Racal 6790/GM -- R-2174A Setup and Install Procedures
The setup for a 6790/GM is not a Plug/Play situation -- It requires a methodical series of steps to get each component to talk to the Interface and Software.
Step 1 -- Set or Check the Jumpers on the A6A1 Board -- (the one connected to the 26 pin circular connector on the rear ...)
6790/GM Communication Card A6A1 Jumper Settings for 232C Mode
Link1 / InstallLink2 / Open
Link3 / Install
Link4 / Install
Link5 / Install
Link6 / Open
Step 2
Fabricate or acquire a complete cable kit from CGT -- for the PC to the Racal 6790/GM. The Circular Female 26 Pin connector is also available from: American Connector Corp. Ph. (305)-591-7530 -- Part Number MS3476L16-26S (Connector) and MS3417-16N (Back Shell) -- about $30 for both. (now used as an Aircraft Connector).
Cable Details (6790GM to PC)
The relevant pin layout of the connectors (DB9 or DB25) is as follows:
Note: The 6790 address will be 37 with address lines set below:
6790 Round 26 Pin Conn. / Description / 6790 End / DB9 Connector on PC / DB 25 Connector on PCA / System Ground / Open
B / Data Out A / to PC Data In RXD / ======> / Received
Pin 2 / Pin 3
C / Data Out Ground / Ground / <=====> / Ground
Pin 5 / Pin 7
F / Data In A / to PC data Out TXD / <====== / Transmitted
Pin 3 / Pin 2
H / Data In B / Jumper to J
J / Gnd. / Jumper to H
K / Receiver address D1-1 / Open
L / Receiver address D1-2 / Open
M / Receiver address D1-4 / Open
N / Receiver address D1-8 Ground for x7 -- 7 units digit / Gnd to c
P / Receiver address D2-1 / Open
R / Receiver address D2-2 / Open
S / Receiver address D2-4 Ground for 3x / Gnd to c
T / Receiver address D2-8 Ground for 3x total address 37 / Gnd to c
U / Parity select if grounded - No Parity if left open / Open
V / Even/Odd Parity leave open / Open
W / Baud Rate setting leave W,X,Y,Z open to set 19200 / Open for 19200
X / Baud rate setting leave open / Open for 19200
Y / Baud rate setting leave open / Open for 19200
Z / Baud rate setting leave open / Open for 19200
a / Gnd. / Not used
b / Gnd / Not used
c / System Ground / Connect to S,T,N
Note 1 -- For 4800 bps ground Y and Z
Note 2 -- a 2 wire shielded cable is fine for this application
Step 3
Verify that 6790/Cable/PC Port are communicating.
The following procedure is normally used to verify the communication link between the PC and the Receiver -- independent of the Visual Radio Program. Any Dumb Terminal program will do -- or - in Win95/98 Accessories/Communications/HypertTerminal -- select the Terminal Program. Also, the original Windows Terminal Program is ideal.
Go to Settings
Select Terminal Settings
Set Local Echo on -- also select inbound/outbound CR/LF on
Select Communication Settings
Set communication options to 19200 -- 8 bits -- no parity N and 1 stop bit
Select the COM port that the Receiver is linked to -- -- Com 1 thru Com 4
Get back to the main terminal Panel and type:
$37S2 and then the Enter key -- this sends the Racal address 37 to the Receiver -- and set the mode to remote -- the Receiver Remote Mode LCD indicator should come on.
Now type F10.00 and then the Enter key -- this will set the frequency to 10 Mhz.
If OK then you are ready to use the VRADIO program.
0 / = / GNDK / L / M / N / P / R / S / T / K / L / M / N / P / S / T
D1-1 / D1-2 / D1-3 / D1-8 / D2-1 / D2-2 / D2-3 / D2-8 / D1-1 / D1-2 / D1-3 / D1-8 / D2-1 / D2-3 / D2-8
0 / 0 / 0 / 0 / 0 / 0 / 0 / 0 / 0 / 50 / 0 / 0 / 0 / 0 / 1 / 1 / 0
1 / 1 / 0 / 0 / 0 / 0 / 0 / 0 / 0 / 51 / 1 / 0 / 0 / 0 / 1 / 1 / 0
2 / 0 / 1 / 0 / 0 / 0 / 0 / 0 / 0 / 52 / 0 / 1 / 0 / 0 / 1 / 1 / 0
3 / 1 / 1 / 0 / 0 / 0 / 0 / 0 / 0 / 53 / 1 / 1 / 0 / 0 / 1 / 1 / 0
4 / 0 / 0 / 1 / 0 / 0 / 0 / 0 / 0 / 54 / 0 / 0 / 1 / 0 / 1 / 1 / 0
5 / 1 / 0 / 1 / 0 / 0 / 0 / 0 / 0 / 55 / 1 / 0 / 1 / 0 / 1 / 1 / 0
6 / 0 / 1 / 1 / 0 / 0 / 0 / 0 / 0 / 56 / 0 / 1 / 1 / 0 / 1 / 1 / 0
7 / 1 / 1 / 1 / 0 / 0 / 0 / 0 / 0 / 57 / 1 / 1 / 1 / 0 / 1 / 1 / 0
8 / 0 / 0 / 0 / 1 / 0 / 0 / 0 / 0 / 58 / 0 / 0 / 0 / 1 / 1 / 1 / 0
9 / 1 / 0 / 0 / 1 / 0 / 0 / 0 / 0 / 59 / 1 / 0 / 0 / 1 / 1 / 1 / 0
10 / 0 / 0 / 0 / 0 / 1 / 0 / 0 / 0 / 60 / 0 / 0 / 0 / 0 / 0 / 1 / 0
11 / 1 / 0 / 0 / 0 / 1 / 0 / 0 / 0 / 61 / 1 / 0 / 0 / 0 / 0 / 1 / 0
12 / 0 / 1 / 0 / 0 / 1 / 0 / 0 / 0 / 62 / 0 / 1 / 0 / 0 / 0 / 1 / 0
13 / 1 / 1 / 0 / 0 / 1 / 0 / 0 / 0 / 63 / 1 / 1 / 0 / 0 / 0 / 1 / 0
14 / 0 / 0 / 1 / 0 / 1 / 0 / 0 / 0 / 64 / 0 / 0 / 1 / 0 / 0 / 1 / 0
15 / 1 / 0 / 1 / 0 / 1 / 0 / 0 / 0 / 65 / 1 / 0 / 1 / 0 / 0 / 1 / 0
16 / 0 / 1 / 1 / 0 / 1 / 0 / 0 / 0 / 66 / 0 / 1 / 1 / 0 / 0 / 1 / 0
17 / 1 / 1 / 1 / 0 / 1 / 0 / 0 / 0 / 67 / 1 / 1 / 1 / 0 / 0 / 1 / 0
18 / 0 / 0 / 0 / 1 / 1 / 0 / 0 / 0 / 68 / 0 / 0 / 0 / 1 / 0 / 1 / 0
19 / 1 / 0 / 0 / 1 / 1 / 0 / 0 / 0 / 69 / 1 / 0 / 0 / 1 / 0 / 1 / 0
20 / 0 / 0 / 0 / 0 / 0 / 1 / 0 / 0 / 70 / 0 / 0 / 0 / 0 / 1 / 1 / 0
21 / 1 / 0 / 0 / 0 / 0 / 1 / 0 / 0 / 71 / 1 / 0 / 0 / 0 / 1 / 1 / 0
22 / 0 / 1 / 0 / 0 / 0 / 1 / 0 / 0 / 72 / 0 / 1 / 0 / 0 / 1 / 1 / 0
23 / 1 / 1 / 0 / 0 / 0 / 1 / 0 / 0 / 73 / 1 / 1 / 0 / 0 / 1 / 1 / 0
24 / 0 / 0 / 1 / 0 / 0 / 1 / 0 / 0 / 74 / 0 / 0 / 1 / 0 / 1 / 1 / 0
25 / 1 / 0 / 1 / 0 / 0 / 1 / 0 / 0 / 75 / 1 / 0 / 1 / 0 / 1 / 1 / 0
26 / 0 / 1 / 1 / 0 / 0 / 1 / 0 / 0 / 76 / 0 / 1 / 1 / 0 / 1 / 1 / 0
27 / 1 / 1 / 1 / 0 / 0 / 1 / 0 / 0 / 77 / 1 / 1 / 1 / 0 / 1 / 1 / 0
28 / 0 / 0 / 0 / 1 / 0 / 1 / 0 / 0 / 78 / 0 / 0 / 0 / 1 / 1 / 1 / 0
29 / 1 / 0 / 0 / 1 / 0 / 1 / 0 / 0 / 79 / 1 / 0 / 0 / 1 / 1 / 1 / 0
30 / 0 / 0 / 0 / 0 / 1 / 1 / 0 / 0 / 80 / 0 / 0 / 0 / 0 / 0 / 0 / 1
31 / 1 / 0 / 0 / 0 / 1 / 1 / 0 / 0 / 81 / 1 / 0 / 0 / 0 / 0 / 0 / 1
32 / 0 / 1 / 0 / 0 / 1 / 1 / 0 / 0 / 82 / 0 / 1 / 0 / 0 / 0 / 0 / 1
33 / 1 / 1 / 0 / 0 / 1 / 1 / 0 / 0 / 83 / 1 / 1 / 0 / 0 / 0 / 0 / 1
34 / 0 / 0 / 1 / 0 / 1 / 1 / 0 / 0 / 84 / 0 / 0 / 1 / 0 / 0 / 0 / 1
35 / 1 / 0 / 1 / 0 / 1 / 1 / 0 / 0 / 85 / 1 / 0 / 1 / 0 / 0 / 0 / 1
36 / 0 / 1 / 1 / 0 / 1 / 1 / 0 / 0 / 86 / 0 / 1 / 1 / 0 / 0 / 0 / 1
37 / 1 / 1 / 1 / 0 / 1 / 1 / 0 / 0 / 87 / 1 / 1 / 1 / 0 / 0 / 0 / 1
38 / 0 / 0 / 0 / 1 / 1 / 1 / 0 / 0 / 88 / 0 / 0 / 0 / 1 / 0 / 0 / 1
39 / 1 / 0 / 0 / 1 / 1 / 1 / 0 / 0 / 89 / 1 / 0 / 0 / 1 / 0 / 0 / 1
40 / 0 / 0 / 0 / 0 / 0 / 0 / 1 / 0 / 90 / 0 / 0 / 0 / 0 / 1 / 0 / 1
41 / 1 / 0 / 0 / 0 / 0 / 0 / 1 / 0 / 91 / 1 / 0 / 0 / 0 / 1 / 0 / 1
42 / 0 / 1 / 0 / 0 / 0 / 0 / 1 / 0 / 92 / 0 / 1 / 0 / 0 / 1 / 0 / 1
43 / 1 / 1 / 0 / 0 / 0 / 0 / 1 / 0 / 93 / 1 / 1 / 0 / 0 / 1 / 0 / 1
44 / 0 / 0 / 1 / 0 / 0 / 0 / 1 / 0 / 94 / 0 / 0 / 1 / 0 / 1 / 0 / 1
45 / 1 / 0 / 1 / 0 / 0 / 0 / 1 / 0 / 95 / 1 / 0 / 1 / 0 / 1 / 0 / 1
46 / 0 / 1 / 1 / 0 / 0 / 0 / 1 / 0 / 96 / 0 / 1 / 1 / 0 / 1 / 0 / 1
47 / 1 / 1 / 1 / 0 / 0 / 0 / 1 / 0 / 97 / 1 / 1 / 1 / 0 / 1 / 0 / 1
48 / 0 / 0 / 0 / 1 / 0 / 0 / 1 / 0 / 98 / 0 / 0 / 0 / 1 / 1 / 0 / 1
49 / 1 / 0 / 0 / 1 / 0 / 0 / 1 / 0 / 99 / 1 / 0 / 0 / 1 / 1 / 0 / 1