Nick VK4PP is working on a nice little add-on board for the µBitx with the following mods incorporated:
- 200hz CW Filter
- Mic Preamp (SMM2167 Module)
- VK3YE LED AGC
- LPF section (Dual relay per filter)
- POP fix for earlier v3 boards, and
- High Pass Filter on RX for BCI option.
Nick is designing it for use with through hole components with the exception of the 100uh inductors underneath the board, which will need to be 1206 Surface Mount devices. At this stage he is hoping to provide the board at $5 each plus post (VK-$1, DX-$3).
Nick VK4PP sent one of his LPFx4 test boards to Warren WA8TOD for blow-by testing. It looks like the bare PCB has excellent isolation between its input and output, of around 90db.
Matched with RF rated and separate in/out relays this board will perform very well. The updated pic above shows a few tweaks and more ground stitching.
The only downside is the US$1.50 each relays (x8). Relay K3 can potentially be reused, or you can source AXICOM relays for a bit more.
Nick is interested in feedback from constructors on the level of demand for these boards.
Nick VK4PP has 45MHz filter boards to fix spurs available now to order. He has installed one himself and it works fine.
Nick has added them to his ordering page. The price is a stunning ONE cent only + postage. Nick says
“Feel free to take up to 10 and also maybe sample the other warez …”
VK4PP Order Form