First Amateur Antenna

I remember, a long time ago, getting a CBRS license and building a ¼ wave groundplane vertical from aluminium tube & fencing wire for 27MHz.

Whilst browsing the ‘net for a suitable 2m antenna for home, I came upon a design that was similar in most respects to the one I had constructed years ago. It was originally designed to be hidden in a loft or suspended from a tree in a portable situation.

Mounting a device that looks like half a dying spider lurking on the roofline is not a ideal method of creating domestic or neighbourly harmony. With this in mind, I decided to utilise an old 2G mobile antenna that had been taking up space in the garage and removed the guts within. The remaining radome props up the radiating element which is the centre conductor of a length of RG58. The groundplane elements are standard iron wire of the co-tanger variety. Tuning was done mainly whilst the antenna was mounted on a 4m length of conduit; easy to raise & lower.

The next issue was to find a suitable mounting location, once again considering the previously mentioned harmoniousness. Listening to the WIA news one Sunday morning, I was reminded of the termination of VHF television services across Australia. Sure enough, the TV antenna on the roof was dual-band. If I removed the surplus elements, there would be enough space to bolt the thing onto the back end of the central boom. The mass of the device would be enough to counterbalance the remaining UHF elements on the other end of the boom.

Cabling is some surplus RG8 through the roofspace with flexible RG58 feeders at each end.

The only other considerations would be the effect of VHF RF output on TV reception and the very low power transmissions from the wireless weather station on the same mast. At this stage it appears that the weather station and TV reception do not suffer from the 5W output from a handheld. A full 10 watts would probably be another story entirely.

Fun and games with an HF dipole of some description can now ensue, now that I am intimately familiar with our residential rooftop.


This entry was posted in Amateur Radio Stuff. Bookmark the permalink.