DDS VFO PARTS LIST
- 20 pin integrated circuit socket (2 required) - $.80 - Mouser: 649-DILB20P-223TLF
-
5 volt regulator - LM-7805 - $1.54. Mouser:
926-LM7805CT/NOPB
- D1 (1N4001) - $.19
Mouser:
621-1N4001
- D2 (1N4148) - $.10 Mouser:
512-1N4148
- Cost: $.10
9. Install six (5) .1 mf capacitors (C1, C3, C4,
C6, C18)- Mouser:
594-K104Z15Y5VE5TL2
- Costs: $ 1.00
10. Install one (1) .22 mf capacitor (C17)
- Mouser: 810-FA14X8R1E22400
- Cost: $.45
11. Install two (2) .01 mf capacitors (C8, C15)- Mouser:
80-C324C103K3G5TA
- Cost: $.50
12. Install the 100 uh inductor (L4)- Mouser: 542-78F101-RC
- Cost: $ .86
13. Install 5 (five) 1K, 1/4 watt resistors (R5, R6,
R9, R11, R15)- Mouser:
71-CCF071K00GKE36
14. Install 1 (one) 3.9k 1/4 watt resistor (R3)- Mouser: 603-MFR-25FRF52-3K9
- Cost: $.10
15. Install 3 (three) 10 K, 1/4 watt resistors (R5, R6, R16)- Mouser: 660-MFS1/4DCT52A1002
- Cost: $.30
16. Install 1 (one) 27 ohm, 1/4 watt resistor (R12)- Mouser: 603-MFR-25FRF52-27R
- Cost: $.12
17. Install 2 (two) 470 1/4 watt resistors (R10, R19)- Mouser:
603-CFR-25JR-52470R
- Cost: $.20
18. Install 1 (one) 100 ohn, 1/4 watt resistor (R8)- Mouser: MF1/4LCT52R121G
- Cost: $.10
19. Install the 10 K trimmer resisor (R18) - used to adjust the DDS
amplifier output level - max output possible is 4.0 VAC, peak-to-peak.- Mouser:
652-3296W-1-103LF
- Cost: $ 2.87
20. Install 2 (two) 100 ohm 1/4 watt resistors (R7,
R13) -
part of 7 Mhz Butterworth Filter- Mouser: 71-CCF07100RJKE36
- Cost: $.20
21. Install 2 (two) 390 pf capacitors (C10, C12) - part of
7 Mhz Butterworth Filter- Mouser:
80-C318C391K3G5TA
- Cost; $.80
22. Install 2 (two) 100 pf capacitors (C7, C13) - part of
7 Mhz Butterworth Filter- Mouser:
80-C315C101J3G5TA
- Cost: $.40
23. Install 2 (two) 2.7 uh inductors (L1, L3) - part of
7 mhz Butterworth Filter- Mouser:
542-78F2R7-RC
- Cost: $.46
24. Install 1 (one) 4.7 uh inductors (L2) - part of
Butterworth Filter- Mouser:
542-78F4R7-RC
- Cost: $ .22
25. Install 2 (two) 10uf 25 volt electrolytics (C2, C5) -
observe the polaity - Mouser:
75-515D106M025JA6AE3
- Cost: $.64
26. Install 2 (two) PN2222A (or equivalent) transistors (Q1, Q2)- Mouser: 512-PN2222ABU
- Cost: $.60
27. Install pin header connectors at the following points:
- Pin headers are available from Mouser or from eBay (cut a large header to fit)
- Power - JP-1 - 2 pin
- Lock / Store - 2 pins
- Program
not required - for in-circuit programming purposes only.
- Encoder - 4 pins
- RIT
- 3 pins
- Buttons - 5 pins
- LEDS - 3 pins
- FREQ OUT - 2 pins
- +5VDC - 1 pin
- used for the LED's
You'll also need:
- AD9850
DDS Assembly (purchase from eBay, Amazon and from other
sources - surf the web). A fully assembled unit costs around $16, and sometimes
even less - shipped free to
your home. Google the internet for options.
- Cost: approx - $16 - varies.
- Optical
encoder w/Knob -
(eBay is an excellent source).
The optical encoder I used is a Bourns ENJ1A-B28-L00128L,
purchased brand new on eBay relatively inexpensively ($21). It outputs 128 quadrature pulses per revolution which the
PIC decodes as 512 changes of state per revolution.
So,
512 state changes (per revolution) x 10 hz for each state change
= 5.1 khz frequency step for each complete (360 degrees)
encoder revolution. Optical encoders with higher state changes
per revolution will obviously result in larger frequency steps per
revolution.
- Light Emitting Diodes (3)
- Mouser
: 941-C503BBCNCW0Y0452 - or equivalent
- VFO A
- VFO B
- SPLIT
- SPST Push Buttons - - buy from either Mouser or eBay.
- VFO Toggle
- SPLIT Function
- FAST Tuning Select (hold for fast tuning)
- SPST Switch - activates the RIT
- 20K (or so) linear taper potentiometer (with knob) which serves as the
RIT control.
- (Optional) Sloping Panel Enclosure
- Mouser: 1456CE3BKBU
- Cost: $22.29