It is not widely different in basic design from the ignition system of nn automobile. ... given for this circuit. The differences are that this diagram calls for unit components which may be obtained without difficulty from any radio supply house. ... $11.50 for the three items. The big ... Here is what you need: f aquot;tii/ fiaxic Circuit: 1 SN4 Strobotron tube, standard 4 prong base. ... Well thata#39;s about all for Thunderbolt.