> I've been told the Ameritron s.s. amps are easily overdriven
> into "garbageland" where they spew noise up and down the
> band. I know this can be done with any amp but they have a
> rep. for being especially prone to do this.
The problem is that Ameritron is sloppy with their design.
The amplifier board in the ALS-600 is almost a part for part
copy of the Helge Granberg/Motorola application note EB104.
The amplifier has a high power gain - in excess of 20 dB for
the transistors - with a gain variation of as much as 4 dB
depending on construction across the 1.5 to 30 MHz operating
range. Ameritron then choose to use ALC to control transmitter
output and accommodate this overdrive.
When ALC is used to reduce the output from most modern solid
state transceivers they do become very "dirty." Instead of
ALC, the Granberg design should be used with 6 or 7 dB of
fixed attenuation up to 6 DB of variable attenuation (1, 2
and 3 dB fixed attenuators) that can be switched into the
circuit on a per band basis. This allows the amplifier to
operate linearly with the full output of most modern solid-
state transceivers - a situation that allows for minimum
ALC and optimal operation.
The same considerations apply to the ALS-1300 which is likely
to be very similar to the ALS-600 with two Grasberg amplifier
modules and a splitter/combiner.
73,
... Joe, W4TV
> -----Original Message-----
> From: amps-bounces@contesting.com
> [mailto:amps-bounces@contesting.com] On Behalf Of Rob Atkinson
> Sent: Monday, February 09, 2009 1:18 PM
> To: amps@contesting.com
> Subject: Re: [Amps] ALS-1300
>
>
> I've been told the Ameritron s.s. amps are easily overdriven
> into "garbageland" where they spew noise up and down the
> band. I know this can be done with any amp but they have a
> rep. for being especially prone to do this.
>
> The price of the ALS-1300 means one more nail in the coffin
> of the Ten Tec Centurion I fear, since Ten Tec boosted it
> into the over $3000 league. Maybe that was part of the
> Ameritron plan. More sales of AL-82s hi hi.
>
> 73,
>
> rob / k5uj
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