Spectrum analyzer on TV head

[Vermes]

This device is a spectrum analyzer using the transformation of frequency.
Block diagram:



This analyzer is a triple superheterodyne. In classic analyzers of this type, reading of measurement results was performed using the oscilloscope tube. In this case, reading is digital. The measurement results and settings are displayed on the graphic display with a resolution of 240x128 pixels with T6963C controller. Microcontroller used is Atmega16, the software is about 6KB of Assembler. Snapshots of the display screen are sent to PC through RS232 (to record the results of measurements). Software for the PC platform was written in Delphi 7.0 with the use of a component ComPort to support RS232.
Parameters:

• input frequency range: 45 – 860MHz
• the bandwidth of the measuring circuit: 4,5KHz; 340KHz
• tuning step: 1.25KHz, 12.5KHz, 62.5KHz, 312.5KHz
• the maximum width of the spectrum displayed on the screen: 75MHz
• sensitivity: about 15uV
• supply voltage: 230V 50Hz
• power consumption: ≤30W
• input impedance: 75ohm
• unit control: pulser and keyboard
• transferring an image from the LCD to a PC via RS232 interface
• sweep speed: ≥60 measurements per second
• presentation of the results of measurements on the graphic LCD display
• resolution of LCD readout field: 240x128 pixels
• FM radio snooping with squelch

Such device allows to perform simple measurements. For example you can specify the frequency of the narrowband signal interfering with the signal of our channel.
Photos of the device:




The housing was made on basis of the Polish digital voltmeter V534.
The following pictures show the measurements made with the spectrum analyzer:
Spectrum of a sinusoidal signal, without modulation:



FM modulation with deviation of 10KHz and 2KHz sequentially:



Piece of radio set band UKF:



Signal from the control image generator - lattice:



Signal from the control image generator – dots:



Unknown and quite mysterious radio signal:



As before, but laboratory narrowband interfering signal with the HF generator was put:



Schematic diagram of the digital module:



Schematic diagram of the analogue module:



Necessary for the tuning of such a system apparatus: 10MHz-2GHz vobulator and generator G4-116 4MHz-300MHz.



Link to original thread – Analizator widma na głowicy TV