The HOST command operates just like the BBS command. It may have been disabled by the sysop, it may have been set to connect to the same station as the BBS, or it may have been set to connect to another host system.
If you enter the command 'HOST ?', then the current setting of the HOST will be displayed.
If enabled, the heard list shows the last few stations heard. The number of entries is limited and set by the sysop so any stations not heard for a while may get pushed out of the list by others heard. Assuming that a station is not pushed out in this manner, the display shows the number of packets heard from that station since it appeared in the list and the time since it was last heard. The time is hours, minutes and seconds. The list also shows the port on which the station was heard ( port 0 is the radio port ), and if it hears IP frames or Net/Rom frames, it adds a note to show that the station is a node and/or a TCP/IP station.
If the list is long enough so that a station is not heard for 12 hours, it will get deleted anyway.
The list may also show a column headed 'Dev.'. This will only be present where the sysop has added to the node a small hardware board that measures the received signal audio level. Specifically, it gives an indication of the peak audio level. By means of a software configuration control and prior calibration, this gets converted into an indication of the transmitting station's signal deviation. It does this by sampling the audio level after every valid packet.
Care must be taken over its interpretation. It does not measure independently the two tone levels - it is assumed that whatever local standards that relate to pre-emphasis ( i.e. use it or not ) have been implemented.
Often, packet stations are set up, and the audio level tweaked until it appears to work reasonably error free. The idea of this add-on is that, having done that, you then connect to the node and display the heard list to see an indication of your actual deviation. It may then be fine tuned to set it correctly. Local advice must be taken over the correct setting as it depends on the channel spacing being used ( e.g. 12.5, 25 or other KHz ).
The meter will give the wrong answer on the following conditions
* A badly distorted audio signal
* Badly off frequency
* Incorrect adherence to local pre-emphasis standards
* A noisy signal
If you connect, then correct your deviation to the correct display then find performance has deteriorated, it indicates one of the above problems. It is not that the meter doesn't work, it is an indication of a fault elsewhere.
It is in your own interest for those around you to use the correct deviation. The list also allows you to see the deviation of others - so apply peer pressure if someone over or under deviates. Remember it is NOT a case of the higher or the lower the better - it is having the setting RIGHT.
The system may also be used to migrate users towards a lower deviation in advance of moving to narrower channel spacing.
The heard list may also show received signal strength. It shows how strong each station is at the receiver. The display will either be in dBm format or in the familiar 'S1 to S9' format ( or 'S9+' for big signals ). To understand this properly will need some guidance from the sysop. By looking at the METER parameters you can find the noise floor in dBm, and if the display is in dBm can subtract one from the other to find out how much stronger your signal is than it needs to be. How accurate this is depends on the radio and its calibration. It could be as close as +- 1 dB or it could be wildly wrong.