25-05-2017, 08:25 PM
The 1804 is now supplied with channel B2 signals from an Aurora standards converter. The local oscillator has been readjusted for max video at the grid connector of the Z66 video amplifier valve. Also peaked up is the grid coil of the mixer valve.
The scope trace shows the video developed across the detector load resistor, a very impressive >12volts P - P. Even more video will be present at the detector when the aerial and first RF amplifier anode and coils have been tweeked up. To tune the receiver to channel B1 the metal tuning slugs will be replaced with iron dust cores.
Even with 12volts video across the detector load resistor there is still no sync crushing. I wish I had same amount of video to drive the CRT grid in my Marconi 702.
Geordie McBoyne.
The scope trace shows the video developed across the detector load resistor, a very impressive >12volts P - P. Even more video will be present at the detector when the aerial and first RF amplifier anode and coils have been tweeked up. To tune the receiver to channel B1 the metal tuning slugs will be replaced with iron dust cores.
Even with 12volts video across the detector load resistor there is still no sync crushing. I wish I had same amount of video to drive the CRT grid in my Marconi 702.
Geordie McBoyne.
