Central Idaho Amateur
Radio Club
     
CIARC - Repeaters - No Business Intermod Prediction
No Business Intermod Prediction

The following table provides a list of frequencies known to be operating from the Valley County radio site located on No Business Mountain - Lookout Peak as of January 4, 2012. This list of frequencies was compiled from visual inspection of placards attached to radio equipment located on-site.


Frequencies were correlated to a licensee, call sign and FRN using the FCC ULS Database search. Operational frequencies for Part 90 stations was also verified using the FCC ULS Database.



No Business Mountain - Lookout Peak - Valley County Radio Site Frequencies
Receive
Frequency
MHz
Transmit
Frequency
MHz
License Organization FRN
46.5800 45.8000 KNAK476 Valley County 0004537809
147.6200 147.0200 KC7MCC Central Idaho ARC 0013601745
154.3750 158.9550 KNEB982 Valley County Communications Center 0007125925
154.3750 158.9550 WNYA692 Valley County 0004537809
155.9925 158.7825 WQJA990 Donnelly Fire Department 0017898677
159.1650 150.9950 WQMR287 Valley County 0019881069

Modeling a 1st order through 5th order intermodulation products, including the 33cm link back-bone for the KC7MCC repeater system, as indicated in the following table, yields no interfering frequencies:


No Business Mountain - Lookout Peak - Valley County Radio Site Frequencies
Receive
Frequency
MHz
Transmit
Frequency
MHz
License Organization FRN
46.5800 45.8000 KNAK476 Valley County 0004537809
147.6200 147.0200 KC7MCC Central Idaho ARC 0013601745
154.3750 158.9550 KNEB982 Valley County Communications Center 0007125925
154.3750 158.9550 WNYA692 Valley County 0004537809
155.9925 158.7825 WQJA990 Donnelly Fire Department 0017898677
159.1650 150.9950 WQMR287 Valley County 0019881069
902.2250 927.2250 KC7MCC Central Idaho ARC 0013601745

Modeling a 1st order through 5th order intermodulation products while replacing the KC7MCC 2-meter repeater with a 70cm repeater and modifying 33cm link back-bone frequencies for a client station, as indicated in the following table, yields no interfering frequencies:


No Business Mountain - Lookout Peak - Valley County Radio Site Frequencies
Receive
Frequency
MHz
Transmit
Frequency
MHz
License Organization FRN
46.5800 45.8000 KNAK476 Valley County 0004537809
154.3750 158.9550 KNEB982 Valley County Communications Center 0007125925
154.3750 158.9550 WNYA692 Valley County 0004537809
155.9925 158.7825 WQJA990 Donnelly Fire Department 0017898677
159.1650 150.9950 WQMR287 Valley County 0019881069
447.5000 442.5000 KC7MCC Central Idaho ARC 0013601745
927.2250 902.2250 KC7MCC Central Idaho ARC 0013601745

If the frequency lists above are incorrect then the intermodulation products prediction results described on this page will not be valid.

The above results only apply to intermodulation products as a possible interference source. Other interference sources, such as a spurious transmitter, are not included in this evaluation.


Since none of the frequencies currently in use at the No Business Mountain - Lookout Peak radio site appear to be involved in generating any Intermodulation Products on their own, and interference persists at the radio site, other causes should be investigated:

To the greatest extent possible, Amateur Radio operators should assist in isolating root cause for an interference event, even if it can be shown that the root cause is not due to part 97 radio equipment. Such assistance is in keeping with Amateur Radio's public service role, helps to elevate the image of Amateur Radio, and assists the site managers that are providing their infrastructure to support Amateur Radio repeater operations.