Lowered power at FT8 frequency extremes

kc1sa
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Lowered power at FT8 frequency extremes Feb 28, 2022 17:39:59 GMT

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Post by kc1sa on Feb 28, 2022 17:39:59 GMT

I am puzzled on why power is reduced at FT8 frequency extremes. Example, on 17m (18.100MHz), TXing below 256Hz and above 2780Hz reduces transmit power eventually to zero at the far extremes. Why is this? FT8 has a 50Hz bandwidth and default FT8 spectrum is set to 3000Hz then I would expect power would be zero out at anything at the 50Hz and below and 2950Hz and above. At first I thought it was my rig (IC-7610) but there is no setting explaining this behavior.

Been using FT8 for a few years and JTDX for a while, but I'm always open to learning.

73,
Steve
KC1SA

w9mdb Users Posts: 199	Lowered power at FT8 frequency extremes Feb 28, 2022 17:42:37 GMT Quote Select Post Deselect Post Link to Post Member Give Gift Back to Top Post by w9mdb on Feb 28, 2022 17:42:37 GMT Because you aren't using Fake It or Rig Split. You are hitting the edges of your transmit bandwidth and one of those settings will solve the problem.

kc1sa
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Posts: 3

Lowered power at FT8 frequency extremes Feb 28, 2022 17:52:57 GMT

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Post by kc1sa on Feb 28, 2022 17:52:57 GMT

W9MDB ... thanks. Like I said, always willing to learn. I'll ponder your answer a bit, but clicking 'Fake it' resolved the issue. I'll have to go back to my other PC (laptop) and see if I had this checked or not. The PC I'm using now is sort of new to the radio environment.

Again, thanks for the help.

73,
Steve
KC1SA

Lowered power at FT8 frequency extremes

Post by kc1sa on Feb 28, 2022 17:39:59 GMT

Post by w9mdb on Feb 28, 2022 17:42:37 GMT

Post by kc1sa on Feb 28, 2022 17:52:57 GMT