RL-20 REV1, 2, and 3 Parts List

**There are no circuitry changes between Revisions 2 and 3, except for convenience 
connection "holes" to +5V for powering a MIC and Audio Amplifier.

All Parts are installed as close to the board as possible, don't over stress the leads 
on Q1. Trim all leads as short as possible. I use flush cutting pliers, just be careful 
if/when using those. I get mine from Harbor Freight - around $4 a pair.

If you are building a radio-less node, depending on your enclosure, you may NOT want to 
install the LEDs and DB9 chassis connector. They can be remotely mounted, and the LEDs 
can serve other roles like using LED3's location as the PTT indicator in radio-less 
applications. LED1's position can be used for a "BUSY" indication when traffic is being 
heard from the network. The yellow LED would then be placed into location LED1.

U1 - CM119A (presoldered)

D1 - BAT43 (observe polarity!)
D2 - BAT43 (observe polarity!)
D3 - BAT43 (observe polarity!)

J1 - DB9 Female Chassis Connector
J2 - USB-B Chassis Jack

LED1 - 3mm Red LED
LED2 - 3mm Green LED
LED3 - 3mm Yellow LED
All LEDs orient with long lead in the round hole.

Y1 - 12 MHz Crystal

Q1 - 2N2222

All Resistors are 1/8 Watt
R1  - 1k
R2  - 10k
R3  - 330 ohm
R4  - 1M ohm
R5  - 22 ohm
R6  - 22 ohm
R7  - 330 ohm
R8  - 1.5k
R9  - 100k Pot (104)

NOTE: Components that are supplied on a "carrier" paper should have their leads cut 
from the carrier near the edge of the paper. Don't try to pull the component away 
from the carrier, otherwise you could damage it.

NOTE: Some components have pre-bent leads and they'll need to be reformed to allow 
the part to fully seat on the surface of the circuit board.

NOTE: Polarized capacitor locations include a "+" (plus sign) silkscreened on the side 
where the positive lead orients.

C1  - 47pF small yellow MLCC (marked 47 or 470)
C2  - 20pF or 22pF small yellow or blue MLCC (marked 20 or 200, or 22 or 220)
C3  - 0.47uF Tantalum 35V (yellow or blue) (observe polarity!) (** See Note Below)
C4  - 20pF or 22pF small yellow or blue MLCC (marked 20 or 200, or 22 or 220)
C5  - 0.47uF Tantalum 35V (yellow or blue) (observe polarity!) (** See Note Below)

** C3 and C5 are supplied as a blue, orange, or yellow part - and they are polarity sensitive.
The positive lead is on the right side when the printing faces you, and the leads are 
pointing down. (either color).

C3 is installed so the printing faces C2 (either color).
C5 is installed so the printing faces R9 (either color).

C6  - 10uF 16 or 25V black electrolytic (observe polarity!)
C7  - 10uF 16 or 25V black electrolytic (observe polarity!)
C8  - 0.1uF .1"LS (Marked "104") (small yellow)
C9  - 47pF small yellow MLCC (marked 47 or 470)
C10 - 47pF small yellow MLCC (marked 47 or 470)
C11 - 47pF small yellow MLCC (marked 47 or 470)
C12 - 4.7uF 25 or 35V small electrolytic (observe polarity!)
C13 - 4.7uF 25 or 35V small electrolytic (observe polarity!)
C14 - 4.7uF 25 or 35V small electrolytic (observe polarity!)
C15 - 47pF small yellow MLCC (marked 47 or 470)
C16 - 4.7uF 25 or 35V small (observe polarity!)
C17 - 100uF NON-POLAR (large black)  (can be installed either way)
C18 - 100uF NON-POLAR (large black)  (can be installed either way)
C19 - 47pF small yellow MLCC (marked 47 or 470)
C20 - 1uF Tantalum (marked 105) (observe polarity!) [added in revision 2 and beyond]

JU1 - 2-pin blue header - with shorting jumper.

MIC +5V "hole" for powering a DTMF microphone in radio-less 
installations [added in revision 2]

AUDIO AMP +5V "hole" for powering a audio amplifier in radio-less 
installations [added in revision 3]

RL-20 printed circuit board (any revision) Violet color board for REV3.
LS = Component lead spacing - 0.1 inches = 2.54mm.
MLCC = Multi-Layer Ceramic Capacitor.