Regarding the story “IBiquity Doubts DPR Performance Claims” (radioworld.com, March 29):
Innovators in the art and science of digital modulation are quick to point out that the iBiquity methodology will be technically obsolete within a decade. On the AM-MW band, relying on phase-modulated narrow sidebands is a substandard approach to digital. iBiquity works great on conventional FM-VHF carriers, but there’s actually room for dozens of digital radio stations on one carrier.
Chief Executive Officer
KY Media Group
Yes Virginia, MRF315A Replacements Do Exist!
Mark Person’s article in the April 10 issue (“Repairs Extend Lives of FM Exciters”) was great. However, he mentions having replaced the amplifier deck in an 802A because he couldn’t get an MRF315A transistor.
He and your readers should know that Advanced Semiconductor makes equivalents to all of the Motorola RF transistors. Their website, www.advancedsemiconductor.com, lists datasheets for what they have available.
Their MRF315A replacement definitely works in the 802A and should be available through Mouser. I have used them with good success.
Mark Persons replies: Glad to know that a company has picked up where Motorola left off. The Continental parts department had no knowledge of that when I called to get parts. The Advanced Semiconductor offering must be recent because Mouser and RF Parts did not have one at the time, probably six months ago.
My other source was NTE Electronics, which offers the NTE360 as a replacement. I was told the NTE transistor was problematic and was not reliable in that exciter. Building transistors to the original Motorola specs and quality is what the industry needed.