06-04-2017, 09:37 AM
Hi Sam,
The range of HMV TV sets that it is said almost bankrupted EMI was the 1807 series which was introduced late 1949. Although alleged to be the most unreliable TVs of all time I'm beginning to question if these sets were really that bad after all?
As for the post war models including the 1804 these were built to the same standards as the pre-war models, everything was built on a truly massive scale. The 1804 weighs in at a hefty 84 pounds!
I can compare this HMV with a similar set, the Marconi VT50. Same electrically, different cabinet presentation.
In an early post I mentioned that the 1804 we are discussing has a Pye FV1 type of double diode interlace filter wired in. In the original EMI design a single diode interlace filter is employed, one section of a D63/6H6 double diode. I will remove the alien interlace circuits and reinstate the original EMI interlace filter. Same goes for the sound IF amplifier valve, the SP61 and it's Mazda Octal valveholder will be taken out and the correct International Octal valveholder fitted along with a KTW61 or equivalent vari-mu pentode.
Geordie McBoyne.
The range of HMV TV sets that it is said almost bankrupted EMI was the 1807 series which was introduced late 1949. Although alleged to be the most unreliable TVs of all time I'm beginning to question if these sets were really that bad after all?
As for the post war models including the 1804 these were built to the same standards as the pre-war models, everything was built on a truly massive scale. The 1804 weighs in at a hefty 84 pounds!
I can compare this HMV with a similar set, the Marconi VT50. Same electrically, different cabinet presentation.
In an early post I mentioned that the 1804 we are discussing has a Pye FV1 type of double diode interlace filter wired in. In the original EMI design a single diode interlace filter is employed, one section of a D63/6H6 double diode. I will remove the alien interlace circuits and reinstate the original EMI interlace filter. Same goes for the sound IF amplifier valve, the SP61 and it's Mazda Octal valveholder will be taken out and the correct International Octal valveholder fitted along with a KTW61 or equivalent vari-mu pentode.
Geordie McBoyne.
