Topics

Speaker Jack

Walter
 

If I use the Speaker jack with headphones, then I naturally have to turn the audio down very low.  However, if doing digital modes then the audio is too low for the signal link. 

What would I need to do to install a second jack for headphones and lower the audio for headphones while leaving the speaker volume up higher? 

Would a simple resistor work or is more required for such a modification?

Is there a place to tap into a constant audio level that is not affected by the volume control?  Kind of like a line level output?

Thanks for your help.
--
73, W9KJO
Walter

Richie Chambless
 

Hello Walter,

I have been doing some work around this same subject. You can take the low-level audio signal to an external amplifier by connecting the signal in to Vol-H (R170). This is the yellow wire coming off of the audio connector (diagram on HF Signals is incorrect). You can also reduce the headphone volume by inserting two small value resistors (under 100 ohm) in series with the output of the audio amp. Do this by connecting the output of the amp to pins 4&5 of the headphone jack. Now put the resistors across pins 1&2. I hope that makes sense! Google the Realistic DX-160 schematic to see what I’m talking about.

Bob Bennett
 

I would also like to have a headphone jack and an internal speaker. How do I wire this?

Bob

Walter
 

On Wed, Feb 28, 2018 at 07:01 am, Richie Chambless wrote:
Hello Walter,

I have been doing some work around this same subject. You can take the low-level audio signal to an external amplifier by connecting the signal in to Vol-H (R170). This is the yellow wire coming off of the audio connector (diagram on HF Signals is incorrect). You can also reduce the headphone volume by inserting two small value resistors (under 100 ohm) in series with the output of the audio amp. Do this by connecting the output of the amp to pins 4&5 of the headphone jack. Now put the resistors across pins 1&2. I hope that makes sense! Google the Realistic DX-160 schematic to see what I’m talking about.
Are you talking about something like this?

Would the Yellow wire signal act kind of like a line out at a constant level?  Does it need a cap to isolate the line from the device plugged into that line? I think it may not be true line level but a constant output level.  The signal link has a control to manage the level.

I am not an EE but still trying to learn and figure out a good way to get this done.

Thanks
 
--
73, W9KJO
Walter

Richie Chambless
 

Yes, the yellow wire is the full signal from the product detector. Check your volume potentiometer to ensure it’s connected to the end (orange should be on middle lug). I would think your external amplifier has a capacitor input on it, so I don’t think another cap is necessary. Check to see if DC is present across the volume pot when the side tone is activated.

Walter
 

On Wed, Feb 28, 2018 at 09:47 am, Richie Chambless wrote:
Yes, the yellow wire is the full signal from the product detector. Check your volume potentiometer to ensure it’s connected to the end (orange should be on middle lug). I would think your external amplifier has a capacitor input on it, so I don’t think another cap is necessary. Check to see if DC is present across the volume pot when the side tone is activated.
Ok The yellow wire does not have enough audio for my Signal Link to work with.  it showed some signals.  I have to reconnect to the 3.5mm Audio Out jack and turn the volume up about half way.  which is too loud for my headphones so I need to install a second 3.5mm for my Head Phones. 

I would be much better if I could find a way to get enough audio separate from the actual audio out to the 3.5mm jack

Thanks for the help all.
 
--
73, W9KJO
Walter

Clark Martin
 

You could use the second audio amp in U1.  The TDA2822 is a dual amplifier.  What you’d need to do is this:

Remove R75
Connect U1-6 to VOL-H.  This will give you an auxiliary sound output that is independent of the volume control.
Connect the + terminal of a 470 µF, 16V electrolytic capacitor to U1-3.
Connect the - terminal of the above cap to your auxiliary out mini jack.

The 470 µF could very likely be much smaller, depending on the input impedance of your Signal Link.
Experiment, it won’t hurt.

You may also want to add a resistor divider between the cap and jack to reduce the signal strength, depending on how much your Signal Link can tolerate.

Considering the problem others are having with the TDA2822 you probably should add a resistor in series with the cap, unless you implement the resistor voltage divider, that will provide the same protection.

Clark Martin
KK6ISP

On Mar 2, 2018, at 10:20 AM, Walter <W9KJO@...> wrote:

On Wed, Feb 28, 2018 at 09:47 am, Richie Chambless wrote:
Yes, the yellow wire is the full signal from the product detector. Check your volume potentiometer to ensure it’s connected to the end (orange should be on middle lug). I would think your external amplifier has a capacitor input on it, so I don’t think another cap is necessary. Check to see if DC is present across the volume pot when the side tone is activated.
Ok The yellow wire does not have enough audio for my Signal Link to work with.  it showed some signals.  I have to reconnect to the 3.5mm Audio Out jack and turn the volume up about half way.  which is too loud for my headphones so I need to install a second 3.5mm for my Head Phones.  

I would be much better if I could find a way to get enough audio separate from the actual audio out to the 3.5mm jack

Walter
 

On Fri, Mar 2, 2018 at 03:50 pm, Clark Martin wrote:
You could use the second audio amp in U1.  The TDA2822 is a dual amplifier.  What you’d need to do is this:
 
Remove R75
Connect U1-6 to VOL-H.  This will give you an auxiliary sound output that is independent of the volume control.
Connect the + terminal of a 470 µF, 16V electrolytic capacitor to U1-3.
Connect the - terminal of the above cap to your auxiliary out mini jack.
 
The 470 µF could very likely be much smaller, depending on the input impedance of your Signal Link.
Experiment, it won’t hurt.
 
You may also want to add a resistor divider between the cap and jack to reduce the signal strength, depending on how much your Signal Link can tolerate.
 
Considering the problem others are having with the TDA2822 you probably should add a resistor in series with the cap, unless you implement the resistor voltage divider, that will provide the same protection.

Clark Martin
KK6ISP

On Mar 2, 2018, at 10:20 AM, Walter <W9KJO@...> wrote:

On Wed, Feb 28, 2018 at 09:47 am, Richie Chambless wrote:
Yes, the yellow wire is the full signal from the product detector. Check your volume potentiometer to ensure it’s connected to the end (orange should be on middle lug). I would think your external amplifier has a capacitor input on it, so I don’t think another cap is necessary. Check to see if DC is present across the volume pot when the side tone is activated.
Ok The yellow wire does not have enough audio for my Signal Link to work with.  it showed some signals.  I have to reconnect to the 3.5mm Audio Out jack and turn the volume up about half way.  which is too loud for my headphones so I need to install a second 3.5mm for my Head Phones.  

I would be much better if I could find a way to get enough audio separate from the actual audio out to the 3.5mm jack
I noticed that the audio IC was dual channel.  I may try this mod.  I'm not an EE so how would you set up a resistor divider?  I can't design but I can certainly follow a schematic and home brew from there. So any specific instructions would help me greatly. 

BTW, the suggestions and mods on this forum have been excellent.  A hardy thank you to all!!!!  :)

 
--
73, W9KJO
Walter

Walter
 

On Fri, Mar 2, 2018 at 06:51 pm, Walter wrote:
On Fri, Mar 2, 2018 at 03:50 pm, Clark Martin wrote:
You could use the second audio amp in U1.  The TDA2822 is a dual amplifier.  What you’d need to do is this:
 
Remove R75
Connect U1-6 to VOL-H.  This will give you an auxiliary sound output that is independent of the volume control.
Connect the + terminal of a 470 µF, 16V electrolytic capacitor to U1-3.
Connect the - terminal of the above cap to your auxiliary out mini jack.
 
The 470 µF could very likely be much smaller, depending on the input impedance of your Signal Link.
Experiment, it won’t hurt.
 
You may also want to add a resistor divider between the cap and jack to reduce the signal strength, depending on how much your Signal Link can tolerate.
 
Considering the problem others are having with the TDA2822 you probably should add a resistor in series with the cap, unless you implement the resistor voltage divider, that will provide the same protection.

Clark Martin
KK6ISP

On Mar 2, 2018, at 10:20 AM, Walter <W9KJO@...> wrote:

On Wed, Feb 28, 2018 at 09:47 am, Richie Chambless wrote:
Yes, the yellow wire is the full signal from the product detector. Check your volume potentiometer to ensure it’s connected to the end (orange should be on middle lug). I would think your external amplifier has a capacitor input on it, so I don’t think another cap is necessary. Check to see if DC is present across the volume pot when the side tone is activated.
Ok The yellow wire does not have enough audio for my Signal Link to work with.  it showed some signals.  I have to reconnect to the 3.5mm Audio Out jack and turn the volume up about half way.  which is too loud for my headphones so I need to install a second 3.5mm for my Head Phones.  

I would be much better if I could find a way to get enough audio separate from the actual audio out to the 3.5mm jack
I noticed that the audio IC was dual channel.  I may try this mod.  I'm not an EE so how would you set up a resistor divider?  I can't design but I can certainly follow a schematic and home brew from there. So any specific instructions would help me greatly. 

BTW, the suggestions and mods on this forum have been excellent.  A hardy thank you to all!!!!  :)

 
--
73, W9KJO
Walter
Thinking a little more about your suggested mod.  Since a potentiometer is used to control the output of u1 to the audio jack (speaker).  Could I measure the value of the pot across Vol-H and Vol-M to discover the resistance value, when set at the desired level, and place a resistor at the input of U1-6 and control the level output at U1-3?  Would that work?
 
I need to place the 4 or 8 ohm resister in each circuit to protect them from shorts too.  Waiting on resistors to arrive.

--
73, W9KJO
Walter

Andy Robins
 

Orange to middle lug of the volume control? Shouldn't that be Yellow? That's certainly what the schematic shows. We are talking uBitx here aren't we?

If I'm wrong about this you may well have explained why I'm getting no audio from my newly finished build. 🤞

Sent from my iPad

Mike Woods
 

Pictures are correct, wire up diagram wrong ...


Unfortunately It’s not the only error,  see this page on uBITx.net as well:


While uBITx.net is a work in progress,  it should be a great introduction to your uBITx.

Mike ZL1AXG



On Sat, 3 Mar 2018 at 7:26 PM, Andy Robins <andy.robins@...> wrote:
Orange to middle lug of the volume control? Shouldn't that be Yellow? That's certainly what the schematic shows. We are talking uBitx here aren't we?

If I'm wrong about this you may well have explained why I'm getting no audio from my newly finished build. 🤞




Don, ND6T
 

I always use an external speaker. I include a switch and headphone jack(s) along with audio limiter for hearing safety and comfort. Details can be found here. 73, Don

Jeff Omundson
 

That's a great idea - thanks for sharing that solution!
- Jeff
AG7NW

Tim Gorman
 

You do realize than an 8ohm resistor in series with your 8ohm speaker
will cut your volume somewhere in the range of half, right?

Do you have enough volume output to be able to cut it in half?

I think the answer is to wire the 8ohm resistor up to the switched
contacts on the jack (or use an internal speaker wired to the same
terminals). This will limit the current in the 470uf capacitor if
nothing is plugged into the jack. If you have something plugged into
the jack then that should limit the charging current into the
capacitor.

The max current will flow at initial turn-on. The impedance of the
capacitor will be Zero regardless of its value so the current is
determined solely by the resistance in the circuit. An 8ohm resistor at
12 volts will see 1.5amp in the circuit. That's still pretty high. The
smaller you make the capacitor, say 47uf instead of 470uf, the quicker
the cap will charge (think RC time constant) resulting in less thermal
energy being input into the 2822.

Using a 16ohm internal speaker might be a better choice. Something
like
www.amazon.com/SPEAKER-REPLACEMENT-MAGNET-WATT-OHMS/dp/B00INBYT3C/ref=sr_1_13?ie=UTF8&qid=1520089328&sr=8-13&keywords=16ohm+speaker


That would bring the initial charging current to under an amp.

Just don't plug in anything external until the radio is turned on.

tim ab0wr

On Fri, 02 Mar 2018 20:19:12 -0800
"Walter" <@whuyckjr> wrote:

On Fri, Mar 2, 2018 at 06:51 pm, Walter wrote:


On Fri, Mar 2, 2018 at 03:50 pm, Clark Martin wrote:

You could use the second audio amp in U1.  The TDA2822 is a dual
amplifier.  What you’d need to do is this:
 
Remove R75
Connect U1-6 to VOL-H.  This will give you an auxiliary sound
output that is independent of the volume control.
Connect the + terminal of a 470 µF, 16V electrolytic capacitor to
U1-3. Connect the - terminal of the above cap to your auxiliary
out mini jack.
The 470 µF could very likely be much smaller, depending on the
input impedance of your Signal Link.
Experiment, it won’t hurt.
 
You may also want to add a resistor divider between the cap and
jack to reduce the signal strength, depending on how much your
Signal Link can tolerate.
 
Considering the problem others are having with the TDA2822 you
probably should add a resistor in series with the cap, unless you
implement the resistor voltage divider, that will provide the same
protection.

Clark Martin
KK6ISP


On Mar 2, 2018, at 10:20 AM, Walter < @whuyckjr
( @whuyckjr ) > wrote:

On Wed, Feb 28, 2018 at 09:47 am, Richie Chambless wrote:

Yes, the yellow wire is the full signal from the product
detector. Check your volume potentiometer to ensure it’s
connected to the end (orange should be on middle lug). I would
think your external amplifier has a capacitor input on it, so I
don’t think another cap is necessary. Check to see if DC is
present across the volume pot when the side tone is activated.
Ok The yellow wire does not have enough audio for my Signal Link
to work with.  it showed some signals.  I have to reconnect to
the 3.5mm Audio Out jack and turn the volume up about half way.
which is too loud for my headphones so I need to install a second
3.5mm for my Head Phones.  

I would be much better if I could find a way to get enough audio
separate from the actual audio out to the 3.5mm jack
I noticed that the audio IC was dual channel.  I may try this mod.
I'm not an EE so how would you set up a resistor divider?  I can't
design but I can certainly follow a schematic and home brew from
there. So any specific instructions would help me greatly. 

BTW, the suggestions and mods on this forum have been excellent.  A
hardy thank you to all!!!!  :)

 
--
73, W9KJO
Walter
Thinking a little more about your suggested mod.  Since a
potentiometer is used to control the output of u1 to the audio jack
(speaker).  Could I measure the value of the pot across Vol-H and
Vol-M to discover the resistance value, when set at the desired
level, and place a resistor at the input of U1-6 and control the
level output at U1-3?  Would that work? I need to place the 4 or 8
ohm resister in each circuit to protect them from shorts too.
Waiting on resistors to arrive.

--
73, W9KJO
Walter

Tim Gorman
 

Don,

I have to apologize here. Wiring the positive lead to the tip and the
ground to the ring does put the two headset speakers in series via the
two ground wires that are connected together. I realized this after
looking at your schematic. Kudo's.

This does have the impact that the speakers will offer twice the
impedance they are designed for. This probably won't be a problem in
most circumstances. In fact it will lessen the initial charging current
for any series isolating capacitor.

tim ab0wr

On Sat, 03 Mar 2018 06:46:49 -0800
"Don, ND6T via Groups.Io" <nd6t_6=yahoo.com@groups.io> wrote:

I always use an external speaker. I include a switch and headphone
jack(s) along with audio limiter for hearing safety and comfort.
Details can be found here. ( http://www.nd6t.com/qrp/speaker.htm )
73, Don

Clark Martin
 

You could just use a 10K potentiometer between VOL-H and U1=6, just like the existing volume control.  Then you could adjust it as needed.  I haven’t looked at the board, it may be possible to mount a trim pot on the RF board.




Clark Martin
KK6ISP

On Mar 2, 2018, at 8:19 PM, Walter <W9KJO@...> wrote:

Thinking a little more about your suggested mod.  Since a potentiometer is used to control the output of u1 to the audio jack (speaker).  Could I measure the value of the pot across Vol-H and Vol-M to discover the resistance value, when set at the desired level, and place a resistor at the input of U1-6 and control the level output at U1-3?  Would that work?
 
I need to place the 4 or 8 ohm resister in each circuit to protect them from shorts too.  Waiting on resistors to arrive.

Tim Gorman
 

Don,

In thinking about this it will be a lot like people who pay no
attention to polarity when wiring up stereo speakers. When you wire up
a headset this way one speaker will be going forward while the other is
going backward.

I've worked on many stereo systems over the past 40 years where this
has happened. If you have asymmetrical damping or if the speaker
motors are not symmetrical you can get all kinds of funky beat notes,
dead spots, etc, especially at the lower frequencies where the audio
power is greater and causes greater motor movement. It also impacts the
clarity of the sound.

Have you ever noticed any kind of audio artifacts from feeding a stereo
headset in this manner?

Go here: http://www.audiocheck.net/audiotests_polaritycheck.php

Listen especially to the guitar in-phase and out-of-phase audio clips.
The brightness and clarity of the in-phase clip is startling. This can
make a huge difference in the ability to sort out voices in a crowded
band.

It may be why so many hams think their stereo headset are so poor when
used in such a manner.

tim ab0wr

On Sat, 03 Mar 2018 06:46:49 -0800
"Don, ND6T via Groups.Io" <nd6t_6=yahoo.com@groups.io> wrote:

I always use an external speaker. I include a switch and headphone
jack(s) along with audio limiter for hearing safety and comfort.
Details can be found here. ( http://www.nd6t.com/qrp/speaker.htm )
73, Don

Michael Hagen
 

A LONG time ago, I used a 1.5V battery on speakers to mark their terminals for phasing with stereos.

You feel the cone Jump in or out to figure out the terminal polarity.  I would just mark them with a felt pen.


73's

Mike, WA6ISP


On 3/3/2018 9:36 AM, Tim Gorman wrote:
Don,

In thinking about this it will be a lot like people who pay no
attention to polarity when wiring up stereo speakers. When you wire up
a headset this way one speaker will be going forward while the other is
going backward. 

I've worked on many stereo systems over the past 40 years where this
has happened. If you have asymmetrical damping or if the speaker
motors are not symmetrical you can get all kinds of funky beat notes,
dead spots, etc, especially at the lower frequencies where the audio
power is greater and causes greater motor movement. It also impacts the
clarity of the sound.

Have you ever noticed any kind of audio artifacts from feeding a stereo
headset in this manner? 

Go here: http://www.audiocheck.net/audiotests_polaritycheck.php

Listen especially to the guitar in-phase and out-of-phase audio clips.
The brightness and clarity of the in-phase clip is startling. This can
make a huge difference in the ability to sort out voices in a crowded
band. 

It may be why so many hams think their stereo headset are so poor when
used in such a manner.

tim ab0wr

On Sat, 03 Mar 2018 06:46:49 -0800
"Don, ND6T via Groups.Io" <nd6t_6@...> wrote:

I always use an external speaker. I include a switch and headphone
jack(s) along with audio limiter for hearing safety and comfort.
Details can be found here. ( http://www.nd6t.com/qrp/speaker.htm )
73, Don





-- 
Mike Hagen, WA6ISP
10917 Bryant Street
Yucaipa, Ca. 92399
(909) 918-0058
PayPal ID  "MotDog@..."
Mike@...

Don, ND6T
 

Certainly! But only with binaural inputs. Especially with my binaural receiver! With a monoaural input, no, I've not noticed any weird effects. I'm just listening to 500 Hz wide CW bandpass. Often less. That, and I am dumb as a stump and probably wouldn't recognize a phase problem if it bit me ;-)
I've used these speakers this way for more than 40 years now and don't think much about them. They just work.
As for the original subject, if taking audio off the hot side of the volume control is insufficient for the sound card, perhaps dual controls working off of the output in L-pad configuration would allow enough level to monitor on headphones (or a good speaker) while maintaining a usable adjustment range for the data. Worth a try. -Don

Michael Shreeve
 

The question was answered some time ago for folk who would like an internal speaker. The solution uses a jack (I believe) with switches just like the one Ashhar provided , just go down through the info till you find the small PDF here : https://groups.io/g/BITX20/topic/4204243

On Sat, Mar 3, 2018 at 11:20 AM, Don, ND6T via Groups.Io <nd6t_6@...> wrote:
Certainly! But only with binaural inputs. Especially with my binaural receiver! With a monoaural input, no, I've not noticed any weird effects. I'm just listening to 500 Hz wide CW bandpass. Often less. That, and I am dumb as a stump and probably wouldn't recognize a phase problem if it bit me ;-)
I've used these speakers this way for more than 40 years now and don't think much about them. They just work.
As for the original subject, if taking audio off the hot side of the volume control is insufficient for the sound card, perhaps dual controls working off of the output in L-pad configuration would allow enough level to monitor on headphones (or a good speaker) while maintaining a usable adjustment range for the data. Worth a try. -Don




--
Michael Shreeve N6GRG
15901 Cloverdale Road
Anderson, CA 96007
530-410-8678
"Don't worry about a thing, 'Cause every little thing gonna be all right!" -Bob Marley