`Bill of materials (parts list)`

UPDATED 13/01/2018

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`Resistors`

All resistors 1/4W Metal film unless otherwise noted.
SMD types are 0603 Imperial unless otherwise noted.

R1 - 10k (phantom power for electret mikes)
R2 - 1k (used as an RF filter with C2)
R3 - 100k (pulldown to keep DC off Q1)
R4 - 10k
R5 - 100k
R6 - 47k
R7 - 6k8
R8 - 4k7
R9 - 47 ohms
R10 - 100 ohms
R11 - 1k
R12 - 1k
R13 - 220 ohms
R14 - 1k
R15 - *deleted*
R16 - 220k (top half of receive amplifier audio attenuator - change value if required)
R17 - 10k (bottom half of receive amplifier audio attenuator and pulldown to keep DC off Q4)
R18 - 220 ohms SMD (top half of TDA2003 negative feedback attenuator)
R19 - 2.2 ohms SMD (bottom half of TDA2003 negative feedback attenuator)
R20 - 1 ohm SMD (TDA2003 HF load resistor)

R21 - 22 ohms (OpAmp decoupling)
R22 - 10k
R23 - 100k
R24 - 7k5
R25 - 15k
R26 - 30k
R27 - 7k5
R28 - 7k5
R29 - 100k
R30 - 75k (corrects DC bias on U1b)
R31 - 4k7 (OR 10k for less EQ) (sets hardware transmit EQ shelf)
R32 - 10k
R33 - 10k (sets gain of U1b) UPDATED (was 1.5k)
R34 - 10k
R35 - 10k
R36 - 180 ohms
R37 - 100k
R38 - 1k
R39 - 1k
R40 - 27k (finely sets bias midpoint of dsPIC ADC, compensates for voltage drop across R56 and R57)
R41 - 10k
R42 - 100 ohms
R43 - 560 ohms
R44 - 10k
R45 - 47k (sets output attenuation to suit transceiver mike gain) Use 22k for 6dB more level, use 10k for 12dB more level.
R46 - 10k - Critical value for ground loop suppression
R47 - 10k - Critical value for ground loop suppression
R48 - 100k - Critical value for ground loop suppression
R49 - 150k (sets DC bias on U2a)
R50 - 100k - Critical value for ground loop suppression
R51 - 1k
R52 - 10k
R53 - 10k
R54 - 10k
R55 - 10k
R56 - 10k
R57 - 10k
R58 - 1k
R59 - 1k
R60 - 10k
R61 - 100k
R62 - 10k
R63 - 10k
R64 - 10k
R65 - 1k
R66 - 1k
R67 - 1k
R68 - 1k
R69 - 1k
R70 - 1k
R71 - 1k
R72 - 1k
R73 - 100
R74 - 100
R75 - 100
R76 - 1k
R77 - 1k
R78 - 220 ohms (sets headphone drive level and affects OpAmp loading)
R79 - 220 ohms (sets headphone drive level and affects OpAmp loading)
R80 - 10k (pulldown to prevent headphone thumps)
R81 - 47 ohms (RC filter with C56 to prevent RF affecting U1a)
R82 - 100 ohms (RC filter with C57 helps RF filter PTT line)
R83 - 1k (has been selected to pass just enough current to switch dsPIC pin 14 RB5 from PTT line)
R84 - 390 ohms (new LED backlight current) Increase value to dim LED.

R100 - 10 ohms to 47 ohms (not critical - used for decoupling and current limiting on 12V rail)
R101 - 100 ohms (current limiting for D19 TOSLINK LED)
R102 - 100 ohms (current limiting for Q9 TOSLINK driver transistor)
R103 - 1k
R104 - 2k2 (sets LED driver IC bright current)
R105 - 20k (sets LED driver IC dim current)
R106 - 1k
R107 - 1k
R108 - 1k
R109 - 10k
R110 - 100k
R111 - 1k (dual colour LED dim current)
R112 - 390 ohms (old LED backlight current) OBSOLETE Use R84 & D20 instead!
R113 - 470 ohms (dual colour LED bright current)
R114 - 1k (sets decimal point bright current)
R115 - 10k (logic pulldown)

`Capacitors`

SMD types are 0603 Imperial unless otherwise noted.
Some SMD pads are enlarged to also enable larger types to be fitted: 0805, 1206 etc.

* Capacitors C0 to C5 have been renumbered

C0 - 2n2 SMD or leaded ceramic (RF bypass) Located at the back of the electret mike element - Very important for electret microphone RF filtering!
C1 - 1uF Tantalum 10V or more (Low leakage audio coupling)
C2 - 2n2 SMD (RF bypass) Very important for input RF filtering.
C3 - 1uF Tantalum 10V or more (Low leakage audio coupling)
C4 - 2n2 SMD (RF bypass) Very important for input RF filtering.
C5 - 100n ceramic SMD (improves PWM filtering)
C6 - 100n ceramic SMD
C7 - 100n ceramic monolithic OR SMD
C8 - 470uF 10V miniature electrolytic 0.1 inch (2.54mm) lead spacing * Critical size - capacitor height less than 10mm
C9 - 4u7 6V or more miniature electrolytic 4x7mm can size
C10 - 100uF 10V miniature electrolytic 4x7mm can size SPECIAL SIZE
C11 - 100n SMD (MKP could also be fitted) (TDA2003 input resistance is typically 150k, so 100n should be adequate for good bass response to below 50Hz)
C12 - 470uF 10V miniature electrolytic 0.1 inch (2.54mm) lead spacing
C13 - 100uF 16V miniature electrolytic 0.1 inch (2.54mm) lead spacing * Critical size - capacitor height less than 10mm
C14 - 100n SMD ceramic
C15 - 220n SMD ceramic
C16 - 1000uF 10V electrolytic 3.8mm lead spacing, 8mm diameter Critical size *Note: Some eBay capacitors of this type have very limited lifespan.
C17 - 10n SMD ceramic
C18 - 10n SMD ceramic
C19 - 100n SMD ceramic
C20 - 100n SMD ceramic
C21 - 22uF to 100uF 16V electrolytic 5x7mm can size * Critical size - capacitor height less than 10mm
C22 - 1000uF 16V electrolytic 0.2 inch lead spacing, 10mm diameter (maximum ~11mm) x16mm high Critical size
C23 - 100uF 10V miniature electrolytic 4x7mm can size SPECIAL SIZE *** On PCB 260 and later, C23 is a 47uF 16V Tantalum SMD size "C" capacitor, mounted on the top layer
C24 - 100uF 10V miniature electrolytic 4x7mm can size SPECIAL SIZE *** On PCB 260 and later, C24 is a 47uF 10V or 16V Tantalum SMD size "C" capacitor, mounted on the top layer
C25 - 10n SMD ceramic (RF bypass for Rx In)
C26 - 10n SMD ceramic (RF bypass for Rx In)
C27 - 10UF 25V miniature electrolytic 4x7mm can size SPECIAL SIZE
C28 - 10UF 25V miniature electrolytic 4x7mm can size SPECIAL SIZE
C29 - 330pF SMD or disc ceramic (RF bypass for U2b)
C30 - 330pF SMD or disc ceramic (RF bypass for U2b)
C31 - 47nF MKP polyester (sets hardware transmit EQ turnover frequency)
C32 - 100uF 10V miniature electrolytic 4x7mm can size SPECIAL SIZE
C33 - 22uF 10V miniature electrolytic 4x7mm can size SPECIAL SIZE
C34 - 100n monolithic ceramic or SMD
C35 - 100n monolithic ceramic or SMD
C36 - 470uF 10V miniature electrolytic 0.1 inch (2.54mm) lead spacing * Critical size - capacitor height less than 10mm
C37 - 100n monolithic ceramic or SMD
C38 - 100uF 10V miniature electrolytic 4x7mm can size SPECIAL SIZE
C39 - 1n SMD OR ceramic disc (analog input antialias filter and RF bypass)
C40 - 1n SMD OR ceramic disc (analog input antialias filter and RF bypass)
C41 - 10u 25V miniature electrolytic 4x7mm can size SPECIAL SIZE
C42 - 10u 25V miniature electrolytic 4x7mm can size SPECIAL SIZE
C43 - 10n SMD ceramic
C44 - 10n SMD ceramic
C45 - 10u 25V miniature electrolytic 4x7mm can size SPECIAL SIZE
C46 - 100p SMD or disc ceramic
C47 - 10u 25V miniature electrolytic 4x7mm can size SPECIAL SIZE
C48 - 100p SMD or disc ceramic
C49 - 22u 10V miniature electrolytic 4x7mm can size SPECIAL SIZE
C50 - 330pF SMD or disc ceramic (compensation for U1a)
C51 - 10n SMD ceramic Not used on prototype **
** If D6 is a through-hole type, C51 can be a large 1206 SMD type mounted on the PCB bottom layer. A leaded ceramic can also be used.
** If D6 is an SMD type, C51 can be a small 0603 SMD type mounted on the top PCB layer.
** With careful placement, a 0603 SMD C51 could also be placed underneath D6 on the top layer.
C52 - 10n SMD ceramic
C53 - 1n SMD ceramic
C54 - Deleted - Replaced with Zener diode D9
C55 - 10u 16V Tantalum OR 1210 SMD ceramic Critical (bypass for internal dsPIC voltage regulator)
C56 - 1u 10V Tantalum OR miniature electrolytic OR SMD 100n to 1uF - Audio coupling to U4.
C57 - 470uF 10V miniature electrolytic 0.1 inch (2.54mm) lead spacing * Critical size - capacitor height less than 10mm
C58 - 10n SMD ceramic
C59 - 10n SMD ceramic
C60 - 10n SMD ceramic - RF grounding for edge tracks on top layer
C61 - 10n SMD ceramic - RF grounding for edge tracks on top layer
C62 - 10n SMD ceramic - RF grounding for edge tracks on top layer Optional
C63 - 10n SMD ceramic - RF grounding for edge tracks on top layer Optional
C64 - 10n SMD ceramic - RF grounding for Output Mini-DIN shell terminal Optional
C65 - 10n SMD ceramic - RF grounding for Input Mini-DIN shell terminal Optional
C66 - 330p SMD ceramic - RF bypass for U1a non-inverting input. Pads near C50 but unmarked on PCB.

These bypass capacitors are not critical in value:
C100 - 47uF 16V SMD size "C" Tantalum not critical
C101 - 47uF 10V or 16V SMD size "C" Tantalum not critical
C102 - 47uF 16V SMD size "C" Tantalum not critical Not used on prototype 1
C103 - 47uF 16V SMD size "C" Tantalum not critical Not used on prototype 1

`Inductors`

L1,L2,L4,L6,L7 - Ni-Zn 3.5x6.0mm Ferrite bead-on-lead were used on the prototype, but Mn-Zn high permeability ferrite will work better at low frequencies.
L3 - 1mH (1000uH) miniature axial leaded RFC (1 millihenry = Brown Black Red)
L5 - 10uH miniature axial leaded RFC Must have less than 1 ohm DC resistance, and greater than 10mA rating
L8 - Ferrite bead on flying lead OPTIONAL Not used on prototype - Mn-Zn high permeability ferrite will work better at low frequencies.

`Diodes`

Diodes D1 to D11 have been renumbered 26/01/2015
Be careful to observe correct polarity.

D1 - Surface mounted 1N4001 OR similar SMD power diode (for reverse polarity protection)
D2 - 3v6 1W Zener diode for CPU overvoltage protection
D3 - 1N4148
D4 - 1N4148
D5 - 1N4148
D6 - 18V 400mW leaded or SMD Zener diode
D7 - 18V 400mW leaded or SMD Zener diode
D8 - 18V 400mW leaded or SMD Zener diode
D9 - 18V to 33V SMD Zener diode (Must be greater than 16V, but below 45V) Optional (For additional protection of Q7)
D10 - 3mm 0R SMD superbright white LED for keypad backlighting
D11 - 1N4148
D12 - 3v3 SMD Zener diode Optional

D100 - 3mm Two wire dual colour red/green LED - SMD LEDs can also be used on commercially made PCB
D101 - 1-digit 7-segment Common-Anode LED display 0.56 inch White
D102 - 3mm Green LED - SMD can also be used on commercially made PCB
D103 - 3mm Green LED - SMD can also be used on commercially made PCB
D104 - 3mm Green LED - SMD can also be used on commercially made PCB
D105 - 3mm Yellow LED - SMD can also be used on commercially made PCB
D106 - 3mm Yellow LED - SMD can also be used on commercially made PCB
D107 - 3mm Yellow LED - SMD can also be used on commercially made PCB
D108 - 3mm Orange LED - SMD can also be used on commercially made PCB
D109 - 3mm Orange LED - SMD can also be used on commercially made PCB
D110 - 3mm Red LED - SMD can also be used on commercially made PCB
D111 - Superbright red LED 5mm or 3mm
D112 - Superbright white LED 5mm or 3mm OBSOLETE Use D10 LED instead!

`Transistors`

Q1 - BC549C NPN TO92
Q2 - BC549C NPN TO92
Q3 - BC557 PNP TO92
Q4 - BC549 or 2N3904 NPN TO92 (NOTE: the 2N3904 package has reversed C and E leads)
Q5 - 2N7000 MOSFET TO92
Q6 - 2N7000 MOSFET TO92
Q7 - BC557 PNP TO92
Q8 - BC549 or 2N3904 NPN TO92 (NOTE: the 2N3904 package has reversed C and E leads)

Q9 - MMBT3904 NPN SMD
Q10 - MMBT3904 NPN SMD
Q11 - MMBT3904 NPN SMD
Q12 - MMBT3906 PNP SMD
Q13 - MMBT3904 NPN SMD
Q14 - MMBT3904 NPN SMD

`ICs`

U1 - M5218L SIP Dual OpAmp
U2 - M5218L SIP Dual OpAmp
U3 - dsPIC33FJ64GP802-I/SP OR dsPIC33FJ128GP802-I/SP 28-pin DIP Digital Signal Controller - Available from Microchip online http://www.microchipdirect.com/ProductSearch.aspx?keywords=DSPIC33FJ64GP802-I/SP *OR* http://www.microchipdirect.com/ProductSearch.aspx?keywords=DSPIC33FJ128GP802-I/SP
U4 - TDA2003 10W audio amplifier
U5 - TDA2822 8-pin DIP 2W stereo audio amplifier (used as a bridged LED driver - these were purchased from G&C on eBay for under $2US for 10)
U6 - SM16126D SMD SOIC-24 16 bit serial constant current common anode LED driver IC

`Regulators`

Reg1 - AMS1117-5 5 volt SMD regulator SOT-223 package
Reg2 - AMS1117-3.3 3.3 volt SMD regulator SOT-223 package
Reg3 - AMS1117-3.3 3.3 volt SMD regulator SOT-223 package

`Switches`

SW1-SW4 - 6x6mm right-angle PCB mount tactile switches, 6.85mm shaft

`Connectors`

J1 - 5.5 x 2.1mm PCB mount DC power socket SPECIAL
J2 - 4-way 0.1 inch (2.54mm) Pin header socket strip
J3,J5,J7,J10 - Ultra-slim 4-pin 3.5mm stereo PCB mount socket SPECIAL "Lumberg 1503-07"
J4,J6 - 8-pin Mini DIN socket SPECIAL
J8 - 10-way 0.1 inch (2.54mm) Pin header socket strip
J9 - 4-way 0.1 inch (2.54mm) Pin header socket strip

Machine pin IC socket strips for U3 (two strips of 14 pins)
14x 2.54mm right-angle header pins for Display PCB 1 connectors (the prototype used the longer pins from a strip of right-angle dual row pin headers) - Gold plated pins are recommended to provide most reliable contact.
*** UPDATE - Instead of using right-angle pins on the Display PCB, the header pin sockets can be mounted on the Display PCB, and straight header pins can be mounted on the main PCB. This is easier. See the blue section on the main page titled: "Simpler PCB pin mounting".
4x 2.54mm straight header pins for Display PCB 1 mechanical mounting - Not used on prototype - Gold plated pins are recommended to provide most reliable contact.
2x 2.54mm dual header pin sockets for Display PCB 1 mechanical mounting - Not used on prototype
2x Matching 8-pin mini-DIN plugs for transceiver fly leads Must match mini-DIN socket pin pattern!
1x Microphone plug to suit transceiver
2x 3.5mm stereo plugs for receive audio OR pre-made 3.5mm to 3.5mm stereo lead
1x 3.5mm Mini-TOSLINK to normal TOSLINK cable for digital audio output Optional

`Misc`

F1 1.65A 30V RUEF135 PolySwitch resettable fuse (ideally use two of these, one on the PCB as shown, and one at the bench power supply)
Hookup wire
Multicore + shielded cable for transceiver microphone adaptor fly leads
Microphone - preferably a unidirectional electret in a stage microphone housing mounted on a boom arm
Small solder lugs for enclosure grounding - Not used on prototype
1mm thick copper CPU shim (eBay) or equivalent copper sheet for heatsinking U4 No insulator required
M3 nut, M3 bolt M3 star washer for heatsinking U4
Acrylic or Polycarbonate sheet for front panel - The prototype used 3mm dark grey acrylic sheet, but this causes problems with the 2.5mm long headphone connector barrel
Adhesive window tint if clear front panel is used - Not used on prototype
Enclosure - The PCB has been designed to fit the economical extruded aluminium BOX-1110 from http://rfsuppliers.com Outer dimensions: 24mm(H) x 70mm(W) x 110mm(L)

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