Richard Prosser wrote:
> Try Googling "Homemade VSWR meter"
> 
> The first link that came up for me was
> <http://ludens.cl/Electron/swr/swr.html> which seems to explain things
> and gives a circuit etc.
> 
> If you want onle like the link you provided, you'll have to source a
> suitable meter - or build one yourself using two separate meter
> movements.
> 
> (Or build a PIC into it to handle the calculations!)
> 
> RP

About 10 years ago, the company I worked with manufactures CB radio 
accessories. I have designed and built a digital autoranging SWR and 
power meter for CB (27MHz) use.  It was on a Motorola 6805R3.

SWR is very easy to measure and calculate. Just use 2 AD inputs and read 
the forward and reflected values on the 2 diode bridges. Then SWR is 
computed using this formula:
SWR = (F + R)/(F - R)
Use the values directly for the readings are directly proportional to 
the square root of the power.

For power, the values must be squared and scaled.

regards,
Reggie
-- 
http://www.piclist.com PIC/SX FAQ & list archive
View/change your membership options at
http://mailman.mit.edu/mailman/listinfo/piclist