[Elecraft] K3 and amplifiers such as ALS-600

[Ignacy Misztal]

MRF150 as used in ALS600 has 17db linear gain at 30MHz, and +20db on
20MHz and below. The gain is reduced to 9-11db across the bands by
swamping the input and by some feedback. It can be recovered by using
smaller or no input resistor and by removing or reducing the feedback
with a risk of some instability. Apparently ALS 600 does not suffer
from instability. The data sheet for MRF150 cites IMD3 at -32db in a
circuit without any feedback.

Linearity is another issue.
Ignacy

On Wed, Jul 22, 2009 at 4:07 PM, Mark Bayern<mark at mlb.net> wrote:
>>"Amplifiers are not such that 100 = 500 so 10 = 50. Solid state at least,
> look at the charts for the 2 meter amps for instance)  Doesn't work that
> way.
>
> _Linear_ amplifiers do hold true to the "100in=500out, so 10in=50out"
> statement.
> If they are not linear amps, don't use them for anything other than CW and
> FM modes.
> Mark
>