EMRFD Message Archive 7741
Message Date From Subject 7741 2012-09-04 20:41:52 kb1uys EMRFD "First Transmitter" Schematic Discrepancy I just purchased a parts kit online for the "First Transmitter" in EMRFD Chapter 1. When comparing the schematic supplied with the kit vs. the EMRFD schematic, there is one connection mismatch between the oscillator and second stage amp.
See the image I uploaded at http://s17.postimage.org/wm37golbj/Untitled.jpg for a comparison of the two schematics.
The EMRFD is absolutely correct and the other is a mistake, correct?
7742 2012-09-04 20:43:43 ka7exm Re: EMRFD "First Transmitter" Schematic Discrepancy The first stage is primarily an oscillator. The goal of the second stage is to amplify the oscillation. From that standpoint both circuits should work. The signal level will be higher with the second stage, and the loading 7745 2012-09-05 09:11:36 Don Wines Re: EMRFD "First Transmitter" Schematic Discrepancy Either one will work, but taking the signal off of the base will produce a much cleaner sine wave than taking it off of the emitter. The down side is a little less drive for the next stage. IIRC this was discussed in the text.