TV modulator mod?

[jhalphen]

Hi to all,

Thanks! E-type2

@Lu Raichu : any analogue source can feed the modulator : NTSC composite output of a digital ATSC box, VCR, DVD player, video camera, test pattern generator, computer,...

"Old school pirates" probably used the VCR as an edited program source.
The VCR's modulator could feed a distribution system (such as a block of condos) and be received as a channel on cable.
However, the VCR modulator connected to an antenna will "Broadcast" to a distance of 3ft-6ft max (and with a snowy picture).

The Blonder-Tongue(s) discussed above have a far more powerful RF output especially the AM-60 series. 60 meaning 60dB/millivolt.

VCR modulators or the classic Radio Shack which outputs on VHF Ch3 & Ch4 radiates 60 to 90dB/microvolt, enough for a coaxial feed direct to your TV, not for OTA Broadcasting.

See attached file giving RF level measurements according to the dB (deciBel) reference level chosen : microvolts, millivolts, power in milliWatts. Impedance is 75 Ohms in TV gear. In radio, it's 50 Ohms. This is important when measuring actual RF power.

Best Regards
jhalphen
Paris/France