Jim Hackett wrote:
What ever happened to the SUPER M.W. radio that some guy here on the group
was building? (Pete?)

--
Jim


Hi Jim,
The radio design is complete................I am just waiting for our
software prople to write the control code for the spectrum analyzer
functions, synthesizer control functions, etc. I have built 3 prototypes
that use a ten turn pot to tune the VCO, and they work quite well. The
latest version uses a GaAsFET MMIC as the loopstick amplifier.
I do have one issue............the TDA1572 seems to act as a good
antenna for picking up 31M band signals, so I need to work out a
shielding scheme. I am not sure if the power supply lines or the chip
itself are picking up the signals, but it shouldn't be to hard to work out.
We have a couple of multi-million dollar projects we are working on
right now, to the software people have put the radio on the back burner
for now.
It could be a blessing in disguise.............I am working on plans for
a Fraction N synthesizer, and I may try a different approach to the
design, using a quad JFET mixer.In its current configuration, the
sensitivity is on a par with the AOR7030, which is ok for MW.
The RF amplifier is a pretty strong device; it will put out 50mW of
linear power, with a 1dB compression point of +18.5dBm. It should be
fairly bulletproof in a congested signal area.
I was going to use an Agilent MG82563, and I still might, but right now,
I am using an RF Micro Devices RF2044, with a source follower ahead of
it to match the impedance of the loopstick to this device.

Pete