Sorry - sine wave, and stable enough so that when it's mixed (with SA602)
with another signal which is then tuned with a radio in sideband mode, it
won't require retuning after warm-up. This more improtant than actual
accuracy of the 12kHz. 100Hz here or there not important.
---
HC4066 +5
+----------------------+ |
+--|MR | [100R]
| | | |
GND | RS RTC Q8 | +--[3.6nF]--[50mH]-->>--+
+-+------------+---+---+ | |
| | | C [100R]
+----[1M]----+ +--[1000R]---B 2N4401 |
| | E +--->>--+
| [500R] | |
| | GND GND
+---[XTAL]---+
| |
[10pF] [10pF]
| |
+------------+
|
GND
The 4066 is being used as an oscillator and a divider, with the
crystal frequency at 6.144 MHz. After being divided by 512, it exits
the counter as a 12kHz square wave and is then sent through a bandpass
filter to make the AC sine wave you need from it. I simulated it with
LTC's SWCADII, and the netlist follows.
The crystal is an Epson CA-301 6.1440M-C and the component values
arount it are from a design guide they have at:
http://www.eea.epson.com/go/Prod_Ad...rystals/go/Resources/TECHNOTES/OSCDESIGNGUIDE
No guarantees, but it's a starting point!
Here's the netlist:
Version 4
SHEET 1 880 680
WIRE -224 432 -224 176
WIRE -224 560 -224 512
WIRE -224 592 -224 560
WIRE -80 432 -80 384
WIRE -80 560 -224 560
WIRE -80 560 -80 512
WIRE -64 176 -224 176
WIRE -32 384 -80 384
WIRE 80 384 48 384
WIRE 144 176 16 176
WIRE 144 336 144 176
WIRE 144 560 -80 560
WIRE 144 560 144 432
WIRE 208 176 144 176
WIRE 352 176 272 176
WIRE 352 240 352 176
WIRE 352 416 352 320
WIRE 352 560 144 560
WIRE 352 560 352 496
FLAG -224 592 0
SYMBOL voltage -224 416 R0
WINDOW 123 0 0 Left 0
WINDOW 39 0 0 Left 0
SYMATTR InstName V1
SYMATTR Value 5
SYMBOL npn 80 336 R0
SYMATTR InstName Q1
SYMATTR Value 2N4401
SYMBOL voltage -80 416 R0
WINDOW 3 -30 212 Left 0
WINDOW 123 -30 240 Left 0
WINDOW 39 0 0 Left 0
SYMATTR InstName V2
SYMATTR Value PULSE(0 5 0 0 0 4.167E-5 8.33E-5)
SYMBOL res 64 368 R90
WINDOW 0 -37 56 VBottom 0
WINDOW 3 -35 56 VTop 0
SYMATTR InstName R1
SYMATTR Value 1000
SYMBOL res 32 160 R90
SYMATTR InstName R2
SYMATTR Value 100
SYMBOL cap 272 160 R90
WINDOW 0 -18 -15 VBottom 0
WINDOW 3 -18 -20 VTop 0
SYMATTR InstName C1
SYMATTR Value 3.6E-9
SYMBOL ind 336 224 R0
WINDOW 0 -47 45 Left 0
WINDOW 3 -66 80 Left 0
SYMATTR InstName L1
SYMATTR Value 50E-3
SYMBOL res 336 400 R0
SYMATTR InstName R3
SYMATTR Value 100
TEXT -258 648 Left 0 !.tran 0 .005 .004 uic