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G0FTD > ERRATA 22.12.05 02:17l 25 Lines 821 Bytes #999 (0) @ WW
BID : 683144G0FTD
Read: DL1LCA GUEST OE7FMI
Subj: Re: Dialectric value help
Path: DB0FHN<DB0THA<DB0ERF<DB0FBB<DB0IUZ<DB0GOS<DB0RES<ON0BEL<F6KMO<KP4IG<
IW2OAZ<ZL2BAU<GB7YKS<GB7SYP<GB7ESX<GB7NNA
Sent: 051221/2348z @:GB7NNA.#31.GBR.EU #:75367 $:683144G0FTD [Witham, Esx]NNA
G0SYR wrote:-
> Have you tried this method ?
> Surely the quarter wave only looks like a short circuit when its
> far end is left open circuit?
> If you terminate a 50 ohm line with 50 ohms you will always measure
> a 1:1 SWR regardless of its length no matter how much you cut off it,
> there will be no dip to measure.
>
> Your method 2 looks better, that should give you a rough idea of velocity
> factor
You're right - I should have said:
Put the 50 ohm resistor in *series* with one side of the line thus :
-/\/\--------------
tx > swr > leave end open ended.
-------------------
So that when the coax looks like a ¬ wave electrically the end will
appear as a short but with a series 50 ohm and the measure SWR would
be 1:1 - does that make better sense ;-)
- Andy -
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