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For v4xx Parallel Port boards only
The M0WWA USB Adapter&Power Converter (built-in USB power supply) is an option for N2PK VNA Windows users.
It allows connecting to a High Speed USB port on PC instead the parallel port, powering at the same time the VNA, Plug and Play feature.
In addition, it can be used for others projects.
The USB Adapter&Power Converter circuitry is divided on two main sections
- The USB High-Speed peripheral controller.
- DC/DC converters.
The USB High-Speed peripheral controller section is a redesign version of David Roberts G8KBB designed to work with his program "My VNA".
It is based on Cypress CY7C68013A. Because by default the USB port only draws 100mA, his software package includes the 500mA USB driver option needed by the USB configuration descriptor.
Comprehensive technical information, drivers installation and updates can be found at:
http://g8kbb.roberts-family-home.co.uk/html/usb_interface.html
Power converters are based on LM3224 from National Semiconductors, a well know, reliable and noiseless step-up PWM DC/DC converter.
It can be powered from 2.5 volts to 6 volts generating 5V and 12V needed to power the VNA from the USB bus.
A carefully PCB layout design, shielding, L/C decoupling and protection circuitry avoid any interference from the USB bus. |
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Dynamic range and power supply noise test
Several assembled and kits versions where distributing to users and verification builders, any "bug" was reported.
All tests have been done with "My VNA" software on Windows XP and Windows Vista 32 operating systems.
DC/DC converter, output ripple. 5mV division. |
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Full scan, transmission mode, open ports.
(click to enlarge)
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Stopband performance, transmission mode, narrow crystal filter.
(click to enlarge) |
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Systen requirements:
(Parallel Port boards only)
High speed USB port on your PC capable of delivery 500mA. Some laptops cannot.
Connect directly to an USB port on your PC, not through an USB hub.
Use a quality High speed USB cable.(included on both versions)
Due to the USB Adapter&Power Converter, working with two detectors draws from the USB port around 450mA, close to the limit, no more peripherals must be connected to avoid to draw excessive current so they must be powered externally.
(The front panel power indicator high brightness LED includes a 3K3 Ohms limiter resistor).
Windows XP or Windows Vista32 operate system.
500mA USB driver included on "My VNA" software package.
Connectors pin assignments match with N2PK and VE3IVM boards.
The USB Adapter&Power Converter with removed cover.
Size: 7.5x5.5x3.0cm.( 2.95x 2.16x1.18in)
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