AN OLD ANTENNA COUPLER

October 08, 2016

AN OLD ANTENNA COUPLER

(....As Used By An Old Radio Operator!)

Recently, I've had several questions about the antenna coupler you've seen in some of the VK3BVW radio shack pictures. It's a fabulous old unit and I use it every day. So this post and the YouTube video below take a closer look at the Tokyo Hy-Power Labs HC-500A.

So, what's an antenna coupler? It is a impedance matching device, used between the antenna and the transceiver or receiver. It is often referred to as an antenna tuning unit (ATU) or simply an antenna tuner. But actually that title is really a bit of a misnomer! In fact, it has no influence on, or tuning of, the antenna itself. The insertion of an antenna coupler in the circuit allows for the maximum transfer of RF energy from a transmitter to the antenna, and for the optimum impedance matching (and hence energy transfer) between the antenna and a receiver.

The Tokyo Hy-Power Laboratory was founded in 1975 by Nobuki Wakabayashi, JA1DJW with its factory near Tokyo in Saitama Prefecture. The company's first products were the HC-500 and HC-2500 antenna couplers for the HF bands. Several years later, new products appeared that included high quality linear amplifiers. Later, they added wide-band mobile linears, automatic antenna tuners and solid-state high powered RF amplifiers. Regrettably, the company finally closed its business on December 24, 2013. You can learn more about the company by heading to the Tokyo Hy-Power Users Club. Manuals and circuit diagrams for most of the company's products are still available on the Users Club website.

I purchased my HC-500A during 1978, making it 42 years old. It's been a long-time partner in my radio hobby activities, and I love it! I expect it will be still going strong for another 42 years.....although I personally don't expect to be still going that long!!

Anyway, here's the video. I hope you find it of some interest.

73 and good DX to you all,

Rob Wagner VK3BVW