I haven't seen a lot of examples out there, but the project seems very
simple; perhaps trivially simple.

First, you build a directional coupler -- there are a number of designs out
there, but none are especially difficult. Then you rectify the voltage and
perhaps amplify it. Feed the two voltages into a microcontroller that does
the math and operates the display (digital of course). Analog isn't going
to be so popular because you not only need a meter (generally harder to get
and expensive these days), but you will need some custom meter face, and
what it needs to look like won't be all that obvious.

You can get 10 bits on a microcontroller A/D pretty easily and cheaply, more
bits will generally cost more, sometimes a lot more. While you don't need
terrific resolution for SWR, you will if you want to measure SWR over a wide
range of power levels. A lot of micros have 5 or 10 A/D's, though, so
perhaps you could get cute and avoid the need for something expensive.

Not many micros have D/As, but many have PWM outputs that can be filtered
and would be plenty enough resolution for an analog meter. The cool part of
that is that you could have your retro instrument, and you could adjust the
output to match the meter face you have.

Of course, if you aren't afraid of a little work, a graphical LCD could be
made to display a meter face .. after all, it's only ones and zeroes g
Some of these color LCDs from cell phones (pricey) are all the rage among
some PIC hobbyists these days.

...

"MAc" wrote in message
...
napisal(a):

You will probably get more responses if you describe what you want in
more detail: frequency of operation, inline or test instrument, self
contained or PC based, remote head, analog or digital display, cost,
commercial or homebrew etc.


;-) ANY ideas. ANY schematics, Any The topic is "direct reading" :-)

mac

the best would be:
analogue,
single meter,
1,8-30
of course homebrew - it's r.r.a.h group