A small heat radiating plate cap connector is also of benefit. A small amount of air flow can greatly increase tube life but care is needed in mounting a fan, especially in those transmitters using 7360 or other sheet beam tubes as balanced modulators since they are easily upset by stray magnetic fields. Given the price of most sweep tubes today it is a good idea to provide forced air cooling for any rig that wasn't originally equipped with a fan. Once initial tune-up is complete then record the values so that future tune-up will be faster with no large out of resonance current flow. This is also the proper method for using a sweep tube equipped SSB/CW rig when the accompanying amplifier requires lower drive. For best life with sweep tube finals, load quickly to rated input and then reduce the input slightly by reducing drive level. Screen grid current soars under high drive/light loading conditions and the screen grid is the most fragile element in most sweep tubes. In addition to minimizing tune-up time and out of resonance high plate current it is also very important to keep the final properly loaded.
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