This was one of the biggest benefits of using Nuvistor tubes in the front end. They are high Gm tubes no doubt, but there are conventional tubes of greater Gm (like the 6DJ8 for example) than commercial Nuvistor tubes. But conventional tubes are subject to greater effects from heating due to their greatly enlarged surface area -- or from heat from another tube section within the same glass envelope, compared to that of a Nuvistor tube. One of their biggest contributions then was helping to minimize drifting.
IF transformers with compromised (and/or) intermittent resonant caps invariably affect IF strip gain and therefore signal strength indications, rather than go so far as to effectively change the frequency the receiver is tuned to. For the IF strip to intermittently shift its tuning peak enough to allow reception of other stations would likely require all the transformers to shift in the appropriate direction and by the same amount -- all of which is highly unlikely, if not impossible. This problem will invariably be found in the RF section of the tuner.......
Dave
IF transformers with compromised (and/or) intermittent resonant caps invariably affect IF strip gain and therefore signal strength indications, rather than go so far as to effectively change the frequency the receiver is tuned to. For the IF strip to intermittently shift its tuning peak enough to allow reception of other stations would likely require all the transformers to shift in the appropriate direction and by the same amount -- all of which is highly unlikely, if not impossible. This problem will invariably be found in the RF section of the tuner.......
Dave
