I am working my way through the book "The Electronics of Radio" by David B Rutledge", which details experiments on the various parts of the circuit as one builds a "Norcal 40A" transceiver, as a practical way to learn about electronics and amateur radio. It is a very good book.

The driver for the Norcal 40A power amplifier is a 2N2222A transistor, and the kit lists a ferrite bead to go over its base lead. This bead is not mentioned in the book, but it is in the kit's component list and circuit diagram. The specified ferrite bead is 0.146" diameter and 0.138" long, of #64 material, but, unfortunately I have lost it, probably long gone up the vacuum cleaner hose.

In my "come in handy" stock I have a bag of anonymous beads, and also some labelled FX1242 (all the correct size). So, my question is, can I use the FX1242 instead, or, if not, can I easily identify a suitable bead from the mixed bag, if there is one.


1 Answer 1


It really isn't all that critical. The bead is being used as a choke to prevent unwanted VHF parasitic oscillations. Any bead in your junkbox should be fine.

  • 1
    \$\begingroup\$ Thanks Dave Tweed,for your reassuring answer. Ironically (almost a good pun there) I found the ferrite bead stuck inside a nut when I checked the hardware bag of the kit. Ah well... \$\endgroup\$ Dec 5, 2012 at 20:09

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.