Re: Just starting out

Nick Kennedy

Well, you've got several elements of it. 

The PHSNA doesn't use a local display or encoder (or any other controls).

There are two main versions. In the terminal version, all the intelligence is in the Arduino sketch and it communicates with you via a serial terminal. 

In the Windows version, the sketch for the Arduino does minimal functions controlling the DDS and reading the ADC while most of the intelligence is in the Windows program which shows your results on your PC as any typical Windows program would.

There are two major hardware components. 

First is an AD8307 log RF power detector circuit. It's in a separate box to keep noise low. Its DC output signal goes to an ADC pin in the Arduino.

The other box contains the rest of the PHSNA hardware, which includes an Arduino, a DDS, post-DDS filtering and amplification and/or attenuation if required. Most of the complexity of the different versions comes from the fact that there are designs for a couple different form-factor eBay DDS boards plus the AmQRP / Midnight Engineering DDS-60 board. Also one post-amplifier used a transistor and another used an MMIC. 

Having this set-up, your calibrated RF output from the DDS box generally goes through the DUT and then to the log power meter and its output goes back to the Arduino.  Other fixtures may be used, such as a crystal measurement fixture or a return loss bridge, depending on what you're testing at the moment.


Nick, WA5BDU

On Sun, Sep 25, 2016 at 5:49 PM, lancer979@... [PHSNA] <PHSNA@...> wrote:

I'm starting out with an arduino nano v3.0 pro mini (on board FTDI and 5v regulator)

I'm hooked up to a 1602 LCD display on D4 to D7 and D12 to D13.

My DDS AD9850 module (125MHz clock) is on D8 to D11.

I'm using a nice AD8307 module - well shielded with an SMA connector - connected to A0.

I have a shaft encoder on D2 and D3

Is this setup anywhere close to a PHSNA as this group defines them?

I'm a little confused with the large number of options and boards members of this group are using.

I don't understand the software (arduino sketches or PC applications) or how they apply.

I hope to start out with something clean and simple then expand to more complexity.

The hope is to do frequency response measurements of filters and crystals to start out with. 

Can anyone in the group help me out?


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