BITX QSO Afternoon/Night, Sunday, March 4, 3PM/7PM Local Time, 7277 kHz in North America, 7177 kHz elsewhere
BITX QSO Afternoon/Evening, Sunday, March 4, 3PM & 7PM Local Time, 7277 kHz in North America, 7177 kHz elsewhere.
Join us as we make contacts from BITX40 to BITX40 on 7.277 MHz in 40 meters!
This is a worldwide event for BITX40 stations starting at 7pm in each time zone. To participate, call CQ BITX on Sunday, starting at?3PM and/or 7PM?your local time. The BITX QSO Night continues through the evening and conditions usually improve after sunset, so it is worthwhile to participate later in the evening.
Suggested Best Operating Practices:
Work at QRP power levels unless conditions require more power.
Call and listen for CQ BITX on the hour and every quarter hour.
It is helpful if you call CQ BITX with your callsign, name and location.?
Repeat your callsign a number of times during your CQ BITX and during QSO's.
Start a QSO by confirming the callsign, location, name and signal report of the other operator.
Say the callsign, name and location of the other operator so others can hear.
If the frequency is busy, avoid long conversations.
After your initial QSO is complete, ask if there are any other stations who would like to contact.
Report your QSO's, discuss propagation, noise, signal reports, audio reports, antenna type, etc. in this thread.
This is an undirected, scheduled event.? The BITX QSO Night relies on you to call CQ BITX to initiate contacts with other stations, so warm up that final and transmit a few calls on Sunday evening.? Talk to you then!
--
John - WA2FZW
|
For me, the most amazing thing about Ian's code is that it allows the uBitx to be computer controlled. I have made many "automated" FT8 contacts using my CECuBitx.? 73 Willy W1LY
On Fri, Mar 2, 2018 at 12:46 AM, Michael Shreeve <shreevester@...> wrote: The quickest way, not necessarily the most educational, is to use the little uploader he introduces called Xloader and use his hex files. He describes the method in the "how to upgrade" spot.?
|
Re: Component in schematic
Pick a coil or
transformer from your library.? Copy it to a new part name.
Then copy and paste
items until you get your transformer you want.? Save as new
Part Name.
Just be sure NOT to
write over the original part, be sure to make a new part.
73's
Mike, WA6ISP
Sorry, I'm try to search eagle library for this component. But
seems find nothing in the internet..
 
The first picture is a trafo with? 6 pins, and the other is look
like coil. Need help here
Thank you :)
--
Mike Hagen, WA6ISP
10917 Bryant Street
Yucaipa, Ca. 92399
(909) 918-0058
PayPal ID "MotDog@..."
Mike@...
|
Re: Component in schematic
Can you explain it more about hoe to modify the component?
Thank you
|
Re: Component in schematic
learn to modify and use 6 dil as a base and mark col symbols arounf it.
On 2 Mar 2018 17:49, < qonita.salimah@...> wrote: Sorry, I'm try to search eagle library for this component. But seems find nothing in the internet..
 
The first picture is a trafo with? 6 pins, and the other is look like coil. Need help here
Thank you :)
|
Sorry, I'm try to search eagle library for this component. But seems find nothing in the internet..
 
The first picture is a trafo with? 6 pins, and the other is look like coil. Need help here
Thank you :)
|
Re: Shipping notification
My ordered 24/12/17. , Get shipment notification 19/2/18? and later 2 weeks received the package today. with India post to Thailand
On Fri, Mar 2, 2018 at 7:40 AM, <vk7hch@...> wrote: And on the 2nd of March, I have it in my hand. Ridiculous isn't it, 2 weeks for an eBay item from the next state, 4 days for an item from India!
Now the much anticipated fun begins!
|
Re: B40 LM386 and ?B TDA2822 and that 470?F Cap
I know that we get away with plugging and unplugging things hot on most of our radios but as for me I will turn off the radio before making any changes. Any thoughts on that?
Dave K8WPE
toggle quoted message
Show quoted text
On Mar 1, 2018, at 10:49 PM, Tim Gorman <tgorman2@...> 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@...> 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.
|
Re: B40 LM386 and ?B TDA2822 and that 470?F Cap
Forgot to say I was parked in Myrtle Beach for two weeks. ?Never saw that kind of corrosion in northern Michigan even with the salt used on the road in the winter.
Dave K8WPE
toggle quoted message
Show quoted text
On Mar 2, 2018, at 3:01 AM, David Wilcox via Groups.Io < Djwilcox01@...> wrote: Or get them free if you fly Delta with the video sets. They are cheap (not very hardy) but they do work.
Also, a side note. ?Left my car with chrome wheels parked in Myrtle Beach, SC, while on vacation. ?Did NOT go to the beach. ?The car just sat a mile or so from the ocean. ?To my surprise my chrome wheels showed significant corrosion upon my return. Protect your gear any way you can AND don't buy any radio that has been kept on a boat in a salt water marina. ?Eventually the corrosion on the circuit board will get you. ?I know from a close friend's experience. ?His used IC 7000 ?failed after a few months. ?The board showed unrepairable corrosion.
Dave K8WPE On Mar 2, 2018, at 12:11 AM, Jerry Gaffke via Groups.Io < jgaffke@...> wrote: They're worth a try, maybe you managed to get some good ones. But in my experience, anything under about $10 in headphones is not worth the bother. Extremely low fidelity, to the point of not being good enough to listen to the news. I agree with Vince, not trivial to put a new connector on most headphones these days. Try it. Better than hacking your $1 headphones is a mono to stereo adapter plug: ? ?? As suggested in a post a couple days ago. Not yet clear if avoiding shorts is sufficient to keep this chip from failing. Some reports of plugging in stereo headphones causing it to fail. Jerry On Thu, Mar 1, 2018 at 08:17 pm, Thomas Sharka wrote:
Headphones are cheap. You can find them at the Dollar Store.
|
Re: B40 LM386 and ?B TDA2822 and that 470?F Cap
Or get them free if you fly Delta with the video sets. They are cheap (not very hardy) but they do work.
Also, a side note. ?Left my car with chrome wheels parked in Myrtle Beach, SC, while on vacation. ?Did NOT go to the beach. ?The car just sat a mile or so from the ocean. ?To my surprise my chrome wheels showed significant corrosion upon my return. Protect your gear any way you can AND don't buy any radio that has been kept on a boat in a salt water marina. ?Eventually the corrosion on the circuit board will get you. ?I know from a close friend's experience. ?His used IC 7000 ?failed after a few months. ?The board showed unrepairable corrosion.
Dave K8WPE
toggle quoted message
Show quoted text
On Mar 2, 2018, at 12:11 AM, Jerry Gaffke via Groups.Io < jgaffke@...> wrote: They're worth a try, maybe you managed to get some good ones. But in my experience, anything under about $10 in headphones is not worth the bother. Extremely low fidelity, to the point of not being good enough to listen to the news. I agree with Vince, not trivial to put a new connector on most headphones these days. Try it. Better than hacking your $1 headphones is a mono to stereo adapter plug: ? ?? As suggested in a post a couple days ago. Not yet clear if avoiding shorts is sufficient to keep this chip from failing. Some reports of plugging in stereo headphones causing it to fail. Jerry On Thu, Mar 1, 2018 at 08:17 pm, Thomas Sharka wrote:
Headphones are cheap. You can find them at the Dollar Store.
|
Re: uBITX - U1 Getting Fried - possible cause
#ubitx
All of the uBitxes don't have the same IC. Mine doesn't look like the one Raj posted. I didn't bother taking a pic since I can't find an angle that will show the part number. I had to use a lighted loupe to see the number and even at that I had to look in a number of different angles. It just looks like a plain unmarked black IC. I can't even make out the logo - if what I was seeing was a logo.
Vince.
toggle quoted message
Show quoted text
On 03/02/2018 01:04 AM, Jerry Gaffke via Groups.Io wrote: Yup, something doesn't seem right.
From post 42723:
I have no idea how R75 could have smoked, except maybe a catastrophic
failure in the TDA2822M
shorted that (normally) input pin to Vcc somehow.
And this from 43122:
I fried mine when I plugged in a stereo sony noise canceling headset.
So it does not only happen with mono plugs.
And this from 43170:
Last evening he turned his radio on and the TDA got very hot
and started smoking for no reason at all.
And this from 43211:
Recently I found some TDA2822's on ebay from China, I got the GQRP
club to purchase a batch ( I bought 50 too ). Tony Fishpool (G4WIF)
setup up a test and found although they worked well at low Volts they
got hot over 7V!:
Might be a few weird ones, I didn't do an exhaustive search.
A 6v regulator to feed the TDA2822 might be our best bet.
Jerry, KE7ER
On Thu, Mar 1, 2018 at 09:41 pm, Vince Vielhaber wrote:
Something doesn't seem right here. At least one person said that the
IC smoked as well as R75. R75 is a 2.2 Ohm resistor connected
between pin 6 and ground. Pin 6 is the + input on amp #2.
--
Michigan VHF Corp.
|
Re: uBITX - U1 Getting Fried - possible cause
#ubitx
Yup, something doesn't seem right.
From post 42723:
? I have no idea how R75 could have smoked, except maybe a catastrophic failure in the TDA2822M?
shorted that (normally) input pin to Vcc somehow.
And this from 43122:
? I fried mine when I plugged in a stereo sony noise canceling headset.
So it does not only happen with mono plugs.
And this from 43170:
? ?Last evening he turned his radio on and the TDA got very hot
and started smoking for no reason at all.
And this from 43211:
? ?Recently I found some TDA2822's on ebay from China, I got the GQRP club to purchase a batch ( I bought 50 too ). Tony Fishpool (G4WIF) setup up a test and found although they worked well at low Volts they got hot over 7V!:
Might be a few weird ones, I didn't do an exhaustive search.
A 6v regulator to feed the TDA2822 might be our best bet.
Jerry, KE7ER
toggle quoted message
Show quoted text
On Thu, Mar 1, 2018 at 09:41 pm, Vince Vielhaber wrote:
Something doesn't seem right here. At least one person said that the IC smoked as well as R75. R75 is a 2.2 Ohm resistor connected between pin 6 and ground. Pin 6 is the + input on amp #2.
|
Re: TDA2822 ill treatment test!
?? FCI Semiconductors.?? Link says TDA7221a as does page header ?but datasheet is for TDA2822M. Mike K5ESS ?
toggle quoted message
Show quoted text
From: BITX20@groups.io [mailto:BITX20@groups.io] On Behalf Of Raj vu2zap
Sent: Thursday, March 1, 2018 10:38 PM
To: BITX20@groups.io
Subject: Re: [BITX20] TDA2822 ill treatment test!? 
At 02-03-2018, you wrote:
Raj,
Good information, that 800ma when shorted.
There is likely a surge that is considerably higher while it charges the cap if you power up the rig
first with no headphones or speaker, then plug in a dead short.
Only there for maybe a couple milliseconds, so would need to use a scope to see it
as a voltage across perhaps 0.1 ohm resistor that is in series with power to the chip.
Was that the stock TDA2822M that came with the uBitx?
Mine has a logo of "FCI" or maybe it's "FOI", where the middle character is filled in to where it is an almost solid circle.
It also says "PI1" and then below it says "TDA2822M".
I have no idea who makes that.
Post 43211 says there's some really bad clones masquerading as TDA2822M's.
There seems to be at least a half dozen different manufacturers of TDA2822 variants.
So any testing had best fully describe manufacturer and markings and such.
Tayda claims to have some? ST/SGS-Thomson TDA2822M's and TDA2822L's at cheap prices:
???
When you click through to the datasheets, you get either a 1995 ST datasheet (for the TDA2822M)
or a UTC datasheet (for the TDA2822L)??? The "L" just means lead free.
A google search for TDA2822M finds this ST datasheet first, dated 2003 and marked "Obsolete":??? ?
I suspect the Tayda parts are not really ST.
Yes, bridge mode would be nice for driving an internal speaker.
But not for driving anything external, were everyone would assume the jack shell is at ground potential.
Jerry
On Thu, Mar 1, 2018 at 07:22 pm, Raj vu2zap wrote: Did some more tests. Normal audio use the current was 60-70mA Dead short with varied drive the current was 300-800mA. At 800mA the chip got hot! The current did not go above 1A at any time. I suspect there are TDA2822Ds masquerading as TDA2822M. Raj . . .
|
The quickest way, not necessarily the most educational, is to use the little uploader he introduces called Xloader and use his hex files. He describes the method in the "how to upgrade" spot.?
On Thu, Mar 1, 2018 at 9:23 PM, Mike Woods <mhwoods@...> wrote:
Mike
It sounds like you haven't yet ventured into the menu system!
Push the encoder (tune) button and turn the dial.?? Wow!
It is pretty self-explanatory, except for the Settings menu.?
Select the settings menu, and wait for it to return to the normal
mode (not menu mode).? Press the encoder button again, and lo and
behold you will find a whole lot more menu items when you turn the
dial.
Hope this helps!
There are a number of references in the code to Farhan's original
(including the pot which has never been in the production uBITx).?
However, virtually the entire code has been rewritten by Ian.
Mike ZL1AXG
On 2/03/18 5:54 PM, Michael Hagen wrote:
Wow, I can't believe
the code he came up with.?? What a Whiz he must be!? To
compile the code you have to put it in a folder with the
main name same as the ino file.? But, you have to know the
that name?? Jack came up with ubitx_20.? It worked.
So the VFOs can be
on other bands?? You can change bands by picking the other
VFO? ? Is there a description of this top line somewhere or
do you have to run the configuration manager?? I? looked
thru the code, thinking I could find a description of what
is on each line.? Could not figure it out much.? Also in the
code he discusses a pot for tuning??? Might be old stuff?
Thanks for the
help,? I will look for the configuration manager.
Mike
On 3/1/2018 8:36 PM, Mike Woods
wrote:
Mike
You obviously got the software to install on your uBITx!
That 14.150k is the frequency of your other VFO (if you are on
VFO A then that is the frequency of VFO B).? This is handy if
you are working SPLIT which is provided for in the KD8CEC
software.? A real contesting feature especially for 40m ...
If you also download the Windows (or Linux) software developed
by Ian KD8CEC called "UBitx Manager" - see the link on
homepage, then you can configure this top line how
you want it.?? From memory that includes putting your callsign
there? if you are sufficiently vain Hi Hi!
73 Mike ZL1AXG
On 2/03/18 5:21 PM, Michael Hagen wrote:
Thanks Jack,
Putting in a
folder with the same name made it compile and load.
I don't have any
thing hooked up, just on USB power.
First line of
the LCD says "14.150k? 50Hz ST"
Second says "?
CW: 7.150.000"
No wires hooked
up, I wonder what 14.150K means.
Might be a place
to put call sign?? So it is garbage from eeprom?
TNX
Mike, WA6ISP
?
On 3/1/2018 6:15 PM, Michael
Hagen wrote:
That file
error ed on compile for me.? I had it all in the same
directory, but not named that.
I knew that
there was no way these files could all link, or know
of each other.
I like
programming, never could understand where the rules
are for the environment.?
Thanks, I just
think this stuff should follow standard Arduino
protocol,? just one big file?
That's what
made it so popular "C for Dummies".
Thanks Jack
Dinner and
then back to it?
Mike, WA6ISP
On 3/1/2018 6:01 PM, Jack
Purdum via Groups.Io wrote:
The file
with setup() and loop() becomes the
"main" INO file. I believe that file is named ubitx_20.ino.
This means you must place all of those files in a
directory named ubitx_20.
Personally, I wish Lee had not done it this way since
making them all INO files means that no type checking
is performed on functions during the compile. It would
be better to keep the one INO file and rename the
others to *.cpp (i.e., C++) files, which would
reinstate type checking.
Jack,
W8TEE
I was looking at
KD8CEC for uBit.
But there are a
lot of ino files when I download?? So
I am lost.
Any instructions
what file to load into Arduino IDE ??
? I don't know what I am doing looking
at the downloaded files.
Is there a name
for the latest version of a file that
is the whole thing?
I tried, just get
errors.?? So I need step by step
instructions.
So where to go,
what file to load into Nano?? If there
are multiple ino files, how does it
know of the others?
If not CEC, what
should I load?
Thanks
Mike,
WA6ISP
?
--
Mike Hagen, WA6ISP
10917 Bryant Street
Yucaipa, Ca. 92399
(909) 918-0058
PayPal ID "MotDog@..."
Mike@...
--
Mike Hagen, WA6ISP
10917 Bryant Street
Yucaipa, Ca. 92399
(909) 918-0058
PayPal ID "MotDog@..."
Mike@...
--
Mike Hagen, WA6ISP
10917 Bryant Street
Yucaipa, Ca. 92399
(909) 918-0058
PayPal ID "MotDog@..."
Mike@...
-- 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
|
Re: uBITX - U1 Getting Fried - possible cause
#ubitx
Something doesn't seem right here. At least one person said that the IC smoked as well as R75. R75 is a 2.2 Ohm resistor connected between pin 6 and ground. Pin 6 is the + input on amp #2.
Vince.
toggle quoted message
Show quoted text
On 03/02/2018 12:20 AM, Jerry Gaffke via Groups.Io wrote: That might help here, though I'm not sure we fully understand the
problem yet.
This resistor would charge up the 470uF cap at power up, so plugging in
a short
or headphones or whatever at a later time would not be so disruptive.
Is that what you have in mind?
Resistor could be 100 ohms, and still charge the cap plenty fast.
And if 100 ohms, could be there at all times in parallel with the
headphones,
so no need for the fancy speaker jack with the switching contacts.
Jerry, KE7ER
On Thu, Mar 1, 2018 at 09:02 pm, RCC WB5YYM wrote:
Could a person add an 8ohm resistor across the speaker jack on the
NC pin? When you plug in the speaker it would open up that load and
the amp would see the speaker.
--
Michigan VHF Corp.
|
Mike
It sounds like you haven't yet ventured into the menu system!
Push the encoder (tune) button and turn the dial.?? Wow!
It is pretty self-explanatory, except for the Settings menu.?
Select the settings menu, and wait for it to return to the normal
mode (not menu mode).? Press the encoder button again, and lo and
behold you will find a whole lot more menu items when you turn the
dial.
Hope this helps!
There are a number of references in the code to Farhan's original
(including the pot which has never been in the production uBITx).?
However, virtually the entire code has been rewritten by Ian.
Mike ZL1AXG
On 2/03/18 5:54 PM, Michael Hagen wrote:
Wow, I can't believe
the code he came up with.?? What a Whiz he must be!? To
compile the code you have to put it in a folder with the
main name same as the ino file.? But, you have to know the
that name?? Jack came up with ubitx_20.? It worked.
So the VFOs can be
on other bands?? You can change bands by picking the other
VFO? ? Is there a description of this top line somewhere or
do you have to run the configuration manager?? I? looked
thru the code, thinking I could find a description of what
is on each line.? Could not figure it out much.? Also in the
code he discusses a pot for tuning??? Might be old stuff?
Thanks for the
help,? I will look for the configuration manager.
Mike
On 3/1/2018 8:36 PM, Mike Woods
wrote:
Mike
You obviously got the software to install on your uBITx!
That 14.150k is the frequency of your other VFO (if you are on
VFO A then that is the frequency of VFO B).? This is handy if
you are working SPLIT which is provided for in the KD8CEC
software.? A real contesting feature especially for 40m ...
If you also download the Windows (or Linux) software developed
by Ian KD8CEC called "UBitx Manager" - see the link on
ubitx.net homepage, then you can configure this top line how
you want it.?? From memory that includes putting your callsign
there? if you are sufficiently vain Hi Hi!
73 Mike ZL1AXG
On 2/03/18 5:21 PM, Michael Hagen wrote:
Thanks Jack,
Putting in a
folder with the same name made it compile and load.
I don't have any
thing hooked up, just on USB power.
First line of
the LCD says "14.150k? 50Hz ST"
Second says "?
CW: 7.150.000"
No wires hooked
up, I wonder what 14.150K means.
Might be a place
to put call sign?? So it is garbage from eeprom?
TNX
Mike, WA6ISP
?
On 3/1/2018 6:15 PM, Michael
Hagen wrote:
That file
error ed on compile for me.? I had it all in the same
directory, but not named that.
I knew that
there was no way these files could all link, or know
of each other.
I like
programming, never could understand where the rules
are for the environment.?
Thanks, I just
think this stuff should follow standard Arduino
protocol,? just one big file?
That's what
made it so popular "C for Dummies".
Thanks Jack
Dinner and
then back to it?
Mike, WA6ISP
On 3/1/2018 6:01 PM, Jack
Purdum via Groups.Io wrote:
The file
with setup() and loop() becomes the
"main" INO file. I believe that file is named ubitx_20.ino.
This means you must place all of those files in a
directory named ubitx_20.
Personally, I wish Lee had not done it this way since
making them all INO files means that no type checking
is performed on functions during the compile. It would
be better to keep the one INO file and rename the
others to *.cpp (i.e., C++) files, which would
reinstate type checking.
Jack,
W8TEE
I was looking at
KD8CEC for uBit.
But there are a
lot of ino files when I download?? So
I am lost.
Any instructions
what file to load into Arduino IDE ??
? I don't know what I am doing looking
at the downloaded files.
Is there a name
for the latest version of a file that
is the whole thing?
I tried, just get
errors.?? So I need step by step
instructions.
So where to go,
what file to load into Nano?? If there
are multiple ino files, how does it
know of the others?
If not CEC, what
should I load?
Thanks
Mike,
WA6ISP
?
--
Mike Hagen, WA6ISP
10917 Bryant Street
Yucaipa, Ca. 92399
(909) 918-0058
PayPal ID "MotDog@..."
Mike@...
--
Mike Hagen, WA6ISP
10917 Bryant Street
Yucaipa, Ca. 92399
(909) 918-0058
PayPal ID "MotDog@..."
Mike@...
--
Mike Hagen, WA6ISP
10917 Bryant Street
Yucaipa, Ca. 92399
(909) 918-0058
PayPal ID "MotDog@..."
Mike@...
|
Re: uBITX - U1 Getting Fried - possible cause
#ubitx
That might help here, though I'm not sure we fully understand the problem yet.
This resistor would charge up the 470uF cap at power up, so plugging in a short
or headphones or whatever at a later time would not be so disruptive.
Is that what you have in mind?
Resistor could be 100 ohms, and still charge the cap plenty fast.
And if 100 ohms, could be there at all times in parallel with the headphones,?
so no need for the fancy speaker jack with the switching contacts.??
Jerry, KE7ER
toggle quoted message
Show quoted text
On Thu, Mar 1, 2018 at 09:02 pm, RCC WB5YYM wrote:
Could a person add an 8ohm resistor across the speaker jack on the NC pin? When you plug in the speaker it would open up that load and the amp would see the speaker.
|
Re: TDA2822 ill treatment test!
That's what my one looks like in my
initial batch uBITx.???? It would be interesting to see photos of
those that have had "the smoke come out".
This is the page that links from FCI to the datasheet:?
And this shows a maximum voltage of 15v.
Mike ZL1AXG
On 2/03/18 5:38 PM, Raj vu2zap wrote:
At 02-03-2018, you wrote:
Raj,
Good information, that 800ma when shorted.
There is likely a surge that is considerably higher while it
charges the
cap if you power up the rig
first with no headphones or speaker, then plug in a dead short.
Only there for maybe a couple milliseconds, so would need to use
a scope
to see it
as a voltage across perhaps 0.1 ohm resistor that is in series
with power
to the chip.
Was that the stock TDA2822M that came with the uBitx?
Mine has a logo of "FCI" or maybe it's "FOI", where
the middle character is filled in to where it is an almost solid
circle.
It also says "PI1" and then below it says
"TDA2822M".
I have no idea who makes that.
Post 43211 says there's some really bad clones masquerading as
TDA2822M's.
There seems to be at least a half dozen different manufacturers
of
TDA2822 variants.
So any testing had best fully describe manufacturer and markings
and
such.
Tayda claims to have some? ST/SGS-Thomson TDA2822M's and
TDA2822L's
at cheap prices:
???
When you click through to the datasheets, you get either a 1995
ST
datasheet (for the TDA2822M)
or a UTC datasheet (for the TDA2822L)??? The "L"
just means lead free.
A google search for TDA2822M finds this ST datasheet first,
dated 2003
and marked "Obsolete":???
?
I suspect the Tayda parts are not really ST.
Yes, bridge mode would be nice for driving an internal speaker.
But not for driving anything external, were everyone would
assume the
jack shell is at ground potential.
Jerry
On Thu, Mar 1, 2018 at 07:22 pm, Raj vu2zap wrote:
- Did some more tests.
- Normal audio use the current was 60-70mA
- Dead short with varied drive the current was 300-800mA. At
800mA the
chip got hot!
- The current did not go above 1A at any time.
- I suspect there are TDA2822Ds masquerading as TDA2822M.
- Raj
- . . .
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Re: B40 LM386 and ?B TDA2822 and that 470?F Cap
They're worth a try, maybe you managed to get some good ones.
But in my experience, anything under about $10 in headphones is not worth the bother.
Extremely low fidelity, to the point of not being good enough to listen to the news.
I agree with Vince, not trivial to put a new connector on most headphones these days.
Try it.
Better than hacking your $1 headphones is a mono to stereo adapter plug:
? ??
As suggested in a post a couple days ago.
Not yet clear if avoiding shorts is sufficient to keep this chip from failing.
Some reports of plugging in stereo headphones causing it to fail.
Jerry
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On Thu, Mar 1, 2018 at 08:17 pm, Thomas Sharka wrote:
Headphones are cheap. You can find them at the Dollar Store.
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Re: uBITX - U1 Getting Fried - possible cause
#ubitx
Could a person add an 8ohm resistor across the speaker jack on the NC pin? When you plug in the speaker it would open up that load and the amp would see the speaker.
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Willy
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Michael Shreeve