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More sweep voltage for the electronic eyeball

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The article "The electronic eyeball" in QST, 1 January 1959, stirred my desire to build a panoramic adapter. After building the unit, I found that I could not get enough sweep voltage from the 12AX7 tube for full linear horizontal deflection.

I gave the problem some thought, thumbed through tube data and then decided to use a 6U8 in place of the 12AX7. The results were gratifying. I had almost twice the linear sweep voltage that I had before. The new circuit for the oscillator-amplifier is shown in Fig. 1. The only additional voltage required is 150 volt regulated for the screen of the pentode section.

Fig 1
Fig. 1. Modified sweep circuit for the Electronic Eyeball All resistors are %z watt unless otherwise specified.

Donald C. Hanna, VE2CD.