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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