I am designing a new digital board. It will act as a shield for the nano, Uno, or mega boards. It can accept a 16 X 2 LCD or a 16 X 4 LCD. A 512Kbit I2C EEPROM as well as an I2C 16 bit expander are included. Two Si570's will be on the board(different I2C addresses). Provisions for the original 10K pot tuning, a mechanical encoder or an optical encoder are included. The board will fit the front panel of the Ten Tec TP-49 case. On the main board, I am replacing the mixers with ADE-1 DBM'S. If you buy 20 they are only $2.49 each. Much simpler than winding the toroids and adjusting the pot for the original mixer! After the 1st mixer, I will add a simple post mixer amp(single 2n3904) and attenuator to properly terminate the mixer.
Dave - WB6DHW <http://wb6dhw.com> On 10/29/2014 11:23 AM, Eldon Brown wrote:
On Wed, Oct 29, 2014 at 7:39 AM, Eldon Brown <eldonb46@xxxxxxxxx <mailto:eldonb46@xxxxxxxxx>> wrote:My suggestions, For the Future: Minima Schematic Rev 2.0 - The schematic should be drawn using Open CAD/CAM tools (maybe KiCAD), but retaining the original layout as much as possible. This schematic should be usable by hobbyist or manufacture to produce; "point-to-point", "Manhattan Style", "Ugly Style" of other wired projects, or it can be used directly to produce PCB's if desired. This revisions should include the following simple and mostly "Classic Minima" compatible modifications: o Single wire Rf386 Bandpass Filter Selection move to pin PC0 o Additional six buttons parallel to the original FN button via a 47K/4K7 resistive ladder; Left/Right, Up/Down, ALT, and the Encoder Pushbutton. o Rotary Encoder pins "A" and "B" connected to PD6 and PD7, pin "C" (the included encoder push button) should be as above. And, I forgot:Minima Schematic Rev 2.0 - should include PD3 and PD4 Exchange, which will support a potential use of a software DDS to replace the hardware SideTone Oscillator.Regards, Eldon Brown 73 - Eldon - WA0UWH - http://WA0UWH.blogspot.com/
