Question:  What are the two screws/nuts on the sides of the case for?

Answer: They are the connection to ground.  Either one can be used (there are two simply for orientational convenience.) Since the entire case is ground, mounting it on a conductive surface such as in an entry panel, which is then in turn grounded, is also good.

Question:  What is the dB loss through the arrestor?

Answer:   When ANYTHING is put into the radio circuit it introduces some amount of loss.  Adding a longer coax, adding connectors, arrestors, etc. all add some degree of loss.  Having said that, most of these items add a minuscule amount of loss (escpecially at HF freqeuncies).  Our arrestors have less than 0.1dB through them, which is difficult to measure, let alone hear.

Question:  Can Morgan arrestors be placed outdoors without weatherproofing, ie: on a ground rod clamp, or do they need to be weather protected?

Answer:   We recommend keeping the arrestors in a weatherproof enclosure, box, etc. as the chassis are not sealed to prevent water ingress.  If put in an entry panel box the connectors do not need to be taped.  If arrestors are mounted on a ground rod clamp we recommend covering them with something such as a bucket.  We realize that mounting them on a ground rod is electrically the best solution, but due to the impossibility of a good permanent weatherproofing (including the dampness of being right on the ground, humidity, etc.) we highly recommend mounting the units on a conductive surface inside an enclosure which is mounted very near to and bonded to a ground rod(s).  Mounting on a ground rod is a good temporary solution or for portable radio operations, etc.