TV preamp FET choice

[Ken Smith]

Paul Burridge wrote: [...]
You'd be better off looking at antennas. No matter how good of an
amplifier you have, if you amplify a crappy signal you get an amplified,
crappy signal. A yagi a those frequencies would fit in the palm of your
hand, and would be a nifty little construction project.

A rombic would be a few feet across. That would be even better. You can
get a 10 degree beam width with just some wire, one resistor and a sheet
of plywood.

 

[John S. Dyson]

You'd be better off looking at antennas. No matter how good of an
amplifier you have, if you amplify a crappy signal you get an amplified,
crappy signal. A yagi a those frequencies would fit in the palm of your
hand, and would be a nifty little construction project.

One big problem with real antennas and typical TV front-ends is that
they don't generally match very well. A properly designed preamp
can provide a perfect interface between a bow-tie antenna (in my
case) and a relatively non-ideal front-end. Even a few feet of
coax can create interesting response variations, and a good preamp
with good (ideal isn't needed) input/output isolation, and good
impedance matching/sourcing will improve system behavior. (It is too
late for me to be coherent, but a preamp can provide more than
just 'some gain.')

John