[Yaesu] Quadra, power increase

Carol L Maher w4clm.ham@juno.com
Wed, 27 Nov 2002 13:00:08 -0500


Dave, 
I do not own a Quadra, but I have had a chance to play with a one.
So that makes me think, why on earth if you own a beautiful piece of
equipment
like this would you even consider attempting to push the envelope when it
comes
to it's power handling capabilities.  On the other hand I have worked on
several
1 Kw solid state amplifiers made by ITT Mackay Marine while I was
aboard a merchant going container vessel.   If the Quadra is
built in a similar manner as the Mackay amplifier,  then they are using
 4- banks  with 2- transistors in each bank / circuit going into a  50
Ohm
combiner network for the full 1Kw output.   I realize that the Quadra
does
not use power transistors per-say.... however it is using Power MOSFETs
in a push pull design.

Consider this before you push the limits of your amplifier or any rig for
that matter.  Do you honestly feel the advise you will receiver on this
forum
or from any other amateur off the street to be better than that from the
Yaesu
Engineers who designed that amplifier ????   When ever any piece of
electronic
equipment is designed, there is a certain amount of headroom built into
the
equipment design  for reliability, voltage variations, and component
reliability.
Note the statement below from the Yaesu web site: "for years of reliable
operation".
 
There is an old saying in electronics and it still holds true today.....
"IF IT WORKS --- DON'T FIX IT "
Regards
Carol L. Maher
W4CLM
Charlotte N.C.

Innovative Ouadra Push-Pull RF Design for 1 kW of MOSFET Power!
Yaesu's engineers have conquered the challenging task of providing
high power output from 160 through 6 meters!* Yaesu's exclusive
Quadra Push-Pull design utilizes 8 rugged MRF-150 MOS FETs for
years of reliable operation. 


> Reply-To: <wr3i@earthlink.net>
> From: "Dave Richards" <wr3i@earthlink.net>
> To: <yaesu@contesting.com>
> Date: Tue, 26 Nov 2002 19:31:46 -0500
> Subject: [Yaesu] Quadra question?
> 
> I have heard that one can get 1500 watts out with a quadra how does 
> one do
> that and is it safe
> Dave
> W1QB

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