04-20-2009, 06:20 PM
I have an ancient Superior Instruments Genometer Signal Generator, which for it's age is pretty accurate. An old Heathkit or Eico would do as well, I usually follow the instructions in the Rider's manuals for the IF alignment, but if I have no schematic, I use a piece of styfrofoam about 2X3 inches upon which I have wound about 12 turns of #20 wire from an old transformer, and I couple that to the 600 cps modulated output of the generator and place it near the loop of the radio for RF alignment. The idea here is to get the radio to listen to the signal generator.
If I have no instructions I couple the signal generator to the ground and the first IF grid (both sides with a .1 mfd 630 volt capacitor so I continue to live, and so does the set I am working on,) and do the second section output, first section output, second section input, first section input in that order whilst keeping a digital meter across the voice coil to peak the response. You can do this by ear, if you can still reliably hear. The louder the better. That is with the tuning capacitor shut down to it's lowest level and the signal generator set to the IF frequency, usually 455 or 456 KC, but sometimes half that value, depending on the model. And I found out that as long as you are close, it doesn't ake a dime's worth of diference if you are off by a KC or two, but I still would like to have a meter to verify the output of the signal generator, and if anyone has a spare, please let me know. Please, not a boat anchor with nixie tubes, although it would be neat.
Tell us what came next!
If I have no instructions I couple the signal generator to the ground and the first IF grid (both sides with a .1 mfd 630 volt capacitor so I continue to live, and so does the set I am working on,) and do the second section output, first section output, second section input, first section input in that order whilst keeping a digital meter across the voice coil to peak the response. You can do this by ear, if you can still reliably hear. The louder the better. That is with the tuning capacitor shut down to it's lowest level and the signal generator set to the IF frequency, usually 455 or 456 KC, but sometimes half that value, depending on the model. And I found out that as long as you are close, it doesn't ake a dime's worth of diference if you are off by a KC or two, but I still would like to have a meter to verify the output of the signal generator, and if anyone has a spare, please let me know. Please, not a boat anchor with nixie tubes, although it would be neat.
Tell us what came next!
