12-06-2008, 10:23 PM
Quote: Is there a way to ensure that the signal generator is working at 260 kHz, without a frequency counter.
You could try listening for the third harmonic which should be at 780kc.
Quote: If we assume that the signal generator is working properly, I assume that I would adjust trimmer 1 until I hear the generator tone from the speaker. How much adjustment might the trimmers need? I'm not sure if I should be seeing something within a half-turn either direction ... just not sure what to expect. Will the trimmer stop at the end of its travel?
If your signal generator is working properly, you should be able to hear it even if the I.F.'s are somewhat off-tune. Typically, you should not have to adjust them more than a half-turn in either direction, since the radio is working.
One thing you might try is to tune the signal generator until you hear the signal through the I.F.'s in the radio and then see what the frequency on the signal generator reads.
Really, unless you have a digital signal generator, an inexpensive frequency counter to measure the accuracy of the signal generator would be the way to go.
Regards,
Ed
