Warning: Transmit Time.
High duty cycle modes such as FM and data modes, (RTTY / FT8 etc.), operate the amplifier at full power all of the
time, unlike modes like SSB and CW that are either intermittent or only reach peak output for very short times. These
high duty cycle modes will run the amplifier much harder and generate more heat in the same amount of time. It should
be noted that the amplifier although capable of being used with these modes, should not be used continuously. We rec-
ommend that the transmission time should not exceed a couple of minutes in order to avoid excessive transistor junction
temperature. The exact time for transmission in these modes will of course depend on numerous factors such as, the am-
bient temperature, how good the ventilation surrounding the amplifier is, if there is sufficient space for freely flowing air
to circulate etc. If the ambient temperature is high this will reduce the total time in transmission. Common sense should
be exercised if the heat sink temperature is high then sufficient time should be allowed for it to cool down before resum-
ing transmission. For high duty cycle modes the amplifier may also be used at less than maximum output power by re-
ducing the input drive level. This will reduce dissipation and also allow the amplifier to be used for longer periods.
Input Drive and Power output.
The BLA350 Plus should give full output power with approximately 10-12W of drive. Excessive input power should be
avoided and the amplifier always used in a responsible manner. If excessive input power is used the amplifier will signal
an error and above 15W input it will return an alarm signal and block transmission. It is important to understand that
accidental input of 100W from the transceiver should be avoided and may cause damage to the amplifier!!!!
Maximum Output Power Considerations.
All amplifiers have a maximum output and this occurs shortly after gain compression where by Pin no longer produces a
proportionate increase in power output. The amplifier should always be operated at a point below its saturated output.
Trying to extract every last watt by overdriving the amplifier will NOT actually help your signal be stronger, you will in
fact cause higher levels of distortion which will make your signal less intelligible at the distant receiver station.
Running the amplifier a little under maximum output power will allow the amplifier to run cooler and make it more reli-
able for many years of use.
As an example consider the following situation.
1 ‘S’ point on a receiver is usually approximately calibrated at 6dB so for example the difference between S5 and S7 is 2
‘S’ points so 12dB.
The difference between 10W and 300W is about 14.8dB which is a big increase to your signal if using the same an-
tenna. Now let’s say for example you run the amplifier at a moderate 250W by reducing the input drive. The difference
between 300W and 250W is less than 1dB which when you compare this to 6dB for 1 ’S’ point is actually very little and
as the amplifier is not running at maximum power will generate less heat, and produce a cleaner output with less distor-
tion that will actually make a difference at the distant receiver.
Warranty.
RM Costruzioni Elettroniche srl
Guarantees that this product is free from manufacturing defects both components and
workmanship for a period of time specified by the law. The warranty commences on the date of purchase. Any work
undertaken for the warranty must be carried out by RM Costruzioni Elettroniche srl or an authorised service centre. The
costs of transportation, duties and insurance between the client and RM Costruzioni srl or the approved service centre
are the responsibility of the client.
The warranty must be requested to the distributor or reseller where the amplifier was originally purchased.
In the case where the original distributor or reseller no longer exists or deals with RM products, RM Costruzioni Elet-
troniche srl will communicate the nearest distributor or reseller to use, or in the instance where this is not possible or
convenient, RM Costruzioni Elettroniche srl will honour the warranty directly. If any repairs are carried out outside of
an approved service centre this will void the warranty and RM Costruzioni Elettroniche srl will not be responsible for
any incurred charges. The warranty will only be honoured if the amplifier has been used for its intended purpose as de-
scribed in this user manual, that the amplifier is returned with its original purchase receipt, returned in its original pack-
ing container, that the serial number is readable, unchanged and that the warranty seals remain intact.
The warranty does not cover the MOSFET power transistors or any aesthetic damage.
Any change to the warranty either by local law or that made by the distributor or reseller directly with the client will be
the sole responsibility of the distributor or reseller and not by RM Costruzioni Elettroniche srl. In the event of any argu-
ment between parties resulting in legal action. It will be agreed to be settled in a court of law in Bologna (Italy).
The purchase of this product assumes that the client has accepted the terms and conditions of this warranty.
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