You do not need ALC with some of the latest rigs as driver. If a linear
needs,say, 50 watts you just program the output to 50 watts in the menu and
thats it. Any comments?
But, there is another problem: how is the relationship beetween peak output
power to spuriouses and noise sideband affected? When you reduce power? This
may not be a problem on short wave but on the higher VHF/UHF bands with
often many stations/ square mile with high radiated power ( high beam gains
) and much more sensitive receivers?
de Hans /SM5KI
----------
>Från: measures <measures@vcnet.com>
>Till: <ki7rw@arrl.net>, "AMPS" <amps@contesting.com>
>Ämne: Re: [AMPS] RE: ALC
>Datum: ons 16 feb 2000 05.42
>
>
>>
>>If it's considered useless, then why is ALC provided?
>
>It is a tradition. Even though ALC makes overshoot nasties, it is
>somewhat useful if say a 200w radio were being use to drive a pair of
>572Bs.
>
>> And why don't
>>manufacturers build their amps so that they can't be overdriven if
>>ALC can't do the job?
>
>This is more complicated than it looks. It depends on how many watts are
>available from the driver and how many watts the amplifier needs. There
>is much variation. RF-NFB resistance is one of the better solutions
>since it acts to improve amplifier linearity while making the amplifier
>harder to drive. .
>
>Consider the issue of filament/heater potential adjustability. This
>planet has line voltages that are all over the place - so why don't
>manufacturers build their amplifiers with a simple filament/heater V
>rheostat and a jack for connecting a measuring instrument?
>During the Internet debate over "The Nearly Perfect Amplifier" (*QST*,
>1/94) , my critics argued long and hard that a rheostat simply would not
>do in filament/heater voltage control because of reliability problems. .
> What a load of codswallop.
>cheers.
>>
>>>From: "measures" <measures@vcnet.com>
To: <amps@contesting.com>
>>>Date: 2/14/00 10:37:26AM
>>>To: "Peter Chadwick" <Peter_Chadwick@mitel.com>,
>>"'rb'"@contesting.com
>>>Subject: Re: [AMPS] RE:
>>>
>>><rbigg@pcola.gulf.net>,
>>> "'amps'" <amps@contesting.com>
>>>Mime-Version: 1.0
>>>Sender: owner-amps@contesting.com
>>>Precedence: bulk
>>>X-Sponsor: W4AN, KM3T, N5KO & AD1C
>>>
>>>
>>>>
>>>>Ron, K5BDJ, asks
>>>>
>>>>>So, is there a strong case for ALC, when the capability is there?
>>>>
>>>>I'll stick my neck out a bit here. ALC as it is usually
>>>implemented is a
>>>>bit like shutting the stable door after the horse has bolted.
>>>
>>>Excellent, Peter.
>....
>
>- Rich..., 805.386.3734, www.vcnet.com/measures.
>end
>
>
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