INMOD is a Telecommunication Analysis Services program that determines which potential interfering transmitter frequencies may cause receiver intermodulation. The mixing of two or more high level transmitter signals in a receiver can result in new signals affecting desired in-band receiver frequencies. In this program, intermodulation products that fall within the user specified frequency tolerance (one-side bandwidth) of each receiver are printed along with the intermodulation frequencies and transmitter frequencies involved. Cumulative statistics on the number of times each transmitter produces an interference and the number of times each receiver may be subjected to interference are printed in a summary table.
This section provides sample runs of the INMOD program. These samples illustrate how to run INMOD in the verbose mode.
The user specifies the transmitter names and frequencies, number of concurrently operating transmitters, receiver names, frequencies, and tolerances, and intermodulation orders (harmonic combination of transmitters that will be used to produce the intermodulation product) to be used in the calculations. When entering data, the default values are retained by entering a carriage return, except for Questions 1, 6, and 7 which ask for transmitter data, receiver data, and intermodulation orders. When entering data for these questions, the default is "A" - for add another value. The other options are "L" - list, "D" - delete, "C" - change, and "Q" - quit. Questions requiring a "yes" or "no" reply require only "Y" or "N" input. Question 5 will initialize the receiver data to be identical to the transmitter data if a "yes" is entered. The self interference option, Question 8, will include in the list of intermodulation products that fall within the frequency tolerance of the receiver those transmitters which have the same frequency as the receiver. The first time the intermodulation program is used, all of the data must be input. When the program is terminated, the input data are permanently saved and become the default data the next time the INMOD program is requested.
Frequency Interference Prediction, CDC-6400 Computer Program (EGG 1183-1509, February,1971).
The main menu below shows that you may have the questions asked in a verbose or concise manner, you may edit by question if you wish to change a question that you have already answered, you may obtain a summary of the current data set, you may process this data set, or you may retrieve an old data set. All saved data sets are given a name such as;
Institute for Telecommunication Sciences
Frequency Intermodulation Model
Version 2.0
2-Nov-92 08:38:06
Choose from the menu:
H = Help
D = Program Description
C = Concise Dialog
V = Verbose Dialog
E = Edit Data
S = Summary of Data
P = Process Current Data Set
R = Retrieve Old Data Set
Q = Quit
Menu (Verbose)?
Enter input data
Transmitters to be included in analyses:
L = List current set of transmitters
D = Delete a transmitter
A = Add a transmitter
C = Change a transmitter
N = No changes
1) Transmitter data (A)? (add some transmitters)
Transmitter site name (up to 20 characters)
1) Transmitter site name (NWS1)?
wysh-fm
Transmitter frequency (between 0.01 and 99999.9999 MHz)
Transmitter frequency ( 162.4000 MHz)? 95.3
1) Transmitter data (A)? (add more transmitters)
Transmitter site name (up to 20 characters)
1) Transmitter site name (wysh-fm)?
WUTK
Transmitter frequency ( 95.3000 MHz)? 105.5
1) Transmitter data (A)? (add more transmitters)
Transmitter site name (up to 20 characters)
1) Transmitter site name (wysh-fm)?
WATE-TV
Transmitter frequency ( 95.3000 MHz)? 82
1) Transmitter data (A)? (add more transmitters)
Transmitter site name (up to 20 characters)
1) Transmitter site name (wysh-fm)?
KM2XKA
Transmitter frequency ( 95.3000 MHz)? 174
1) Transmitter data (A)? (add another transmitter)
Transmitter site name (up to 20 characters)
1) Transmitter site name (wysh-fm)?
NEW-TV
Transmitter frequency ( 95.3000 MHz)? 180
1) Transmitter data (A)? (add another transmitter)
Transmitter site name (up to 20 characters)
1) Transmitter site name (wysh-fm)?
WBIR-TV
Transmitter frequency ( 95.3000 MHz)? 192
1) Transmitter data (A)? n (no more transmitters)
Maximum number of concurrently operating transmitters (between 2 and 5)
2) Max no. of Transmitter (5)? (user wants 5)
Receiver tolerance option
C = Common bandwidth for all receivers
S = Separate bandwidth specified for each receiver
3) Receiver tolerance opt ( Common )? S (input each separately)
Do you want to use the same names and frequencies for the
receivers that were used for transmitters (Y or N)?
5) Use same data for receivers ( No )? y (use same names/data)
95.3000 wysh-fm
4) Receiver tolerance ( .0500 MHz)? .2 (user wants to add separate
105.5000 WUTK tolerance)
4) Receiver tolerance ( .2000 MHz)?
82.0000 WATE-TV
4) Receiver tolerance ( .2000 MHz)?
174.0000 KM2XKA
4) Receiver tolerance ( .2000 MHz)? 6
180.0000 NEW-TV
4) Receiver tolerance ( 6.0000 MHz)?
192.0000 WBIR-TV
4) Receiver tolerance ( 6.0000 MHz)?
Receiver frequency Tolerance Name
(MHz) (MHz)
1) 95.3000 .2000 wysh-fm
2) 105.5000 .2000 WUTK
3) 82.0000 .2000 WATE-TV
4) 174.0000 6.0000 KM2XKA
5) 180.0000 6.0000 NEW-TV
6) 192.0000 6.0000 WBIR-TV
6) Receiver data (A)? c (user wants to change an entry)
Receiver number? 3
Receiver site name (up to 20 characters)
6) Receiver site name (WATE-TV)?
Receiver frequency (between 0.01 and 99999.9999 MHz)
Receiver frequency ( 82.0000 MHz)?
Receiver tolerance (greater than 0.0001 MHz)
6) Receiver tolerance ( .2000 MHz)? 6
6) Receiver data (A)? n (no more changes)
Intermodulation orders to be included in analyses:
L = List current set of intermodulation orders
D = Delete an intermodulation order
A = Add an intermodulation order
C = Change an intermodulation order
N = No changes
7) Intermod order (A)? l (list inmod orders)
No intermodulation orders
7) Intermod order (A)? (add orders)
Intermodulation order (between 2 and 6)
Intermodulation order (3)? (inmod order 3 is chosen by default)
Intermodulation order (3)? 5 (add inmod order 5)
Intermodulation order (5)? (return on empty line ends input)
Intermodulation orders to be included in analyses:
L = List current set of intermodulation orders
D = Delete an intermodulation order
A = Add an intermodulation order
C = Change an intermodulation order
N = No changes
7) Intermod order (A)? l
Intermodulation order(s)
1) 3
2) 5
7) Intermod order (A)? n (no more orders)
Do you want to have self interference included
in the list of intermodulation cases?
8) Calculate self interference (No )?
Output options
L = List intermodulation products to your terminal
S = Save output on disk to download via DOWNLOAD program.
B = Both list to your terminal and save to disk.
9) Output opt (List)?
(list data to screen - If you have a large
data set and wish to retrieve it later
rather than spend the time now to capture
it to your screen, you may save the data
to disk(as a *.calc file described above)
and retrieve it with the DOWNLOAD program
described on the Bulletin Board)
Do you want a summary of the input data (Y or N)? y
Frequency Intermodulation Products-Inmod
2-Nov-92 08:38:06 Page
Data summary
Number of transmitters = 6
Number of receivers = 6
1) Transmitter data
Frequency Name Frequency Name
(MHz) (MHz)
1) 95.3000 wysh-fm 2) 105.5000 WUTK
3) 82.0000 WATE-TV 4) 174.0000 KM2XKA
5) 180.0000 NEW-TV 6) 192.0000 WBIR-TV
2) Maximum number of concurrently operating transmitters = 5
3) Tolerance option = Separate
5) Receiver data option = Yes
6) Receiver data
Frequency Tolerance Name
(MHz) (MHz)
1) 95.3000 .2000 wysh-fm
2) 105.5000 .2000 WUTK
3) 82.0000 6.0000 WATE-TV
4) 174.0000 6.0000 KM2XKA
5) 180.0000 6.0000 NEW-TV
6) 192.0000 6.0000 WBIR-TV
7) Intermodulation orders
1) 3
2) 5
8) Self interference option = No
9) Output option = Prin
Do you want to process this data (Y or N)? y
1
Frequency Intermodulation Products-Inmod
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Intermodulation order = 3
Max. no. of concurrently operating transmitters = 5
Two transmitter intermodulations
Receiver name Receiver no. Im prod. Diff. Interfering transmitter nos.
(MHz) (MHz)
WATE-TV 3 85.1000 3.1000 1 2
WBIR-TV 6 186.0000 -6.0000 4 5
KM2XKA 4 168.0000 -6.0000 5 6
Three transmitter intermodulations
Receiver name Receiver no. Im prod. Diff. Interfering transmitter nos.
(MHz) (MHz)
NEW-TV 5 184.2000 4.2000 1 2 4
KM2XKA 4 169.8000 -4.2000 1 2 5
WBIR-TV 6 190.2000 -1.8000 1 2 5
NEW-TV 5 181.8000 1.8000 1 2 6
WBIR-TV 6 187.3000 -4.7000 1 3 4
WBIR-TV 6 193.3000 1.3000 1 3 5
KM2XKA 4 178.7000 4.7000 1 3 6
NEW-TV 5 178.7000 -1.3000 1 3 6
WATE-TV 3 77.3000 -4.7000 1 4 6
WATE-TV 3 83.3000 1.3000 1 5 6
WBIR-TV 6 197.5000 5.5000 2 3 4
KM2XKA 4 168.5000 -5.5000 2 3 6
WATE-TV 3 87.5000 5.5000 2 4 6
Transmitter intermodulation cases
Transmitter name Transmitter no. Transmitter freq. No. of cases
(MHz)
wysh-fm 1 95.3000 11
WUTK 2 105.5000 8
WATE-TV 3 82.0000 6
KM2XKA 4 174.0000 6
NEW-TV 5 180.0000 6
WBIR-TV 6 192.0000 8
Receiver intermodulation cases
Receiver name Receiver no. Receiver freq. No. of cases
(MHz)
wysh-fm 1 95.3000 0
WUTK 2 105.5000 0
WATE-TV 3 82.0000 4
KM2XKA 4 174.0000 4
NEW-TV 5 180.0000 3
WBIR-TV 6 192.0000 5
Frequency Intermodulation Products-Inmod
2-Nov-92 08:38:06 Page 2
Intermodulation order = 5
Max. no. of concurrently operating transmitters = 5
Two transmitter intermodulations
Receiver name Receiver no. Im prod. Diff. Interfering transmitter nos.
(MHz) (MHz)
WBIR-TV 6 192.0000 .0000 4 5
Three transmitter intermodulations
Receiver name Receiver no. Im prod. Diff. Interfering transmitter nos.
(MHz) (MHz)
WBIR-TV 6 194.4000 2.4000 1 2 4
WATE-TV 3 77.7000 -4.3000 1 2 6
WATE-TV 3 87.9000 5.9000 1 2 6
KM2XKA 4 171.6000 -2.4000 1 2 6
NEW-TV 5 180.6000 .6000 1 3 4
WBIR-TV 6 193.9000 1.9000 1 3 4
KM2XKA 4 174.6000 .6000 1 3 5
WBIR-TV 6 187.9000 -4.1000 1 3 5
KM2XKA 4 175.9000 1.9000 1 3 6
NEW-TV 5 175.9000 -4.1000 1 3 6
WATE-TV 3 83.3000 1.3000 1 4 5
WATE-TV 3 80.1000 -1.9000 1 4 6
WATE-TV 3 86.1000 4.1000 1 5 6
NEW-TV 5 177.5000 -2.5000 2 3 4
KM2XKA 4 171.5000 -2.5000 2 3 5
WBIR-TV 6 195.0000 3.0000 2 3 5
NEW-TV 5 183.0000 3.0000 2 3 6
WATE-TV 3 81.5000 -.5000 2 5 6
Four transmitter intermodulations
Receiver name Receiver no. Im prod. Diff. Interfering transmitter nos.
(MHz) (MHz)
WBIR-TV 6 190.8000 -1.2000 1 2 3 4
NEW-TV 5 177.1000 -2.9000 1 2 3 4
KM2XKA 4 176.9000 2.9000 1 2 3 5
KM2XKA 4 172.8000 -1.2000 1 2 3 6
WBIR-TV 6 196.2000 4.2000 1 2 4 5
WATE-TV 3 79.1000 -2.9000 1 2 4 5
KM2XKA 4 178.2000 4.2000 1 2 5 6
WBIR-TV 6 191.5000 -.5000 2 3 4 5
NEW-TV 5 179.5000 -.5000 2 3 4 6
WATE-TV 3 81.5000 -.5000 2 4 5 6
1
Frequency Intermodulation Products-Inmod
2-Nov-92 08:38:06 Page 3
Transmitter intermodulation cases
Transmitter name Transmitter no. Transmitter freq. No. of cases
(MHz)
wysh-fm 1 95.3000 20
WUTK 2 105.5000 19
WATE-TV 3 82.0000 16
KM2XKA 4 174.0000 14
NEW-TV 5 180.0000 14
WBIR-TV 6 192.0000 13
Receiver intermodulation cases
Receiver name Receiver no. Receiver freq. No. of cases
(MHz)
wysh-fm 1 95.3000 0
WUTK 2 105.5000 0
WATE-TV 3 82.0000 8
KM2XKA 4 174.0000 7
NEW-TV 5 180.0000 6
WBIR-TV 6 192.0000 8
Choose from the menu:
H = Help
D = Program Description
C = Concise Dialog
V = Verbose Dialog
E = Edit Data
S = Summary of Data
P = Process Current Data Set
R = Retrieve Old Data Set
Q = Quit
Menu (Edit)?
q
Would you like to save the data for the site just entered (Yes) ?
(The input data you entered will now be saved in a *.ques file described
above).
End Inmod