Steve N3SB has alerted constructors to a small collection of documents, photos, test results, and a calibration procedure that his Carroll County Amateur Radio Club (Maryland USA) has been putting together at:
The following link directly to the documents and reports:
- Kit Building Committee Report August 2018 – uBITX Intro
- Kit Building Committee Report September 2018 – uBITX Harmonics and Spurs
- Kit Building Committee Report October 2018 – uBITX Harmonics and Spurs Update
- USB Connector Modification
- Both-sides Headphone Audio
- Fan, Battery, Connector, PA power Mods
- Grounding Modification
- RF power vs Supply Voltage Inspection
- Outboard Relays Design Document
- Minor Heatsink Modification
- Micro-BITX Calibration Instructions
- Reducing AF Input Amplifier Harmonics
- CW Tone Amplitude Reduction
- Calibration Theory
- uBITX Microphone Notes
Peter VK3YE asks, “Do you live in Melbourne (or at least in Victoria, Australia?”
Every few months there is a QRP and homebrew gathering at Chelsea beach near Melbourne. The next is this Saturday, July 28, 3pm near the lifesaving club. This time the group is having a “Bring your Bitx (or uBitx)” theme.
So if you have a Bitx/uBitx or are curious about them it could be worth coming along if you’re in the area.
There is a Facebook group for the µBITx in addition to the BITX20 list that represents the primary source of news articles on this website.
One of the members of the Facebook Group (Ufi Auttorri) has produced a diagnostic guide for constructors who are facing problems with their µBITx. While it is still a work in progress, and won’t cover all issues arising with the rig, it is an excellent starting for constructors who have run into issues. You can find it here:
After pointing out an out-of-date reference on uBITx.net to wire up diagram faults on the HF Signals website, Patrick W7PEA has set out to develop the Wiki (already on the BITX20 IO GROUP website), starting with a more fully developed Wire Up and Assembly Guide.
Because this is a Wiki anybody can contribute to the effort.
Wire up diagram
This immediately revealed a PDF developed by Bob W4RJP. This began as a simple wiring diagram to assist in wiring up the uBitX and was never intended for publication. While Bob’s µBitX is still mostly stock, over time I did revise the diagram to include a few options as well as beneficial corrective actions identified by other builders.
Júnior PY2ADA has made some Portuguese videos of his µBITx available to view on his Youtube channel here:
John, WA2FZW, noted a suggestion from a friend that if you are designing your own PCB, the PCB Shopper website will help find the cheapest PCB manufacturer:
Kerr Smith confirms this recommendation saying, “This site is definitely worth using when you are looking to get PCBs made. The last time I used it it suggested ALLPCB which had an offer on at the time so I got 5 boards for $5 with free courier shipping (my PCBs arrived in 5 days).
“I would highly recommend using the site to see which PCB fabricators are currently the cheapest. You can then do a bit of research and get some user reviews and decide if you want to get your boards made with them.
“There are so many different PCB manufacturers this site makes it really easy to get an initial price per PCB for lots of them with you only needing to enter in some basic data such as PCB size and number required etc.”
Glenn, VK3PE, suggests that his measurements of DC levels and RF levels at various points in the PA driver section from Q90 onwards (with a 12.5v supply. ~8W out) might be of interest to some.
Neo VU3NEO has created a series of step by step videos on how to wire up the Ubitx that are available on Youtube.com. They can be found here: