[FAQ-1151] Use of the Band Target column in the HTML5 programmer
Page Type: REFERENCE
When programming scanners in the HTML5 system, the software automatically associates broadcast channels with the geographically nearest feed site. While it is always possible to manually override this automatic selection and tie a channel to a desired feed site, it is advantageous to automate systematic preferences. When defining feed sites, the Band Target column provides a way to adjust the automatic default feed site selection process (the system's guess of the best feed site to use for a channel) in various ways that are systematic in nature.
The Band Target column is found in the HTML5 programmer, on the entry screen where feed sites are defined.
Band Target is normally left blank. However, values can be entered for the following situations to systematically adjust the system's automatic algorithm for guessing which feed site is optimal for receiving a broadcast channel:
1) CO-LOCATED SCANNERS WITH DIFFERENT ANTENNAS
Sometimes two (or more) feed sites are co-located, with radio scanners connected to different antennas, optimized to receive different frequency bands.
The distance from a channel to each co-located feed site will be identical, so the usual method of "choose the nearest feed site" will be ineffective for correctly allocating channels to co-located scanners.
The Band Target field provides a way to describe the characteristics of co-located scanners, so the system can automatically associate channels with the radio that is best suited to receive the content.
If the radio scanners at a feed site are connected to an antenna optimized for a particular band (or should only receive channels within a frequency range), then you may enter the range like this:
... to mean that the feed site should be preferred (over other co-located feed sites) for channels that broadcast in the range 118 MHz to 139 MHz.
For each location (set of co-located feed sites), it is recommended that no frequency range be specified for one feed site number. This will be a "catchall" feed site used for channels that aren't within the specified frequency bands of the other co-located feed sites. There is no need to specify a band for every feed site number.
Note: If you want to specify only a single frequency to receive, you must still enter a range, but this may be a zero-size "range" such as 154.25-154.25
Note: This feature is *only* used to select among co-located feed sites, and is only relevant when the location of these co-located scanners is closer to a broadcast channel than any other feed site location. This value does not affect (1) how the feed site will be scored relative to feed sites at other locations, (2) where a channel is received if a particular feed site has been manually specified for receiving the channel, or (3) what channels from the nationwide channel database are listed in the programming interface.
2) CO-LOCATED SCANNERS AND RECEPTION OF P-25 SYSTEMS
Sometimes two (or more) feed sites are co-located, with radio scanners of different models (or different squelch settings) optimized for receiving different types of radio signals. In particular, it sometimes happens that certain radio scanners are dedicated to receiving P25 systems, while other co-located scanners receive all other traffic.
In this case, enter the value P in the Band Target field for the feed site intended to receive P25 systems. Then the automatic system will direct P25 channels to this feed site's scanners, and non-P25 traffic to the other scanners.
3) FILL-IN RECEIVE SITES ONLY FOR NEARBY SIGNALS
When a feed site has poor antenna or reception conditions, and is intended to operate as a "fill-in" receive site for nearby channels.
To illustrate the problem, suppose there are two receive sites -- 10 in a good location on a tall tower covering a wide area, and 20 in a valley as a fill-in site for a few communities within five miles of the scanner radio.
Without using the Band Target feature, the automatic system would effectively create a capture zone behind site 20 (as seen from site 10) where all channels would be automatically assigned to 20, since it is the geographically nearer feed site. But in reality 20 can only hear signals that are very strong from that location, and it would be better to let 10 (with the tall tower) monitor channels that are beyond 20's narrow coverage area (even if those channels are closer to 20).
In this situation, enter a value like "M5" (for Miles - 5). You can choose the desired maximum range for this feed site.
Note: This does not mean, for example, that the site will be preferred for all channels within five miles. It is obviously possible for a feed site to be within such a defined circle from two or more feed sites, and if the Band Target of another feed site is blank that is equivalent to M-Infinite (no distance limit). So if a channel is nearer to another eligible feed site, the other feed site will be preferred. The M value is only a limit that prevents the feed site from being preferred for channels that are at more than a certain distance.
4) EXCLUDING A RECEIVE SITE
Sometimes it is desired that *no channels* be automatically assigned to a feed site. This may happen, for example, when the customer wants a scanner used only for specific channel(s) that are manually tied to that scanner. Another scenario is if one scanner is being used for testing purposes, and not for normal operations.
In this situation, enter M into Band Target for the feed site. Technically this is equivalent to M0, and means that the feed site will not be considered for channels more than zero miles away from the receive site.
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Rangecast FAQ - ID 1151 - last updated 18 October 2017 Images shown - [block]