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Aircraft headset speaker impedance and ubitx #ubitx

Adrien F4IJA
 

Hi everyone! 
I've ordered yesterday my ubitx and I'm thinking upon the boxing and peripherals to add. 

I already have a great quality tourism aircraft headset with mic and was thinking about using it with the ubitx to have comfortable equipment for my ears.

But the impedance of the speakers is 600 ohms. I've red that the IC audio output is for something about 8 ohms. So what should be the behavior with 600 ohms? Does it will work in your opinion or best : did someone already test it?

Thank you for your kind answers.
73
Adrien F4IJA

pat griffin
 

Adrien,
I have used aviation headsets a good bit with the ubitx and others and the speakers are usually 10-15 ohms. The 600 ohm will likely not work very well without a little audio step down transformer.  On the other had, the electret mic might work very well.
73,
Pat

Pat Griffin AA4PG
http://www.cahabatechnology.com/aa4pg.html


From: BITX20@groups.io <BITX20@groups.io> on behalf of adrien.grelet@... <adrien.grelet@...>
Sent: Saturday, August 24, 2019 8:21 AM
To: BITX20@groups.io <BITX20@groups.io>
Subject: [BITX20] Aircraft headset speaker impedance and ubitx #ubitx #ubitx #ubitx
 
Hi everyone! 
I've ordered yesterday my ubitx and I'm thinking upon the boxing and peripherals to add. 

I already have a great quality tourism aircraft headset with mic and was thinking about using it with the ubitx to have comfortable equipment for my ears.

But the impedance of the speakers is 600 ohms. I've red that the IC audio output is for something about 8 ohms. So what should be the behavior with 600 ohms? Does it will work in your opinion or best : did someone already test it?

Thank you for your kind answers.
73
Adrien F4IJA

Adrien F4IJA
 

Thank for letting me know. I'll try to measure my actual headset speaker impedance to be sure of that. 

Ian Reeve
 

I see no reason why the electret mic should not be satisfactory but I have my doubts on the 600 oh impedance head phones.The uBITX requires 8 ohms to around 32 ohms to match most earphones.I suspect that you would get very little output into 600 ohms.


From: BITX20@groups.io <BITX20@groups.io> on behalf of adrien.grelet@... <adrien.grelet@...>
Sent: Saturday, August 24, 2019 3:52:15 PM
To: BITX20@groups.io <BITX20@groups.io>
Subject: Re: [BITX20] Aircraft headset speaker impedance and ubitx #ubitx #ubitx #ubitx
 
Thank for letting me know. I'll try to measure my actual headset speaker impedance to be sure of that. 

Adrien F4IJA
 

I've tested the headset and the resistance which is not really the impedance seems to be 63 ohms on the 6.35 mm jack. I guess the 6.35mm jack is for speakers and the 5mm for the mic.

Could you please confirm that? 

Ian Reeve
 

I would say your deduction is correct as regards the Jack plugs. The one where you measure the 63 ohms is the headset,the mic if electret should measure as a open circuit.Does each Jack plug just have two connections,the tip and sleeve?


From: BITX20@groups.io <BITX20@groups.io> on behalf of adrien.grelet@... <adrien.grelet@...>
Sent: Saturday, August 24, 2019 4:09:39 PM
To: BITX20@groups.io <BITX20@groups.io>
Subject: Re: [BITX20] Aircraft headset speaker impedance and ubitx #ubitx #ubitx #ubitx
 
I've tested the headset and the resistance which is not really the impedance seems to be 63 ohms on the 6.35 mm jack. I guess the 6.35mm jack is for speakers and the 5mm for the mic.

Could you please confirm that? 

 

Hi,

The 600 ohms sounds more like a spec for the mic.  Perhaps it is a dynamic one, where 600 ohms would be quite typical.

73,


Mark.

Ian Reeve
 

Agreed typical measurement for a dynamic mic but not electret.


From: BITX20@groups.io <BITX20@groups.io> on behalf of Mark - N7EKU <n7eku@...>
Sent: Saturday, August 24, 2019 4:36:31 PM
To: BITX20@groups.io <BITX20@groups.io>
Subject: Re: [BITX20] Aircraft headset speaker impedance and ubitx #ubitx #ubitx #ubitx
 
Hi,

The 600 ohms sounds more like a spec for the mic.  Perhaps it is a dynamic one, where 600 ohms would be quite typical.

73,


Mark.

Tom, wb6b
 

Hi,

Because the earphones are directly over your ears, would it be possible that you don't need as much power to drive them, and 600 ohms would provide sufficient power to possibility supply more volume than needed? Likely the audio output of the amplifier is not bothered by driving 600 ohms vs 8 ohms. 

Another question. Would the impedance of the earphones be higher for AC (the audio) than DC, as measured by an ohmmeter? That would be the case for a transformer and the earphones seem to be a transformer like device when the magnet is moving in the coil, when driven by audio. 

It is possible that earphones are not very efficient and the DC and AC impedance are nearly the same.

Tom, wb6b

Adrien F4IJA
 

Thanks everyone for your answers. I've well measured something opened on the 5mm jack connector. So maybe it's the mic. 

So it seems that :
6.35mm jack is for headset and is about 60 ohms
5mm jack is for mic and acts like an open circuit. 

Does anybody with that kind of aircraft headset could confirm that the mic is well on 5mm jack and headset is 6.35mm jack? 

If yes I guess that kind of headset could work. I'll give it a try. 

Adrien F4IJA
 

OK I've the confirmation here : https://sennheiserusa.happyfox.com/kb/article/51-pj068-microphone-plug/

The 6.35mm jack is well for the headset. 

Gordon Gibby
 

Give it a try! The higher impedance of the earphones will probably not bother you at all, if anything the audio level may be lower but that’s easy to deal with.  




On Aug 25, 2019, at 02:53, "adrien.grelet@..." <adrien.grelet@...> wrote:

OK I've the confirmation here : https://sennheiserusa.happyfox.com/kb/article/51-pj068-microphone-plug/

The 6.35mm jack is well for the headset. 

Adrien F4IJA
 

On Sun, Aug 25, 2019 at 02:21 PM, Gordon Gibby wrote:
Give it a try! The higher impedance of the earphones will probably not bother you at all, if anything the audio level may be lower but that’s easy to deal with.  
 


 

On Aug 25, 2019, at 02:53, "adrien.grelet@..." <adrien.grelet@...> wrote:

OK I've the confirmation here : https://sennheiserusa.happyfox.com/kb/article/51-pj068-microphone-plug/

The 6.35mm jack is well for the headset. 

 It's very hard to find jack adapter from 5.23mm to 3.5mm (mic).

I've ordered a 6.35mm to 3.5mm to test the headset only for now on the supplied jack connectors.

Stay tuned for results! 

Gordon Gibby
 

Use  clip leads or simple wires to try it out


On Aug 25, 2019, at 12:20, "adrien.grelet@..." <adrien.grelet@...> wrote:

On Sun, Aug 25, 2019 at 02:21 PM, Gordon Gibby wrote:
Give it a try! The higher impedance of the earphones will probably not bother you at all, if anything the audio level may be lower but that’s easy to deal with.  
 


 

On Aug 25, 2019, at 02:53, "adrien.grelet@..." <adrien.grelet@...> wrote:

OK I've the confirmation here : https://sennheiserusa.happyfox.com/kb/article/51-pj068-microphone-plug/

The 6.35mm jack is well for the headset. 

 It's very hard to find jack adapter from 5.23mm to 3.5mm (mic).

I've ordered a 6.35mm to 3.5mm to test the headset only for now on the supplied jack connectors.

Stay tuned for results! 

ajparent1/KB1GMX
 

All my Aircraft headset are 600 ohm nominal for speaker and mic.
[include DC, Plantronics, and Telex]

They should work fine. for RX audio and note some are Electret
or dynamic and the levels can be very different.

Allison

Adrien F4IJA
 

I'll try when I'll receive the ubitx. If after that anyone has idea about where to find adapter from 5.23mm jack to 3.5mm, that could be highly appreciated, because I've no luck on searching the Internet for now.

Many thanks

iz oos
 

I have a 2000ohm headset which I have used in a 4 ohm speaker output of a drake receiver. Using a matching audio transformer indeed the volume increased significantly. In fact I could hear some hum when the volume was at minimum. In practice I prefer to use the headset without the transformer and just use the volume.


Il 25/ago/2019 14:22, "Gordon Gibby" <ggibby@...> ha scritto:
Give it a try! The higher impedance of the earphones will probably not bother you at all, if anything the audio level may be lower but that’s easy to deal with.  




On Aug 25, 2019, at 02:53, "adrien.grelet@..." <adrien.grelet@...> wrote:

OK I've the confirmation here : https://sennheiserusa.happyfox.com/kb/article/51-pj068-microphone-plug/

The 6.35mm jack is well for the headset. 

Gordon Gibby
 

I have bought sockets for those before, and then just use a couple pieces of wire to go to the mail plug.  Whip out that soldering iron and get some practice.  This is ham radio!


On Aug 26, 2019, at 04:05, "adrien.grelet@..." <adrien.grelet@...> wrote:

I'll try when I'll receive the ubitx. If after that anyone has idea about where to find adapter from 5.23mm jack to 3.5mm, that could be highly appreciated, because I've no luck on searching the Internet for now.

Many thanks

Wayne Leake
 

 Way back in the 1950's, I wired a headphone jack into the speaker output on my radio.
 Bear in mind that the headphone was high impedance, several K ohm.
 It worked quite well, and the speakers were rated at 3.2 Ohm mostly back then.
 Presently I have a bunch of 600 ohm headsets that came out of a school, and I may just try connecting to an 8 ohm output, such as the kind used in BITX40's, and more. These are headsets that will be reasonably comfortable to wear.
 Many mikes are rated at 600 ohm, usually dynamic.
 I have a mike from a Midland that is rated at 600 ohm, but I am wondering if it is an electret mike, as it tests as being an open circuit.
 That or the element is blown.
 With speaker, headphones and mikes, they will work with a mismatch most of the time.
 Won't hurt to try using it as an electret if it tests as an open element

 Wayne WA2YNE