Important  Information

Ubitx.net provides help for constructors:  Preventing catastrophes and providing guides, fixes and modifications for your µBITx.  We are an information site only and not associated with HF Signals.


WARNING:  As shipped, your µBITx  v3  or v4 board will probably not be compliant with emission requirements.  It has been found to generate spurs and harmonics.  There are now simple fixes available to address these issues.  Make sure you apply them prior to operating the transceiver on an antenna.

CAUTION : If you power up the µBITX without the pull-up resistor the µBITX is likely to go into CW transmit. Make sure you install the 4.7k pull up resistor on the CW key pin!

v3 Board?  – There are known issues with WX brand TDA2822 chips (U1): Read this.  Earlier UCI and later socketed TDA2822 are not affected.   You will probably want to do the audio pop mod at least.

v4 Board? – If your audio is distorted see this article.  Note that audio output is reduced over the v3 board.  If you use a low impedance speaker you may need an additional amplifier module (LM386, TDA2822, etc.) to get adequate volume. The audio pop mod is not required on v4 boards.

v5 Board?  – It is too early to say as yet whether this is compliant, but early indications suggest that some boards on some bands may not be fully compliant, but they are a lot closer to compliance than v3 and v4 boards.  At 30dB down or more your spurs and harmonics will be in milliwatts!


SHIPPING:  µBitx orders were shipping within one or two working days of being ordered, but there seem to be delays with the v5 board currently of around 2 weeks. You should receive a shipping notification through PayPal once your product has been shipped. Estimated delivery times:

EU:         IndiaPost: 2-5 days  DHL: 2-5 days
US:         IndiaPost: 10 days     DHL: 2-5 days
Asia:      IndiaPost: 2-4 days   DHL: 2-4 days
AU/NZ: IndiaPost:10 days      DHL: 5-7 days

BITX QSO DAY:   Every Sunday – 3PM & 7PM Local Time – 7277 kHz in North America, 7177 kHz elsewhere.

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