The NPR article mentioned that as parts broke down, they were replaced with what was available and power was lowered over time. I wonder if X E R F is still out there in a diminished way? Pat, K9JAUAt 03:28 PM 1/24/2011, you wrote: > I am not surprised. That is just a lot of power any way >you look at it. > > When XERF first came on in the thirties, the transmitter >tubes had to be specially ordered. The transmitter was >water-cooled. I wonder, back in the late sixties or seventies, >if when the US and Mexico negotiated a better broadcasting setup >for the AM band, they just turned down the screen voltage on >that monster and kept it loafing along on 50,000 >Watts. Just think, that transmitter was designed to put out >500,000 watts all day long so it probably could do 50 K for the >next 75 years and just get a little dusty. > > Seriously, it was probably full of PCB oil and hard to >keep going so they probably just scrapped it and bought a modern >transmitter. >Pat Byrne writes: > > martin, > > I also heard on an old NPR broadcast that XERF would bring close > > flying birds out of the sky to their demise. And I believe, in their > > heyday there were a number of "super power" stations just across our > > southern border. > > Pat, K9JAUAt 12:00 PM 1/24/2011, you wrote: > > > I recently finished reading a book about one of the > > >biggest medical fraudsters in US history who snake-oiled his way > > >to riches during the 1930's in the United States and then from a > > >powerful AM radio station on the Mexican border. His name was > > >John R. Brinkley and he called himself a physician though he had > > >no valid medical degree. > > > > > > Most of the book is not directly radio-related, but > > >there is a brief description of Brinkley's Mexican boarder radio > > >station which later became XERF and I am sure some of you > > >remember the preachers selling all kinds of stuff that one could > > >hear after dark on XERF. > > > > > > XERF's transmitters were just across the river from Del > > >Rio, Texas and, at one time, were 500,000 Watts directional in > > >to the United States. > > > > > > People report that at night, the antenna towers arced > > >with green flashes. XERF leaked in to telephones in town, could > > >be heard on things that weren't even electronic such as bed > > >springs, and made the headlights of cars come on even when they > > >were supposed to be off as they drove around town. > > > > > > XERF transmitted on 735 KHZ in the mid thirties and many > > >of the radios were TRF or Tuned Radio Frequency receivers. These > > >were the predecessors of the superheterodyne radios we are more > > >familiar with. In a TRF radio, you have 1 or more tuned circuits > > >which you peak and tweak until they are centered on the > > >frequency of the radio station you want to listen to. There is > > >no IF, no conversion, no nothing; just tuned tank circuits of > > >sometimes dubious Q factor between the antenna and detector. > > > > > > If you ever had a crystal radio or have seen an old > > >radio from the early part of the last century, it was a TRF. > > > > > > In the 1930's, XERF had such a power-house signal at > > >night that people trying to listen to other radio stations in > > >other parts of the AM band suffered interference from Brinkley's > > >transmitter no matter where they tried to tune. > > > > > > It was a combination of tremendous AM transmitter power > > >coupled with basically poor quality receivers. > > > >