Hi Shaun, I HAVE NO IDEA I got mine at no cost from a group called the Country Cousins. I think Handi Hams also have one ore at least used to have one. It is possible that you can find a fellow ham to build one for you. Basically it is just a audio oscillator. The same thing that is used as a practice oscillator for CW. You should be able to have one built for $10 or $20 and I am not sure how much that is there. I hope this helps. 73. Walt WA4QXT New London CT [log in to unmask]