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MH-31 Microphone low output


Sid Boyce
 

Has anyone experienced low microphone level from the MH-31?

With the ODY-2's 1W I get no movement with the SWR meter set to 5W PEP full scale.

My setup ODYSSEY-2 --> 100W PA ex-IC737. At first I thought the problem was with the PA.

If I scream into the MH-31, I can talk it up beyond full output, speaking normally or blowing equivalently I get only a few watts output.

Using local audio electret mic to a USB audio dongle  with the PiHPSDR v2 I can drive the amp close to 200W PEP into a dummy load speaking at a normal voice .

73 ... Sid.

--
Sid Boyce ... Hamradio License G3VBV, Licensed Private Pilot
Emeritus IBM/Amdahl Mainframes and Sun/Fujitsu Servers Tech Support
Senior Staff Specialist, Cricket Coach
Microsoft Windows Free Zone - Linux used for all Computing Tasks


Neoklis Kyriazis
 

Has anyone experienced low microphone level from the MH-31?
No, but I found this article that may confirm your problems.
https://www.iarc.org/~4x1mk/modifying_the_MH-31_Yaesu_microphone.html

--
Best Regards
Neoklis - Ham Radio Call:5B4AZ
http://www.5b4az.org/
https://www.qsl.net/5b4az/index.html


David Fainitski
 

Hello, Sid.
My MH-31 mic was tested with PowerSDR Wich has "mic 20db preamp" settings and also program mic amplification settings.
No any problems.
Dynamic microphones like MH-31 required 20db preamp option on, unlike electret microphones.


Reto HB9TRT
 

Hi Sid, 
also no problems here with the MH31. Good modulation and normal power output at the 1W PA from Ody-2. 

vy 73
Reto


Sid Boyce
 

Thanks Neoklis,
Looks great, I'll do that mod.
73 ... Sid.

On 16/09/2020 14:23, Neoklis Kyriazis via groups.io wrote:
Has anyone experienced low microphone level from the MH-31?
No, but I found this article that may confirm your problems.
https://www.iarc.org/~4x1mk/modifying_the_MH-31_Yaesu_microphone.html

--
Best Regards
Neoklis - Ham Radio Call:5B4AZ
http://www.5b4az.org/
https://www.qsl.net/5b4az/index.html

--
Sid Boyce ... Hamradio License G3VBV, Licensed Private Pilot
Emeritus IBM/Amdahl Mainframes and Sun/Fujitsu Servers Tech Support
Senior Staff Specialist, Cricket Coach
Microsoft Windows Free Zone - Linux used for all Computing Tasks


Sid Boyce
 

Thanks David,
That's absent from pihpsdr.
73 ... Sid.

On 16/09/2020 14:57, David Fainitski wrote:
Hello, Sid.
My MH-31 mic was tested with PowerSDR Wich has "mic 20db preamp" settings and also program mic amplification settings.
No any problems.
Dynamic microphones like MH-31 required 20db preamp option on, unlike electret microphones.
--
Sid Boyce ... Hamradio License G3VBV, Licensed Private Pilot
Emeritus IBM/Amdahl Mainframes and Sun/Fujitsu Servers Tech Support
Senior Staff Specialist, Cricket Coach
Microsoft Windows Free Zone - Linux used for all Computing Tasks


Sid Boyce
 

Thanks Reto,
As I am using the pihpsdr, I'll do the mod with the electret mic.
73 ... SId.

On 16/09/2020 21:29, Reto HB9TRT wrote:
Hi Sid,
also no problems here with the MH31. Good modulation and normal power output at the 1W PA from Ody-2.

vy 73
Reto
--
Sid Boyce ... Hamradio License G3VBV, Licensed Private Pilot
Emeritus IBM/Amdahl Mainframes and Sun/Fujitsu Servers Tech Support
Senior Staff Specialist, Cricket Coach
Microsoft Windows Free Zone - Linux used for all Computing Tasks


David Fainitski
 

Sid, is there no 20db preamp option ?
Should be there.


Sid Boyce
 

Hi David,
Not in pihpsdr.
Just the Local Microphone  and Compression.
I have not tried adjusting Compression to see if that would give a usefull boost.
73 ... Sid.

On 17/09/2020 14:28, David Fainitski wrote:
Sid, is there no 20db preamp option ?
Should be there.
--
Sid Boyce ... Hamradio License G3VBV, Licensed Private Pilot
Emeritus IBM/Amdahl Mainframes and Sun/Fujitsu Servers Tech Support
Senior Staff Specialist, Cricket Coach
Microsoft Windows Free Zone - Linux used for all Computing Tasks


David Fainitski
 

Hi, Sid
I can't believe it, even Quisk has this option. Did you try to reach g0orx ? This is the serious issue.


Sid Boyce
 

Hi David,
It's something I'll bother him about later as we recently were chasing a problem on a PiHPSDR v2 connected to HermesLite2 which turned out to be a tick box for local microphone selection not showing up on that screen.
When I took a screen snapshot it was there - so it was just a problem with contrast.
Two Raspberry Pi official LCD's, one OK and the other with the problem.
73 ... Sid.

On 18/09/2020 14:49, David Fainitski wrote:
Hi, Sid
I can't believe it, even Quisk has this option. Did you try to reach g0orx ? This is the serious issue.
--
Sid Boyce ... Hamradio License G3VBV, Licensed Private Pilot
Emeritus IBM/Amdahl Mainframes and Sun/Fujitsu Servers Tech Support
Senior Staff Specialist, Cricket Coach
Microsoft Windows Free Zone - Linux used for all Computing Tasks