>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
>> Anyway Im curious as to db gain vs s-unit. As I understant one S unit =
>> aproximately 6 db however on my local repeater one gentleman is adimant that
>> it's 3 db = 1 sunit. Im 95% sure it is 6=1s unit but when in slight doubt I
>> confer with the wizards on tower talk. :--}
>
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
>There is no standard conversion from dB to S-unit.
>
>On my FT-857D, I measured with a step attenuator and signal generator and
>found something like this:
>
>barely audible to S1 : lots of dB, don't remember how many, but way more
>than 6dB
>S1 - S2: 1dB
>S2 - S3: 1dB
>S3 - S4: 2dB
>S4 - S5: 3dB
>S5 - S6: 4dB
>S6 - S7: 5dB
>S7 - S8: 6dB
>S8 - S9: 6dB
>S9 - +10: actually 10dB, same for +20 and +30
>
>Just on my rig, 1 S-unit can be anything from 1dB to 6dB. It just doesn't
>mean anything.
>
>Measuring the rig's audio output voltage with the AGC off and the RF gain
>turned down so the audio doesn't distort is a better way to compare
>antennas....
>
>Another good method , but takes practice to do on the air is using a step
>attenuator to check signal levels by attenuating everything to the SAME
>S-unit reading (say, just barely S5), and comparing the difference in
>required attenuation between the two things you're trying to measure.
>
>S-units can be useful for quick checks, but you do need to actually know
>what a S unit is on your particular radio.
>
>73
>Dan
>_>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
Going from 100 watts to 1000 watts is 10bB measured in power dB (10xlog)
Isn't the S-meter measuring voltage dB's (20xlog)
Is that why I normally see a 20dB (voltage) S-meter increase when a station
increases power from 100 watts to 1000 watts.
Mark N1UK
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