benzandstra@planet.nll but the last l should be removed
www.zanco.nl http:// home.planet.nl/~benzandstra
WebMaster: Ben Zandstra
Speccie is made of lowcost parts. The heart of the analiser consists of an I2C controlled tuner from a TV, VCR or Satellite Receiver.
This tuner is controlled by an on board I2C interface which receives the commands from the “Speccie” software.
Software, hardware and diagrams are not copyright, however, the right to disassemble the software is prohibited.
In the diagram you can locate the following parts:
SAA1300, I2C controlled switch for switching LNB voltage to 14 or 18 V, and to turn on or off the 22 kHz signal for High Band reception
PCF8591, I2C ADC chip, from which the software can read the analog value of the signal strength at the given frequency.
74LS05 converts the parallel port to an universal I2C interface.
Signal strength comes from the AGC output of the tuner, or from a “separate” circuit where one can “design” or choose their own LOG convertor.
Today, 16-01-2004, I replaced the FI1216 tuner note by the English version. I received some questions about the tuner not giving AGC output at pin 21, but you have to add one wire inside the tuner, as is described in the “note FI1216.doc” which is at the Speccie Diagrams page
12-03-2005: Thanks to Gerhard, OE3GQW, a problem in the software is solved. Frequency switching apeared to soon on both UHF bands. Software version is now 1.2 E which will switch to medium at 170 and to UHF at 450 Mhz.
12-03-2005...... I assume everyone wonders how it looks. I did receive some requests to post some photo’s of Speccie hardware. Here are: