Very nice pair of first issue Nullard xf1,s. Large horseshoe getters. Codes xf1/B8D & xf1/B7I (August 1957 & April 1958). Tested 45/30 @ 32 milliamps and 47/30 @ 34 milliamps. No shorts/gas.

I have many other xf1's not listed...inquire if interested.

Check my other listings for hundreds of other excellent EL34s in all price ranges I do combine shipping if you want to create your own quad.