v5 in GE Phoenix SX case #ubitx #firmware #ft8 #antennas

Jens Kaemmerer

Very happy with my recently finished build of the (unmodified) uBitx v5:

Antenna: QRPGuys 'no tune end fed half wave' antenna 'inverted V' configuration (20m/40m, ~60ft of 22 AWG wire)
Computer:  Raspberry PI 3
Soundcard: Sabrent USB adapter (uBitx MIC/SPK are directly connected to the soundcard, no
additional isolation transformer or additional capacitor seem to be required)
Case: recycled GE Phoenix SX Vhf radio (required a lot of changes to fit in the uBitx)
Firmware: CEC Firmware v1.120 for uBitx v5

How does it work in the middle of Silicon Valley / California?

My initial results:

- SSB voice is not possible because of high noise
- KGO AM transmitter is only 8 miles away from my QTH and is causing
Broadcast Interference (BCI) across a wide frequency spectrum in the
20m/40m band
-> a magnetic loop antenna might be able to address the BCI issue
or the addition of a 'BCI filter' as discussed in this forum

Other suggestions on how to address this issue are welcome.

- FT8 is working and I was able to complete a few QSOs with stations
1300 miles away (CM87 <-> EM16)
- very few WSPR messages have been received (signal are too
- send WSPR messages (with either the CEC firmware or Wsjtx)
been received by other stations
- FT8 send/recv maps are attached

- was able to receive AARL's W1AW CW HF 'propagation bulletin'

-jens (KM6ZJV)

Jens Kaemmerer

Update after using the uBitx for about 2 weeks:

Listening to SSB voice was possible for strong signals after setting IF shift to 3000
(CEC firmware)

1) interference from the KGO AM station is now gone
2) it is possible to listening to strong SSB signals (I use the Half Moon Bay SDR radio
to get an idea of where a strong signal can be found and then tune the uBitx to that
frequenc. S9+ SSB signals at Half Moon Bay can generally be heard by the
uBitx in Silicon Valley).

-jens (KM6ZJV)