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Eddie

freespace has nothing to do with Henry's model with & without radials,

his chart shows the sigma with radials is stronger at 30 kilometers than the sigma without radials,


The larger the negative dbm number on the left of Henry's chart the weaker the signal is,


i get -89.7dbm without radials & -90.2dbm with the radials, .5db loss with the radials,


its not a new way of measuring signal strength, s-meters have never been a way of measuring anything,


they are just a relative indicator, they use the rigs agc line voltage to indicate signal strength,

they should be calibrated @ -73dbm or 50 microvolts for s-9 @ 6db per s-unit,


above 30mhz meters are calibrated @ -93dbm or 5 microvolts for s-9 @ 6db per s-unit


or that's how it should be but i never saw a radio that was 6db/s-unit, closest i have seen is my jrc @ 3db/s-unit,

half a s-unit increase on a radio meter just means the meter moved, its not measuring in any calibrated units

your half a pound could be 2 or 3 times my half pound increase,


the rsp1a has 4 calibrated s-meters,

one of the meters is the dbm meter scaled from -140dbm to -20dbm,


think of it as a very low power watt meter that measures voltage across 50ohms @ the antenna socket in the nanowatt, picowatt, femtowatt & attowatt ranges & displays the wattage relative to 1mw in -dbm or -decibel milliwatts.


the higher the negative number the weaker the signal

look at the charts in this thread

https://www.sdrplay.com/community/viewtopic.php?t=3582