Specs for a Decibel Products DB420 Antenna.
PS - Nice job on sys gain and losses, N3DAB. Very good explanation.
Some useful formulae:
Power gain = 10 * LOG (power in / power out)
(if in and out are reversed the result will be a negative number instead of pos, or vice versa).
Also. For a starting point. 1 Watt in a 50 Ohm circuit = 0.0 dBW.
To convert from Watts, to dB referenced to 1 Watt.
10 watts = 10 LOG (10/1) = +10.0 dBW , and
50 watts = 10 LOG (50/1) = +16.9 dBW , and
100 watts = 10 LOG (100/1) = +20 dBw
To convert from dBm (1 milliwatt 50 Ohm Reference point) to dBW, substract 30 dB. ie, +30 dBm = 1 Watt = 0 dBW.
Nice thing about working in dB is that you add gains and substract losses, then convert back to watts for ERP which can be stated in Watts or dBW. Steve NU5D
On 5/31/06, [EMAIL PROTECTED] <[EMAIL PROTECTED]> wrote:
I question that 9.2 dB antenna, is it actually 9.2 dBd or 9.2
dBi ??
Neil - WA6KLA
---- Original Message ----
From: [EMAIL PROTECTED]
To: [email protected]
Subject: RE: [Repeater-Builder] Re: Wount To Find Out About Buiding A
New Repeter
Date: Wed, 31 May 2006 14:36:47 -0000
>Jim,
>
>First add all the System Gains (SG)in dbW measurements, from that
>figure you then subtract all your Sytem Losses (SL)in dbW, the result
>
--
Ham Radio Spoken Here.....NU5D
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