Analogue TV - Quality comparisonsSignal source was a DVD player (Minato G1 cheap junk from Tesco) feeding composite video into an 1990s vintage Panasonic NV-F55 VCR which was used for its modulator. While under test no signal was fed to the aerial input of the Sony, so the only signal present was the DSB output of the modulator. This was fed into the Device Under Test (D.U.T.) and then fed into the antenna input of a Sony SLV-E7 VCR (1993 vintage) The baseband output of this was fed into my ATI All-In-Wonder TV/Graphics card to do the video capture.
A VCD 2.0 was prepared with a high-res MPG still
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| original | received at 59dBuV |
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You can compare the original source from which the VCD was made with the signal as received at nominal minimum signal level above. I didn't use the tuner of the ATI All-in-Wonder as this is in the PC and therefore expected to have a poor noise figure due to interference from the PC. The frequency of the modulator was measured, with the vision carrier at 612.31 MHz, which is somewhere between channel 38 (607.25) and 39 (615.25). The Panny used a free-running modulator, so adjusting this closer is not easy, but the Sony is a able to tune between channels so this is not a problem.
Signal levels and frequency were measured using a Promax 4 CATV analyser manufactured by Promax, with a relative precision of ±1dB and an absolute accuracy of ±2dB
Picture quality with decreasing signal levels
real aerial measurement of DTT performance with decreasing signal levels + adding booster
experiment demonstrating boosters don't compensate for aerial deficiencies
Improving noise figure with boosters
Selecting and siting your TV aerial
Why DTT is different from an analogue install
