Sunday, March 15, 2020

An illicit friend from the good old days

NRG Pro 3, rear panel
A recent posting by Thomas K4SWL reminded me of a radio I built from a kit a long time ago. In fact, I couldn't even remember if I still had it. A deep search of the shack's dungeon revealed on old box, tucked away - far away, under other old radio memories.

I excavated the box and opened it with all the anticipation of an archaeologist, not quite remembering if it really was in this box and, if so, just what did it look like. I'd last laid eyes on it over 20 years ago. It had almost gotten a friend - the one for whom I built it - in trouble.

Here's that brief story:

It was the late 1990's in Montclair NJ. A friend played guitar in a local band and wanted to get some air time for a few of their original songs. He knew his chances of getting his tunes played on a commercial FM station hovered somewhere between zero and none. And - this is key - he'd seen Pump Up The Volume and knew that I knew a "bit about radios".

NRG transmitter interior

My friend - I'll call him "Don" since that was (and still is) his name - wondered if there was some way he could be outfitted with a radio similar to that in Pump Up The Volume, and, if so, what would his range be. I told him that a lot depends on the antenna's location.

Funny thing about Don: besides being in a rock & roll band, he was also a caretaker for a Montclair church. A church with a very tall belltower. A belltower that he had access to. Do you see where this is going? Furthermore, Don and his wife lived on church property as part of his caretaker responsibilities.

At the 1-watt setting (13.8V, 470mA DC in) The labels are Photoshopped here for illustration, ie they're not on the actual case

The more we talked about his idea, the more we realized that the belltower was just begging to host a 5/8-wave vertically polarized antenna for 89.1 MHz.

Also in the 1990's a guy name Steve Dunnifer in Berkeley CA was making the news for defying FCC orders to cease and desist the operation of his own FM station. Steve responded to this order by designing and selling FM transmitter kits of various power outputs. "Do you want to whisper to your neighborhood or yell to the city?"

But research and economics led me to NRG Kits for Don's transmitter and another vendor (I can't remember the name) for a 25-watt amp. I built the transmitter and antenna first, then we installed everything in the belltower and a closet just beneath the uppermost level where AC was available to power the transmitter and audio source.

At the 4-watt setting (13.8V, 690mA DC in)

With Don's band's music being fed into the still-unhoused transmitter (and no amp yet) we got in Don's car and drove around Montclair, a university town just west of NYC. I wish I could describe to you the smile on Don's face - it just wouldn't go away. I think the main phrase, uttered repeatedly over and over as we got further and further away was "Holy shit!" accompanied by a non-stop grin.

We ended up in Wayne NJ, still hearing the music from the parking lot of Deerbrook mall. Four watts, booming all the way out there, thanks to that godly-tall antenna.

Maybe in a future post I'll tell you how and why Don eventually went off the air - but for now, back to the Old Beast:

As you can see, I never did wire the On/Off switch - the rig is turned on just by plugging in the power cord. The lights flicker as the PLL circuitry finds it proper place (based on DIP switch settings for the freq) and then, with three greens and no red, RF power is delivered. It is a mono transmitter but the audio in area receivers sounds amazing.

An actual review of the radio is here and the manual is here.

And here I am - a legit ham, a CW DXer...what am I going to do with this thing.....? No one listens to FM anymore anyway. Good thing, I guess.


  1. Funny, I listed to AM more than FM these days. There is a local station with "traffic and weather on the 8's" I listen to during my 115-mile round trip daily commute, to get the latest traffic info.

    Otherwise, I stream podcasts via Bluetooth from my cell phone through the radio. Kind of like radio on demand...

    1. Same here Dave - news and weather on AM mostly. If I'm on a road trip and want music, I stream it from Pandora. I think FM has taken the place of Muzak as background music for businesses. Not many listen to FM on purpose anymore.
      73 - John

  2. FM is still popular in New York City...there are about 100 pirates broadcasting to immigrant communities every day:

    1. An interesting link - thanks.
      73 - John

    2. check this one too: