Looks like like a slow blow. I might have gotten the wrap a little tighter, if you look there is space between the center and the wrap. It dissipates the heat quicker and the filament is stabilized. I would have put a silver cap on one end and a copper with gold plate on the other end. Things I noticed, things I might have changed. :-)
It also relieves your pocket book of 125.00-175.00 less than a lot of others. I'll make my own goop! Thank you.
Regards