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> 10 fet varactor uhf tuners atv down converters 70MHZ if
10 fet varactor uhf tuners atv down converters 70MHZ if
FET Varactor UHF Tuner - ATV Down Converter - 70MHz IF
Originally manufactured as a television receiver component for TV channels 14 - 83 ( 470 - 890 MHz ). Amateur radio operators discovered that it could be tuned below and above that range to reach the 420 MHz and 900 Mhz amateur radio bands in which some of the hams transmit amateur television. For that purpose; an ordinary television set to channel 4 would display the down converted picture. Other uses: a poor man's spectrum analyzer, as a front end for voice communications reception, or down convert the CATV 59 from Ramsey Cube CCD cameras to view the picture on common TV sets.
Dimensions: 3 1/4 x 2 1/8 x 15/16 inches ( not counting pins and "F" connector )
Representative Schematic Diagram ( Radio Shack 277-220 ):
Single page hook up instructions:
Note: The instruction sheet states that IF output is on TV channel 2 but this listing is for a custom built tuner identical to the one the instruction sheet was written for in every respect except: output is on TV channel 4. The same is true with schematic diagram. Only differences are IF filter parts values: L17, L18, L19, C26, C28.
power supply components not included; only the tuner module itself
download printer friendly documentation => adobe acrobat pdf (92 kb)
