OK, I should explain a bit more about the amplifiers. 50-1000 MHz is an
amplifier with a 950 MHz band width, and we may indeed be able to make
the device work on the 1200 MHz band so it could be even more. Now,
notice how much work is put into making your HF amplifier work legally
on just 1-30 MHz. Lots of filters, etc. We need spurious emissions to be
greater than 60 dB down across much of that range to satisfy U.S.
regulations for Amateurs. We need it to be free of parasitic
oscillation. We need it to have low-pass filters for the selected bands.
So, this is down as "the next project" and is a really non-trivial one,
and we have to make both a handheld and mobile/base version. To make the
current device is hard enough and we're not going to make it wait for
this since single-band amplifiers like the ones from Down East Microwave
are easily available.
To give you an idea of what is involved in making the transceiver legal,
the I/O modulator is self-balancing. To do this there are two DACs which
provide a + or - offset to the I/O inputs, and there is a logarithm
detector that can be switched in instead of the 100 mW amplifier to
measure carrier or sideband suppression. There are four plug-in bandpass
filters for your selected bands, used on both receive and low-power
transmit, or they can be switched out and external filtering can be used.
All of this is necessary to give us that greater than 60 dB down
spurious at just 100 mW.
Thanks
Bruce
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