Hopefully the internet will allow a wider dissemination and actual owner pictures from our scrapbook. Diodes are 50 volt rating, etc. We have over specified the components to provide for long life time. The aluminum box could be changed to a waterproof one but the price would be prohibitive. The reason for using Radio Shack is that the home constructor can find them easily.
Every major town has one.
I can get better pricing from Jameco, Digi-key, Mouser, etc, however most of you do not have commercial accounts with them. Hence the parts list for Radio Shack. The market is too limited to support an entirely new different sized antenna. Remember it takes twice the inductance to get to 160 meters from 80. The present 160 meter add on coil will get you there and a lot cheaper.