11-04-2007, 09:46 PM
Model 60 is a superheterodyne 
I'm not too thrilled with the Model 60 sets. They can be capable of decent performance - not fantastic, but decent. It generally requires replacement of all paper and electrolytic capacitors and ALL resistors to achieve this, however. (Hey, that has been my experience. YMMV.)
That said, however, you should be receiving your local Chicago stations on the low end of the AM dial with no problems, assuming you have some sort of antenna on it, even a few feet of wire. When you aligned the set, did you carefully adjust the low end AM padder, "rocking" the tuning condenser as you adjusted? This is critical for best performance, as this adjustment brings the front end in line with the set's IF.
To properly do this, you need to set your signal generator for 600 kc, then tune in the signal. Now adjust the trimmer slightly off one way, and follow the signal by retuning the tuning condenser. If it gets softer, adjust (and tune) in the opposite direction. But if it gets louder (as indicated by your VTVM or oscilloscope), do it again...and keep doing this until the signal does not improve any further. You will reach a point where the signal begins to decrease, and at this point you want to reverse direction and hit that peak again. This is what is meant by "rocking." Afterwards, readjust the high end trimmers for maximum output.
Once you hiit that "peak" on the low end, the dial may not indicate 60. It may be a few kc above or below 60. This is normal.
I'm not too thrilled with the Model 60 sets. They can be capable of decent performance - not fantastic, but decent. It generally requires replacement of all paper and electrolytic capacitors and ALL resistors to achieve this, however. (Hey, that has been my experience. YMMV.)
That said, however, you should be receiving your local Chicago stations on the low end of the AM dial with no problems, assuming you have some sort of antenna on it, even a few feet of wire. When you aligned the set, did you carefully adjust the low end AM padder, "rocking" the tuning condenser as you adjusted? This is critical for best performance, as this adjustment brings the front end in line with the set's IF.
To properly do this, you need to set your signal generator for 600 kc, then tune in the signal. Now adjust the trimmer slightly off one way, and follow the signal by retuning the tuning condenser. If it gets softer, adjust (and tune) in the opposite direction. But if it gets louder (as indicated by your VTVM or oscilloscope), do it again...and keep doing this until the signal does not improve any further. You will reach a point where the signal begins to decrease, and at this point you want to reverse direction and hit that peak again. This is what is meant by "rocking." Afterwards, readjust the high end trimmers for maximum output.
Once you hiit that "peak" on the low end, the dial may not indicate 60. It may be a few kc above or below 60. This is normal.
--
Ron Ramirez
Ferdinand IN
