On 09/13/16 19:45, David Mennerich wrote:
Has anyone here used this before? Perhaps this would help me 'hear' a little better with my Arrow antenna, and I could use it for V/U and U/V modes. For those of you that operate with an Arrow, do you use this preamp or some other preamp? It appears there are other preamps out there that are more expensive, but require one per band (V or U). This one will cover both - seems like a good option, just wanted to get your thoughts.
Hello David,
You may have missed my previous post, due to no subject in the title.
If you're looking for a shoestring-budget LNA for 2m, the U310 JFET preamp has been a good performer for me.
http://www.ham-radio.com/n6ca/50MHz/50appnotes/U310.html
I've constructed one in a spare project box, and the gain (12dB) is right on the predicted value. I have not verified the NF, but it is claimed to be near 1.0dB. I built in in one evening, with some extra evenings diagnosing a capacitor issue. Use a multi-turn piston trimmer for the 1-10pF drain capacitor, as the output tuning is very sharp.
I've changed the layout a bit, but here's an early picture of the unit:
The air-core inductors are not difficult to wind on a 1/4" drill bit.
Not as fancy as a GaAsFET or pHEMT device, but it works just fine to hear AO-85 and AO-7 with a non-ideal satellite antenna (folded horizontal dipole) at 10 degrees above the horizon.
--- Zach N0ZGO