David N8DAH is now producing a very handy digital interface kit. This is a Gordon Gibby KX4Z design, and it features:
- On board 5v regulator that you can power from 12-13.8v or you can leave it off for direct 5v input.
- Built in VOX PTT via reed relay
- PTT LED
- Input and Output gain control
- Audio Isolation transformers 600:600ohm
The kits are available for:
US$15 unassembled or US$20 assembled
SM0JZT has installed a G4HUP buffer amplifier in his µBITx and uses an RTL-SDR dongle externally. This is an alternative to the approach used by KD8CEC to add an RTL-SDR that gives much wider bandwidth (i.e. the bandwidth is not limited by the 45MHz filter). The G4HUP buffer amplifier can be purchased here in either fully built-up form or in kit form. Order the 50MHz unit is what you need (it has an LPF above 50MHz and requires no modifications to work on 45MHz).
This gives you the best of worlds – a low-cost transmitter and an equally low-cost SDR receiver. Thanks to SM6MOJ for bringing this to our attention.
Vince, N2AIE, worked Tom VE3THR and Bill NG1P tonight on 7.277 out of his QTH in Cedar Rapids IA. These were his first uBitx contacts with other uBitx and bitx40 rigs.
Vince has loaded (after some angst) the KD8CEC firmware, and has the rig interfaced with Ham Radio Deluxe (in both directions). His rig also has a 3.5in touchscreen Raspberry pi for digital modes built in on the right hand side of the front panel as illustrated above.
Take a look at the rear panel of his rather attractive build: