Batboard

I'm installing a xtl5000 uhf and vhf in a rack housing with a power supply . Do I need 2 power supplies or can I use a single mount 13.vdc supply and splice it

You can certainly use one so long as it has enough current to be able to handle both of them TXing at high power (even if you don't intend to TX at the same time, it's still good practice). Mid power, high power?

Until about a year ago I ran two XTLs (one a high power), one 900 mHz Spectra, and an 800 mHz Astro Spectra in the same carpeted rack, all powered by a 30 Amp. Astron switching supply. I had the high power XTL turned down to 70 watts and it did fine. The Astron sat in the bottom of the rack, behind a vent panel, along with the speakers the radios required. Later on I sold both XTLs and replaced them with a single APX 7500, and now in the open space sits an Icom 208 that I rarely use. The rack is an 8RU carpeted box I got on eBay, and if I was at home, which I'm not, I'd put up a photo of the finished unit, which if you'll pardon the boast is, I think, pretty slick. Nothing beats having all the wires and similar stuff hidden from view.