Pre-amps(LNA) for SDR and other receiver only

[j***@earthlink.net]

In the worst of conditions from an static discharge standpoint no premplifier is
going to help dig signals out of the noise you are receiving. Under those
conditions you are limited by outside noise except in highly unusual circumstances.

{o.o} Joanne

In looking for some pre-amps with low noise figure, since my source of
the past, Hamtronics, no longer makes theirs in a wideband or anything
than a VHF configuration. (Seems they are on the road to clear out and
shutdown from the looks of things, :( )
http://lna4all.blogspot.com/2013/04/lna-for-all-low-noise-amplifier-
for.html
Meets the LNF goal, wide band, but a few items came up.
It doesn't do phantom power by default, and seems to by reading this page
highly susceptible to ESD issues thus rendering a pre-amp useless in the
middle of the worst conditions when you need it most. I've used numerous
Hamtronics ones for years and they don't have any thing on the input
either, but that this comes up on their site, seems to lead to the hint
their IC v. the GasFET of the Hamtronincs is much more susceptible to
this issue....
Any one using these???
Any one done the listed mods for coax/phantom power?
Cases? $102 with a metal case v. $30 for the board and connectors..Plus I
have to open their case to add the SMD coil to do phantom power... Any
one using this outside and what case did you build. modify???
Other hints about LNA (<0.8 db, or better) with 30-970Mhz coverage
minimum, if it goes higher great, but at a minimum need the above.
Thanks.

[Doug]

In looking for some pre-amps with low noise figure, since my source of
the past, Hamtronics, no longer makes theirs in a wideband or anything
than a VHF configuration. (Seems they are on the road to clear out and
shutdown from the looks of things, :( )

Have you looked at the products of Mini-Circuits Labs? They do make
fully packaged and powered amplifiers, but they are quite expensive.
They also make small integrated amplifiers that can be mounted on
a microsrtrip circuit, with connectors and 5-volt power, and these
tend to sell for just a few dollars each. You probably have to buy
onesies from Mouser or someplace, I don't think MCL sells them
in single unit quantities.
Look up the company on the 'net and look for low noise amplifiers,
surface mount.
You can make a small microstrip board to mount the amplifier on
out of FR4 circuit board. On a 60 mil board, a 50 Ohm line is 120 mil
width. Just put the circuit together like the data sheet with connectors
of your choice and apply 5V power and you're in like Flynn.

--doug, WA2SAY

[Mike Jameson]

This LNA works great for me and uses the same PSA4-5043+:

https://www.cosycave.co.uk/product.php?id_product=316

Mike

--
Mike Jameson M0MIK BSc MIET
Email: ***@scanoo.com
Web: http://scanoo.com

Post by Doug

In looking for some pre-amps with low noise figure, since my source of
the past, Hamtronics, no longer makes theirs in a wideband or anything
than a VHF configuration. (Seems they are on the road to clear out and
shutdown from the looks of things, :( )
Have you looked at the products of Mini-Circuits Labs? They do make

fully packaged and powered amplifiers, but they are quite expensive.
They also make small integrated amplifiers that can be mounted on
a microsrtrip circuit, with connectors and 5-volt power, and these
tend to sell for just a few dollars each. You probably have to buy
onesies from Mouser or someplace, I don't think MCL sells them
in single unit quantities.
Look up the company on the 'net and look for low noise amplifiers,
surface mount.
You can make a small microstrip board to mount the amplifier on
out of FR4 circuit board. On a 60 mil board, a 50 Ohm line is 120 mil
width. Just put the circuit together like the data sheet with connectors
of your choice and apply 5V power and you're in like Flynn.
--doug, WA2SAY