"SpamHog" wrote in message
oups.com...
I was poring over a HW-9 schematic already.

Very cool, cept it's anything but broad range: doubler/tripler, mixers,
LOs, all sorts of acrobatics that cut down the number of components but
make the whole more inflexible.

Right now I am thinking about using:

- a signal generator

- 1 driver and 2 or 3 massively derated finals in parallel, all AB
class or so, with broadband RF transformers, i/o at 50 ohm or so

- perhaps a bit of negative feedback

- putting all the filtering at the end, such as 3 tank circuits with
3-section VC + pi network; doing so would possibly simplify the
mechanics of providing effective shielding.


I have no idea in what the HW-9 differs from the HW-8 in the transmitter
stages.

I know the receiver of the HW-9 is more elaborate than the direct reception
of the HW-8.

I do not feel comfortable with broadband signal generators in transmitters
since they tend to be noisy and jittery.

To some extend, it could work on FM, but I doubt the results will be worth
anything in SSB.

Signal generators produce also lots of spurious; filtering at the end stage
will be a real challenge.

I still have the intention to use the "inj." output of a Drake R4B, mixed
with the output of an x-tal oscillator (somewhere around 6 MHz, I don't
remember exactly) to send on the frequency the R4B listens on.

With some fiddling, you could find in every receiver a frequency to mix with
a fixed oscillator to get the same effect.

The resulting signal will need filtering before any amplification, so much
for your wish to go broadband!

On the other hand, filtering over a broad band at the end stage is OK only
if you intend to use a dummy load at all times (HI). A real antenna will not
present the required impedance over the entire frequency range to the output
of your filter. The garbage you intended to filter will only be partially
taken care of.

So you see, quite a challenge!