I apologize if my questions were vague. I am trying to find out if the
op-amps designated as U102A, B, C, and D are the typical 741 op-amp or
another type such as the 301 or 3140. I am assuming the resistors
shown in the schematic are 1/4 watt because it appears the circuitry is
not using much power. Also, I am assuming the capacitors are ceramic
disk as opposed to electrolytic because there is no polarity
designation shown in the schematic. Please let me know if my
assumptions are correct or if my thought process is flawed.

Upon further study of the tone generator schematic, it appears the
32kHz clock (crystal oscillator???) is another circuit that was
detailed in the September '04 article. The output of this clock feeds
into the digital dividers marked U101, U102, and U103. Can a generic
1N4001 diode be used in connection to the divider, or are there special
considerations that need to be taken into account?

Again, any help will be greatly appreciated. I am undertaking this
venture to calibrate my RST marker receiver.

thanks again,

Kent