"998cc" wrote in
et:

I am looking for ways to improve my receive for 2-meter SSB weak
signal work. I am running an Icom 706 MkIIG and a M2 5WL yagi. I
understand mast mounted preamps bring the signal up significantly.
Doe any one here use one for 2M SSB? What are your experiences?

Russ, you may find the article at http://www.vk1od.net/gt/index.htm of
interest. It includes a model framework to allow you to calculate the
improvement that you would obtain from a LNA.

One thing to bear in mind is that laboratory tests of LNAs do not usually
revean the amount of noise that will be generated in the LNA as a result
of intermodulation processes... so it is unlikely to perform quite as
well as indicated. At the same time, the same issue exists for the
transceiver.

The good thing is that your 5WL Yagi will have a good deal of selectivity
whereas it is certainly lacking in the '706IIG and in many of the lower
cost preamps (no money wasted on filtering).

At the end of the day, it depends very much on your own noise
environment, noise generated by IMD in your radio, and the equipment
configuration. Hams tend to regard ambient noise as not an issue on
144MHz, but it probably is if you live in a residential area... and high
ambient noise will limit the benefit of a LNA.

Owen