Cost effective C band Dicke radiometer reference load:

- homebrew waveguide load (37k) wedge prototype made from cardboard and a section of waveguide

- another view (42k) of the "Ferro" impregnated tapered cardboard waveguide load

- the measured (11k) return loss between 3.3 and 4.4 GHz (ham & TVRO/terrestrial allocations) - tnx OH2LKV :-)

- for the uninitiated this means that only about 1 % of forward power is reflected :-)

- photo of the cardboard pieces (23k) before taping into a wedge form

- so what is this "Ferro" stuff (37k) anyway ???

- empirical ohm meter and 2.45 GHz high power experiments showed favourable characteristics...

...albeit with a phenomenal smoke screen effect...toxicity unknown...

- "Ferro" is a Finnish domestic speciality that is used for cleaning and dyeing fire stoves and is called "Liesimusta" in Finnish

- I am reasonably sure that the manufacturer will bear no responsibility whatsoever in this misuse of their fine product ;-)

- prototype wedge dimensions: 130 mm long, 58 mm wide at base, taper on one side of the waveguide broad side

- a longer wedge could produce even better results, but this time I was limited by the available waveguide section length

- my friend Masa, JA1ATI, succesfully uses a Japanese product called "Hot Cairo" which is a thermal heating "hot bag"

- after opening the protective bag, the fine iron powder reacts with air and produces heat for about 24 hours

- I have never seen this "Hotto Kairu" (74k) equivalent of the traditional hot water bottle outside Japan

- this appears to be yet another domestic iron powder speciality ;-)

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Updated 09.01.2003