On 4/8/2012 9:01 PM, Jim Thomson wrote:
> LMR-400db .666 db
> LMR-400UF .799 db
> RG-213U 1.024 db
RG213 is not a spec, it's a very broad generic description. There are
RG213s built with thin copper braid and others with heavy copper braid.
The loss in cable is a direct function of how much copper they use to
build it. Based on resistance data, Davis's 213 is directly equivalent
to LMR400 for use on the HF bands.
## say what. Run 200 feet of 213-U into a dummy load at the far end, with
a wattmeter 1 foot before the dummy load.
You'll need far more precise instrumentation than a Bird to measure a
difference of 0.1 dB Rather, you'll need a scope, RF voltmeter, or
spectrum analyzer that can resolve 0.01dB, you'll need to measure by
substitution, and you'd better make a bunch of measurements and compare
73, Jim K9YC
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