That is a design for a 40 Watt VHF RF Power Amplifier for
**the FM broadcast band**.
In most countries broadcasting by persons not possessing the
proper license and authorization to do this is illegal.
Don't quite take me at my word? Check out this site where
such notices of violation are posted as action progresses
against illegal/improper broadcasting (as well as other
violations of 'radio law') are posted:
>That is a design for a 40 Watt VHF RF Power Amplifier for
>**the FM broadcast band**.
>In most countries broadcasting by persons not possessing the
>proper license and authorization to do this is illegal.
>Don't quite take me at my word? Check out this site where
>such notices of violation are posted as action progresses
>against illegal/improper broadcasting (as well as other
>violations of 'radio law') are posted:
>And next time, *please* mention the band/freq range for which
>the amplifier/device is intended for.
>Incidently, this particular design has been on the web for
>quite some time and is linked to from most LPFM and 'pirate
>broadcaster' web sites.
o Designed to amplify the output of an exciter with an output
power *significantly* under 1 watt
o requires +28 VDC
o capable of 20dB gain (ideally .5 W in would yield 50 W out)
o contains *no* TR relay
Let's look at the "givens" (the usual amateur gear's output
power capability, the DC power usually available and other
o Most amateur gear in the one-watt class are FM hand-held
portable radios - with a 2 to 5W high power and 1/2 to one
watt low power capability.
o Most FM *mobile* and even base gear output powers range from 10 W
to over 45 W
o Any amplifier used with "unit-ized" (integral receiver and
transmitter in one package) require a companion amplifier
to contain the function of a TR relay to bypass the Power amp
o Most mobile gear utilizes +12VDC/+13.8VDC power input
o Most passenger vehicles manufactured today are equipped
with "12 V" systems
Now tet's look at what must be 'modified' for use of this amplifier
on the Six Meter amateur band (an octave lower in frequency
than the FM broadcast band - at least here in the former 13
o Complete redesign of the input matching LC network
o Complete redesign of the output matching LC network
o Complete redesign of the low-pass output LC filter (you will
wind up with an illegal amount of 2nd harmonic coming out of
this amplifer if this isn't redesigned!)
The bias circuit is probably usable. That's the only upside.
With the list of the above "givens", the list of items required
to be modofied for use on a band nearly an octave lower and in
light of the this design's capabilities - I see a big 'disconnect'
in any moves to simply modify it for amateur service on six ...
there are better designs with different devices that are
better suited for amateur use.