Topband: Cutting Delay Lines

[Ed Stallman]

Thanks Wes and thanks all who replied directly . I've received some very 
good information. I should be good to go

Ed N5DG


On 7/13/2016 9:45 AM, Wes Stewart wrote:
> 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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