Date: Sun, 16 Apr 2000 04:55:37 -0400
From: "'Geri' Kinzel, DK8KW" <DK8KW@compuserve.com>
Subject: LF: Special Measurements 2 by OH2LX
To: rsgb_lf_group@blacksheep.org
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Hello Veino,

>   2. Due to ITU and EBU requirements we are engaged
>   to use relative unit dB(mW), after some problems
>   with our customers we have adopted "dBmW" instead
>   of normal "dBm". In fact ITU regularly uses "dBW".
>   Is the use of "dBu" based on some agreements?<

thank you very much for your valuable measurements. I recall we already
discussed the misleading unit we see from time to time. The only reason I
was using dBu (not dB microVolt but dBu) is that the relatively cheap
selective level meters I use (Praecitronic MV6/62 and Siemens D2108) were
originally used for level measurements on telephone lines, with 0 dBu =
0.775 Volt at 75 Ohm. In the meantime I have found a way to measure the
actual field strength by means of a 1m diameter loop, so I know the
relationship between my receiver signal strength and the field strength (0
dBu equivalent to 108 dBuV/m) , so I recently changed the information in my
logbook on my homepage into dB microVolt/m. I believe that this, together
with the CCIR curve give a better indication about the propagation modes
and probably the ERP someone uses -- at least in direct comparison.

Best 73

Geri, DK8KW (W1KW)

P.S.: hope you catch my signal one of these days, I would love to have a
figure on my field strength in OH ... pretty small, as I suppose, with 30
mW ERP

P.S.2: Veino, a question to you as the expert: are the CCIR curves valid
for ERP or EIRP? The curves state that they were calculated for a power of
1 kW from a "short monopole" antenna. Does this mean, we are comparing our
curves to 1kW EIRP? Is the 40 kW radiated power of DC39 that Gamal and I
measured (in comparison to the CCIR curves) EIRP or ERP?