Digital Power Meter Page

Power meter panel

Back side

Log detector

The power meter uses two Logarithmic Amplifier detectors (A & B on the display)

The Log used is Analog Devices AD98307

FEATURES of AD8307

I used this circuit to make my power meter with this features:

Digital power meter and Field analayzer function
Two 50 Ohm input
Retur Los measurement ( with external directional coupler)
Up 500 MHz with max 2 dB linearity (compensed with frequency calibation stored on memory)
Digital display power or field with 0.1dB resolution
-70 dBm to + 15 dBm dinamic range
Calibration stored into non volatile memory , (user modifiable)
Log of received data from detectors (this data are sended via RS232 to a PC in EXCEL compatible format)

Analog Data are processed and displayed on 2 x 16 LCD display

With external directional coupler SWR is displayed too

PCB and programmed pic available on request

Documentation:

Nel file PDF che segue c'è l'articolo comparso su Radio Kit di Giugno aggiornato come testo e piastre circuito stampato

Power meter + network function

Adding a DDS board to the power meter a Network funtion is performed.

Network uses an AD9851 DDS to perform Sinusoidal generation 1Hz - 80 MHz;

FEATURES:

Direct frequency dialing with TV infrared controller
Programmable sweep: step time, step numbers, step size ( 1Hz - 10 MHz step)
Data log-out: on the RS232 interface ( log1, log2 & frequency)
analog ramp output for X channel of external oscilloscope
analog output of Log detetectors 1 & 2 for the Y1 & Y2 channels of external oscilloscope

The DDS board

Crystal filter displayed on PC with this network

With the use of Netscope program, see related Netscope link, a graphic rappresentation on PC is possible.

Another project with DDS: Digital VFO for Drake series transceiver : DDS-4 Digital VFO

For more informations write to

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