@rugster Read the review on HB and this ...about the Decade MS-100
"Next, we took the unit and set it up in a test location typical to the use of other Part 15 FM transmitters. We adjusted the audio with the help of our Belar FM modulation monitors and then took a drive around. Those assisting with the test were totally floored! The MS-100s coverage put our C. Crane and other bench reference FM transmitters to shame. We called upon local installer Joe from PelhamBroadcasting.com for some unbiased input. His first premonition was that the transmitter was out of adjustment. Unfortunately, an email to Decade confirmed that our unit was set to the Canadian 1mW specification instead of the 250µV/m at 3 meter specification set forth by the Federal Communication Commission. Our "awe" turned into more of an "oh".
"The review stalled for more than a month while we attempted to locate an engineer who both had access to an FM field intensity meter and would be willing to assist us in re-calibrating the unit. Lucky for us, PelhamBroadcasting.com decided to purchase a new and freshly calibrated field strength meter and Joe helped us in resetting the RF level of the transmitter. It took a little time to get the adjustment in line, since the transmitter's own circuitry emits more than the allowable field strength when the cover is removed from the unit."
"Once set to the proper field strength we proceeded to resume the evaluation. The transmitter performed similarly to our previous tests of other Part 15 FM transmitters. Very sensitive FM radios equipment with directional antennas with some factor of gain would pick up the transmitter to a distance of past 150 feet, while typical FM portables used for testing lost a usable signal within 50 to 100 feet."
Shows how "puny" the FCC field strength really is. Nice it's working out for you though.
Yes, that's what I was referring to in the other thread. Was rather surprised about the emission with the top cover off being over the field strength limit allowed by FCC 15.239.
For what it's worth.. Can't presently cite it, but do recall FCC documentation saying changing from a steel enclosure to a plastic one (or vice-versa) would requires a recertification of the unit. I don't recall specifically what the reference was, it ma have been part 15 FM or AM or maybe referenced TIS,. Or possibly all three --- I recall coming across reading it and being surprised that the transmitter enclosure itself played a factor in certification.
@richpowers I know from my lab visits that any changes yes do need recertification but I am not sure about the enclosure material from plastic to metal. The switch to metal also included the audio input change from RCA jacks to 1/4" TRS jack.
There could have been a second certification as the first Decade's were made in 1997. But looking up the certification for Canada the certification approvals were on Jan 1/2008. That may have been when they changed to the metal cabinets. The FCC certification is still 1997.