Date   
Re: U1 fried

Jerry Gaffke
 

Re-read this post:  https://groups.io/g/BITX20/message/42723

Adding a series 8 ohm 1/2 watt resistor between the uBitx board and your phone jack should 
safely prevent any damage, though it will reduce the maximum available audio.

Could be that 4 ohms is sufficient.
 
Jerry


On Wed, Feb 28, 2018 at 10:49 am, Walter wrote:
So what is the universal fix?  if a mono jack is plugged into a stereo jack on another electronic device it does not destroy the audio output of those devices.

How do they prevent damage on many other devices with stereo jacks?

Re: U1 fried

Jerry Gaffke
 

I'm glad that works for you.
But when concocting a recommended solution across thousands of rigs,
we'd best somehow make the rig survive an audio short to ground.   
Or this forum will getting traffic about fried TDA2822M's for years to come.


On Wed, Feb 28, 2018 at 10:55 am, Thomas Sharka wrote:
I just wired the stereo jack as a mono jack. The signal goes to the tip and the ground goes to the sleeve. The ring isn't connected. Now when I plug in a pair of stereo headphones, I only get one channel, but if I plug in a mono jack, I get sound. When I swap plugs, the short never happens.
 
 

Re: Ubitx case #ubitx

Mike Woods
 

There is a news article about Carl's case on uBITx.net, but you are right, it should be discussed in the enclosures page.  I will update the page shortly.

73 Mike ZL1AXG


On 1/03/18 4:17 AM, Neil Goldstein wrote:
Should we add Carl's case to the ubitx.net enclosures section.

I purchased one of these, by the way, and the quality is excellent!!

--Neil, W2NDG


--
Mike Woods
mhwoods@...

Re: Shipping notification

vk7hch@...
 

EVENT CATEGORY
01 Mar 18 5:40 AM - Customs status updated - MELBOURNE,AUSTRALIA

Further Details - Shipment has been given a release by Customs.
Next Steps - Unless there is an adhoc exam or a stop by another regulatory authority the shipment will proceed to delivery

 

 

Re: ubitx standoffs #parts

Michael Hagen
 

Here is my BitX..

3D printed spacers, Knobs, and Bezel.  It is like cheating to make exactly the spacer you need!  Since they are ABS, I can heat a 4-40 bolt on the stove and TAP them with treads too.   The LCD Backlight has a bump at one end,  so to get the LCD parallel you need an inside spacer about 1/8".

Mike, WA6ISP

 

From: BITX20@groups.io [mailto:BITX20@groups.io] On Behalf Of Michael Hagen
Sent: Wednesday, February 28, 2018 11:18 AM
To: BITX20@groups.io
Subject: Re: [BITX20] ubitx standoffs #parts

 

They are metric 3 mm.  So you have to use 3mm bolts those for the supplied spacers.

Most places have plastic spacers too.  Get 4-40 size ones.  Un-threaded 0.096" or 0.1" and you can use #4 sheet metal screws or self thread 4-40 screws.  Check Mouser.  Or mail order surplus, like All Electronics.

Buy long ones and cut them off to the length you need.   The ACE and other local hardware stores have brass and Al. tubing for model making.

K&M Metals or some name like that.  Al. , Brass, or Copper is easier to work with than steel.

You could cut up spacer from them too.  Could even go to putting nuts at the other end?

Our local ACE has a whole section of hardware, including Metric.

 

73's Mike WA6ISP

 

 

On 2/28/2018 8:20 AM, R S via Groups.Io wrote:

This Group is mighty nice.  I have enjoyed it tremendously for a while now and have learned from others here.  I have a question now.  I have installed my xbitx in an old junked Repeater Case, no testing yet, but I would like to have better choices with the standoffs for the board and display.  The display is a little too far in for my total liking.  Maybe you can see with pics.  Not finished yet.  What are the threads per inch (maybe 4-40) and so on?  I ordered some from Mouser but were surely not what I wanted and expected.  Any help is surely and greatly appreciated.

Ron
KJ4FFG



-- 
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@...

Fw: [BITX20] Another shipping Notification Update

Richard
 

-----Original Message-----
From: Richard Stanley
Sent: Wednesday, February 28, 2018 4:56 PM
To: BITX20@groups.io
Subject: Re: [BITX20] Another shipping Notification Update


My paypal still says nothing but just got a text message from DHL asking for
£27
Their website says delivery by end of business on Monday (y)

Richard G7OED

-----Original Message-----
From: Vince Vielhaber
Sent: Wednesday, February 28, 2018 4:20 PM
To: BITX20@groups.io
Subject: Re: [BITX20] Another shipping Notification Update

Check paypal in case you just didn't get the notice.

Vince.


On 02/28/2018 08:13 AM, Daniel Conklin wrote:
I ordered mine on the 29th of December 2017, and I haven't gotten notice
of shipping yet.
Dan W2DLC
--
Michigan VHF Corp. http://www.nobucks.net/ http://www.CDupe.com/
http://www.metalworkingfun.com

Re: ubitx standoffs #parts

Jerry Gaffke
 

For those in the US, bereft of a 3D printer, our local ACE Hardware store has an amazing
collection of nuts and bolts and spacers, nylon and brass and steel, imperial and metric.
Including some nice generic knobs for electronics.   

Nylon spacers are easily cut to size with an Xacto knife.

Jerry, KE7ER



On Wed, Feb 28, 2018 at 12:10 pm, Michael Hagen wrote:

3D printed spacers, Knobs, and Bezel.  It is like cheating to make exactly the spacer you need!  Since they are ABS, I can heat a 4-40 bolt on the stove and TAP them with treads too.   The LCD Backlight has a bump at one end,  so to get the LCD parallel you need an inside spacer about 1/8".

 

Re: ubitx standoffs #parts

Arvo W0VRA
 

On Wed, Feb 28, 2018 at 01:38 pm, Jerry Gaffke wrote:
ACE Hardware store has an amazing
collection of nuts and bolts and spacers, nylon and brass and steel, imperial and metric.
Including some nice generic knobs for electronics. 
I was just there last Saturday to get some M3 screws.  I didn't even think to look for knobs!  I'll pay more attention next time, and maybe have some coffee before I go.

Re: U1 fried

John
 

I fried mine when I plugged in a stereo sony noise canceling headset.
So it does not only happen with mono plugs.

Hopefully the spare TDAs with sockets will arrive soon so Incan start troubleshooting my no power problem.
To be on the safe side and avoid another wait I also ordered some IRFs ;)


John

Re: Another shipping Notification Update

Larry Smith
 

ordered my Ubitx Dec. 27, 2017
Rcv'd yesterday Feb.27, 2018.
had to be here and sign for it re DHL
73
WA9DOH

On Wed, Feb 28, 2018 at 7:13 AM, Daniel Conklin <danconklin2@...> wrote:
I ordered mine on the 29th of December 2017, and I haven't gotten notice of shipping yet.
Dan W2DLC


Re: U1 fried

Jerry Gaffke
 

So where did you get your spare TDA2822M's?

The TDA2822M is $7 for two on ebay, quite expensive for what it is.
Mainline distributors like Mouser and Digikey say it's discontinued.
ST no longer makes it, sources may be drying up.

My uBitx has a part on it marked "TDA2822M" but no ST logo, not sure who makes it.

Banggood has this amp, photos show it to be stuffed with a UTC2822H clone, but I'm having no luck finding a source for that chip either.
  https://www.banggood.com/TDA2822M-1W-x-2-Dual-Channel-Audio-Amplifier-Stereo-Module-Board-Volume-Control-p-1067736.html

Someday we might need to find a replacement.
Maybe a little PC board with 8 header pins.
Stuff it with a bunch of mmbt3904's if nothing else.

Curious that the stereo headset fried the TDA2822M.
Perhaps it presented too low an impedance when first plugged in for some reason? 

Not at all clear from the datasheet that the TDA2822M will survive a 4 ohm speaker
when powered from a 12v+ supply.

Jerry, KE7ER


On Wed, Feb 28, 2018 at 02:22 pm, John wrote:
I fried mine when I plugged in a stereo sony noise canceling headset.
So it does not only happen with mono plugs.

Hopefully the spare TDAs with sockets will arrive soon so Incan start troubleshooting my no power problem.
To be on the safe side and avoid another wait I also ordered some IRFs ;)

Re: troubleshooting no TX SSB #ubitx #ubitx-help

John
 

I did have power on CW, at least the first day before so smoked U1 with a stereo Sony noise canceling headset.
I didn't have my straight key yet bit i just shorted a cord that i had plugged in the key jack.

Had some trouble getting the scope to sync but the signal on the collector of Q6 was much stronger than the Mic input.

Scope has 10MHz bandwidth so it should work on the lower bands.

Most likely the TDA will arrive saturday than i can start from scratch again.
Will measure the voltages as you mentioned. But as CW seemed to work the first day I thought I had to look somewhere in the modulating circuitry. Have the schematics printed but in my professional career I worked more with higher voltages.
Am not afraid to try but just need some guidance as I am fairly new to radio electronics.

John

Re: Ubitx case #ubitx

Mike Lichtman
 

Let me second Neil's evaluation of Carl’s cases. They are excellent and he is a great ham to deal with. 73 Mike KF6KXG

Re: U1 fried

John
 

I ordered them from China, but on eBay I found an US seller with the TDA2822L. Specs seemed to be similar.

Maybe I was to slow plugging the headset I.

John

ubitx pcb size

Joe Parisella <joe.parisella@...>
 

can one confirm the actual dimension of the ubitx board L by W ?

Tnx

Re: troubleshooting no TX SSB #ubitx #ubitx-help

Jerry Gaffke
 

Yes, if you can transmit CW then it has to be somewhere between Q6 and Q22,
since CW is transmittted by unbalancing the modulator immediately following Q22.
If the receiver works, then the three mixers and local oscillator are ok.
So if you still have trouble transmitting SSB, then it's Q6 or one of the bidi amps on the TX side,
and the bidi amps seldom give us trouble.

You could try unbalancing the modulator by injecting 5vdc through a series 4.7k resistor
at T7 pin 3 (and pin 5).  This is how we generated CW on the Bitx40:  
    https://github.com/amunters/bitx40/blob/master/CW-CARRIER%20wiring.png
If that does transmit CW, then it has to be around Q6.

Your 10mhz scope may just barely see something in the 12mhz IF section through Q42, 
and probably nothing at all in the 45mhz IF section at Q20,21,22.
If you wind up debugging those sections, you may need to build a diode RF probe or something similar.

Jerry


On Wed, Feb 28, 2018 at 02:50 pm, John wrote:
But as CW seemed to work the first day I thought I had to look somewhere in the modulating circuitry. Have the schematics

Re: troubleshooting no TX SSB #ubitx #ubitx-help

John
 

Don't know when I get to it.. but I will follow your lead.
I already ordered some germanium diodes to build a RF probe.

To be continued..

John

Re: ubitx pcb size

Mike Woods
 

On Thu, 1 Mar 2018 at 11:55 AM, Joe Parisella <joe.parisella@...> wrote:
can one confirm the actual dimension of the ubitx board L by W ?

Tnx

Re: U1 fried

Clark Martin
 

The TDA2822M data sheet lists an absolute maximum one amp output output current.  Since this chip is apparently prone to blowing out on short circuit I would add a .5A fast blow fuse in the speaker line, between the PCB and the headphone jack.  It doesn’t need a fuse holder, it could be soldered in (using a fuse with pigtail leads).  It would still be easier and cheaper to replace than the amp IC.

I’ll likely add this mod to my µBitx.  I don’t intend to short it out but then almost no one does.


Clark Martin
KK6ISP

On Feb 28, 2018, at 2:22 PM, John <jjczon@...> wrote:

I fried mine when I plugged in a stereo sony noise canceling headset.
So it does not only happen with mono plugs.

Hopefully the spare TDAs with sockets will arrive soon so Incan start troubleshooting my no power problem.
To be on the safe side and avoid another wait I also ordered some IRFs ;)

Re: U1 fried

Jerry Gaffke
 

Better be a pretty darn fast fuse.

I'll go with an 8 ohm 1/2 watt series resistor to limit current.
At least till I find a good source for TDA2822M chips.
I'm fairly certain that resistor will offer sufficient protection.

Jerry


On Wed, Feb 28, 2018 at 03:51 pm, Clark Martin wrote:
The TDA2822M data sheet lists an absolute maximum one amp output output current.  Since this chip is apparently prone to blowing out on short circuit I would add a .5A fast blow fuse in the speaker line, between the PCB and the headphone jack.  It doesn’t need a fuse holder, it could be soldered in (using a fuse with pigtail leads).  It would still be easier and cheaper to replace than the amp IC.
 
I’ll likely add this mod to my µBitx.  I don’t intend to short it out but then almost no one does.