[ARC5] A simple receiver improvement

[Kenneth G. Gordon]

On 14 Jan 2014 at 12:56, Ian Wilson wrote:

> Ken,
> 
> In principle you could just use an L-network or something to couple
> more energy from the antenna to the tuned circuit of the first RF
> stage. However .. this will reduce the selectivity of that tuned
> circuit, so you may run into diminishing returns.
> 
> 73, ian K3IMW

That is an idea.

However, I looked up some balun design math.

Z2 = n^2*Z1

where n = the turns ratio, Z2 = one impedance and Z1 = the other.

n in this case turns out to be about 4.4

This means that one would wind 5 turns on the "primary" side, and 22 turns 
on the secondary side to achieve a 50:4.1K balun.

Now I have to figure out which mix of toroid I would have to use.

This seems do-able and small enough.

Ken W7EKB