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Old 15th Jul 2014, 10:38 pm   #7
Top Cap
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Join Date: Mar 2006
Location: Watford, Hertfordshire, UK.
Posts: 1,270
Default Re: Building a Spitfire transmitter kit

Most criticize the unit for poor Bass on transmission, this can be improved by changing C14 100uF to 470uF. I also found the tuning LED seemed to improve in indication by placing a 1N4148 diode across R34 (Anode to 0V and cathode to the cathode of D2).
I also drilled a suitable hole in the top cover for adjusting the antenna tuning as I found it needed re-tweaking with antenna placement.
I added some labels on the rear which should hopefully print to almost right dimensions by loading into MS Paint and setting the print size option to 100%.

The only odd thing I noticed about the design was the fact that they include a stabilised 12V DC supply with the unit yet the internal 3-terminal regulator is also 12V. I have not worked that one out yet
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