Converting kit to 20 meters


I currently don't have a good 40 Meter antenna so I'm planning on just working 20 Meters for now.  My question is "How difficult is it to remove the specific transformers and/or capacitors to convert the standard 40 meter unit to a single band 20 Meter unit?"  I am concerned that I could damage the PC board if I am not careful in removing the existing parts.

In my opinion, It would helpful if I could buy a "band-free" version of this kit so that one could build it for different bands.  The price is so low that I could buy/and build one for each band.  I don't want to add relays and extra parts to facilitate multi-band operation.

I would fiddle around with different displays, etc. if I had two or more units.  My planned operation is  CW and FT8.

Richie Chambless


There are only a few changes to convert the BitX 40 to 20 meters. First, the band pass filter and output low pass filter must be changed. As the original BitX was on 20 M, you could use those values for the low pass filter. For the band pass filter, this website has 160-10 covered with the same topology as the BitX. Next, the VFO frequency needs to be changed. I don’t know about doing this with the Raduino as mine uses the VFO from QRP Labs. You can search this forum for plenty of discussion on that. Also, you will need to change your BFO frequency depending on Your choice of VFO frequency (high side vs low side). 

Richie Chambless