microHAM SMORF, Manual

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ALARM 1 MENU – ALARM SETTINGS
ALARM SETTINGS menu serves for two purposes. First to let choose and adjust sound alerts for all importance
levels of alarms, second for definition of IN and OUT port behavior.
SMΩRF allows to choose from four (4) types of sound for audible alarm alerts. Each sound can be cycled and
adjusted in level. Sounds can be set for each sensor individually.
At the SMΩRF's rear panel two pairs of RCA jacks are located. Each pair belongs to its sensor, one jack of the
pair is input IN, second is output OUT. Input can be set for one of two functions, PTT or INHIBIT. Output can be
also set to PTT or INHIBIT function independently of input setting. For both input and output, active level can be
individually set by POLARITY setting.
Now it is necessary to explain how to use these inputs and outputs. On some power meters you can find similar
RCA jacks with description to connect one to PTT output of the transceiver and second to keying (PTT) input of
the power amplifier. Oh, there is nothing worst you can do for your amplifier as well as transceiver. When SWR is
higher than normal and power meter trips SWR alarm, radio and amplifier is already delivering power under
these critical, dangerous conditions to misbehaving load. Breaking PTT line from the radio to amplifier, while
radio is still driving the amplifier causes even worse situation, amplifier is forced to hot switch input and output
relay, putting even more stress on tube or final transistors and radio is consequently connected to misbehaving
load. If you like your equipment, never do this.
Proper sequence when SWR gets high is to force radio to stop generating power as quickly as possible. Only
when radio is not generating any power the PTT line to amplifier can be released or safely switched to receiving
state.
Since SMΩRF supports configurable function for each input and output, there are several usage scenarios
according to the radio and amplifier capabilities.
Transceivers with inhibit input
Best option is to use inhibit output from the SMΩRF provided your transceiver has INHIBIT input. All Yaesu
radios as well as Elecraft's K3, K3S and Ten-Tec Orion/II have inhibit input. Driving inhibit input on the radio is
only sure way to disable power generated by transceiver, regardless of how radio was switched to transmit.
1.
Configure OUT to INHIBIT, POLARITY NORMAL. Normal polarity inhibits power when output is open,
what is default, fails safe operation of all above radios.
2. Connect OUT of the SMΩRF to the inhibit input of the transceiver.
Further setup depends on other components.
•
If you are connecting SMΩRF to setup with our Station Master or Station Master DeLuxe, connect its
INHIBIT output to IN port of the SMΩRF and configure IN to INHIBIT, POLARITY NORMAL.
•
If you don't have our SM or SMD but you have amplifier with KEY OUT signal, also connect this keying
output to IN port of the SMΩRF and configure IN to INHIBIT, POLARITY NORMAL. If amplifier has
reversed keying output (Expert amplifiers), set IN polarity to REVERSE.
•
If you don't have either of above, connect transceiver's PTT output to IN port of the SMΩRF and
configure IN to PTT function, POLARITY NORMAL.
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