"Jim-NN7K" . wrote in message
...
One other thing might check out, is the Salt Water Dummy Loads
(on several web sites). One mearly uses (can, Jar with lid),
and with metal plates attached to coax connector, filled
with salt water - Fill with water, then with ohm meter , add
Salt until the brine hits 50 ohms! Tho, don't know how high
frequency it is reliable to, should work to at least 50 MHz.
Jim NN7K


Back in the mid-1960's there was an article in QST where they did this.
The load will definitely be frequency dependent as demonstrated by
experimental results. Also the salt used will effect the results. From a
theoretical standpoint, the mobility of ions is dependent on the size of
the ion. The bigger the ion, the slower it will move. This conveniently
explains much of what is seen in ground losses and is why electrolytic
capacitors are essentially useless above 1 MHz. The ions cannot move fast
enough in the small times seen per cycle, so the current falls off. Ion
mobility also decreases as the temperature drops which explains why
electrolytic capacitors also do poorly at low temperatures.

I have done as Jim suggested when testing a kilowatt amplifier on 80
Meters. The load is useless if the water boils!

73, Dr. Barry L. Ornitz WA4VZQ