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I measure my tube inventory by the 25 gallon tote however my stock of 6LQ6's are getting thin. I was a Motorola radio tech for the better part of 25 years and accumulated a lot of RF service tubes along with the usual 6GH8s and related low signal TV tubes which go back to my youth messing with TV's.
The problem with the Mag is it's looking for greater than 8 volts P-P on the grid of the 6LM8 pentode, the schematic calls out a volt or so but so far experience says otherwise. I made an op-amp based input interface with 10db of gain using an LT1252 video op-amp using the mfr example schematic however it was hitting the rails at +/-12v driving the 1st video amp crushing the peaks.
I may pick up the project again over the weekend if the replacement tuner shows up, USPS promised a friday delivery however that was pushed back to saturday. I used to be a rural route carrier and know low priority packages are not delivered on the weekends around here.
The big picture plan is to get the replacement tuner in place, run thru the IF once more with the marker gen and bring everything back to "stock" as I've made so many mods over the 40+ years I can't remember them all. It's an original family set and I inherited it in early 85 when it was replaced in favor of a 27" Zenith S-3 however this one died from a shorted K/G1 short on the red gun and ran in this condition overnight. It had the A/V inputs and was left on with only black/burst and no one noticed the set was on, Magnavox won the longevity battle.
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