[TMC] 50 ohms vs. 70 ohms

[H.L.]

Hello again:

I would like to raise another more general issue that I have not 
found in ER or QST.  How serious is the mismatch between 50-Ohm and 
70-Ohm systems and cables? Many TMC transmitters and linear 
amplifiers are 70 ohms, but most ham radio antenna tuners, 
wattmeters, baluns, and antennas are specified as 50 ohms.  Also, 
useful one-foot up to ten-foot coax cables found at ham flea markets 
are usually 50 ohms. Can we ignore the differences? Is the power loss 
trivial--especially for short length cables?

My apologies if this issue has already been covered--please let me 
know where to find the discussion or article.

73 Hal KK6HY
email: kk6hy at arrl.net