Topics

SB II 20m patch

Don, ND6T
 

Steve, Sascha, Joel, and others that are interested in 20m operation with the Slop Bucket II;
K6STN graciously loaned me his 20m SB2 so that I could try out the firmware fix. Attached is
my contribution in the form of SLOPBUCKET_II_REV 1.03a.ino

 

The Problem

 

When we move operation above the IF frequency (a bit above 9 MHz) the original algorithm of
subtracting the operating frequency from the BFO frequency to produce Lower Side Band produces
an error. The bands below the IF frequency work nicely, just 20m won’t work for Lower Side Band
nor CW (which is also on the lower side of the operating frequency in this rig). Since most of the
builds are for other bands we need to maintain that operation.

 

The patch

 

By adding a few lines of code to the PLLwrite() function that organizes the data to be sent to the
clock chip I was able to insert a couple of conditional instructions that enabled the two missing modes
on 20m. This was done by subtracting the BFO frequency from the operating frequency and changing
the direction of the offset for CW operation.

 

Small menu change

 

Steve’s addition to the menu adding the ability to erase the EEPROM was most welcome! However,
for me at least, the labels were confusing. So I changed my label from “Rsw” to “Funct” (for Function)
and changed my label from “Esw” to “Enter” since those were the labels on my button and knob.
Yes, I am easily confused (and getting worse by the day!).

 

Many thanks for making the kit and for making it up-gradable, Steve. For months this has become
my go-to radio for SSB. Many complements on the signal, both SSB and CW. Better than my big Icom.
And so easy on the batteries, too.