I posted a file, copy attached that is
a collection of additions for the uBitx board. I posted this, but
it never showed, so I am restating it here.
I am working on the board which I will describe below. Please
comment if you see anything to improve or other features to add,
and if you are interested in a PCB or a kit which I might offer it
there is interest.
U4 is an audio amp to replace the problematic TDA2822. U3A and Q1
etc. form the AGC circuit, not original. U3B is a log amp the
drives an analog S meter (the digital one is better) that is in my
enclosure. U1 is a switch to put the CW filter in or out of the
circuit. (Note there is a drawing error +VM shouldn't connect to
The Cheybchev 750 Hz LPF 0.1 db ripple
I/O JP2 and JP3 plug into connectors soldered on the underside of
the uBitx. The odd pins connect to the Raduino and audio
connectors. The even pins are hardwired to the uBitx.
Chebychev Low pass filters, 0.5 dB ripple for the external linear
amp I posted previously.
Relays for the above filters. Copied from and driven by the uBitx
New driver for IRF510s. connects between VR1 and the output of T10
which is removed.
n 6/9/2018 9:01 PM, BITX20@groups.io
This email message is a notification to let you know that a
file has been uploaded to the Files area of the BITX20@groups.io
A collection of accessories and improvements for the uBitx. See
post for description
You can access this file at the URL:
The Groups.io Team