Total posts : 45366
Way back when I watched a telephone installer fish wire through a conduit. He had a small spool of HTCC (high tenacity cotton cord) on a bobbin with a mushroom shaped end and this was pushed through the pipe with compressed air from a small hand pump. Sounds similar to MRAM’s suggestion.
My install will involve 10 foot lengths of CPVC which I bought years ago with this in mind for my ham antenna feed but that project never got off the ground (or under it). The plan is to fish some cord through the 10 foot length, then through a coupler, then through the next 10 foot length. The two pipes will then be glued together via the coupler and the cord will be through both. The process will repeat for each 10 foot length as it is added.
Long runs can be hard to pull and the process can be helped with a soap solution or talcum powder to lubricate the wire. Pull boxes are sometimes used at intervals to shorten the pulls.
My total run is 40 feet. When the cord is used to fish the wire another cord will be pulled along with the wire. This will leave a cord in the conduit for future additional wires. I have learned to always leave a cord in a conduit or raceway so additional wires can be pulled without having to do any fishing.
Re the safety, the ground wire is bonded to the house ground at the point of entry. Fortunately for me the entry is very close to the electrical panel and the house ground stake wire is right there. The remote transmitter is also grounded to a buried wire. The power and audio lines are connected to ground at entry through spark gap tubes which conduct at 70 to 90 volts. These are inexpensive (about $1 ea. if memory serves me) and they are available from Mouser.
If your point of entry is not near the electrical panel then I recommend running a heavy (#8 copper or #6 aluminum) wire from the electrical panel ground to the entry ground. Some use a ground stake at the entry but I don’t like this because in the event of a lightning strike there will be a high potential difference between the entry stake and the house ground stake. This voltage will appear in and on your radio equipment. By using the house ground only this voltage is minimized.
In any case your local codes will apply and may differ from what I described.