Lucky wrote:

Mark,

Ratso Shackups only shows 1 MOV. Here is the product and 2nd link is the
specs.

http://www.radioshack.com/product.as...t%5Fid=276-568

specs:
http://support.radioshack.com/suppor...oc38/38010.htm

Lucky

That MOV is intended for use with 120vac. It won't do anything unless it sees
at least 184 volts.

With that MOV on the 13.8v line, if the fuse blows because of too much voltage,
odds are there will be too much smoke pouring out of your radio to find the fuse
holder so you can change it.

You want one rated to start triggering just a little beyond what your 13.8v
power supply should put out.

I think one rated for 15v is probably optimum, and I don't think I'd bother with
anything designed to trigger above 17v.