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565rffeedback [2021/07/17 12:50]
pa1ap [As mentioned before two main factors determine success for the Orion]
565rffeedback [2021/07/17 17:58] (current)
pa1ap [My take away’s are:]
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 1.3- The choice to use front panel microphone connector and using the internal microphone amplifier works well despite my bad scenario setup when following point 1.1. 1.3- The choice to use front panel microphone connector and using the internal microphone amplifier works well despite my bad scenario setup when following point 1.1.
  
-1.4- The choice to use the read panel din connector and using an external microphone amplifier and 600:600 audio transformer works well despite my bad scenario setup when following point 1.1.+1.4- The choice to use the rear panel din connector and using an external microphone amplifier and 600:600 audio transformer works well despite my bad scenario setup when following point 1.1
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 +.
  
  
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 1- Turn down the hardware mic gain to zero. 1- Turn down the hardware mic gain to zero.
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 2- Turn down the output power to 5 watts. 2- Turn down the output power to 5 watts.
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 3- Turn down the mic gain to the lowest value possible while monitoring the ALC led following your voice while transmitting. 3- Turn down the mic gain to the lowest value possible while monitoring the ALC led following your voice while transmitting.
  
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 4- Turn on the speech processor and set it to level 9. 4- Turn on the speech processor and set it to level 9.
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 5- Transmit and if the Orion starts transmitting on its own without you speaking you know something needs to change. In my case the Orion activated ALC without me speaking. ​ 5- Transmit and if the Orion starts transmitting on its own without you speaking you know something needs to change. In my case the Orion activated ALC without me speaking. ​
  
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 ===== Before and after experience ===== ===== Before and after experience =====
  
-Before the antenna system setup change the Orion hardware mic gain was set to 10dB and mic gain set to 100. Still my ALC led faded away at times (not always) and it was frustrating. Stations reported my audio sounded raw and to much low frequency audio. My solution was to move the TX EQ low pass to a higher value and this sounded better according to responding stations. Same experience when using the rear connector, connecting through 600:600 ohm audio transformer,​ Behringer voice optimizer and the same Heil PR-781 microphone ​the resultRaw sounding audio. Stations did not complain but I did not get any compliments for great audio either.+Before the antenna system setup change the Orion hardware mic gain was set to 10dB and mic gain set to 100. Still my ALC led faded away at times (not always) and it was frustrating. Stations reported my audio sounded raw and to much low frequency audio. I blamed the microphone at that moment. My solution was to move the TX EQ low pass to a higher value and this sounded better according to responding stations. Same experience when using the rear connector, connecting through 600:600 ohm audio transformer,​ Behringer voice optimizer and the same Heil PR-781 microphone. ​The result was still  raw sounding audio. Stations did not complain but I did not get any compliments for great audio either.
  
-After the change the Orion started to behave like it should according the manual. The hardware mic gain set to 0 db and the mic gain is around 80 now. ALC led is lively following my voice at all times. Stations report and compliment on audio quality. ​ Speech processor can be set to level 9 and the Orion keeps working like expected. ​ Right now I am using the speech processor at level 6 and it really works well. +After the change the Orion started to behave like it should according the manual. The hardware mic gain set to 0 db and the mic gain is around 80 now. ALC led is lively following my voice at all times and regardless of output power. Stations report and compliment on audio quality. ​ Speech processor can be set to level 9 and the Orion keeps working like expected. ​ Right now I am using the speech processor at level 6 and it really works well. 
  
 ===== My take away’s are: ===== ===== My take away’s are: =====
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 1- Using front microphone connector is more sensitive for RF feedback however when you get your system configuration correctly it will work very well. Take my bad scenario setup as an example. 1- Using front microphone connector is more sensitive for RF feedback however when you get your system configuration correctly it will work very well. Take my bad scenario setup as an example.
 +
 2- Using the rear din connector is indeed less sensitive for RF feedback however additional components are needed and in the end all you do is using an external microphone amplifier with perhaps some voice optimisation. Is it worth the money? 2- Using the rear din connector is indeed less sensitive for RF feedback however additional components are needed and in the end all you do is using an external microphone amplifier with perhaps some voice optimisation. Is it worth the money?
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 3- When your antenna is not perfectly balanced you will have the consequence of the resulting unbalanced common mode signal. Not providing a path to a “ground” means the common mode signal will arrive at the Orion and hence suffer from RF feedback. 3- When your antenna is not perfectly balanced you will have the consequence of the resulting unbalanced common mode signal. Not providing a path to a “ground” means the common mode signal will arrive at the Orion and hence suffer from RF feedback.
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 3.1- A coax fed dipole with a current balun at the center will force balance between the two legs of the dipole. The effect of the current balun will be a significant common mode rejection and hence small (if any)  resulting RF at the opposite side of the coax. Until the dipole is used on other than designed frequencies. 3.1- A coax fed dipole with a current balun at the center will force balance between the two legs of the dipole. The effect of the current balun will be a significant common mode rejection and hence small (if any)  resulting RF at the opposite side of the coax. Until the dipole is used on other than designed frequencies.
-3.2- A balanced open feedline has low loss and great advantages being able to be used on other than designed frequencies. ​ However it assumes a balanced dipole which is only theory. More likely you have an unbalanced system resulting in resulting ​RF at the other end of the balanced feedline but now with only small loss. In a way this great advantage has also great disadvantages.+ 
 +3.2- A balanced open feedline has low loss and great advantages being able to be used on other than designed frequencies. ​ However it assumes a balanced dipole which is only theory. More likely you have an unbalanced system resulting in RF at the other end of the balanced feedline but now with only small loss. In a way this great advantage has also great disadvantages. 
 4- Always ensure resulting RF at the transmitter can travel somewhere else than your microphone cable, headphone cable and such like. Ensure the path for resulting RF has a very low impedance compared to all your other cables. ​ 4- Always ensure resulting RF at the transmitter can travel somewhere else than your microphone cable, headphone cable and such like. Ensure the path for resulting RF has a very low impedance compared to all your other cables. ​
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 4.1- Ferrite chokes will help here to increase impedance towards paths you don’t want the resulting RF signals to travel. 4.1- Ferrite chokes will help here to increase impedance towards paths you don’t want the resulting RF signals to travel.
  
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 +===== difference between firmware 1 and firmware 2/3 =====
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 +There is no real confirmation available but from experience firmware 1 was less sensitive for RF feedback. The real change has been DSP firmware and the audio processing. I can only guess that somehow the processing delay has changed in combination with the ALC interaction. Perhaps the hang-time changed too. In the end I believe the response to RF feedback is different but it does not change RF feedback taking place.
  
 I am certainly not an expert on this topic. I hope this description will support others when RF feedback occurs with the Ten-tec Orion. ​ Best regards, Onno pa1ap I am certainly not an expert on this topic. I hope this description will support others when RF feedback occurs with the Ten-tec Orion. ​ Best regards, Onno pa1ap
  

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