On Thu, 02 Jul 2015 06:12:33 -0700, Jeff Liebermann
wrote:
(...)
where the maximum power at 50 ohms for transmitters, and lowest loss
for 75 ohms (air dielectric) for CATV were derived. The rest of the
connected devices (PA, filter, antenna) simply conformed to these
standards.

Continuing from where I accidentally hit the "send" button...

It might be interesting to measure the output impedance of your HF
xmitter. All you need is a dummy load, and an RF voltmeter, RF probe
and voltmeter, or oscilloscope.
1. Turn down the xmitter RF output to some level where you won't blow
up your test equipment and so that it doesn't go into high VSWR
protect mode. My guess is about 10 watts is about right.
2. Measure the RF voltage across the output connector both with a
load (Vload) and without a load (Vno_load).
3. If measuring peak voltage, convert RMS by multiplying by 0.707. If
measuring peak-to-peak, divide by 2 and then multiply by 0.707.

Output_Impedance = 50 ohms (Vno_load - Vload) / Vload

It's been many years since I've done this, so I can't recall the range
of values that I obtained. I do recall that it was surprisingly large
and precipitated a few heated discussions in the lab. Also, the
output impedance will change with output power level but I don't
recall how much.


--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558