A chronology of mods

Dan W2DLC ordered his µBITx on December 29, 2017 and received it on March 2, 2018.

It was a version 3 with the WX branded TDA2822 audio chip.

(1) By the time he was ready to assemble it, Ron, W7HD had posted a fix using a voltage regulator.  This was his first mod and he has had good working audio since then.

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(2)The second mod he implemented was installing the KD8CEC firmware which was more intuitive for me and solved some issues such as keying responsiveness.

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(3) The third mod was to add a short USB cable from the Arduino Nano to allow data access outside the case.

(4) The fourth mod was adding the click-pop suppression kit from Don ND6T, Wayne VA7AT, and kitted by Kees K5BCQ.

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(5) The fifth mod was the RF output peaking mod suggested by Howard Fidel WB2VXW

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(6) The sixth mod was the ND6T AGC kit that he got from K5BCQ at the same time as the click-pop kit.  When he installed the AGC kit, he used Kees’s installation suggestions for mounting it on the main board.  He also added an RF attenuator/gain control as suggested by ND6T, and hooked a wire from J1 to the purple analog wire on the Raduino to provide an S meter.

http://www.nd6t.com/uBITX/AGCkit.htm

(7) While he had the board on the table, R250 was changed to 100K to reduce the sidetone level and C1 cap was replaced with a 1μF to shape the CW note.

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(8) Then  the relays were changed out for  Axicoms  as suggested by Mike W0MNE, to reduce harmonics when using SSB on the lower HF bands.

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(8) Finally, he replaced L7 and L5 with SMT inductors as suggested by Raj VU2ZAP to reduce spurs on the higher HF bands.

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Dan is very happy with how well my uBITX functions at this point.  He has placed it in a small Apache case behind an aluminium faceplate that he fabricated.  The whole thing is pretty rugged and works well with a three cell 18650 battery pack.

Dan says he finally has the spy radio he has always wanted.

Overall Reference 

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