|UHFSDR||995x||BPF||100W LPF||1.5KW Diplexer||HSUSB||Si570|
Kit assembly is now available.
Contact Chris at < firstname.lastname@example.org> or
(5-11-12). Production boards are on hand. More Details
RF amplifiers require low pass filters to get rid of harminics. This series of boards will provide a low pass filter to block the harmonics from getting to the antenna, and a high pass filter to route the harmonics to a 50 ohm "dump" resister. Each section is a 7 pole Chebychev low pass and 7 section high pass filter. Unlike a low pass only filter, this filter presents a good match to the amplifier at all frequencies. The boards are approximately 8" by 2" on .126" FR4 with 2oz copper for each band.
The board contains 7 relay switched 5 pole low pass filters.
Circuitry is provided for control via a I2C bus connection.
Test points are provided for manual operation. The board is 3.0" by 7.2 ".
Production boards and kits(PCB and Parts, no case) available now. .
The UHFSDR is a Software Defined Transceiver covering the 1.75 MHz to 700 MHz frequency range. A Si570 is used for frequency control. Two LVPECL 4 GHz max.flip flops produce I and Q LO signals at 1/2 the Si570 frequency. A pair of 1-1000MHz Double Balanced Mixers are used to convert signals to and from base band. A receiver pre-amp (2dB noise figure) and a transmit pre-amp(50mW max output) are provided as well as antennal switching plus provision for separate receive and transmit connections. For additional information, download the Assembly Manual. The BOM, schematic, and board layout are Here. A HiRes(3.7MByte>) picture of the completed board is Here
Alan - W6ARH is selling a full kit including the PCB, Si570(1400 MHz version), and all PCB parts. Contact Alan at <email@example.com>
I am offering a Mini-Kit containing the mixers, RF transformers, rec and tx mmic amps, rf switches, and the ADuM1251. The PCB is NOT included.
A spreadsheet with the remainder of the parts needed(except the Si570) for upload to Digikey is here
A CSV text file with the remainder of the parts needed(except the Si570) for cut-paste to Farnell is here.
The Si570 may be ordered at
A 1" by 1.35" circuit board has been designed for the Si570 programmable crystal oscillator chip. The board contains the Si570, a 3.3V regulator, a bidrectional level shifter for the I2C inputs, an optional droppoing resister(for 12V use),sma outputs, and headers for I2C control, power input, VCXO control(used on Si571 only), The board will also work with other oscillators in the standard 5 X 7 can.
For documentation go here
The parts kits contain the following:
2 - 10uF; 3 - .1uF; 3 - .01uF; 1 - 200K; 2 - 49.9; 4 - 1K; 1 - GTL2002; 1 - LP2992AIM-3.3V, PCB
For a discussion of this board and associated software being developed join the DDS_Controller Group .
Discussion group for a group buy of parts for the 995x board is here .
Parts list for 995x-R1 here
Parts list for 995x-R3 here
. I have included values for 3 different LPF designs depending on the clock frequency used. Uncheck the values for L1,L2 and L3 as well as C26-C32 for the LPF freq. you are not using.
Band Pass Filter
The BPF board contains 6 Band Pass Filters. Each can be up to 7 element Cheb. or elliptic in complexity. Coils can be any size from 0603 to 1810. The schematic shows my design for six 7 element filters designed for a general coverage receiver from 1.8 to 30 MHz. The filters are selected by 3 CMOS control lines. In addition, the board has transformer input and the control and RF grounds are joined at a single point.
Click on BPF Board on left for board design documentation and engineering measurement made on the board.
Production boards and kits are now available.
This board was part of the Software Defined Transceiver. A Cypress CY7C68013A provides a high speed (480Mbps) USB 2.0 interface and an 8051compatable microprocessor. The design has been ported over KICAD. This would be a good board to use with 192 KHz A/D and D/A converters. High speed USB 2.0 is specified as 40 times faster than "full speed" USB 2.0 that is in the PIC USB devices. These boards are also compatable with the N2PK VNA.
Basic Parts(except CY7C68013A and headers and PCB)
Headers + Matching Plugs