Date   
Re: U1 fried

Rick Price
 

I'll have him save it as he is taking it out of the board as I write.  Don't know if the writing is still legible.
Rick

Re: TDA2822 ill treatment test!

Vince Vielhaber
 

The chip is only rated for 15 volts. Is it possible that the ones that are experiencing smoke are also getting more than 13.8v? Possibly a spike?

Vince.

On 03/01/2018 12:02 PM, w7hd.rh wrote:
I suspect the 2A limit on his power supply saved the chip!

Ron W7HD


On 03/01/2018 10:00 AM, Joe Puma wrote:
Thanks for taking one for the team Raj. 👍🏼👍🏼👍🏼
On Mar 1, 2018, at 7:04 AM, Raj vu2zap <@Raj>
wrote:


Having used TDA2822 for decades and never had a failure of any kind
even with the chip running very hot,
I got this urge to short my uBitx audio output and see it the chip
blows.

Power supply 13.6V
Current limit 2A

Touching the volume control leads produces a loud 50Hz hum. At this
volume I directly shorted the wires
at the EP jack. The chip got mildly warm thats it.

No smoke or explosions ! I think that some may have got
bad/defective/BY chips..

Cheers

--
Raj, vu2zap
Bengaluru, South India.




Re: U1 fried

Vince Vielhaber
 

Is it too late to get the mfgr and date code from that bad chip?

Vince.

On 03/01/2018 12:02 PM, Rick Price wrote:
My brother-in-law and I each have a radio that we received last week,
ordered 12-25-17. Speaker and amp chip have worked great with no heat unitl
last night. Last evening he turned his radio on and the TDA got very hot
and started smoking for no reason at all. Current went up to almost 1 amp in
receive as it got hot. Beginning to believe there is a batch of bad chips.
Already ordered several replacements and sockets. I am going to try the
speaker lead 4 ohm resistor in mine before it goes.

Rick
KN4AIE


Re: TDA2822 ill treatment test!

w7hd.rh <w7hd.rh@...>
 

I suspect the 2A limit on his power supply saved the chip!

Ron W7HD

On 03/01/2018 10:00 AM, Joe Puma wrote:
Thanks for taking one for the team Raj. 👍🏼👍🏼👍🏼
On Mar 1, 2018, at 7:04 AM, Raj vu2zap <@Raj> wrote:


Having used TDA2822 for decades and never had a failure of any kind even with the chip running very hot,
I got this urge to short my uBitx audio output and see it the chip blows.

Power supply 13.6V
Current limit 2A

Touching the volume control leads produces a loud 50Hz hum. At this volume I directly shorted the wires
at the EP jack. The chip got mildly warm thats it.

No smoke or explosions ! I think that some may have got bad/defective/BY chips..

Cheers

--
Raj, vu2zap
Bengaluru, South India.




--
W7HD - NAQCC#7587 OMISS#9898 KX3#6966 LinuxUser#415320

Re: U1 fried

Rick Price
 

My brother-in-law and I each have a radio that we received last week,
ordered 12-25-17. Speaker and amp chip have worked great with no heat unitl
last night. Last evening he turned his radio on and the TDA got very hot
and started smoking for no reason at all. Current went up to almost 1 amp in
receive as it got hot. Beginning to believe there is a batch of bad chips.
Already ordered several replacements and sockets. I am going to try the
speaker lead 4 ohm resistor in mine before it goes.

Rick
KN4AIE

Re: TDA2822 ill treatment test!

Joe Puma
 

Thanks for taking one for the team Raj. 👍🏼👍🏼👍🏼

On Mar 1, 2018, at 7:04 AM, Raj vu2zap <@Raj> wrote:


Having used TDA2822 for decades and never had a failure of any kind even with the chip running very hot,
I got this urge to short my uBitx audio output and see it the chip blows.

Power supply 13.6V
Current limit 2A

Touching the volume control leads produces a loud 50Hz hum. At this volume I directly shorted the wires
at the EP jack. The chip got mildly warm thats it.

No smoke or explosions ! I think that some may have got bad/defective/BY chips..

Cheers

--
Raj, vu2zap
Bengaluru, South India.




Re: full rig power control unit

Vince Vielhaber
 

Will any of these packages that have been mentioned do automatic routing? Or are you required to do all the runs manually?

Vince.

On 03/01/2018 10:12 AM, Michael Hagen wrote:
Lt Spice is a circuit simulator. Not for Layout of PCBs. Use one of
the online PCB programs folks have been discussing here on the group.
Look back through the posts on PCB Layout Software. Any of them will
require a learning curve.

For instance, that circuit uses some small SCRs. Not a real popular
part, you might get to make the Model (s).

There is a schematic model and its matching PCB model. Start with the
schematic program and create a nice schematic before going to PCB. It
will transfer its connections (netlist) to you PCB. It will find many
mistakes (inconsistancies between schematic and layout). If you are
real careful, you can make PCBs that are correct the first time!

PCB layout is Really Fun! Better than crossword puzzles.

73's

Mike, WA6ISP


On 3/1/2018 4:33 AM, Walter wrote:
If I wranted to build a circuit like this one is there a software to
help me layout a perfboard for the circuit. I have LTSpice but I
don't see anything to layout a perf board in it. It just may be that I
don't know where that feature is in the software.
--
73, W9KJO
Walter
--
Mike Hagen, WA6ISP
10917 Bryant Street
Yucaipa, Ca. 92399
(909) 918-0058
PayPal ID "MotDog@..."
Mike@...

Re: U1 fried

Bill KC5SB
 

I ordered mine from eBay - plan to use the socket this time.  Should arrive today.  Still have to wait for my R75 replacement though.

https://www.ebay.com/itm/5PCS-STMicroelectronics-TDA2822M-TDA2822-Sockets-Dual-Audio-Amplifier-New-IC/292172486301?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649

Re: TDA2822 ill treatment test!

Jerry Gaffke
 

That's good news.

You've addressed the most obvious way in which it might fail,
though perhaps what causes it to fail is not quite that simple.

I wonder if hfsignals has stuffed the same part into all rigs thus far,
or has perhaps been switching between manufacturers,  

Jerry


On Thu, Mar 1, 2018 at 04:05 am, Raj vu2zap wrote:
Having used TDA2822 for decades and never had a failure of any kind even with the chip running very hot,
I got this urge to short my uBitx audio output and see it the chip blows.

Power supply 13.6V
Current limit 2A

Touching the volume control leads produces a loud 50Hz hum. At this volume I directly shorted the wires
at the EP jack. The chip got mildly warm thats it.

No smoke or explosions ! I think that some may have got bad/defective/BY chips..

Re: smoke

richard stafford
 

Raj,
I believe the issue is the relay.
Voltage in at U1 is 0, both transmit and receive.
Q16 collector voltage is 1.75 receive and 0.6 transmit.
I am going to try to substitute an Omron G5V-2-DC12.
Thanks,
Richard

On Feb 27, 2018, at 19:37, Raj vu2zap <@Raj> wrote:

Start by checking voltages and somewhere where it is low or dropping off will give you a clue.
Check for components running really hot.

Since you mention TX side tone fading off, check the audio amp voltage..

I suspect that you power supply is limiting voltage/current due to some short.

Raj

At 27/02/2018, you wrote:
GM all:
My bitx40 initially functioned well with all CW modifications except for initial problems with relay activating with each key closure, despite speed. Tx-Rx initially to pin 15 along with cw carrier, as per text. Changed connections according to photos (Tx-Rx D7 at pin 16, carrier D6 at pin 15 and side-tone to D5 pin 14). All seemed fine, then smoke. No visible damage. Now transmit output is down to about 1 watt, receive audio present but very soft despite full AF gain, and side tone volume on transmit is initially at the usual volume but fades to the same low receive volume after a couple of seconds. Power at the antenna stays at about a watt.
Went through Farhan’s trouble shooting; no audible change when touching antenna input. Toroids look ok.
Great rig, and despite these issues I wouldn’t trade it for anything else, except perhaps my HT 37 and Drake 2B.
Thanks in advance for your help. Great site as well, by the way.
Richard
KD0NPM


Re: full rig power control unit

Michael Hagen
 

Lt Spice is a circuit simulator.  Not for Layout of PCBs.  Use one of the online PCB programs folks have been discussing here on the group.  Look back through the posts on PCB Layout Software.  Any of them will require a learning curve.

For instance, that circuit uses some small SCRs.  Not a real popular part, you might get to make the Model (s).

There is a schematic model and its matching PCB model.  Start with the schematic program and create a nice schematic before going to PCB.  It will transfer its connections (netlist) to you PCB.   It will find many mistakes (inconsistancies between schematic and layout).  If you are real careful, you can make PCBs that are correct the first time!

PCB layout is Really Fun!  Better than crossword puzzles.

73's

Mike, WA6ISP


On 3/1/2018 4:33 AM, Walter wrote:
If I wranted to build a circuit like this one is there a software to help me layout a perfboard for the circuit.  I have LTSpice but I don't see anything to layout a perf board in it. It just may be that I don't know where that feature is in the software.
--
73, W9KJO
Walter

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

Re: Raduino Connections #bitx40

Arvo W0VRA
 

On Thu, Mar 1, 2018 at 06:15 am, James Wilson wrote:
One of my students found that their Raduino module is missing the 4 pin connector.  Instead, the Raduino has a 16 pin male header on the same edge of the board where the connector usually is.  If I install the 4 pin female to the end four pins will it work.
It sounds like his B40 came with a µB Raduino.  The differences between the two Raduinos are the software (easy to rewrite) and the headers.  The B40 Raduino has a 5 pin header and an 8 pin header; both get wires.  The µB Raduino has a 16 pin header that plugs into the main board and an 8 pin header that gets wires.

If you can make the correct connections from the B40 board and controls to the Raduino per the wiring diagram and get the right software on it, it will work.

Re: Looking for Completely Functional Dual-Band 20/(17/15/10/6) Meter QRP Rig with SSB/PSK #bitx20help

Jack, W8TEE
 

I agree. Anyone who thinks the interplay between the rig and the antenna (aerial) isn't work talking about probably hasn't done much QRP work.
Jack, W8TEE


From: Bill Bates <billy.bates@...>
To: BITX20@groups.io
Sent: Thursday, March 1, 2018 8:09 AM
Subject: Re: [BITX20] Looking for Completely Functional Dual-Band 20/(17/15/10/6) Meter QRP Rig with SSB/PSK #bitx20help

I have just been reading this thread with great interest as I have a Bitx 40 and I'm having trouble with my aerial, so I consider it both relevant & worthwhile, please keep it going 😊, regards Bill, G6ATO

From: Jerry Gaffke via Groups.Io
Sent: ‎26/‎02/‎2018 04:39
To: BITX20@groups.io
Subject: Re: [BITX20] Looking for Completely Functional Dual-Band 20/(17/15/10/6) Meter QRP Rig with SSB/PSK #bitx20help

There are plenty of threads here I'd just as soon skip over, and often do.
Perhaps you can do the same.
I for one am fine with discussions of antennas (that seems very appropriate) 
and with discussing the pros and cons of the Bitx radios vs others. 

Jerry, KE7ER


On Sun, Feb 25, 2018 at 08:13 pm, Rod Self wrote:
I, for one, am very tired of off-topic general discussions about radios and antennas on the bitx20/ubitx group.

Please let this thread die, or move it to another discussion group.

A good guideline: if it does not involve a bitx or utibx, it probably does not belong here.


Raduino Connections #bitx40

James Wilson
 

One of my students found that their Raduino module is missing the 4 pin connector.  Instead, the Raduino has a 16 pin male header on the same edge of the board where the connector usually is.  If I install the 4 pin female to the end four pins will it work.

Re: U1 fried

Mike Yancey
 

https://www.taydaelectronics.com

US$ 0.19 (nineteen cents) for the 8-pin PDIP / US$ 0.73 for the SMT version.

Mike Yancey, KM5Z
Dallas, Texas

Re: Second batch of uBITX shipping? #ubitx

Daniel Conklin <danconklin2@...>
 

I ordered mine December 29, 2017 and hadn't heard anything up until last night.  Then the shipping notice appeared in the middle of the night and it is scheduled for delivery today, March 1, 2018!
Dan W2DLC

Re: Looking for Completely Functional Dual-Band 20/(17/15/10/6) Meter QRP Rig with SSB/PSK #bitx20help

Bill Bates
 

I have just been reading this thread with great interest as I have a Bitx 40 and I'm having trouble with my aerial, so I consider it both relevant & worthwhile, please keep it going 😊, regards Bill, G6ATO


From: Jerry Gaffke via Groups.Io
Sent: ‎26/‎02/‎2018 04:39
To: BITX20@groups.io
Subject: Re: [BITX20] Looking for Completely Functional Dual-Band 20/(17/15/10/6) Meter QRP Rig with SSB/PSK #bitx20help

There are plenty of threads here I'd just as soon skip over, and often do.
Perhaps you can do the same.
I for one am fine with discussions of antennas (that seems very appropriate) 
and with discussing the pros and cons of the Bitx radios vs others. 

Jerry, KE7ER


On Sun, Feb 25, 2018 at 08:13 pm, Rod Self wrote:
I, for one, am very tired of off-topic general discussions about radios and antennas on the bitx20/ubitx group.

Please let this thread die, or move it to another discussion group.

A good guideline: if it does not involve a bitx or utibx, it probably does not belong here.

Re: full rig power control unit

Walter
 

If I wranted to build a circuit like this one is there a software to help me layout a perfboard for the circuit.  I have LTSpice but I don't see anything to layout a perf board in it. It just may be that I don't know where that feature is in the software.
--
73, W9KJO
Walter

Re: U1 fried

Claude-Alain Baumgartner
 

The TDA2822 obviously can not stand the 12V. After having blown two TDA2822's, I soldered a socket in its place, and made an adapter for the LM386, which never failed at 12V.
Here is the wiring:

LM386 pin:     2  -  4   TDA2822 corresponding pin
                       3  -  7
                       4  -  4
                       5  -  1
                       6  -  2

Very simple and effective.
73's
HB9CGL Claude

TDA2822 ill treatment test!

 

Having used TDA2822 for decades and never had a failure of any kind even with the chip running very hot,
I got this urge to short my uBitx audio output and see it the chip blows.

Power supply 13.6V
Current limit 2A

Touching the volume control leads produces a loud 50Hz hum. At this volume I directly shorted the wires
at the EP jack. The chip got mildly warm thats it.

No smoke or explosions ! I think that some may have got bad/defective/BY chips..

Cheers

--
Raj, vu2zap
Bengaluru, South India.