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Equipment / Re: Why 50 ohm coax cable?
« on: January 08, 2021, 2145 UTC »
My response was directed more at the hobby world and not the commercial world.
Even so, can't recall ever seeing a SWR meter in a land-mobile or avionics repair shop.
The Bird 43 was (is) the go to instrument for checking transmitter/antenna power
output performance. For example, if a mobile unit rated 40 watts is putting out
40 watts with, say, a couple of watts reflected... that unit is going to go out the door.
(The SWR would work out to about 1.6:1.)
Nobody is going to tinker with it for an hour or two, much less bill the customer,
trying to get the reflected power down to zero.
In the ham world, if you want to or feel the need to address the 50 ohm to 75 ohm impedance mismatch,
you can always build a 1/12 wave matching section.
btw... there just so happens to be an article in this month's QST regarding the construction
of a 50 to 75 ohm matching transformer.
Of course, for receive only application, all this is of less concern.
Even so, can't recall ever seeing a SWR meter in a land-mobile or avionics repair shop.
The Bird 43 was (is) the go to instrument for checking transmitter/antenna power
output performance. For example, if a mobile unit rated 40 watts is putting out
40 watts with, say, a couple of watts reflected... that unit is going to go out the door.
(The SWR would work out to about 1.6:1.)
Nobody is going to tinker with it for an hour or two, much less bill the customer,
trying to get the reflected power down to zero.
In the ham world, if you want to or feel the need to address the 50 ohm to 75 ohm impedance mismatch,
you can always build a 1/12 wave matching section.
btw... there just so happens to be an article in this month's QST regarding the construction
of a 50 to 75 ohm matching transformer.
Of course, for receive only application, all this is of less concern.