On Jun 16, 5:05 pm, "Joel Koltner"
wrote:
Just curious... does anyone know what sort of architecture you find in your
typical HT or mobile "receives everything from 100kHz - 1.3GHz!" radio to
generate such a vast range of frequencies while still keeping the prices so
low (plenty are available for $200, and I can't expect the LO makes up a
particularly large percentage of that total price)? I would tend to lean
towards something PLL-based given the typically channelized nature of
available frequencies, but a single PLL would still need a VCO with a huge
tuning range. So... perhaps a pair of mixed PLLs, with one doing the fine
tuning and another the coarse tuning (having been multiplied up from a low
frequency)?

I attempted to decipher the schematic included with my Yaesu FTM-10R, but
everything is so tiny it was rather hopeless!

I don't suppose any of the reviews ever go through and sweep the LOs while
watching for the worst case spur conditions, do they?

---Joel

The one I had used triple conversion superhet. Mircoprocessor
controlled.
The first IF was like 336Mhz to 10.7Mhz to 455Khz. There was no front
end. just direct conversion to the IF. So all the micro had to do was
control the oscillator from 336Mhz to 900Mhz using up conversion on
the low bands and down conversion on the higher bands. Cell phone band
was locked out. Guess what you can pick cell phone band on the image
frequency back in the day.

73

N8ZU