2014-05-28, 18:07
A very good question 
We use two gain-adjustable amplifiers on the PCB that amplify 2 x 30dB ~ 1,000 times.
We could do with one amplifier, BUT we want to be able to regulate the entire range of 1-60dB.
Preamp gives too much signal even with a very small antenna, that's why.
You might ask, "why not a shorter antenna?"
Because the non-uniformity of component capacity would make the amplifiers too different.
As now, an antenna of 10cm/Ø 1.5mm, work the same on all amplifiers.
/richo
We use two gain-adjustable amplifiers on the PCB that amplify 2 x 30dB ~ 1,000 times.
We could do with one amplifier, BUT we want to be able to regulate the entire range of 1-60dB.
Preamp gives too much signal even with a very small antenna, that's why.
You might ask, "why not a shorter antenna?"
Because the non-uniformity of component capacity would make the amplifiers too different.
As now, an antenna of 10cm/Ø 1.5mm, work the same on all amplifiers.
/richo