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
_______________________________________________
Amps mailing list
Amps@contesting.com
http://lists.contesting.com/mailman/listinfo/amps
|