I've operated the 7 Line for going on 25 years. As much as I love the rig, I have always thought that the VFO knob was on the small side and the finger hole too shallow, especially to get full use of the RV75's variable rate tuning,
Tyco/Alcoswitch makes a machined aluminum knob virtually identical to the 7 Line's original knob, their part number KN1751BS1/4. This knob is five times heavier than the original Drake knob, giving a flywheel effect that is definitely an improvement. However this knob has gotten to be expensive, over $30 at Mouser, and the finger hole is too shallow for my finger. I think I may have found an even better solution than the Alco knob. I recently ordered from Surplus Sales of Nebraska the VFO knob for the Collins KWM-380 ($18/ea new). It's bigger than the original 7 Line knob, much bigger. And I no longer have 1 kHz analog markings on the old knob's skirt. But the extra diameter is just what I was looking for and the finger hole is nice and deep. The color of the Collins knob is great match to the 7 Line's color, too. Here's a link to a picture of knob on the 7 Line: http://www.members.aol.com/leecraner/Knob.jpg In order to retain the analog dial tracking without the Drake knob skirt, I had to add a 3/8" (ID) O ring behind the new knob: http://www.members.aol.com/leecraner/Oring.jpg I recognize that modifying a rig, especially a venerable one such as the TR7, is not for everyone. However, for my old fingers, the new knob is a definite improvement. 73 Lee WB6SSW
