> > I'm surprised that none's mentioned the PRE-1 & 2 preamps that K9AY
> > builds. I tested the PRE-2 in my company's lab and found it has an
> > excellent IP3 and very good rejection of BC signals. I don't have the
> > numbers in front of me, but I believe they were 50 dB or better.
>
> 50dB is a heap of TOI, so the amplifier must have some very beefy
> components.
>
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Brad meant 50 dB for BCB filter rejection, not TOI.
The highpass filter in the PRE-1 and PRE-2 has typically 20 dB rejection
at 1600 kHz, a 35+ dB notch at 1450 kHz, and 48+ dB rejection at
frequencies below 1350 or so. This is the same preamp supplied with the
K9AY Loop systems, but set to slightly lower gain.
Passband sweeps are included in product data on my web site:
www.aytechnologies.com -- select 'PRODUCTS' then 'PRE-1' or 'PRE-2'
TOI and noise figure are typical for a medium power NPN (2N3866)
feedback amplifier -- +22-25 dBm input TOI and estimated 4 dB NF.
73, Gary
K9AY
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