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 U3.)
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
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
Uploaded By: Howard Fidel
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