[Elecraft] Volume

[al_lorona@agilent.com]

Hi, Everybody,

A recent thread about receiver volume reminded me of an experience that has left a deep impression on me.

I was doing some business up at TriQuint Semiconductor in Oregon about three years ago. That's where Rick Campbell, KK7B, happens to work. Rick, of course, is famous for homebrew direct conversion receivers and lots of other QRP projects. 

One of the days I was there, I really lucked in. The TriQuint ham radio club was having a lunch meeting and Rick was the guest speaker. I was invited and couldn't wait to meet him. He presented a design for a simple D-C receiver and crystal-controlled transmitter that was to be a club project. His purpose was to get everybody building something and using it on-the-air. And it was a real cute and elegant design.

Anyway, during the course of his talk, he got off on a tangent in the following manner. He had brought in a prototype of the receiver and transmitter built with brass nails tacked into a wooden board. (He was presenting real simple construction methods as a related topic.) As he spoke, he actually cut a dipole for 40 meters, talked some more, attached the antenna to the receiver, talked more, connected the batteries and the headphones, and suddenly invited the group up to the front to tune around and listen. 

The very first guy to put the headphones on listened for a few seconds and then said, "Gee, can't you make it any louder?" And that was Rick's cue. Suddenly, he became passionate. First off, he said that everybody says the same thing about his receivers: that none of them has enough volume.

Then he said that we have grown much too accustomed to simply cranking up the volume. "If you're driving and you want to hear something on the radio, you turn it up, but then a few miles down the road you can't quite hear it so you crank it up a little bit more, and what you don't realize is that your ears are, little by little,  getting de-sensitized to the sound. You are actually doing damage to your hearing!"

He continued, "The same thing goes for our modern ham receivers. AGC and lots of audio have allowed us to blast our poor ears with sound, and this accounts for the fact that few hams have really good 'ears' anymore!" He went on a long and fascinating explanation about how in the early days of radio, guys really had excellent 'ears', that they could easily hear below the noise floor, and that crystal radios produced almost no audio, forcing the operator to really develop an acute sense of hearing. He solemnly pulled out a book he had with him  of dozens of radio designs from the 20s, 30s and 40s and spoke of incredible feats of tuning and listening. 

He actually has a philosophy which involves listening as a matter of habit at vanishingly low audio levels, both to protect his hearing and to maintain that keen sense of hearing that the early pioneers had. He has a quite romantic notion of radio and a deep respect for the skill of those early operators, and he bemoans the fact that all we know how to do is turn it up, up, up until we lose that ability to pull out the weak ones, in the best case, and do damage to our most precious ears in the worst.

I waited my turn in line and when I put the headphones on, sure enough the little output transistor was barely putting any sound into them. I closed my eyes and concentrated on the signal in the receiver. After a few minutes of this, it really is amazing how much you can hear with only a modest effort.

This experience has led me to treasure my ears more and take better care of them, especially when wearing headphones. As for the ability to hear below the noise level, I can only practice, and in the process, interestingly, I am seldom left wanting for much more audio volume in a receiver.

Regards,

Al  W6LX