Hi all - the original G2DAF amplifier (notice I didn't say Linear!) used a
pair of
QY3-125.
John ZS5JF
----------
> From: Peter Chadwick <Peter_Chadwick@mitel.com>
> To: 'marv gonsior' <w6frmarv@juno.com>; 'amps' <amps@contesting.com>
> Subject: RE: [AMPS] DAF Amp
To: <amps@contesting.com>
> Date: 13 July 1999 06:04
>
>
> Marv says:
>
> >Please let me make it clear that I am NOT an advocate of the DAF
> >amplifier
>
> The DAF was a development of the G2MA amp, which used a single 813. The G2MA
> was pretty similar, except that instead of rectifying the RF for directly
> drivng the screen, it used the rectified RF to control a 6Y6G clamp tube and
> allow the screen voltage to vary. (If you remember clamp tubes, you're
> getting old!) As I remember it, the G2MA was a dodgy thing to set up for
> what were considered 'acceptable' results; I have severe doubts as to
> whether or not they would be considered 'acceptable' today. I know the write
> up said that you needed a 'scope to set it up, which gives fair warning. It
> was a quick and dirty (in more ways than one!) of adapting an AM rig to SSB.
> In those days, the UK limit was 150 watts DC input to the plate of the
> final, so popular PAs were one 813 or two 807s. Some people were getting all
> modern with 6146s, but they were a bit expensive. The original write up on
> the G2DAF as I remember it suggested that although DAF used 4-125As, some
> other people had successfully used 813s.
>
> >Here's to more LINEAR amplifiers!
>
> A qualified YES to that - because as has been stated several times on this
> reflector, many 'linears' are capable of being far more 'linear' than the
> transceiver that is used to drive them. It's then a case of 'Garbage in -
> bigger garbage out'.
>
> 73
>
> Peter G3RZP
>
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