OK. Since this is a question that comes up occasionally, I have gone though
the Files area and listed files that show schematics for various
*Where are the schematics?*
First, about the variations.
· There were two types of DDS boards from eBay that would work with
the system, which we called Type I and Type II. The differences are mainly
in the layout, so if you are not using N5IB’s custom boards it may not
· There were also AD9850 and AD9851 DDS boards.
· Jim and Jerry determined that the post-DDS filter provided on the
eBay boards was not adequate, so they designed a new filter to be used.
· The system uses an additional amplifier after the DDS to provide
some gain, followed by an attenuator to assure a constant 50 ohm output
impedance. One version of the amplifier used a 2N5109 transistor and a
later version used an MMIC.
· The AD8307 board followed the schematic of Hayward and Larkin
fairly closely so there aren’t many variations in the schematic. Some
options for the type of op-amp to be used were provided. Also, a zener on
the input to the ADC was removed because it adversely affected accuracy.
Now, for the locations of some schematics:
*For the power meter:*
Go to the folder Files>AD8307 Power Meter>
You will find the schematic of the AD8307 circuit as designed by W7ZOI and
W7PUA, redrawn by N5IB. This file is called “W7ZOI W7PUA RF Power
In the same folder you find information on calibrating the circuit and on
use of the optional analog meter movement. There is also a spreadsheet
listing acceptable substitutes for the AD820 op-amp.
*Other schematics for the system:*
Files>PHSNA version using DDS-60 DDS module & Arduino NANO
In this folder is a file called PHSNA for DDS60 and Arduino NANO -
Prototype Builders Notes.pdf
a schematic using an Arduino with the Midnight Designs DDS-60 board:
Files>Type-1 PHSNA - version using Type-1 DDS module & Arduino UNO
In this folder is a file called COMBO 2N5109 Schematic and Layout.pdf
This file shows using the DDS with the 2N5109 post-DDS amplifier. It also
includes a schematic of the AD8307 circuit.
The same folder also contains the file: PHSNA ERA-3+ Type I DDS rev6r10.pdf
which shows using the type I AD9850 DDS with an ERA-3+ MMIC post-amplifier.
Files>Type-2 PHSNA - version using Type-2 DDS module & Arduino UNO
In this folder is a file called: PHSNA Type II Details 21 MAR 2014.pdf
It shows use of the “Type II” DDS from eBay. It shows how to modify the
filter on the DDS board with a schematic for the improved filter. The full
schematic for DDS plus Arduoino and the ERA-3+ MMIC is shown.
All of these folders also contain other files with useful information on
calibration, coil winding, BOMs and so on.
Again the file “PHSNA FAQ Sheet.pdf” at the top level of the Files area has
useful information on the overall system including a description and photos
of what is meant by Type I and Type II DDS boards.
On Tue, May 8, 2018 at 7:40 AM Ambro IW2FVO <ambrogio.riboli@...>