PAL-M

NTSC being the "natural" choice for countries with monochrome standard M, the choice of a different color system poses problems of incompatibility with available hardware and the need to develop new television sets and production hardware. Walter Bruch, inventor of PAL, explains Brazil's choice of PAL over NTSC against these odds by an advertising campaign Telefunken and Philips carried out across South America in 1972, which included colour test broadcasts of popular shows (done with TV Globo) and technical demonstrations with executives of television stations.[1]

PAL-M signals are identical to North American NTSC signals, except for the encoding of the color carrier. Therefore, PAL-M will display in monochrome with sound on an NTSC set and vice versa.

PAL-M is incompatible with 625-line based versions of PAL, because its frame rate, scan line, color subcarrier and sound carrier specifications are different. It will therefore usually give a rolling and/or squashed monochrome picture with no sound on a native European PAL television, as do NTSC signals.

PAL-M being a standard unique to one country, the need to convert it to/from other standards often arises.

• Conversion to/from NTSC is easy, as only the color carrier needs to be changed. Frame rate and scan lines can remain untouched.
• Conversion to/from PAL/625 lines/25 frame/s and SECAM/625/25 signals involves changing the frame rates as well as the scan lines. This is achieved using complicated circuitry involving a digital frame store, the same method used for converting between NTSC and the 625/25 standards. The fact that the colour encoding of PAL-M and PAL/625/25 is the same does not help, as the entire signal goes through an A/D-D/A conversion process anyway.

However some special VHS video recorders are available which can allow viewers the flexibility of enjoying PAL-M recordings using a standard PAL (625/50 Hz) colour TV, or even through multi-system TV sets. Video recorders like Panasonic NV-W1E (AG-W1 for the USA), AG-W2, AG-W3, NV-J700AM, Aiwa HV-MX100, HV-MX1U, Samsung SV-4000W and SV-7000W feature a digital TV system conversion circuitry. Some recorders support the other way around, being able to playback standard PAL (625/50 Hz) in 50 Hz-compatible PAL-M TV sets, such as the Panasonic NV-FJ605.

The PAL color system (either baseband or with any RF system, with the normal 4.43 MHz subcarrier unlike PAL-M) can also be applied to an NTSC-like 525-line (480i) picture to form what is often known as "PAL-60" (sometimes "PAL-60/525," "Pseudo-PAL," or "Quasi-PAL"). This non-standard signal is a method used in European domestic VCRs and DVD players for playback of NTSC material on PAL televisions. It's not identical to PAL-M and incompatible with it, because the colour subcarrier is at a different frequency; it will therefore display in monochrome on PAL-M and NTSC television sets.

Before SBTVD, from 1999 to 2000, the ABERT/SET group in Brazil did system comparison tests of DTV under the supervision of the CPqD foundation.

The comparison tests were done under the direction of a work group of SET and ABERT. Originally, Brazil including Argentina, Paraguay and Uruguay are planned to adopt the DVB-T system. However, the ABERT/SET group selected ISDB-T as the best system among ATSC, DVB-T and ISDB-T.

The outdoor coverage of field-tests result in "Brazilian digital television tests" show that ISDB-T is most robust system in Brazil.

• ABERT/SET Brazilian digital television tests

The analog PAL-M was scheduled to be supplanted by a digital high-definition system named Sistema Brasileiro de Televisão Digital (SBTVD) by 2015, and finishing in 2018. However, SBTVD was later replaced by the Brazilian variant of the ISDB standard, ISDB-Tb, which features SBTVD's characteristics into the originally-Japanese digital norm.