neazoi
Advanced Member level 6
Hi, I want to build an RF power meter for QRP powers (<10W) on HF (<30MHz).
I have seen this circuit https://www.qsl.net/va3iul/Homebrew...10kHz-10GHz_LED_Bargraph_Powermeter_W1GHZ.gif (the top side).
He uses the AD8307 log amplifier and a linear scale LM3914.
The use of the AD8307 is optimum but this costs a lot.
So I think instead to use this circuit **broken link removed** Which uses a "linear" amplifier but a log display LM3915.
Since I am going to calibrate the display later on, do you think that the second solution is ok?
Either of the two circuits to use, I will use this display for higher resolution https://www.qsl.net/n6bg/thunt/ledsmtr.html Do you think that this can be used as it is with the LM3915?
I have seen this circuit https://www.qsl.net/va3iul/Homebrew...10kHz-10GHz_LED_Bargraph_Powermeter_W1GHZ.gif (the top side).
He uses the AD8307 log amplifier and a linear scale LM3914.
The use of the AD8307 is optimum but this costs a lot.
So I think instead to use this circuit **broken link removed** Which uses a "linear" amplifier but a log display LM3915.
Since I am going to calibrate the display later on, do you think that the second solution is ok?
Either of the two circuits to use, I will use this display for higher resolution https://www.qsl.net/n6bg/thunt/ledsmtr.html Do you think that this can be used as it is with the LM3915?