FCC Shuts Down 434 Space Shuttle Video

It seems that a company by the name of Code Alarm makes remote car security and auto starter Part 15 devices that is operating on 433.97 MHz and was having its range decreased from 200 ft to 20 ft every time the Space Shuttle transmitter on 434 MHz, operated by Chris, N8UDK, was on the air in Clawson, Michigan. Code Alarm made a formal complaint to the FCC.


Pat Patterson of the FCC contacted N8UDK because Chris had a copy of his license on the rack as required and asked Chris to shut down his transmitter in response. Chris cooperated and told the FCC where the switch was at the site and they confirmed that his transmitter was the cause of Code Alarms problem.



I emailed Chris the applicable Part 15 Rules. Chris asked Pat Patterson if Code Alarm was Part 15 compliant and if so, stated that hams have priority in the 420-450 MHz band over Part 15 and that one of the conditions of getting a FCC ID for the device is to accept all interference from other services as well as not interfering. Pat Patterson said he would check out the rules, do some further tests and get back to him.



A day later Pat Patterson confirmed to N8UDK that he was well within the FCC Rules and OK'd turning the Space Shuttle retransmission on 434.0 MHz back on. Further, Pat Patterson asked if Chris could talk to the engineer at Code Alarm, which he did. The engineer apparently was not aware of the ham band and that hams could run over 1 KW if they wanted to, much more than the 32 watts that Chris was running. Code Alarm had just recently changed to 433.97 from 315 MHz.



This was the second incident for Chris with new Part 15 device companies where he worked things out cooperatively on an engineering and FCC Rule basis with the company this year. Johnson Controls drove up with some new Chryslers and met with Chris to make some tests with their tire pressure sensors. They found no mutual interference and were appreciative for the time and cooperation.



Congratulations and a big pat on the back to Chris Oesterling, N8UDK, on a very professional and successful handling of what is an increasing problem in our ham bands. If you see Chris in booth 207 at Dayton, give him an Attaboy.



Tom O'Hara, W6ORG

ARRL Technical Advisor for ATV and Spectrum Management