Gentlemen,
I can second your observation that 3-phase power feed is superior to
single-phase.
When power levels much more than 1 kVA input are used,
it is possible to observe poor AC regulation with keying even on European
standard 230V outlets.
If constant power regulated switch-mode power supplies, such as in the Collins
HF-8023/32, are used,
the lowered input voltage will be compensated by a higher line current, making
the situation worse.
There is a marked difference in AC line regulation when comparing transmitters
with the same output power
using 3-phase and 1-phase connections. My own Standard Radio SSA1000 1 kW+
transmitter for example,
using a 3-phase 230/400 V AC feed, does not blink any lights in the house
even when transmitting full power into a mismatch.
It appears that the standard European practice to provide 3-phase 230/400 V
power,
usually fused at 20A or 25A per phase,even to small dwellings
is a blessing for the QRO enthusiast.
73/
Karl-Arne
SM0AOM
----- Original Message -----
From: <ka1xo@juno.com>
To: <genewill@ordata.com>
Cc: <amps@contesting.com>
Sent: Sunday, November 16, 2003 8:22 AM
Subject: Re: [Amps] Benefits of 3-phase power?
>
> Dear Gene,
> Having been fortunate to have 3-phase power available in the lab where we
> Type-Accepted DC Powerplants for cellular transmit sites I took advantage of
> the situation and hooked up a strip chart recorder to the three hot legs of
> the 5-wire service and to the three wire service of the split single phase
> mains supply to be able to tell the customer about sags and surges. While
> both services suffered equal amounts of transient pulses, measurable from 3
> nS up to 1mS, and in equal amplitude, the three-phase service suffered less
> than one-third the amount of events from 1mS to 1S. The customer decided to
> bring in 3-phase power to as many sites as were possible, the big hurdle
> being the nearby availability of three-phase lines in the street.
>
> The everyday advantage to using 3-phase mains is smaller wire diameter and
> lighter motor frames for the same HP.
>
> But who has 3-phase going to their house?
>
> Hal
> KA1XO
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