PCS-Electronics

You think wrong.

There is no difference between the 5W and 15W version
other than the power supply. The PCB used is the same,
so are all of the components on board.

The original 5W version had its own on-board mains power
supply, which was too weak for 15W.

How are you measuring the power, using CB SWR?

It might really be that PCI MAX ULTRA is not giving it
enough drive. Remember, this old model has been replaced
by PCI MAX 2004 and now 2005 so it is kind of old. We have
been shipping these boosters with the 2004 model.

We have a VSWR meter from 0 - 1000 Mhz. It is a professional unit. We don't play with CB

So most likely it is the PCI Max Ultra Board. Just not giving enough Umph?

What is the most power input to the AMP?
What is supposed to be the output from the Ultra and 2005, with external power?

Don't be so sure about your SWR. I have a pro unit here and
I just found it is conservative. I had MAX PRO I tested in a pro
lab just recently and it gave 8W whereas it showed 6 on my meter.

PCI MAX 2005 is giving more power than the old ultra card.