NC-20 Revision 1.1 Manual Errata

Schematic

1. Page 2. U3 should be type TUF-1, not a TFM-2 as shown.

2. Remove C3, 0.01uF, from the schematic, it is not required.

Construction Manual

1. Page 1. Introduction. First paragraph, last sentence. The word "of" is missing from the sentence "It should easily meet the requirements of most QRP'ers, from the most competitive contester to the casual operator".


2. Page 5. Section 2 - Rear Panel. Bottom of second column. Add new sentences after first sentence of last paragraph on this page: "Carefully file the anodizing away from rear panel GND screw hole on the inside of the rig. This will allow a better GND connection from the PCB GND to the rear panel."


3. Page 6. Section 3 - Front Panel. Bottom of first column. Add new bullet: "Carefully file the anodizing away from VR2's fixing hole on the inside of the rig. This will allow a better GND connection from the PCB GND to the front panel."


4. Page 6. Section 4 - Regulators/Power Supply Components. Item 73, D1, should be type 1N5822 (not 1N914).


5. Page 7. Section 5 - VFO. Second column, just above the photograph. Change the stuff inside the brackets to read "Clockwise, that is, from left to right as you look at the toroid".


6. Page 8. Section 5 - VFO. Top of second column. The 6-32 nylon screw should be fitted from the topside of the PCB (so as to match the L1 Assembly diagram), not the underside.


7. Page 8. Section 5 - VFO. Second column, last two bullets. Item 42, C8, should be 10pF NPO and Item 40, C86, should be 2pF NPO.


8. Page 11. Section 10 - Audible Frequency Annunciator. Second column, where it deals with the four things that you may/may not hear from the AFA, in case a) please note that if the VFO frequency is below 4.9MHz or above 5.1MHz the AFA will not work and you'll hear no tones.


9. Page 12. Section 12 - Keyer and Transmit Control. First bullet. The second instance of Item 66 should be Item 64, C94, 0.47uF.


10. Page 13. Section 13 - Receiver. Second column, Item 88, U3, should say "TUF-1 (marked as TFM-2 on the PCB legend)."


11. Page 13. Section 13 - Receiver. Second column. Add Item 41, C17, 5pF NPO to the list of parts to be fitted at this point.


12. Page 16. Section 14 - AGC. First column, second bullet. R102 should be R103 and R101 should be R102. The paragraph should read "With reference to sheet 2 of the schematic, fit resistor R103 (680Ohm, item 13) into the PCB in position C65. Then, using the photograph below as a guide, turn the PCB over and solder R102 (2.2KOhm, item 17) onto the….".


13. Page 28. Appendix F - Parts List. Item 22 should be a 6.2KOhm 1% resistor with color band markings Blu-Red-Blk-Brn-Brn. This part will be found in the sub-bag of 1% resistors supplied in the kit.


14. Page 30. Appendix F - Parts List. Item 113 should be a metal 6-32 nut, not nylon. You will find two 6-32 nuts in the kit, one is item 106 and the other item 113.

15. Remove C3, 0.01uF, from the design totally. It is not required, and can cause problems if you do the XIT mod.

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