Don,
You are confusing what I said by throwing in the 75 ohm line. Look again
what I wrote and remember that I said it was with all 50 ohm line.
73
Gary K4FMX
> -----Original Message-----
> From: Amps [mailto:amps-bounces@contesting.com] On Behalf Of
> donroden@hiwaay.net
> Sent: Wednesday, January 14, 2015 4:08 PM
> To: amps@contesting.com
> Cc: amps@contesting.com
> Subject: Re: [Amps] Input SWR revisited
>
> Yes, and if I add another 1/4 wave of 75 ohm cable to the length, the
> transmitter is now looking into a 2:1 ( 100 ohm ) Load
> and will start folding back.
>
> So saying :
>
> > the SWR will always remain the same at the radio no matter what length
> > of cable is used (except for cable loss) or what the load impedance
> is as
> > long as that load impedance remains the same.
>
> doesn't stand the test of practical transmission line theory.
>
>
> Don W4DNR
>
>
>
>
>
> Quoting TexasRF@aol.com:
>
> > Good question Don. You have to keep in mind that the 100 ohm load will
> make
> > for a 1.333 swr in the 75 ohm coax. At a length of one quarter
> wavelength
> > the 100 ohm load impedance is transformed to 56 ohms, which is pretty
> close
> > to 50 ohms and looks like a low swr to the radio.
> >
> > But, the swr inside the 75 ohm coax is still 1.333 at all points along
> the
> > cable.
> >
> > 73,
> > Gerald K5GW
> >
> >
> >
> >
> >
> >
> >
> >
> > In a message dated 1/14/2015 12:13:49 P.M. Pacific Standard Time,
> > donroden@hiwaay.net writes:
> >
> > Explain the case where a 100 ohm load ( 2:1 ) can be a 1:1 swr at the
> > transmitter with a length of 75 ohm cable. I've changed the cable
> > length and improved the SWR.
> >
> >
> >
> > Don W4DNR
> >
> >
> >
> > Quoting Gary Schafer <garyschafer@largeriver.net>:
> >
> >> It means that-- if you are looking at the SWR at your radio and
> there is
> > a
> >> tuner after the SWR bridge, any changes in cable length after the
> tuner
> > will
> >> show a change in SWR at the radio if you do not touch the tuners
> tuning.
> >> This assumes that the load on the end of the cable is not 1:1.
> >>
> >> 2nd, the SWR will always remain the same at the radio no matter what
> > length
> >> of cable is used (except or cable loss) or what the load impedance
> is as
> >> long as that load impedance remains the same.
> >>
> >> 73
> >> Gary K4FMX
> >>
> >>> -----Original Message-----
> >>> From: Amps [mailto:amps-bounces@contesting.com] On Behalf Of
> >>> donroden@hiwaay.net
> >>> Sent: Tuesday, January 13, 2015 2:01 PM
> >>> To: amps@contesting.com
> >>> Subject: Re: [Amps] Input SWR revisited
> >>>
> >>> Clear as Mud .........
> >>> What does it all mean ???
> >>>
> >>> Don W4DNR
> >>> _______________________________________________
> >>> Amps mailing list
> >>> Amps@contesting.com
> >>> http://lists.contesting.com/mailman/listinfo/amps
> >>
> >>
> >
> >
> > _______________________________________________
> > Amps mailing list
> > Amps@contesting.com
> > http://lists.contesting.com/mailman/listinfo/amps
> >
> >
>
>
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