[TenTec] FW: Corsair vs Corsair II

[Steve Hunt]

Jerry,

Both the L and the C in the diplexer parallel arm are fixed value; so 
low Q sounds good, given the tolerance issue :)

However the L in the series arm of the diplexer is adjustable, and the 
book says to tweak that for max received signal, as you'd expect.

73,
Steve G3TXQ



On 13/03/2013 20:29, Jerry Haigwood wrote:
> Hi Steve,
>      Ah, this is funny.  I was typing this email to inform you that I think
> the value of L5 should be 0.33 UHy when I received your email.  I didn't
> measure L5, I just took a guess that it might be 0.33 uHy and plugged that
> into the resonance formula.  As you know it comes out at 8.76 MHz - much
> closer to 9.0 MHz.  So, it appears TenTec chose to use a diplexer with a
> higher Q - perhaps 18-20 based on the predicted value of L6.  I have never
> tried a high Q diplexer so I cannot comment on whether this better or not.
> I have noticed prominent receiver designers typically use a Q of 1.  One of
> the reasons I speculate is that a diplexer with a Q of 1 is a bit more
> tolerant of component values.
> Jerry W5JH
> "building something without experimenting is just solder practice"
>