Elecraft AF1 Audio Filter Errata - Manual

A F 1 K I T C H A N G E S A N D M A N U A L E R R A T A
R e v . A - 4 , J a n u a r y 2 3 , 2 0 0 8
T H E F O L L O W I N G C H A N G E S T O T H E A F 1 M A N U A L M U S T B E M A D E
B E F O R E P R O C E D I N G , O R Y O U R A F 1 W I L L N O T F U N C T I O N C O R R E C T L Y
1. Page 2, Parts List, line 9: Change the color code of R1 to (brn-grn-blk-brn-brn).
2. Page 2, Parts List, line 15: Change the color code or R17 and R13 to (org-blu-yel).
3. Page 2, Parts List, line 18 (R5): Delete “(503)” and add to the end of the description: “6 pin”
4. Page 2, Parts list: Add the following at the bottom of the table:
Misc #24 Wire, Solid, Green, Insulated 6” E760008
5. Page 3, first step: Change the color code for R1 to (brn-grn-blk-brn).
6. Page 3, first step: Change the color code for R17 to (org-blu-yel).
7. Page 3, first step: Change the color code for R13 to (org-blu-yel).
8. Page 5, first step: Change J2 to J3.
9. Page 5, second step: Change the first sentence to read,
“Install six-pin dual potentiometer R10 as follows:”
10. Page 5, Add the following between the first and second steps:
If the circuit board in your kit is Revision A (shown in the lower left corner on the top of the board), make the
following changes so it will work properly with an monaural plug at the input and a stereo plug at the output. (This
will be corrected in future revisions of the board.)
At the pins of J1 (AF IN) on the bottom of the board, use a sharp knife to cut and remove the segment of
the trace shown below. Use the green insulated wire to make a jumper to reach between the pin on J1
shown and the small hole at the circuit via where the trace passes through to the top of the board. This
change isolates the ring connection so a monaural plug at J1 it won’t short the audio to ground.
At the pins of J3 (AF OUT) on the bottom of the board, install a jumper between the pins shown below.
Use a short section of the green insulated wire or a discarded component lead. Take care to ensure the
middle connection of J3 is not shorted to ground. This ties tip and ring together so audio is present on both
at the output.
JUMPER
CIRCUIT
VIA
J1 - AF IN J2 - AF OUT
CUT TRACE HERE
JUMPER
BE CAREFUL
NOT TO CREATE
A SHORT TO
GROUND HERE