flex6400m SSB signal is bad.

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  • Updated 2 weeks ago
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Hello! I want to say that the flex6400m SSB signal is bad. With this quality, SSB only works on DX.ESSB and is not close. It seems that the current of the output transistors is clamped. The transmitter works in class C.
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ua3lm

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Posted 3 weeks ago

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mikeatthebeach .

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Try hooking a 50 ohm Dummy Load with the Flex6400M

Listen for Distortion in a remote Receiver with Headphones

RF can get into cabling easily

Try at different output powers

Electric Elements Mics seem better to me than Dynamic
Mic elements but that my personal Preference with
RadioSport Mic Headsets and my Flex6600M

Try different Mic Selections from the Menu
Settings - That may help rather than the
Default selection

73 Mike
(Edited)
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ua3lm

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Well, of course, I checked for 50 ohms. I have no RF interference. The essence of the distortion is that the ssb signal is clamped. It sounds like a class C transmitter. The transmitter band is 0-3200 Hz, and the transmitter sound is already TS-870. At the transceiver for $ 500, the ssb signal looks cleaner on the air than the flex6400. I use the Heil pr-40 microphone. I tried to connect it to the 3.5mm jack, I fed it through the MIC100 to the rear ACC connector. Audio ssb transmitter does not get any better. Alas.
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ua3lm

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I think that the manufacturer for getting a good lmd3 transmitter underestimated the quiescent currents of the output transistors and pre-transistors. Therefore, the linearity of the ssb signal has decreased. At flex 1500, 3000, 5000 you can independently control the quiescent currents of the output transistors, there are no such problems.
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Bill -VA3WTB

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This is not normal, the 6400m should have no transmit problems like your having.
Why not a help desk ticket? surprised you have not started one by now.
(Edited)
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ua3lm

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The normal sound of the transmitter is obtained if it is formed separately. Now I use the MIC-100 microphone amplifier and feed the sound into the 3.5mm microphone jack. Microphone amplification 0.
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Michael Walker, Employee

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Please test with the hand mic that shipped with the radio.  If the problem still exists, please open a support ticket.  Doing this will ensure that we are attempting to debug this at a very simple configuration.  

You have not mentioned what level you are driving the radio at.  Possible try ensuring that the Peak bar on the Level meter never reaches the right end of the scale.  I keep mine about -5db on a 6600 with a RadioSport headset and I do not hear the same thing.  


Mike
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ua3lm

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microphone gain on the -10db indicator. Not more !!! I realized that flex is just a line input, unlike sunsdr2 pro. Sunsdr has many different audio tweaks to the microphone amplifier input and that’s good! Flex doesn't have this, and therefore it is necessary to make the sound separately and feed the finished audio to the 3.5mm input! For me, the factory microphone is no good, it has poor sound. There are no low frequencies, for example, like heil pr-40. But if you need a flex for DX or just talk, then a simple microphone goes straight into the 3.5mm jack. But I need more! I need an ESSB! Without external audio processing, the flex sounds poor and dry, a spiky sound. Flex, do the modulator input as sunsdr2 pro!
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Bill -VA3WTB

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I have talked to many people on a 6400, just one this morning and many of them sound really good. The one this morning was using a pr 781 into the input jack and he sounded mello with full range audio ESSB if you would.

What they all mostly have done was work on the EQ, the Flex has a really good EQ but like anything,,you have to spend time to set it right.

One thing I discovered on my 6500 is I need to run almost all EQ sliders below the 0 mark, other wise the EQ can drive the PROC to hard.
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ua3lm

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Many radio amateurs like the sound of flex. Do you ask such radio fans as WZ5Q about your audio, what will it say about the flex transmitter? We talk about different things. Not all people are demanding. Thank!
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ua3lm

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Я не говорю, что гибкость на снаряде! Он работает ! Но для хорошего звука вам необходимо использовать внешние источники обработки звука.
I would like that in the future the manufacturer would carefully approach the transmitter. By preparing the audio transmitter.
(Edited)
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ua3lm

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Gentlemen, thank you all who responded! the issue is resolved!