We recently installed a Gap Challenger DX antenna in our backyard and ran some coax cable into the basement of our house to our amateur radio operating station. Getting the coax close to the basement was an adventure in itself – digging in various ways through solid clay most of the way. The last six feet of the length is the subject of this fine blog post.
I wanted to have the coax cable inside of Schedule 40 PVC pipe for protection from the elements, etc.. I soon realized that getting a pipe under our concrete sidewalk could be quite a challenge. Our sidewalk runs along the house from our back door out to the driveway and garage. I decided to check the internet for methods that others had used. That was one of the best things I did.
Several methods were documented in various ways on the internet. Some involved mechanical drills. Others involved high pressure sprays of various types. In fact, I almost used a high pressure spray that my supervisor at work loaned me. After thinking about the resulting mud hole I decided to think that through a bit more. I finally ran across a YouTube video of a fellow that fashioned his own drill bit out of the very PVC pipe he was going to use.
Bingo! The first photograph is of the “sharp end” that we made out of a section of PVC pipe. A couple of tips. First – make sure you make this length of conduit / pipe is AT LEAST as long as the length that you need to tunnel under.
The idea is to fashion one end of a length of PVC pipe or conduit at a 45 degree angle point or sharper. Leave the other end absolutely flat. The sharp end goes against the dirt. Put a piece of wood against the flat end and hammer the wood with a heavy sledge hammer. TIP – as hard as it seems to drive the pipe into the dirt – it is a LOT harder to pull the pipe back out!
One option would be to make the conduit pipe long enough so that you don’t have to pull it back out. This method leaves you with a thoroughly clogged conduit. You could try and clean it with a long metal rod and perhaps some high pressure water – but then you’re back to a mud hole. We opted to tap it in a ways, pull it out, clean it out – and then repeat.
The method that we used worked quite well for the 2 – 3 foot distance that we needed to tunnel. I seriously wouldn’t think it would be too practical to tunnel under a driveway. Perhaps it would work, but here’s one catch. One needs to hammer the pipe a ways into the soil and then pull it out before it is too hard to do so. The farther you tap it in the more friction there will be on the pipe. This is somewhat of a trial and error process. If the pipe does get stuck turning it and trying to bend it might help loosen the soil around it enough to get it loose.
Soil conditions also play a part in the amount of work you need to do with this method. Trying to drive the pipe, sharpened or not, into solid clay can be a tough task. Driving it through wet soil can be much easier. On the flip side, moist to wet soil can create suction when you try and pull the pipe back out. Somewhere between the two extremes is a sweet spot.
Would this ham radio operator use this method again? I sure would. The section of PVC pipe probably cost us $2 if that. Good luck with your antenna installation project! It’s interesting that sometimes, the more you get into ham radio the less the amount of time you actually spend on the radio. Last fall was spent digging ditches, etc.. This summer I hope to spend some more time on the air – possibly on a lake at the same time doing some fishing. I haven’t tied any flies for quite a few years – those adventures are for a different blog someday.
Jon Kreski – AB9NN– Appleton, Wisconsin / Green Bay, Wisconsin area
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