM. It is located just
below Q5 & Q& in the lower left. (An easy method is to "tack" a 470 OHM
^ watt resistor across the existing 2200 OHM . The later FT101's & ZD re
quire that diodes D5 & D6 be jumpered (shorted instead of changing R-28.
To use the ICOM hand helds, IC2,3,4 connect a 20K resistor from the AIR-1
PTT output (tip to the ICOM mike input along with a direct connection to the
AIR-1 AFSK output (ring . This provides the necessary HIZ pull to ground and
activate the transmitter without shorting the audio.

CHAPTER 1
‘AIR-1’ PRELIMINARY CHECKOUT
After unpacking your unit, make sure that power to the computer
is turned off, then plug the Microlog AIR-1 into the “expansion port”
(The same one used for game and memory expansion modules), so that
the components are on top, facing up. If you are using an expansion
board, the components should face the front. Turn on the computer
and video monitor. For clarity, only the VIC-20 display is shown in the
following examples. The “64” display has one long top line with the
same information as the two lines of the VIC-20. The word
“MICROLOG” will appear on the screen for several seconds then the
following "TOPLINE” displav should appear on the video screen of the
VIC-20:
R B 0 6 0 W P M N O R U
O 0 0 : 0 0 U T C
This indicates that the system is set to receive (R) RTTY Baudot (B)
code at 60 WPM, and that the built-in dual tone demodulator is
selected in the Normal (NOR) mode with the “UNSHIFT on SPACE”
feature enabled (U). The ‘O' on the second line is the ’red-dot’
singletonc tuning indicator. A four digit HH:MM clock which should
start advancing is displayed on the second line.
The “Split Screen” cursor will be displayed in the left ccnter of the
VIC screen in blue, white on the C-64. The receive text cursor will be
at the bottom left VIC screen in black, yellow on the C-64. If using a
monochrome (black and white) TV/monitor, colors will appear as
shades of gray.
In the event that the above does not appear on your video
monitor’s screcn, chcck the cable between the computer and the TV
monitor to make sure that it is not shorted or open. You may also have
to adjust the TV monitor's various controls such as brightness, contrast,
etc. Some monitors provide a switch which selects a low or high im-
pcdence input. You should select the low impedence (75 OHM) input.
Also, if your monitor has a “PICTURE-DATA" switch it should be in
the “DATA” position.
Some basic programs require the full 38K C-64 memory, which
means you will have to unplug the AIR-1. Do not unplug with power
on, It’s also a good idea to disconnect all radio cables from the AIR-1
before unplugging it. An A.C. ground fault between your radio and
the computer could damage both the AIR-1 and the computer.

CHAPTER 2
* AIR-1’ SYSTEM
FAMILIARIZATION
2.1 KEYBOARD:
Your VIC-20 or ‘*64” keyboard has a total of 67 keys including all
of the familiar Alpha-Numeric keys. In addition there are special sym
bol keys, and two keys, namely ‘SHIFT’ and ‘CTRL’ which are always
used in conjunction with another key. The SHIFT key(s) are located on
the bottom row and the CTRL key is located on the left side above the
RUN/STOP key.
Note that some of the key tops have two symbols. For example, the
4 and the $ symbols are engraved on the same key top. Much the same
as in a standard typewriter you must hold the SHIFT key down while
pressing the 4 key in order to type the $ symbol. The CTRL key is used
in a similar manner.
In the following description, references are made to various con
trol functions or commands. These commands are executed by
simultaneously pressing the CTRL (or SHIFT) key plus one other key.
For example, a request to press (or type) ‘CTRL X’ means that you
must hold down the CTRL key, and while holding it down, press the X
key, then release both keys. Similarly, to type or press ‘SHIFT X’ means
that you should hold down the SHIFT key, and while holding it press
X. As soon as the X key has been pressed you can release both keys.
After familiarizing yourself with the location of the various sym
bols on the keyboard, type some Alpha-Numeric text. Observe that the
characters you have typed are displayed on the upper part of the screen
above the split-line. The ‘INST/DEL’ key which is located on the right
side of the top row may be used to correct typing errors. Notice that
typing ‘INST/DEL’ erases the previously typed character.
You can go to the “BASIC” computer mode by typing ‘CTRL’ and
Commodore keys. Since you are then under the restraints of “BASIC”
language, to go back to AIR-1 communication mode you must type:
SYS 40969 then the ‘RETURN’ key for the VIC-20. USE: SYS32777
then return on the “64.”

The split-screen option is user selectable. The ‘CTRL S’ command is
used to toggle the split-screen option on and off. To remove the split
screen and use the entire video display for receive text,
TYPE: ‘CTRL S’ (HOLD 'CTRL’ KEY AND PRESS ‘S')
In the non split-screen mode, you can still enter text into the buffer, you
just can’t see it appear before it's transmitted.
2.2.1 ADDITIONAL VIDEO COMMANDS FOR C-64:
The screen and text colors can be changed with a single control
command. “CTRL G” followed by a 4 digit number will change the
following:
2.2 VIDEO DISPLAY COMMANDS:
CTRL G
f
W screen background color
-►real time receive/transmit
-►transmit buffer
-►top line status display
The fs arc the same as the 64’s color codes as shown on page 139 of the
64 manual with one exception. To utilize a single digit for all 16 colors,
you must enter it in “Hexadecimal” that is 0 through F instead of 0
through 15. The colors are as follows:
0 = Black 4 = Purple 8 = Orange C = Med Gray
1 - White 5 = Green 9 = Brown D = Light Green
2 = Red 6 = Blue A = Light Red E = Light Blue
3 = Cyan 7 = Yellow B = Dark Gray F = Light Gray
The colors will change upon typing the forth digit. Note: The default
colors are:
(6) Blue Top line
(1) White TX buffer
(7) Yellow Real time RX/TX
(E) Light Blue Screen
These colors were picked as the best compromise for both color and
monochrome display. You can experiment with different color patterns
,to~Suit your individual requirements. Suggestions: 0657, 1AE0, 192A,
569D, 062C. Yoop
\
Note also, the tuning indicators and the RX buffer flags are always
displayed in red, except when jumping to AMTOR where they change to
the same color as the top line.
You can move the entire video display horizontally with the CTRL
H command. This should take care of monitors with limited horizontal
sync tracking range.

2.3 XMIT/RCV COMMANDS:
Typing SHIFT RUN/STOP’ or SHIFT RETURN’ (hold SHIFT’,
press ‘RUN/STOP’) places the system in the transmit mode. Observe that
the top line display has changed and is now displaying:
T B 0 6 0 W P M N O R CHAR
indicating that the system is now in the Transmit Mode (T), the AFSK
MARK/SPACE frequencies are NORmal at 2125 and 2295 HZ, respect
ively, and that each character will be transmitted as it is being typed
(CHAR), Type some Alpha-Numeric text and observe that the typed text
is displayed above the split-line and also below the split line. The text
which is displayed below the split-line represents the actual text as it is
transmitted. The text which is displayed above the line represents the
entries into the system’s text buffer.
Return the system to the receive mode with the RUN/STOP key by
itself or by typing ‘CTRL CLR/HOME’ (hold the ‘CTRL’ key and press
the key labled ‘CLR/HOME’). Observe that the top line display has
changed indicating that the system is in the Receive mode. Type in some
text and note that it is no longer displayed below the split line.
2.4 SPEED SELECTION COMMANDS:
NOTE: the right hand bracket ] is the symbol for a terminated command
sequence which required further keyboard input such as speed select or
memory store. When you first initiate these commands, you should not
see anything on the screen. If you see the ‘ ] ’ it means that particular
command has been terminated. Hitting‘CTRL X’ twice for example will
only terminate the command without it taking affect.
The operating speed (TTY and MORSE) is selected by means of the
‘CTRL X’ command. The allowable RTTY BAUDOT speeds are 60, 66,
75, 100, and 132 WPM. ASCII code speeds are 110 and 300 baud. For
MORSE, speeds from 5 to 149 WPM are permitted. To select an RTTY
(BAUDOT) speed of 66 WPM (SAME AS 50 BAUD), first type ‘CTRL B’
if not in BAUDOT already, then:
TYPE: CTRL X’ (SPEED SELECT COMMAND
NOTHING SHOWS ON THE
SCREEN)
TYPE: 66 (DESIRED SPEED)
TYPE: ‘CLR/HOME’ (OR ANY NON-NUMERIC KEY
PRINTS ])

Observe that the top line displays
R B 0 6 6 W P M N O R
To select an RTTY (BAUDOT) speed of 100 WPM (same as 75 baud),
TYPE: ‘CTRL X‘
TYPE: 100
TYPE: ‘CLR/HOME’
Observe the speed display on the top line is now 100 WPM.
To select an RTTY (ASCII) rate of 110 baud,
TYPE: ‘CTRL A’
System will automatically go to 110 BAUD when ASCII is selected,
Observe that the top line displays A-110 BD (BAUD) where the ‘A’ in
dicates that the selected code is ASCII.
To select an RTTY (ASCII) rate of 300 baud, (no need to type ‘CTRL
A’ since you are already in ASCII)
TYPE: ‘CTRL X’
TYPE: 300
TYPE: ‘CLR/HOME’
Note, if you are in 300 BAUD ASCII, to change to any other speed or
code, you must first go to 110 BAUD ASCII. The jump from 300 BAUD
ASCII to MORSE or BAUDOT directely is not allowed.
Go back to RTTY (BAUDOT) speed of 60 WPM (Same as 45 baud),
TYPE: ‘CTRL B’
TYPE: ‘CTRL X’
TYPE: 60
TYPE: ‘CLR/HOME’
(ASCII stands for American Standard Code for Information Inter
change, whereas ‘BAUDOT’, pronounced ‘BAW DOUGH’ is a man’s
name.)
NOTE, you can omit the ‘CLR/HOME’ key if you enter the speed with
three digits, 110, 066, 075 etc., since the program automatically ter
minates the command on the third digit.

2.5 MORSE/TTY SELECT COMMANDS:
Enter the MORSE mode by typing ‘CTRL M’ {hold ‘CTRL’, press
M) and the top display line should read:
R M 0 2 0 W P M N O R
indicating MORSE (CW) mode with speed set for 20 wpm. The system
will remember the previous MORSE and RTTY speed when changing
to and from modes. Go to the transmit mode by typing ‘SHIFT
RUN/STOP’ and observe that the display has changed and the letter *T’
has replaced the ‘R’ on the left top display line. Turn up your audio
channel volume, and type in some letters and numbers. You will hear
the MORSE code as it is displayed below the split-line. To change the
speed use the ‘CTRL X’ command. Also, when the text buffer is empty,
if desired, the MORSE equivalent of a “diddle", BT, can be sent. Type
‘CTRL D’ to toggle the “diddle” mode on/off. To select a MORSE
speed of 17 words per minute,
TYPE: ‘CTRL X’
TYPE: 17 (NEW SPEED)
TYPE: ‘CLR/HOME’ (OR ANY NON-NUMERIC KEY)
Observe that the newly entered MORSE speed is now displayed on
the top line. Any MORSE speed from 5 to 149 WPM may be selected.
NOTE: In |he receive mode, the displayed MORSE speed will
usually be within plus or minus one digit of the transmit speed you set.
As you receive some MORSE characters, the receive speed readout will
track the incoming speed, (assuming speedlock is not enabled) but will
not change the selected transmit speed.
Return the system to BAUDOT TTY mode by typing ‘CTRL B\
The top line should display,
T B 060WPM NORCHAR
2.6 CLOCK COMMANDS:
The AIR-1 includes a real time clock with a 4 digit display of hours
and minutes, and a 3 character time zone. When the unit is first turned
on the clock is reset to 00:00. You can set the clock to start at any time
by means of the ‘CTRL K’ command. For example, initialize the clock
to start at 1758GMT,

TYPE: ‘CTRL K’ (CLOCK SET COMMAND—CLOCK
DISPLAY WILL FREEZE)
TYPE: 1758GMT (DESIRED TIME AND ZONE)
TYPE: ‘CLR/HOME’ (THIS STARTS THE CLOCK)
The clock will be restarted at 1758GMT as soon as you hit the
‘CLR/HOME’ key (or any non-numeric kev)and the 2nd video line will
display: 17:58 GMT
The clock obtains its timing reference from the CPU Crystal fre
quency and should maintain good accuracy. The clock will have to be
reset if power is lost.
The system's clock time can be transmitted by means of the ‘CTRL
C’ command. Type ‘CTRL C' and observe that the clock time is
displayed on the lower half of the screen as it is being transmitted. If
you turn up the reference tone, you can hear the TTY code being
transmitted, as you send the time.
2.7 MEMORY STORE/RETRIEVE COMMANDS:
The AIR-1 VIC-20 version includes a number of user program
mable memories. There are 8 message memories of 128 characters
each, 2 ID memories of 64 characters each, a WRU memory of 11
characters, and 2 Selective print memories of 11 characters each. You
can store messages at any time, even during a transmission. In the
“64", the first 7 memories contain 512 characters, #8 has 384
characters, other memories are the same as the VIC-20 version.
You can store your call-sign into the ID memory by means of the
‘CTRL £' command. For example, to store the call sign W1USA,
TYPE: ‘CTRL £' (HOLD ‘CTRL' AND PRESS KEY
NOTHING SHOWS ON SCREEN)
TYPE: ‘SPACEBAR' (PUTS A WORD SPACE)
TYPE; WTUSA
TYPE: ‘CLR/HOME’ (EXITS MESSAGE STORE MODE
PRINTS ])
As you type the call-sign in, it will be displayed above the split-
line. You can correct typing errors by means of the ‘INST/DEL’ key.
To retrieve and transmit the stored call-sign simply press the key.
The call letters previously stored will be inserted into the text buffer for
transmission and displayed above the split-line.
You can store a second call sign by using the CTRL I command.
For example, to store the secondary call sign K3ICH/4,
TYPE: CTRL I’
TYPE: ‘SPACEBAR’
TYPE: K3ICH/4
TYPE: ‘CLR/HOME’

The secondary call sign will be transmitted by pressing 'SHIFT ’
with a “space” preceding it. You will find it useful to use the secondary
ID to store the call of the station you’re calling.
To store a message into any one of the 8 available message
memories you must first type 'CTRL’, and memory number (1 to 8),
then enter the message text, and terminate by typing ‘CLR/HOME*.
For example, to enter: CQ CQ CQ DE N3JL N3JL N3JL into memory
number I,
TYPE: 'CTRL l ’(HOLD ‘CTRL', PRESS T)(N O DISPLAY)
TYPE: CQ CQ CQ DE N3JL N3JL X3JL (TEXT DISPLAYS)
TYPE: CLR/HOME’ (SHOWS *]’ ON SCREEN)
To send this stored message, simply press and release the ‘F -l’ key
(right hand function keys). In a similar fashion you can store and
retrieve messages from the other 7 memories.
If your message is longer than the selected number of characters it
will simply overflow' into the next message memory location. For exam
ple, if you store a message that overflows into memory 2, it will be pro
perly retrieved in its entirety by typing ‘FI’. If you type ‘F2’, you will
retrieve the last remaining characters of the message, which over
flowed into ‘F2\
You must use the ‘CLR/HOME’ key, or any ‘CTRL’ key to ter
minate and exit the message store mode. If you do not, you will con
tinue to store characters until you have filled the entire message buffer.
Normally, each of the user programmable memories in the VIC-20
version is 128 characters, which leaves about 2,400 characters for the
text buffer. By typing CTRL ‘ v ’ (up/down cursor) you can create a
receive buffer of 1,000 characters. Typing the same key 4 0 ’ by itself
will send this new memory. The text buffer is shortened to about 1,400
characters when this additional receive buffer is enabled. See Section
7.2.3.for more information on utilizing this receive buffer and “64”
data.
You can also recall and transmit two permanently programmed
messages. Pressing ‘CTRL’ followed bv the “Q” key, will recall the
“QUICK BROWN FOX ...” message', and following the “CTRL” by
the “R” key, will recall the “RYRYRY ...” message.
Up to 11 characters may be stored into the WRU (Who Are You)
memory. To enter the desired keyword,
TYPE: ‘CTRL = ’ (HOLD ‘CTRL’, PRESS ‘ = ’)
TYPE: XYZ . . . (UP TO 11 CHARACTERS)
TYPE: ‘CLR/HOME* (PRESS THE ‘CLR/HOME’ KEY)

The WRU memory functions as follows. Whenever the AIR-1
‘hears’ or receives the stored WRU KEYWORD exactly, it will
automatically go into the transmit mode and, after a short delay send
whatever is stored in the ID memory three times (your call sign), along
with the contents of the text buffer and then return to the receive mode.
The two selective print memories can store up to 11 characters each.
These are entered exactly as for the WRU memory except that you access
these memories by typing ‘CTRL 9' and 'CTRL 0 ’ respectively.
When the system ‘hears’ the specific string stored into the “9”
memory, the printer port will be enabled, and when it ‘hears’ the string
corresponding to the one stored in “0 ” memory, the printer port will be
disabled. Manually typing ‘CTRL P’ or ‘CTRL V’ also enables/disables
the printer port. See Chapter 6 for more info.
To display the current contents of these 3 memories press 4CTRL>'
(period key). The contents of the “9” memory are shown next to PON:
(printer on), and the contents of the “0 ” memory are shown next to
POFF: (printer off).
The “ = ” memory contains the WRU KEYWORD, shown next to
WRU.
You will hear the words, “SEL CAL” (SELECTIVE CALL) and
“KEYWORD” used interchangeably on the air.
Sec Section 7.2.3 for information on creating ‘OFF-THE-AIR’
Receive Memory.
2.8 TRANSMISSION MODE COMMANDS:
The AIR-1 has a number of transmission modes. In the
CHARaeter mode (this is the system default mode), each character is
transmitted as it is typed. In the WORD mode, an entire string of
characters is transmitted as soon as the spacebar key is pressed. In the
LINE mode the typed characters are transmitted as soon as the
‘RETURN’ key is pressed.
The system should be in the transmit mode displaying a ‘T* on the
left top line; if not, type ‘SHIFT RUN/STOP’. Enter the WORD mode
by typing CTRL W’ (hold ‘CTRL’ and press the ‘W* key) and note that
the status display on the top line indicates that the WORD mode is
active.
Now as you type a word, it will be displayed above the split-line.
Press the spacebar on the keyboard and notice that the entire word is
displayed below the split line as it is being transmitted. Go back to

CHAR mode by typing ‘CTRL W’ again, and note the mode displayed
on the screen: CHARaeter, WORD, LINE mode.
Now enter the LINE mode by typing ‘CTRL L \ Type in some text,
and it will be displayed on the upper part of the screen above the split-
line. Nowr press the ‘RETURN’ key and the text will be transmitted and
displayed below the split-line.
Note that in the WORD and LINE modes you can edit your text by
means of the ‘INST/DEL’ key since it will not be transmitted until you
press the ‘SPACEBAR’ or ‘RETURN’ keys respectively. If you are a
“hunt and peck” typist, the W'ORD (or LINE) mode will smooth out
your typing and make it sound professional.
Return to CHAR mode by typing ‘CTRL W’ or ‘CTRL L’ again.
CHAR should then appear if you are in transmit mode.
2.9 TEXT EDITING COMMANDS:
The SPLIT-SCREEN option lets you see what you type, and
allows you to correct typing errors before they are transmitted. If you
are in the transmit mode, you can enable the WORD or LINE mode as
explained above. In the receive mode you can compose and edit larger
segments of text. Place the system in the receive mode by typing ‘CTRL
CLR/HOME’. Type in some Alpha-Numeric text and see it displayed,
as you enter it, on the top half of the screen in blue. The characters you
are typing are also stored into the system’s text buffer memory. When
the buffer fills up it inhibits further entry of characters.
You can correct typing mistakes by pressing the ‘INST/DEL’ key.
Pressing this key will cause the previously entered character to be
erased and you can correct it. Each press of the ‘INST DEL’ key will
erase one character. Your edited text can be transmitted by typing
‘SHIFT RUN/STOP’. This places the system in the transmit mode, and
all characters entered into the text buffer will be displayed below' the
split line as they are transmitted.
The entire text buffer may be cleared at any time by typing ‘CTRL
CLR /HOME’. This will also clear the screen and place the system in
the receive mode.
You can repeat a segment of text by means of the ‘ —’ key. To
repeat the transmission of a text segment first type ‘SHIFT —' (press
the ‘SHIFT’ and ‘ —’ keys). This serves to point to the beginning of your
text. Now enter your text, which will be transmitted if you are in the
transmit mode. Press the ’ key and the text will be repeated. Press it
again and it will be repeated for the third time. For example, with the
system in the receive mode,

TYPE: NAME IS
TYPE; ‘SHIFT SPACEBAR
TYPE: JOHN
TYPE: *-• (PRESS *-* 2 TIMES)
This will be entered into the text buffer and will be displayed
above the split line as
NAME IS J JOHN - -
The “CHECKER BOARD" on the screen is a symbol for the
‘SHIFT and the other two symbols represent the repeat function as
entered in the text buffer.
Now press ‘SHIFT RUN/STOP’ or ‘SHIFT RETURN' to enter the
transmit mode. Observe the text which is displayed below the split-line
as it is being transmitted. The word JOHN is sent 3 times, with a space
between.
A segment of text may be repeated continuously, until stopped, by
means of the ‘CTRL —’ command. The procedure is similar to the
above example except that you type ‘CTRL — ’ in place of For ex
ample, to send a continuous CQ message,
TYPE: ‘SHIFT (THIS SETS “BEGIN TEXT
POINTER”)
TYPE: ‘RETURN’ (WILL START NEW LINE)
TYPE: CQ CQ CQ CQ DE N3JL N3JL N3JL
TYPE: ‘CTRL
observe the following display above the split line
S a
CQ CQ CQ CQ DE N3JL N3JL N3JL £
The “CHECKER BOARD” is the symbol for shift - . The reversed
left arrow is the symbol for the RETURN (carriage return and line
feed) key. The £ is the symbol for the infinite repeat key as entered in
the text buffer.
This text will now be transmitted continuously as long as you are
in the transmit mode (‘SHIFT RUN/STOP’). Transmission will stop as
soon as you go to the receive mode (‘RUN/STOP’) — it will restart if
you return to the transmit mode by pressing ‘SHIFT RUN/STOP’. You
can also stop the continuous repeat function by pressing the TN-
ST/DEL’ key and removing the infinite repeat command from the text
buffer. If you type ‘CTRL — ’ and reinsert this command it will start
again.

CHAPTER 3
‘AIR-1’ TRANSCEIVER
CONNECTIONS
The AIR-1 provides all of the interfaces required for direct hookup
to your transceiver (or transmitter and receiver). For the following
description refer to the rear connection diagram, (Page B-3)
3.1 CW KEYING:
The ± KEY jack provides the necessary connections for both
positive (cathode, solid state) and negative (grid block) keying of most
transceivers or transmitters. Before you actually make the connection
to your keying line make sure that the open key voltage and closed key
current do not exceed the following:
maximum negative keying voltage
maximum key-down negative current
maximum positive keying voltage
maximum positive key-down current
-150 volts
50ma
40 volts
100m a
Most popular modern transceivers will be within the allowable
keying ratings, and you will be able to utilize this solid state ± KEY
jack on the AIR-1.
Check your transmitter CW keying specifications or verify them
by actual measurement. Place a voltmeter across the transmitter CW
keying line and ground. For negative keying connect the positive
voltmeter lead to ground, the negative to the keying line. For positive
keying reverse the voltmeter leads. With your transmitter on in the CW
mode note this open key voltage. For positive keying transmitters place
a milliamp meter in series with the CW keying line and ground. Close
the keying line and note the value of this key down current. Typically,
grid block keyed rigs use about -40 to -60 volts on the key to cut off the
tube(s). Key down current is usually only a few milliamps. Most solid
state rigs switch + 12 volts to ground with key down current being only
about 5 to 20 ma. In the event your transmitter keying requirements
exceed the above listed ratings, do not use the ± KEY jack for CW key
ing. You will have to use an external keying relay (see Appendix A —
External Relays).

NOTE; The keying outputs are directly connected to the collector
of transistor switches through a series diode. NPN for positive and PNP
for negative voltage. These are driven into saturation and therefore the
outputs are pulled to within about 0.7 volts from ground. If your radio
requires that the positive voltage keying line be pulled to a few tenths
of a volt from ground, you can short out diodes D-5 and D-6, (lower left
board). (This can also be accomplished by installing jumpers J2 and J3
on the C-64 version board. See Page B-3.)
3.2 TTY KEYING:
If your transmitter has provisions for FSK (Frequency Shift Key
ing) and the keying requirements are within the voltage and current
limits described for CW, you can use the ± KEY output for RTTY as
well as CW. You will have to measure the voltage and current re
quirements of vour transmitter’s FSK keying line just as vou did for the
CW key.
If you choose to use the AFSK (Audio Frequency Shift keying)
which is provided in the AIR-1, simply connect a shielded cable be
tween the AFSK-PTT jack on the AIR-1 and the microphone input of
your transceiver. The AIR-1 AFSK output is preset at the factory for
MARK = 2125HZ AND SPACE = 2295HZ. By placing your
transceiver in LSB you will transmit proper RTTY shifts. Some
transceivers have an RTTY receive position which you can use instead
of the LSB position.
NOTE: Even though the sideband phone convention is to use LSB
on 160, 80 and 40 meters and USB above, the RTTY convention is to
have “mark high” on all HF bands (when using LSB, the absolute
transmitted frequency of the 2125HZ “mark” would be “higher” than
the 2295HZ modulated space frequency). The VHF/UHF AFSK con
vention on the other hand, is to have “mark-low” which of course
would occur when using the same 2125HZ mark and 2295HZ space
tones to amplitude or frequency modulate a carrier.
Use of RTTY with FM (Frequency Modulation) on the VHF or
UHF bands will also require the use of AFSK. Simply connect the
AFSK output on the AIR-1 to your FM transceiver microphone input.
3.3 TRANSMIT/RECEIVE SWITCHING:
The AIR-1 has provisions for automatically switching your
transceiver between receive and transmit. The jack labeled AFSK-PTT
provides a closed contact to ground whenever the AIR-1 is in the
transmit mode. The PTT control will open its grounded contact as soon
as you have switched the system from transmit to receive mode
(‘RUN/STOP’ command).

The T/R control output (PTT)is a solid state switch capable of
handling a positive voltage of up to + 40 volts at a maximum of 100
ma. These limits are well above the requirements of most modern
transceivers. In the event that the T/R switching will not handle your
radio’s requirements, you will have to use an external relay for T/R
control (see Appendix A — External Relays).
The AFSK-PTT jack (tip) should be connected to your
transceiver’s PTT (Push To Talk) line, or the transmit/receive switch
ing jack usually found on a rear panel connector of most transceivers.
The AFSK output is available on the “ring” of this 3 circuit jack. For
details refer to the rear connection diagram.
3.4 AUDIO INPUT:
Audio from your receiver (transceiver) is connected to the SPKR
AUDIO jack on the AIR-1. Connect a shielded cable between the
speaker output of your transceiver (receiver) and the SPKR AUDIO in
put on the AIR-1. You will note that there are two “SPKR AUDIO”
phono jacks on the AIR-1. These are jumped on the board. This allows
you to plug one cable from your radio to the AIR-1, and one cable out
to your external speaker, eliminating the need for a “Y” connector.
Refer to the diagram showing the AIR-1 rear connections.

CHAPTER 4
1 AIR-19 RTTY OPERATION
The AIR-1 contains an AFSK demodulator designed to receive
both amateur and commercial RTTY signals. If you are not familiar
with RTTY, it is suggested that, before proceeding further, you read
one of the RTTY-PRIMER handbooks.
The “WIDE-NARROW” switch selects between 170HZ “NAR-
ROWr” shift, and 425/850HZ “WIDE” shift.
At the present time the 170HZ shift is in almost exclusive use by
amateur RTTY' operators. The standard tones for USA amateurs are
2125HZ mark frequency, and 2295HZ space frequency, whereas the
European amateur standards are 1275HZ mark and 1445HZ space.
Since both utilize 170HZ shift they are fully compatible on HF RTTY.
As a matter of fact all tone pairs utilizing 170HZ shift will be compati
ble on HF RTTY.
Selection of inverted RTTY reception is accomplished by means of
the ‘CTRL (minus) command. ‘CTRL + ’ (plus) selects normal
(noninverted) RTTY operation. These commands are valid for receive
and transmit.
The selected mode is always displayed on the top video line as
NOR or INV whenever the system is in the Transmit or Receive mode.
In addition to the dual tone AFSK demodulator, which is the
preferred detection method the user has the option of selecting a single
channel (MARK or SPACE only) detector for reception of RTTY. The
‘CTRL N’ command is a toggle action function used to switch between
the AFSK demodulator, and the single channel detector. When using
the SINGLE TONE method, the receiver is tuned to an 800 HZ beat
note and the RTTY cross hatch tuning aid is inhibited. In its place, a
“GRID-BLANK” is displayed. This indicates that the single tone detec
tor has been selected. In the normal rec ^tion mode this 800HZ note
represents the MARK whereas in the inverted mode it represents the
SPACE tone. You would use the single tone indicator red dot for tun
ing. This single tone detector is only suitable for HF RTTY and can not
be used on VHF where AFSK is utilized. Also, note that since the single
tone circuit is optimized for Morse code which is usually a much slow'er
“BIT" rate, it is not suitable for the higher RTTY speeds of 110 and 300
BAUD.