Topband: Cutting Delay Lines

[Wes Stewart]

I have no idea how critical the phase shift is for your design, but I'll offer a 
couple of caveats. Unless you have characterized your cable, you don't know Vf 
or Zo. Furthermore, both of these vary with frequency.  These effects are 
probably in the noise and with your instrumentation you will never know the 
difference.  That said, finding a phase length at a multiple frequency doesn't 
necessarily predict the phase length at the design frequency.


On 7/12/2016 8:04 PM, Ed Stallman wrote:
> I'm cutting a 40 degree and a 20 Degree Delay line using RG6 at 1.83MHz for a  
> receive 8 circle array ! I know the velocity factor of the RG6 and have all 
> the math worked out .
>
> After doing the calculations and trimming the RG6 back , I'm looking for  X=0 
> at 4.118 MHZ ( or as close to X=0 as possible )
>
> Now to my question: I'm finding the X=0 to be a broad range , looks to be + - 
> 50 KHz on my MFJ 259b .. I know , I need a better analyzer ... Can I double of 
> quadruple the frequency to narrow the span where X=0?
>
> Thanks Ed N5DG
>
>
>
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