I received this email from some one today. I am putting in some of his comments. We talked about pure signal and he can't understand why Flex radios are so bad on transmit. I didn't think they were that bad, and the 6000's are no better. Is it true the finals are dirty?
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Posted 4 years ago
Tim  W4TME, Customer Experience Manager
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Official Response
Bill,
For your question, as asked, the answer is no, the finals of our transmitters are not "dirty".
The FCC is the federal regulatory body that specifies the maximum allowable spurious emission as per Part 97.307 (d) and subpart (e).
"(d) For transmitters installed after January 1, 2003, the mean power of any spurious emission from a station transmitter or external RF power amplifier transmitting on a frequency below 30 MHz must be at least 43 dB below the mean power of the fundamental emission. For transmitters installed on or before January 1, 2003, the mean power of any spurious emission from a station transmitter or external RF power amplifier transmitting on a frequency below 30 MHz must not exceed 50 mW and must be at least 40 dB below the mean power of the fundamental emission. For a transmitter of mean power less than 5 W installed on or before January 1, 2003, the attenuation must be at least 30 dB. A transmitter built before April 15, 1977, or first marketed before January 1, 1978, is exempt from this requirement."
"(e) The mean power of any spurious emission from a station transmitter or external RF power amplifier transmitting on a frequency between 30–225 MHz must be at least 60 dB below the mean power of the fundamental. For a transmitter having a mean power of 25 W or less, the mean power of any spurious emission supplied to the antenna transmission line must not exceed 25 μW and must be at least 40 dB below the mean power of the fundamental emission, but need not be reduced below the power of 10 μW. A transmitter built before April 15, 1977, or first marketed before January 1, 1978, is exempt from this requirement."
Our radios meet or exceed the aforementioned requirements.
On the issue of if and when we plan to offer adaptive predistortion as a feature in the FLEX6000 Signature Series SDRs, that question has been answered in a previous post ( https://community.flexradio.com/flexradio/topics/adaptive_predistortion)
For your question, as asked, the answer is no, the finals of our transmitters are not "dirty".
The FCC is the federal regulatory body that specifies the maximum allowable spurious emission as per Part 97.307 (d) and subpart (e).
"(d) For transmitters installed after January 1, 2003, the mean power of any spurious emission from a station transmitter or external RF power amplifier transmitting on a frequency below 30 MHz must be at least 43 dB below the mean power of the fundamental emission. For transmitters installed on or before January 1, 2003, the mean power of any spurious emission from a station transmitter or external RF power amplifier transmitting on a frequency below 30 MHz must not exceed 50 mW and must be at least 40 dB below the mean power of the fundamental emission. For a transmitter of mean power less than 5 W installed on or before January 1, 2003, the attenuation must be at least 30 dB. A transmitter built before April 15, 1977, or first marketed before January 1, 1978, is exempt from this requirement."
"(e) The mean power of any spurious emission from a station transmitter or external RF power amplifier transmitting on a frequency between 30–225 MHz must be at least 60 dB below the mean power of the fundamental. For a transmitter having a mean power of 25 W or less, the mean power of any spurious emission supplied to the antenna transmission line must not exceed 25 μW and must be at least 40 dB below the mean power of the fundamental emission, but need not be reduced below the power of 10 μW. A transmitter built before April 15, 1977, or first marketed before January 1, 1978, is exempt from this requirement."
Our radios meet or exceed the aforementioned requirements.
On the issue of if and when we plan to offer adaptive predistortion as a feature in the FLEX6000 Signature Series SDRs, that question has been answered in a previous post ( https://community.flexradio.com/flexradio/topics/adaptive_predistortion)
(Edited)
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