Eric,
Thanks for the detailed response. The velocity factor is .66 for RG-214
vs. .695 for RG-400. So, if the length isn't supercritical, couldn't I just
use 14 inches tee center to tee center for my RG400 jumpers?
What does the length of the cables between cavities affect in the duplexer
system? I seem to vaguely recall it had an effect on the bandpass to band
reject slope and the position of the notch (separation?) , but I'm not
completely sure of this.
Steve
WA6ZFT
On Monday 30 May 2005 15:26, Eric Lemmon wrote:
> Steve,
>
> I gotta admire a guy who is willing to do all of the engineering
> calculations for duplexer jumper cables! The optimum jumper length must
> consider the length of the loops that are within the cavities. However, in
> this particular case, Sinclair has already done the hard part.
>
> Sinclair fabricates the Q-202G harness as a complete assembly using crimp
> connectors and tees, with RG-214/U double-shielded cable. You can use
> RG-400/U cable if you account for the slight difference in velocity factor.
> Keep in mind that Sinclair can meet their Q-202G specs over the entire
> 138-174 MHz band, using only two harnesses, so the lengths are not
> supercritical.
>
> The standard harness for the 150-174 MHz band measures about 12" between
> the centers of the cavity tee connectors. The harness for the 138-150 MHz
> band measures about 14" between centers. You can purchase the harness
> directly from Sinclair for about $120. Visit www.sinctech.com for more
> information.
>
> 73, Eric Lemmon WB6FLY
>
> > ---- Steve Rodgers <[EMAIL PROTECTED]> wrote:
> >
> > The way I plan to estimate the cable lengths is to do a lambda/4
> > calculation for 146MHz, and multuiply it by the velocity factor for RG400
> > to yield the true length. This is what I was able to glean from the
> > Sinclair documentation. Is there anything else I need to consider?
>
> Yahoo! Groups Links
>
>
>
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