Hi Neil,

I have the same problem when transmitting on my 20 meter EFHW antenna. The problem is too much RF near the radio. If you install a 1:1 common mode filter choke on your antenna feed line that will keep the RF from coming back down the feed line and into your radio. Also make sure your SWR is low. Until the weather warms up I can't use my 20 meter antenna on my uBixt. BTW, I have this problem on other radios in the shack also, not just the uBitx.

Joel
N6ALT

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@...> 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. ( )
73, Don

--

I wired the two wires to the plug so they contacted the tip and middle element of the 1/8" stereo jack. That way my monaural or stereo connections both work fine. On the stereo the base ring never touches a conductor so both stereo channels are activated. The monaural plug will make contact properly as well.?

I don't remove or insert jacks from the plug whilst the radio is running.?

Hi Tim! So to clear this up. So wire the "tip" only and use a 1/8" stereo to mono adapter for stereo headphones right? (That would work as a safe solution. Not saying it is the only one.)

I was less confused before I stated reading what some people suggested here.

Randy

Mike,

How do the two speakers in a stereo headset get wired in series?
Usually the positive lead from one goes to the tip and the positive
lead of the other goes to the ring. Then they have common ground lead
connected to the sleeve.

Connecting one positive lead to the tip and the other positive lead to
ground doesn't wire the speakers in series. It leaves the speaker with
its positive lead wired to the tip with no return path to ground. It
leaves the speaker with its positive lead wired to ground with no
driving signal and no return path to ground either.

For the speakers to be wired in series the ground lead of one would
have to get connected to the positive lead of the next one. You can't
do that by grounding the positive lead of just one of them and leaving
the ground lead of both floating.

tim ab0wr

On Fri, 2 Mar 2018 22:19:40 -0600
"K5ESS" <k5ess.nothdurft@...> wrote:

What Vince is proposing is that the stereo jack be wired with the
TDA2822 output going to the tip, ground going to the ring, and the
sleeve floating (not grounded). A speaker with a mono plug will get
its ground because the sleeve will connect to the ring terminal (the
cause of a shorting the TDA2822 output in the original wiring). A
pair of stereo phones will have the two elements connected in series
between the tip and ring connections.

Mike

K5ESS



-----Original Message-----
From: [email protected] [mailto:[email protected]] On Behalf Of Vince
Vielhaber
Sent: Friday, March 2, 2018 9:23 PM
To: [email protected]
Subject: Re: [BITX20] B40 LM386 and ?B TDA2822 and that 470?F Cap





On 03/02/2018 10:06 PM, Tim Gorman wrote:

Respectfully -

If you wire the positive output of the 2822 to both the tip and
ring

terminal on the TRS jack and the ground lead to the sleeve
terminal

and then plug in a mono plug you *will* short the positive lead
from

the

2822 to ground.

I didn't, nor would I ever tell someone to do that.

Wiring the ground to the ring lead is *NOT* what the wiring

instructions for the ubitx show. It shows wiring the positive
lead

from the 2822 to both the tip and the ring lead. That will be a

potential disaster for anyone plugging in a mono plug.

It's been pointed out in the past that there are errors in the wiring
diagram. If it says that, I'd call that an error. I haven't looked
at the diagram that closely.

If you wire the ground lead to the ring terminal then how is a
stereo

plug going to work? There will be no ground connected to the
sleeve

lead of the headset.

Simple, the ground, that's not connected, is common to both sides.
Plug the headphones in and get a connection from tip to ring and a
non-connected ground putting the two speakers in series and sound
from both.



Vince.

Thomas,

You pretty much nailed it. And there is an isolating capacitor on the
output, a 470uf one. It's a point I hadn't considered. The problem is
that when you connect that capacitor from the positive output of the
2822 to ground what happens to the 2822? It's going to look like a dead
short for audio. Is the 2822 designed to feed a dead short for AC? At
the very least you will get no audio output at the jack. At worst you
will get a large current load on the 2822 trying to feed the
short.

tim ab0wr

On Sat, 3 Mar 2018 03:59:14 +0000 (UTC)
"Thomas Sharka via Groups.Io" <sharkatw@...> wrote:

I'm with you. The standard for audio outputs on a communications rig
doesn't include stereo headphones. That said, the inclusion of an
isolating capacitor on the output just makes good sense.?

Sent from Yahoo Mail. Get the app

On Friday, March 2, 2018 10:06 PM, Tim Gorman <tgorman2@...>
wrote:

Respectfully -

If you wire the positive output of the 2822 to both the tip and ring
terminal on the TRS jack and the ground lead to the sleeve terminal
and then plug in a mono plug you *will* short the positive lead from
the 2822 to ground.

Wiring the ground to the ring lead is *NOT* what the wiring
instructions for the ubitx show. It shows wiring the positive lead
from the 2822 to both the tip and the ring lead. That will be a
potential disaster for anyone plugging in a mono plug.

If you wire the ground lead to the ring terminal then how is a stereo
plug going to work? There will be no ground connected to the sleeve
lead of the headset.

I am going to use one of my mono jacks. Then I don't have to worry
about how the jack is wired. If I need a mono-stereo adapter I have
several. In fact, the headphones I use most often have a mono-stereo
switch built in.

tim ab0wr




On Fri, 2 Mar 2018 16:14:50 -0500
"Vince Vielhaber" <vev@...> wrote:

No, you missed the point.? It's not in bridge mode, so one side is
already ground.? If you hook the ground up to the ring and not the
sleeve, the sleeve will get ground in a mono plug but both speakers
in a stereo headset will get sound.? No need to butcher headphone
cables or buy an adapter, gold or otherwise.? Just wire it right.
Shit, you got a ham ticket and you managed to wire up your bitx, you
should be able to wire up a headphone jack - "you" not necessarily
referring to you, Tim, rather whoever is setting it up.

Vince.



On 03/02/2018 11:07 AM, Tim Gorman wrote:

Vince,

You missed the point. If you wire the tda2822 to both the tip and
the ring and then plug in a mono headphone you *will*, in almost
every case, short the output of the tda2822 to ground via the ring
lead.

You will melt the tda2822 sooner or later by doing so - plus get
nothing in the headphone.

tim ab0wr

On Thu, 1 Mar 2018 23:22:48 -0500
"Vince Vielhaber" <vev@...> wrote:
?

Ever cut the connector off of a pair of them and try to wire on a
new one?? The point, that you obviously missed, wasn't that
headphones are cheap, it's that there's no reason to do what Tim
was suggesting and that you can wire up to the tip and ring and
have it work with both stereo and mono headphones.

Vince.



On 03/01/2018 11:17 PM, Thomas Sharka via Groups.Io wrote:?

Trendy Headphones Stereo 3.5mm Plug In-Ear Earbuds Earphones
Headset For Phones | eBay
<>

Headphones are cheap. You can find them at the Dollar Store.
$ 0.99 ???

???


? ? Trendy Headphones Stereo 3.5mm Plug In-Ear Earbuds Earphones
Headset For Ph...

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Length: 110cm/43.30"(Approx.). High quality in ...
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Sent from Yahoo Mail. Get the app <>


On Thursday, March 1, 2018 11:12 PM, Vince Vielhaber
<vev@...> wrote:



So you're saying that if I want to use a pair of stereo
headphones I have around here I should cut the connector off of
it and wire it up to a mono plug?? Yeah...? I'll get right on
that.

Vince.


On 03/01/2018 10:49 PM, Tim Gorman wrote:?

If you insert a mono plug into a TRS jack the ring terminal of
the jack is almost always shorted to ground (i.e. the sleeve).
If you wire the output of the 2822 to both the tip and ring
terminals and then insert a mono plug there simply isn't any
doubt that you are probably going to short the output of the
2822 to ground. Bad things will happen.

There is no reason to wire the output of the 2822 to both the
tip and the ring terminals. If you have a stereo headset then
wire both headset leads to tip of the plug and only wire up
the tip lead on the socket. Then if someone inadvertently
plugs in a mono plug you won't short the output of the 2822 to
ground.

I agree that the large charging current going into the 470uf
cap could stress the 2822, perhaps only causing a failure
after a number of on/off cycles. That's something that would
be hard to diagnose!

I have modified my schematic to show using a 47uf cap being fed
with a 1 amp fuse from the 2822. If I ever get a chance to
actually finish up my ubitx it will be interesting to see if
the 1 amp fuse is sufficient.

tim ab0wr

On Thu, 01 Mar 2018 15:39:50 -0800
"Jerry Gaffke via Groups.Io" <jgaffke@...?

<mailto:[email protected]>> wrote:?

?

And subsequent replies have suggested this may not be
sufficient.

Some seem to fry when plugging something into the headphone
jack even if there is no short to ground involved. Or when
powering up the rig. Our best guess now is that there are
significant currents involved when that 470uF cap suddenly
has to charge up to Vcc/2 And that some clone TDA2822's may
be weaker than mainline manufacturers.

On Thu, Mar 1, 2018 at 03:31 pm, Christopher Miller wrote:
?

One of the first replies suggested not wiring the ring, and
using a mono to stereo adapter cable if stereo headphones are
required.

?

?

--
? Michigan VHF Corp.?
<>
<>
<>

1. It doesn't matter what you would tell someone to do. What matters
is the wiring instructions provided for the radio.
2. Connecting the positive output to both the tip and the ring is not a
wiring error if a mono plug is never used. It is meant to allow the use
of stereo headphones with a stereo jack.
3. How do the left and right speakers in a stereo headset get wired in
series internally? All of my stereo headsets have separate leads for
the left and right speaker with a common ground. For them to be wired
in series would require separate ground leads for each speaker with the
ground lead of one tied to the positive lead of the next. They just
aren't wired that way. Connecting the positive lead of one speaker to
ground, i.e. the ring lead, simply doesn't put the speakers in series.

tim ab0wr

On Fri, 2 Mar 2018 22:23:27 -0500
"Vince Vielhaber" <vev@...> wrote:

On 03/02/2018 10:06 PM, Tim Gorman wrote:

Respectfully -

If you wire the positive output of the 2822 to both the tip and ring
terminal on the TRS jack and the ground lead to the sleeve terminal
and then plug in a mono plug you *will* short the positive lead
from the 2822 to ground.

I didn't, nor would I ever tell someone to do that.

Wiring the ground to the ring lead is *NOT* what the wiring
instructions for the ubitx show. It shows wiring the positive lead
from the 2822 to both the tip and the ring lead. That will be a
potential disaster for anyone plugging in a mono plug.

It's been pointed out in the past that there are errors in the wiring
diagram. If it says that, I'd call that an error. I haven't looked
at the diagram that closely.

If you wire the ground lead to the ring terminal then how is a
stereo plug going to work? There will be no ground connected to the
sleeve lead of the headset.

Simple, the ground, that's not connected, is common to both sides.
Plug the headphones in and get a connection from tip to ring and a
non-connected ground putting the two speakers in series and sound
from both.

Vince.

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" <W9KJO@...> 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 ?F, 16V electrolytic capacitor to
U1-3. Connect the - terminal of the above cap to your auxiliary
out mini jack.
The 470 ?F 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@...
( 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

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

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 73, Don

Hi all,?

I have been using my uBITX in a case I purchased from Carl Beck, W5BEK.
I love the radio!

I have one issue going on.? When I transmit on 20 Meters the Raduino switches into menu mode (Band Select)
I'm sure this is a wiring issue, and I probably need to clean up the cross-wiring internally, but it's tough with the cross-connects between some of the components.? I am using VERY short wires to the antenna connector.?
My question to the group is: What should I do from the following list, or all of them, or anything else?

1. Use shielded wire bundles to all of the pots and connectors (All Electronics has some nice shielded wire bundles in 2, 3, 4, and 5 conductors)
2. Use some RG-174 to the antenna connector (about an inch, currently just wire)
3. Tie all grounds together with the copper tape on the insides of the case
4. Devise some sort of shield around the raduino

Thanks in advance

--Neil, W2NDG

开云体育

I’m assuming you’re using a good antenna.

I'm finding the uBitx signal/noise ratio on CW to be almost intolerable. ?The background hiss is loud and irritating, and weaker signals get lost in it. ?I haven't tried hardwiring in a narrower filter, but when I plug in a Hi-Per-Mite SCAF from another rig, suddenly the background noise drops way down and signals that I didn't know were there pop out of the background. ?Obviously to be a cw rig, my uBitx will have to have a narrower filter, and plan to install a Hi-Per-Mite SCAF. ?But I'm wondering if others are finding this issue.
Howard K4LXY

BITX40 ord 2/24/2018, shipped 3/3/2018, sched delivery 3/7 - terrific
now for the uBITX ordered 3/1/2018 ):>

开云体育

Hi Justin, If you want to change vfo, i think ?you should check for kit to built vfo. Hans Summer make really amassing kits. It Can even be controlled by gps

Did you open the sketch file or entered it with Cut&Paste??
Could be that a <SPACE> was changed to <SHIFT-SPACE> which usually you cannot easily ?distinguish in the editor. Maybe manually typing in the source code from the line the compiler complains about could help.