I think what most posters are missing is the FCC has not ruled on the 15
db gain limitation. They simply refused to grant a WAVIER to one
specific company. The FCC will rule on the 15 db limit for "ALL"
commercial amps. I believe the commenters to the FCC who were worried
about the general power level creeping up, the sellers of "legacy" amps
being limited, or hams exceeding the legal limit are misplaced. Sure
there are already hams running far more than the legal limit. OTOH
when I run 1500 watts to a 10db gain antenna the ERP is 15 KW in one
direction.
We have been able to purchase amps that exceed the 15 db limit and far
exceed the legal limit for years. They just had to either be imported,
or home built. IE Tetrode amps from Australia or China. When tuned and
driven properly, these amps have a very clean signal.
A high gain amp, would have to run 3 KW out for a 3 db advantage. Even
imported amps capable of that are not cheap!
Also, there is the issue of required overhead in amps capable of running
the legal limit on any mode, no time limit. There are really just three
options. The very expensive auto tune amps, imported amps (neglecting
those with attenuators on the input), or home brew. A manual tune amp
that has enough overhead to run 1.5 KW, any mode with no time limit does
push the price up a bit. The biggest problem with Tetrode amps is
mistuning and driving rigs with ALC controlled output running at reduced
power. With a Tetrode the screen current is peaked rather than peaking
the output. It's a minor difference but it makes a noticeable difference
in the quality of the signal. Check any of the ARRL handbooks for the
last 5 years or so.
73
Roger (K8RI)
On 12/28/2016 4:05 AM, Morel Grunberg wrote:
From ARRL Bulletin:
FCC Denies Expert Linears’ Request for Waiver of 15 dB Rule, Petition
Pending
12/27/2016
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