Date   
Re: Escaping smoke #ubitx

Jerry Gaffke
 

Not clear why this is happening, but:

The TDA2822M is rated for operation with a supply between 1.8v and 15v, which is an amazing range,
and suggests the output drivers are pretty low impedance.
Since we are running it at 12v (or more), which is near the top of its range, a shorted output could indeed be all it takes.
Specs and graphs in the datasheet stop at a 9v supply, it's only the spec for the supply voltage that 
suggests 15v might be ok.  

If you run the TDA2822M output to a stereo headphone jack with both ears getting sound,
then plugging in a mono jack will short the output to ground. 

If you wind up replacing the TDA2822M, you might lift pin 1 and insert a 4 or 8 ohm 1/2 watt resistor in series there as a precaution.

If really paranoid, perhaps add an 8 or 9v linear regulator (or string of diodes) to reduce Vcc into the TDA2822M.

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.

How many have blown?   Maybe 2 or 3?  In all cases, is it possible the output got shorted?

Jerry, KE7ER


On Sat, Feb 24, 2018 at 04:54 pm, Bill KC5SB wrote:
Yep, one of the speaker leads could have been grounded - not sure.  Whatever happened, U1 came out on the short end of the stick.  Note to self - be careful with speaker leads.
Examination of the solder joints on the bottom of the board indicate no problems and quality workmanship.

Re: Escaping smoke #ubitx

Joe Puma
 

Glad I saw this. You wouldn’t think you would smoke something by shorting the speaker leads. That can easily be done by plugging in a headphone jack or not having the headphone jack wired correctly the first time. Be careful! ;) 


Joe



On Feb 24, 2018, at 7:54 PM, Bill KC5SB <blmerideth@...> wrote:

Yep, one of the speaker leads could have been grounded - not sure.  Whatever happened, U1 came out on the short end of the stick.  Note to self - be careful with speaker leads.
Examination of the solder joints on the bottom of the board indicate no problems and quality workmanship.

Re: Escaping smoke #ubitx

John
 

Mine might have shorted when I plugged the headphones in. 

I did also check the bottom of the board and that looked fine. Guess there is a bus than placed in the board to connect the under and upper copper plane? Otherwise I would think that some solder on the upper side would connect that trace a little better.

John

VARA HF digital on BitX

KC9SGV <kc9sgv@...>
 

Hi All,
Have a look at VARA.
It is a new Milspec digital mode adjusted for the U.S. HF (or VHF) ham bands.
Meaning it satisfies all the current FCC legal requirements for HF digital.
< 300 baud, < 2.4 KHz bandwidth.
52 Carriers in orthogonally spaced subcarriers.
Multiple OS platforms.
Thruput speeds comparable with P3.....

Full Winlink functionality using the Winlink Express radio email client in Telnet mode.

"VARA is a High Performance HF modem based on OFDM modulation. VARA Modem, brings state of the art Military grade technology to new and existing HF data.

Introduces a new standard of technology available for Amateur and Commercial use. Designed for operation within a SSB Bandwidth of 2400 Hz."

https://rosmodem.wordpress.com
(Scroll down)

Who would be the first to run VARA on a BitX radio ?
Please post the results (with pictures) here.
 
Bernie,
KC9SGV
 
 

Re: Escaping smoke #ubitx

Jerry Gaffke
 

The uBitx and Bitx40 are built on a quality FR4 fiberglass-epoxy pc board with plated through holes.
Check the mounting holes in the four corners, you can see a metal cylinder fully connecting the top and bottom pads.
That's true of all holes on this board.
No need to solder pins to more than one side of the board.


On Sat, Feb 24, 2018 at 05:28 pm, John wrote:
Mine might have shorted when I plugged the headphones in. 

I did also check the bottom of the board and that looked fine. Guess there is a bus than placed in the board to connect the under and upper copper plane? Otherwise I would think that some solder on the upper side would connect that trace a little better.

Re: VARA HF digital on BitX

Joe Puma
 

If you want to try another method, I had success with a raspberry pi running Dire Wolf a software TNC and I am able to control a uhv/vhf Radio with and I used a ft-840 with success for winlink on HF.  I ran the RMS express from a Windows PC and connect to the Rpi/direwolf via tcpip and used the Winmore mode with ease on HF.  

I had a Bitx40 on a raspberry pi already with wsjtx and can do ptt with a com port but now that ubitx has CAT control it makes it even easier.  






On Feb 24, 2018, at 8:29 PM, KC9SGV <kc9sgv@...> wrote:

Hi All,
Have a look at VARA.
It is a new Milspec digital mode adjusted for the U.S. HF (or VHF) ham bands.
Meaning it satisfies all the current FCC legal requirements for HF digital.
< 300 baud, < 2.4 KHz bandwidth.
52 Carriers in orthogonally spaced subcarriers.
Multiple OS platforms.
Thruput speeds comparable with P3.....

Full Winlink functionality using the Winlink Express radio email client in Telnet mode.

"VARA is a High Performance HF modem based on OFDM modulation. VARA Modem, brings state of the art Military grade technology to new and existing HF data.

Introduces a new standard of technology available for Amateur and Commercial use. Designed for operation within a SSB Bandwidth of 2400 Hz."

https://rosmodem.wordpress.com
(Scroll down)

Who would be the first to run VARA on a BitX radio ?
Please post the results (with pictures) here.
 
Bernie,
KC9SGV
 
 

Re: VARA HF digital on BitX

Michael Hagen
 

Oh My, what language was that in, didn't get one word understood!  Martian perhaps?

Oh, I am so Obsolete!  Soilent Green Time?

Hi .. Hi.. Hi...

Mike WA6ISP (Remembering my favorite Band Dire Straights and Mark Knofler ,  Dire Wolf never had a #1 cut?)


On 2/24/2018 5:39 PM, Joe Puma wrote:
If you want to try another method, I had success with a raspberry pi running Dire Wolf a software TNC and I am able to control a uhv/vhf Radio with and I used a ft-840 with success for winlink on HF.  I ran the RMS express from a Windows PC and connect to the Rpi/direwolf via tcpip and used the Winmore mode with ease on HF.  

I had a Bitx40 on a raspberry pi already with wsjtx and can do ptt with a com port but now that ubitx has CAT control it makes it even easier.  






On Feb 24, 2018, at 8:29 PM, KC9SGV <kc9sgv@...> wrote:

Hi All,
Have a look at VARA.
It is a new Milspec digital mode adjusted for the U.S. HF (or VHF) ham bands.
Meaning it satisfies all the current FCC legal requirements for HF digital.
< 300 baud, < 2.4 KHz bandwidth.
52 Carriers in orthogonally spaced subcarriers.
Multiple OS platforms.
Thruput speeds comparable with P3.....

Full Winlink functionality using the Winlink Express radio email client in Telnet mode.

"VARA is a High Performance HF modem based on OFDM modulation. VARA Modem, brings state of the art Military grade technology to new and existing HF data.

Introduces a new standard of technology available for Amateur and Commercial use. Designed for operation within a SSB Bandwidth of 2400 Hz."

https://rosmodem.wordpress.com
(Scroll down)

Who would be the first to run VARA on a BitX radio ?
Please post the results (with pictures) here.
 
Bernie,
KC9SGV
 
 

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

Re: Escaping smoke #ubitx

William R Maxwell
 

My thoughts too, Jerry. I suspect that the uBITX is many builders' first exposure to double sided boards with plated through holes.

Bill, VK7MX



On 25/02/2018 11:03 AM, Jerry Gaffke via Groups.Io wrote:
I suspect that solder job is just fine, 
Have you gotten around to looking at those pins from the bottom of the board?

The surface mount parts are autostuffed.
The through-hole parts are then hand-added.
All you need is a good fillet of solder connecting pin to pad on the back of the board
where the hand soldering job was carried out,

On Sat, Feb 24, 2018 at 03:37 pm, John wrote:
I used my phone to look closely at U1 and was shocked about the soldering. So guess while waiting for parts I can check all soldering and create a case.

Re: cases

Sunil Lakhani
 

Seems good John, but you could have retained the original white paint, It is easy to remove the labels which are screen painted and can be removed by applying some petrol on a piece of cloth and just removing the label, this process does not effect the color on the panel.

Sunil VU3SUA
https://amateurradiokits.in

Re: Escaping smoke #ubitx

Bill KC5SB
 

I ordered 5 TDA2822M IC's with sockets and several 2.2 ohm resistors for R75.  I intend to use the IC sockets. 
Tomorrow I'm going to pull U1 and R75 from the board and use a signal tracer to see if I am getting audio into this stage.  I think I should be able to pick off the signal at the wiper of the volume control (?).  Is there any risk to doing this?

After the parts are replaced I plan to use the bench supply to bring the voltage up slowly and carefully watch and monitor temperature after I replace U1 and R75.  I was fiddling with speaker jack and don't remember the exact sequence of events before the catastrophic failure.  I will report back after the parts come in.  Thanks for the replies guys.

Re: VARA HF digital on BitX

Joe Puma
 

That’s how I feel sometime when learning radio electronics. :)

Have a look yourself. 

KD2NFC 


On Feb 24, 2018, at 8:58 PM, Michael Hagen <motdog@...> wrote:

Oh My, what language was that in, didn't get one word understood!  Martian perhaps?

Oh, I am so Obsolete!  Soilent Green Time?

Hi .. Hi.. Hi...

Mike WA6ISP (Remembering my favorite Band Dire Straights and Mark Knofler ,  Dire Wolf never had a #1 cut?)


On 2/24/2018 5:39 PM, Joe Puma wrote:
If you want to try another method, I had success with a raspberry pi running Dire Wolf a software TNC and I am able to control a uhv/vhf Radio with and I used a ft-840 with success for winlink on HF.  I ran the RMS express from a Windows PC and connect to the Rpi/direwolf via tcpip and used the Winmore mode with ease on HF.  

I had a Bitx40 on a raspberry pi already with wsjtx and can do ptt with a com port but now that ubitx has CAT control it makes it even easier.  






On Feb 24, 2018, at 8:29 PM, KC9SGV <kc9sgv@...> wrote:

Hi All,
Have a look at VARA.
It is a new Milspec digital mode adjusted for the U.S. HF (or VHF) ham bands.
Meaning it satisfies all the current FCC legal requirements for HF digital.
< 300 baud, < 2.4 KHz bandwidth.
52 Carriers in orthogonally spaced subcarriers.
Multiple OS platforms.
Thruput speeds comparable with P3.....

Full Winlink functionality using the Winlink Express radio email client in Telnet mode.

"VARA is a High Performance HF modem based on OFDM modulation. VARA Modem, brings state of the art Military grade technology to new and existing HF data.

Introduces a new standard of technology available for Amateur and Commercial use. Designed for operation within a SSB Bandwidth of 2400 Hz."

https://rosmodem.wordpress.com
(Scroll down)

Who would be the first to run VARA on a BitX radio ?
Please post the results (with pictures) here.
 
Bernie,
KC9SGV
 
 

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

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

Jack Purdum
 

I've not used PSK, but search this group as I think there are some who have used it with PSK. The µBITX directly supports SSB and CW. Pretty hard for me to think of a better deal for someone who is just getting started.

Jack, W8TEE



From: Mark via Groups.Io <mboston72@...>
To: BITX20@groups.io
Sent: Saturday, February 24, 2018 5:34 PM
Subject: Re: [BITX20] Looking for Completely Functional Dual-Band 20/(17/15/10/6) Meter QRP Rig with SSB/PSK #bitx20help


Hello Jack,

Another option. Maybe I can get in contact with a local HAM club. It would probably be best for me to join one anyway.

Can you tell me if this uBit has both SSB phone & PSK?

Thanks,

Mark


Re: Ubitx case #ubitx

Sunil Lakhani
 

One from several models of ubitx  case is coming up and is  ready, pictures will be posted today also the pre orders will be open by Sunday, 

Also suggestions required for making various models for bitx and ubitx. 

We have some Bitx3B case selling on our ebay store Fusion Radio that some hams are using for ubitx, these are a bit larger, but the smaller and compact ones are coming up now on our website https://amateurradiokits.in

We hope to provide various colors and designs for users of ubitx,bitx and other transceivers.

We have been providing Kits and cases for a decade now, so the trend continues,

Thanks and best of 73s

Sunil VU3SUA

Re: cases

John Sharpe
 

Thanks Sunil,

I liked the colour change though! I should put some more labels on the front, not sure which is the best way to do that,

John



On 25 Feb 2018, at 1:28 pm, Sunil Lakhani <vu3sua@...> wrote:

Seems good John, but you could have retained the original white paint, It is easy to remove the labels which are screen painted and can be removed by applying some petrol on a piece of cloth and just removing the label, this process does not effect the color on the panel.

Sunil VU3SUA
https://amateurradiokits.in

Re: Dynamic mic on ubitx

 

Has to work and work it does. I proposed this for Bitx40 as I needed more gain for my Yaesu mic.
in uBitx it is possible to put a preset to control mic gain.

Raj

At 24/02/2018, you wrote:
Dave wrote,

"Modifications to use a Dynamic Mic.
Referring to the uBITX Schematic. The Gain of the Mic PreAmp is controlled by R63 in the Emitter of Q6 to C62/R64. It basically decouples the audio bypass of R64 by C62 to limit gain for the high output Electret Mics. Replacing R63 with a Zero Ohm resistor and putting a 10K at the Mic input should allow a Dynamic Mic to work now with a Mic Gain Control. Also R60 that supplies Mic BIAS to the Electret-Condenser Mic needs to be removed. If there is not enough Gain still, you might have to reduce the value of R64 to maybe 470 Ohms or so. If you cannot look at your transmitted signal on a scope at least listen to your audio on another receiver to verify you are not causing distortion.

More Gain for the Electret Mic
To simply get more gain with an Electret Mic you might try dropping another 47 Ohm chip resistor on top of the existing R63 by soldering another chip resistor one end at a time.

Dave WI6R"

Has anyone actually performed this mod? Does it work?

--
73, W9KJO
Walter

Re: Schematic Drawing Software

Ashhar Farhan
 

If you dont want to use software at all, there are three alternatives:
1.draw with your hand
2. Draw with ms paint
3. Do it on upverter.com

On 24 Feb 2018 11:27 pm, "Mike Bryce" <prosolar@...> wrote:
yes!

Diptrace is the one I use all the time now.

I tried most of them as well, found Eagle way to expensive, although it has a huge following.

Eagle is size restricted with no limit on pins
dip trace is pin limited (300) with its free version but any sized pcb.

Mike, WB8VGE
SunLight Energy Systems
The Heathkit Shop
http://www.theheathkitshop.com/
J e e p
o|||||||

On Feb 23, 2018, at 7:26 PM, Larry Cicchinelli <k3pto@...> wrote:

Hi,
I 2nd the vote for DipTrace.  I have been using it for over 10 years.  I have used several different CAD software programs in the past, both professional and hobby.  DipTrace is by far the easiest to learn and use.

Re: Schematic Drawing Software

 

Mr. Farhan, 

Do you use upverter? Do you mind sharing, for how long? To what extent?

I looked at their model, it seems to be free for some level of service then inside app charges for more? But, I had to dig to find that.

How viable to do what....and to what level? 

It sounds like a interesting concept, but to use something like this it is useful to know what the limits are for free, before investing time in something to almost achieve and then  run into a money wall.

I  did not register, yet, but probably will when rested and look at it again tomorrow.

Craig
KM4YEC

#ubitx Calibration resolution #ubitx

ge_clipboard
 

Hi Joel

Thanks for the link. All is working well except that I still have different soundresults with the if-shift in lsb and usb mode.

73, Gerald - HB9CEY

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

Mark KC1JCD
 

Jerry

Thanks for the suggestions.
An antenna for 40m will do better if higher than 20', but 20' could be a good start. Antennas can be made of most anything from 28 gauge magnet wire to discarded house wiring to galvanized steel electric fence wire, perhaps held up with nylon string.

I'm reading over your message. I will be adding it to the antenna section of my expanding HAM text file.

I think you have a point too, about my expectations. I was looking for a rig as small as possible, with at least two bands that is SSB & PSK capable. This doesn't seem to be realistic for my price-range.

I have considered learning CW. I did some research on it to find that it might take a month or more to get somewhat proficient. I should learn that, at least enough to be able to fumble my way through getting a message across. That would open up even more options. There are multi-band Mountain Toppers available & the Pixie that are back-packable. Making my own radio & learning CW are excellent investments.

The 40m has less congestion than the 20, & I can access it with a more compact antenna than I thought.
40m is generally an easier band to operate on anyways as it tends to be less competitive than 20m.

I did not find that information on the webpages I've read on frequency band characteristics.

Regardless of the rig I choose, now, I know that it has to include the 40m if multiband, or only the 40 if mono.  

Jerry, I'm grateful for you spending the time to provide these suggestions.

Mark

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

Mark KC1JCD
 

Hi Patrick,

Yes, I agree. I quickly put myself through a course on this while studying for the exam. It was a brief introduction to the major topics that I could observe. This included YouTube videos & web sites. I planned on going back over it, for a more thorough understanding of each subject, starting with the most important ones first. It appears that would include antennas. David Casler (KEØOG), has some excellent info on this.

Thanks, Mark