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Old June 18th 06, 06:16 AM posted to rec.radio.amateur.antenna
Richard Clark
 
Posts: n/a
Default Feedline impedance query

On Sun, 18 Jun 2006 05:10:58 GMT, Owen Duffy wrote:

On Sun, 18 Jun 2006 16:34:19 +1200, "David & Margaret McBeth"
wrote:

If I join 2 lengths of 93 ohm coax to give 46.5 ohm impedance will the db
loss on the line be greater,less or the same as a single lengthof the coax?
ZL2DG


Presumably by "join 2 lengths" you mean to connect two lengths in
parallel.

If the loss factor L is the loss in one length of the cable, won't the
loss in two parallel lengths be Plost=Pin/2*L+Pin/2*L, so Plost/Pin=L?



Hi Owen,

Hmm, each time I look at these equations, something is missing, but I
don't know what (probably because it is missing).

Simply put, two lines in parallel lose as much power as one line.
Nothing to be gained in that regard.

73's
Richard Clark, KB7QHC