Re: A homemade diode power sensor for HP meters
开云体育Hi Paul sounds like you have re engendered the 435? and you say you have achieved a 65 dB dynamic range? that is excellent and good for most Amateurs to ?6 Ghz ?but a lot want 10 Ghz? ?suggest you write it up for one of the magazines that Pay just as mater of interest? other than lots of Time ( I assume Weeks ) how much did it cost excluding the donor 435 ? Personally I repair the 432 and 435 meter usually it is the meter face and help UK Amateurs out with parts Paul ? From: [email protected] [mailto:[email protected]] On Behalf Of paulswed ? The diode approach would be the way to go. Like many of you I also like the large scale HP power meters. You can pick the bodies up for nothing. Though suddenly there seems to be a magical market for a body without sensors. An approach I recently took that has worked was to leverage the analog devices power sensors into a 435 body. This approach really couldn't use anything?inside of the 435. The Analog device sensor in a small box with very flexible?cable goes to an arduino that maps the linear to the log scale of the 435. Since the sensor works from?+15 to -50db I reused the switch to select new scaling in 10 db steps. Also to create a broad range 0 to -50 db scale. I like the meter a lot and it now sets on top?the real HP-435. The real one for very accurate readings to 18 GHz the new one good to 6 GHz. It really works well as I rarely need .25 db accuracy on anything. The Linear to log was quite a challenge as I learned. Though the meter is very nice this was a complex project so not sure its useful to many. If the diode approach can work as Dave says then that would be the best approach with the least building challenge. If you don't need 18GHz bandwidth maybe you can get away with larger components. Regards Paul WB8TSL |
Paul Bicknell