Hi all,
I use the signal of DCF39 in order to test my antennas.
I read off the values from the METER. of a RYCOM receiver.
So far only the DB scale of the instrument interested me.
Among them are two further scales, which indicate RMS VOLTS.
Ranges:
DECIBELS -20 - +2
RMS VOLTS 0 - 10
RMS VOLTS 0 - 3
Entry right above: 1MW 600 ohms
The values indicated for DCF39:
+2 DECIBEL, 9.8 RMS VOLTS and >3 RMS VOLTS
(attenuator in position -30dB).
My slide rule says: 2 dBm with 600 ohms = 0.98 V Ueff
and RMS (roots mean square) nevertheless Ueff means or?
(setting instead of dBm dBuV comes on 1,6uV. Completely beside it.)
How does it come to that "potential" difference ?
regards
Uwe/dj8wx
|
