XL 3000 FM Transmitter

User Report on BEXT XL 3000s transmitters
By Bill Traue CSRE, 8-VSB, AMD,
who recently installed two XL 3000s
Bill Traue Technical Service LLC, Idaho Falls, ID 83401.
Recently I was on the receiving end of a conference call between a station owner in Wyoming and the manager of the local airport. One of the owner’s FM stations had suddenly developed a problem with spurious emissions and was interfering with aircraft communications in the area. The first question I asked was if the interference was being heard on 121.5 MHz, the distress frequency and it was not. Only slightly relieved, I advised the station owner to shut down that transmitter immediately and I would come and get him back on the air, sans interference.
I felt that the interference was coming from the stations’ old FM transmitter. Although a solid-state model it occupied a full rack about a tall as Frankenstein. I hoped it wasn’t IM interference from things like rusty tower joints. When I arrived in town I stopped at the studio first and picked up a brand-new BEXT XL3000, still in the unopened box, which was waiting there for another project. I took it up the transmitter mountain and installed it as quickly as possible, moving the AC wires from the old transmitter to the new, the antenna coax with 7/8” flange and the composite audio from the processor to the Mux input on the rear of the transmitter. (The XL3000 can be ordered for single phase power or three phase, as can its larger brother the XL6000).
I prefer to operate a new transmitter into a dummy load for a week to wring out any problems and become more familiar with it. But there was no time for that since this station was off the air. BEXT provides the transmitter documentation on a USB thumb drive and they are also available via a front panel USB connection even if the transmitter is not powered up. I resigned myself to slowing down long enough to fire up my laptop computer and read up on what this new transmitter required of me to get it working on the air. I realized after a minute that the colorful touch screen user interface on the front of the XL series transmitter was all I needed and I put the PC away. I intuitively changed the frequency, lowered the preset power down to nothing and pushed RF ON. The cooling fans come up to full speed for a few seconds then slow down to just what is required to manage things thermally. I slowly raised power and with no reflected power, I went right up to 3000 watts. Then I called the airport manager and asked if the interference was gone. He checked around on his radios and found no trace of it.
As I drove down the hill and around town, listening to the new transmitter, I noticed how great it sounds- a noticeable improvement from the old transmitter in the Frankenrack. The XL3000 takes up only three rack spaces leaving lots of room for other gear.
The next morning I returned to make sure the transmitter was happy in its new home. I called up the airport manager again to verify that there was no interference with his radios and there was none. I drove the signal out as I left the area and enjoyed the improvement in sound.
Two months later, I asked the station owner if the XL3000 had been stable so far, and it has. Several listeners have commented to him how great the station sounds and asked what they had done. I think the upgrade in sound is due to the direct FM at carrier frequency design. You can keep spending thousands on the latest greatest audio processing but if you don’t have the design found in this BEXT XL series working for you, you are just creating louder noise.
We plan on buying several more of these new XL series transmitters.
Bill Traue
Bill Traue can be contacted at billtraue@gmail.com