KD8DFL TAK-40 ECO Page

List of Engineering Change Orders for TAK-40, KD8DFL PCB Board Sets

Original ECO located here: Original TAK-40 ECO

  • TAK-40 ENGINEERING CHANGE ORDERS
  • Revised: July 23, 2008
  • Feb 2009, Cross-checking against KD8DFL v1.2 board & BOM by KI6GPH and AF6NZ
  • Previous revision was dated July 9. Changes appear in blue.

Open ECOs for v1.2

  • ALERT: U106 and U107 should both be 74HC125 chips. DO NOT INSTALL 74AC125. This chip will not function correctly. Do not confuse these chips with U102, a 74HC14 chip.

New Issues Needing Research:

  • Ground Plane Connections: (AF6NZ) The ground connections for the following seem too small: VFO board L301, Digital board voltage ground (large thru-hole below C101), and IF board ground ring. Upon close inspection they have very thin traces from the ground plane to the ring connection. I don't think the impedance is very low between these two points, and current carrying capability - especially during any heavy repetitive switching could introduce quite a bit of ground bounce. I plan on removing some of the solder mask from the ground plane and solder bridging the plane to the ring. Any digital signal propagation PhDs out there wanna chime in?
  • VR202: (AF6NZ) On the v1.2 board, VR202's wiper goes to the anode of D207, and VR202's upper contact goes to R227 alone. The schematic has VR202 upper contact going to the junction of D207 and R227, and the wiper apparently to either end of the pot. Updated Schematic 9-26-08 and board do not agree. Is there Updated Schematic to the Updated Schematic? Or is the board wrong?
  • RMCLR: (AF6NZ) Will using the 1K to 10K resistor in the RMCLR position allow both transceiver and icsp? Or is it jumper exclusively for transceiver operation, and 1K to 10K for programming in-circuit exclusively?
  • C109: (KI6GPH) Previous ECO says " C109: Recommendation: Do not install." Why shouldn't it be installed?

ECOs needing verifying that they are fixed in v1.2

  • WIRING CHANGES
    • (Check KD8DFL v1.2 PCB) R227 (4.7K) connects to upper contact of VR203, should connect to wiper. Recommendation: Do nothing. This is correct per the latest (June 1) version of the schematic.
      • (AF6NZ) R227 connects to upper contact of VR202 (not 203) and wiper goes to Anode of D207. Updated Schematic 9-26-08 and board do NOT AGREE!!! Is there Updated Schematic to the Updated Schematic
      • (KI6GPH) Schematic 9-26-08 is the latest I know of. That schematic does contain some typos. Maybe ask the arrlhbc group?

ECOs Verified Fixed in v1.2 PCB and BOM

The following are ECOs for previous versions of the TAK-40 bill of materials, schematic, or pcb files. These are all fixed in the KD8DFL v1.2 pcb and bill of materials.

  • SILK SCREEN ERRORS
    • (Fixed on KD8DFL PCB rev 1.2) C104 mislabeled as C124.
    • (Fixed on KD8DFL PCB rev 1.2) Label for C401 obliterated upon PC board separation
    • (Fixed on KD8DFL PCB rev 1.2) C414 mislabeled as C415
    • (Fixed on KD8DFL PCB rev 1.2) C221 mislabeled as C22, located between L201 and L202
    • (Fixed on KD8DFL PCB rev 1.2) J105 mislabeled as H2
    • (Fixed on KD8DFL PCB rev 1.2) L207 is mislabeled as R207. L207 is on the left side of the board between C234 and C240. R207 (which is marked correctly) is on the upper right between C210 and C217.
    • (Fixed on KD8DFL PCB rev 1.2) R118 mislabeled as R188
    • (Fixed on KD8DFL PCB rev 1.2) R211 (near pin 1 of U2064) is not marked on silk screen.
    • (Fixed on KD8DFL PCB rev 1.2) R214 (near base of Q201) is not marked on silk screen.
    • (Fixed on KD8DFL PCB rev 1.2) R239 (to the right of C222) is not marked on silk screen
    • (Fixed on KD8DFL PCB rev 1.2) R233 (below Q204) is not marked on silk screen.
    • (Fixed on KD8DFL PCB rev 1.2) R305 (adjacent to C311) mislabeled as R1
    • (Fixed on KD8DFL PCB rev 1.2) R405 mislabeled as R406
    • (Fixed on KD8DFL PCB rev 1.2) R406 mislabeled as R405
    • (Fixed on KD8DFL PCB rev 1.2) U102 mislabeled as U3
    • (Fixed on KD8DFL PCB rev 1.2) ECO regarding mislabeling of R208, and R209 has been rescinded. Leave these parts labeled as delivered.
  • UNUSED COMPONENTS
    • (Updated BOM) VR101. Install 100K resistor in its place (unless you are using VR101 to control contrast on lcd)
    • (Updated BOM) R252, which connects between pins 4 and 5 on U201, is not present on the schematic. Recommendation: Do not install. This was an attempt to improve the mixer balance and it didn’t work out. (From WA2EUJ)
    • (Updated BOM) C109: Recommendation: Do not install.
    • (Pin 6 is grounded on KD8DFL v1.2) Pin 6 on J105 is not connected to ground. Recommendation: Do nothing. Pin 2 is grounded, pin 6 is redundant.
    • (Updated BOM) R109 connects to J101 Pin 15, which is unused. Installation of R109 is optional.
  • MISSING COMPONENTS
    • (Fixed on KD8DFL PCB rev 1.2) C255, which connects to the collector of Q201, is missing from the PCB design (present on the schematic). Recommendation: Solder C255 across L203 prior to installation. Remember not to get L203 too close to the ground plane. (from WA2EUJ)
    • (Fixed on KD8DFL PCB rev 1.2) C415 missing, C414 mislabeled C415. Recommendation: Change label to C414.
    • (Fixed on KD8DFL PCB rev 1.2) C415 missing from board. Install across R403 prior to installation.
    • (Deleted from BOM) R210 is not on schematic, although it is on the Bill of Materials.
  • WIRING CHANGES
    • Upper contact of VR201 is grounded, should be floating. Recommendation: using an Exacto knife, cut the traces to ground around the upper pin before installing VR201.
    • Cathode of D208 does not connect to Cathode of D209. Recommendation: Install a jumper between these two points.
    • VR202 connects to J201 pin 10. Should connect to pin 9 on J201. Recommendation: Cut trace, install jumper from VR202 to J201 pin 9.
    • C248 (minus side) floating. Should connect to drain of Q208, also floating. Recommendation: Install jumper to between the pins on C248 and Q208 that aren’t connected to anything else.
    • Collector of Q301 not connected to +5V. Recommendation: Jumper to ungrounded side of C310.
    • C413 is not grounded. Recommendation: Jumper nearest pin of C413 to cathode of D403. Jumper the other side of C413 to ground.
    • Pin 14 on U104 not connected to +5V. Recommendation: Jumper U104 Pin 14 to non-grounded side of C106.
      • (AF6NZ) The problem statement is somewhat incorrect - the voltage is variable, not a constant +5V. Fix works, though.
    • R122 is not connected to +5V. Recommendation: Jumper R122 pin (next to C110) to the empty hole where C109 was supposed to be.
    • Pin 12 on U103 is not grounded on board. Recommendation: Install jumper to center pin of VR101 (VR101 is unused).
    • RMCLR (next to C108, looks a resistor on the silk screen) must be jumpered for transceiver to operate. A wire jumper will allow this. If you intend to enable in-circuit reprogramming of the PIC (recommended), a resistor should be installed. Recommendation: Install a resistor of value 1K to 10K ohms across RMCLR.
    • U102 Pin 7 not grounded. Recommendation: Install jumper across top of board from U102 Pin 7 to U103 Pin 12.
    • U105 Pins 12 and 31, and JPRGM Pin 3 not grounded, although they appear to be grounded. Recommendation: Jumper one of these pins (your choice) to ground side of OSC101. This fixes all three.
    • J106 not grounded. Jumper J106 Pins 2 and 4 to U106 Pin 7.
    • R121 (10K ohms) needs to be connected to +5V, Jumper R121 to U106 Pin 14.
    • U104 has floating pins, which is bad practice. Jumper Pins 8 and 9 to U104 Pin 7.
  • SUBSTITUTIONS
    • (Updated BOM) R303 may be dropped to 100 Ohms. Try this if the VFO does not oscillate.
    • (Updated BOM) Q204, Q206, Q207, Q208, Q303 may utilize either 2N7000 or BS170 transistors. The pin configurations are different for each transistor.
    • (Updated BOM) If running cables to the front panel longer than 6 inches, R101 through R108 may be replaced with 1000 ohm resistors.
  • MISCELLANEOUS
    • (Verified BOM) Y101 is the ceramic resonator (looks like a capacitor), not a 4 MHz crystal.
    • (Updated BOM) R217 should be 390 ohms. It is on the Bill of Materials with two different values.
    • (Verified BOM) R214 should be 4700 ohms. It is on the Bill of Materials with two different values.
    • (Verified BOM) R117 should be 910 ohms. It is on the Bill of Materials with two different values.
    • (Verified BOM) R121 should be 10K ohms. It is NOT on the Packing List.
    • See also notes in the Wiring Changes section regarding jumpers.
    • (Updated BOM) R208 is 100 ohms, and located next to Q202.
    • (Fixed on KD8DF LPCB rev 1.2) R208 misidentified on schematic as R209.
    • (Updated BOM) R209 is 560 ohms, and located adjacent to U201.
    • (Fixed on KD8DFL PCB rev 1.2) R209 appears on schematic twice.
    • (Verified BOM) R113 (1M ohms) is on the parts list twice under two values. However, this value is not critical; 100K ohms has been tried and works well.
    • (Verified BOM) R221 (3.3K ohms) is not on the parts list. It was not included with your kit.
    • (Verified BOM) R223 (1000 ohms) is not on the parts list. It was not included with your kit.
    • (Updated BOM) R227 (4.7K ohms) is not on the parts list. It was not included with your kit.
    • (Verified BOM) R244 (3.3K ohms) is not on the parts list. It was not included with your kit.
    • (Updated BOM) R251 (100K ohms) is not on the parts list. It was not included with your kit.
    • (Updated BOM) R403 (22 ohms) is on the schematic and packing list twice. It is correctly marked on the circuit board.
    • (Updated BOM) R404 (1000 ohms) is correctly labeled on the circuit board. R404 resistor is mislabeled as R403 on the schematic and parts list.
    • (Updated BOM) C209 (0.1 uf) is not on the parts list. It was not included with your kit.

Errata on v1.1 Boards

KD8DFL TAK-40 PCB issues Revision 1.1 Board
(from KD8DFL folder on ARRLHBC file section)

  • (KI6GPH) Mail from Raymond Larrick, KD8DFL on 16 Feb 2009: "There are no known issues with the V1.2 PCBs. I think everything has been addressed"
  • All the following were verified fixed on the v1.2 board by AF6NZ:
  1. VCC and ground are tied to the same pin of C109
    • FIX for v1.1: Drill larger than the hole and drill the ground connection from the component (top) side of the PCB, DO NOT GO THROUGH THE PCB. Next use a resistor lead clipping or other wire and make a jumper from pin 1 to pin 2 of C109.
  2. Pin 2 of OS101 ground tie shorts to trace
    • FIX for v1.1: Cut the ground tie that shorts to the trace but leave the others.
  3. Pin 3 of J103, ground tie shorts to trace.
    • FIX for v1.1: Cut the ground tie that shorts to the trace but leave the others.
  4. Pin 7 of U3, ground tie shorts to trace
    • FIX for v1.1: Cut the ground tie that shorts to the trace but leave the others.
  5. Pin 2 of C107, ground tie shorts to trace.
    • FIX for v1.1: Cut the ground tie that shorts to the trace but leave the others.
  6. Ground plane for J103 floating. (AF6NZ) GND plane runs under connector on V1.2 Digital PCB
    • Fix for v1.1: Add wire jumper to near by ground plane
  7. U102 is labled U3 on the PCB.
    • Fix for v1.1: Change ID with marker, Will fix in next PCB revision
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