EMRFD Message Archive 20

Message	Date	From	Subject
20	2006-07-15 09:51:36	Hari G	EMRFD CHP-7 (Sch 7.11)
Hi All ,    Did any one of you try making the power meter given  in 7.11  ? iam building one with a  difference,  instead of the meter ckt iam using a pic 16F876 so that it does the calculation for me.   Volts  = ( A/D Counts x 500 ) / 1024 Power = (Volts x Volts ) / 50x2 db = 10x log10(power) (Many thanks to W7AAZ for those long emails ! are you here Bill ? )   I would like to know if i calibrate with some known DC voltage  as i dont have a known  signal source.   Best Regards  Hari (VU2GHB)
22	2006-07-15 12:49:05	Roger Hayward	Re: EMRFD CHP-7 (Sch 7.11)
Hari: FB on the construction of the power meter with a PIC processor. I've implemented a similar setup (using the AD8307 and an 18F452), and it has worked very well (see www.ka7exm.net and look for "PIC Power Meter," or jump on the yahoo! group "picpower.") You will need some form of an RF source to get an initial calibrati
24	2006-07-16 01:45:25	Hari G	Re: EMRFD CHP-7 (Sch 7.11)
Roger ,    Many thanks , i do have a DDS as signal gen but i was doubtful of that and the bandwidth of CRO i have at home is only 15MHz.I can take this to my MQ and measure on a better scope.   Best Regards  Hari(VU2GHB)    On 7/16/06, Roger Hayward <ka7exm@yahoo.com> wrote: Hari: FB on the construction of the power meter with a PIC processor. I've implemented a similar setup (using the AD8307 and an 18F452), and it has worked very well (see www.ka7exm.net and look for "PIC Power Meter," or jump on the yahoo! group "picpower.") You will need some form of an RF source to get an initial calibrati