I just stumbled across your post and I thought that the following URL may be of some assistance (if you haven't already purchased an RF meter). www.qsl.net/n9zia/wireless/appendixF.html#8
There you'll find schematics for building two "LED RF Signal Meters". The first one has a bandwidth of 100MHz - 2.5GHz (uses an AD8313) and the second one is "DC" - 500MHz (uses an AD8307). These meters have indicator LEDs that show RF signal strength levels from -70dBm to +10dBm.
With a 20dB pad added to the signal meter's input I'll be able to tell when the RF level reaches +30dBm, which is the maximum input level for my RF Explorer-3G Combo handheld RF spectrum analyzer (its second input can handle +5dBm max).
I built the 500MHz LED RF signal meter years ago and it has served me well. Now that I've purchased the RF Explorer I'll be building the 100MHz - 2.5GHz version of the meter soon. I plan to use these simple RF meters to pre-test some RF signals before I subject my RF Explorer to a potentially damaging level of signal. The LED RF signal meters use a pair of diodes for some input protection.