Date   
Re: Received my uBitx!

Chuck, N1KGY
 

>I got mine yesterday also,  ordered 2/17.
This is exciting news - I ordered mine on 2/19.

As for the 2822 chips, I've decided to put a regulator in their B+  line before ever powering them up.

Thanks!

Re: Popped Audio Chip #ubitx

 

Joe,

Since you put in a new chip and no audio.. could mean a short at the speaker jack or speaker.

If you turn up the volume does the current go up? does the chip get warm ?

Did you have any audio earlier before the smoke ?

Raj

At 16/03/2018, you wrote:
Greetings,


I finally got my uBitx assembled and in the case of it's final destination.. I checked my wiring on everything, and nervously applied power.. Display came up and I was happy.. turned the VFO for a sec and watched the frequency changed.. pushed in to change function.. all at once.. I smelled the magic smoke smell and the audio chip went pop... I happened to look in my parts bins and I have happened to have a few more.. it appears from a different manufacture, and these are the "M" flavor. I replaced the audio chip.. but I have no audio, via headphone or speaker.. I turned it off.. wanted to check with the group..

73 de Joe KB5VJY k

Re: Digital BFO Mod: Terrible Audio! #bitx40help

Tim Gorman
 

Ryan,

One thing to remember is that crystal filters have always been
considered to be *upper* sideband filters primarily.

They don't have infinitely steep firewalls at each end of the bandpass.
Think of a crystal filter having a slope of 60deg on the low frequency
side and a 45deg slope on the upper frequency side. It's not that
bad but it illustrates the point.

The filter works best when the carrier is on the low frequency side of
the crystal and the audio is above the carrier. The high frequencies in
the voice are usually lower in power anyway so the increased slope on
the upper frequency side of the filter still provides adequate
attenuation.

If you switch and put the carrier on the upper frequency side of the
filter and the audio lower in frequency than the carrier then you are
using your filter where it works the worst. It's not so bad for
transmitting other then it doesn't suppress the carrier as well but for
receiving it tends to let low frequency noise *and* signal through more
than if you use it as an upper sideband filter.

This is also why receivers using such a method often sound so different
on lsb than on usb. Low frequencies in the voice are emphasized much
more when using the filter as a lsb filter than when used as an usb
filter.

The reason for this is that crystal filters are based on the resonant
frequencies of the crystals, the capacitances associated with the
holder, and the stray capacitances of the filter itself. Resonant
crystals can be seen as a combination of resistance, capacitance, and
inductance, just like any resonant circuit. As you go higher in
frequency the capacitance provides less impedance and the higher
frequencies are attenuated less [impedance = 1/(jwC)]. That and the
holder capacitances and stray capacitances provide lower impedance
paths around the filter as the frequency goes up. So you get less
attenuation on the high frequency side.


At the risk of boring everyone, using crystal filters as lsb filters
was done a *lot* in times past when it was difficult to provide two
vfo's of such high frequency that had any stability at all. It was far
easier and worked better to use one of the same crystals as in the
filter as your bfo. You could pull it with a parallel capacitance to
place it on one side of the filter or the other, and being based on a
crystal the bfo would be pretty stable. You just had to live with the
shape of the filter.

This is one of the less appreciated design choices Farhan has done. By
using such different frequencies in the second stage he has been able
to invert LSB signals into USB signals at the filter stage. Thus he
makes the best use of the crystal filter for both USB and LSB
received signals.

Rather than show a bunch of math just remember that when you subtract
the oscillator frequency from the signal you maintain orientation of
the sideband. When you subtract the signal from the oscillator you
invert the sideband.

In the ubitx the first mixer inverts a lsb received signal to usb and a
usb received signal to lsb by subtracting the signal from the vfo. The
second mixer then uses the lower frequency oscillator to maintain the
45mhz usb signal and the higher frequency oscillator to invert the
45mhz lsb signal back to usb. When you look at the block diagram for the
ubitx remember that when it says (33Mhz on USB/57Mhz on LSB) that he is
talking about the 45Mhz signal, not the received signal.

tim ab0wr

On Thu, 15 Mar 2018 00:13:32 -0700
"Ryan Flowers" <geocrasher@...> wrote:

See, this is why I posted. I know I'm in over my head. I don't fully
understand the crystal filter and where its passband is positioned.
You just gave me good information though, so thank you. And Tim, the
variables and equation used is

vfoOffset + frequency) VFO Offset of 11984800 + frequency displayed
(7mhz) and oh my, I just realized I'm doing it backwards which is one
reason I am having such a hard time. I do most of this late at night
and it shows lol. Thanks for causing me to re-evaluate that. This
would explain why I was getting FT8 only in what I thought was LSB
mode. I modified the code to subtract displayed frequency from
carrier, outputting 5mhz instead of 19, and adjusted the USB/LSB
frequencies based on what you said Jerry, and they were dead on. 

I fired up the rig and did some basic testing and the audio was very
clean. I hooked up the PC and had an FT8 QSO by answering nearly the
first CQ I saw. Success! Thanks so much for the help, guys. 

I still want to understand how the 5 crystals all being on the same
frequency works. I think the X5 crystal has a capacitor to pull the
frequency up to adjust the passband, and the 119984800 which I
mistakenly thought was my offset is not, but is rather the original
LSB frequency I was *using* as the offset on my QRP Labs VFO. Because
now I'm seeing that I'm a few khz low on the display, which I suppose
makes sense since my offset is equally low. I have some adjusting to
do.

Thanks again- you guys have saved me tons of frustration.

--
Ryan Flowers - W7RLF
MiscDotGeek.com ( http://miscdotgeek.com )
Multi Band BITX40 ( http://miscdotgeek.com/bitx40-digital-jt65/ )
The BITX40 FAQ ( http://miscdotgeek.com/unofficial-bitx40-faq )

Re: Micro BitX No Audio TDA2822?

Tim Gorman
 

A series resistor also tends to act like a treble tone control. Low
frequencies with higher audio power levels tend to get attenuated more
by a higher voltage drop while lower power audio high frequencies don't
get attenuated as much.

YMMV as far as the actual effect on the ear.

tim ab0wr

On Thu, 15 Mar 2018 19:22:33 -0700
"Jerry Gaffke via Groups.Io" <jgaffke=yahoo.com@groups.io> wrote:

Quiescent current into the TDA2822 is around 6ma, peaks can be 1 Amp.
Though 100ma might be sufficient for moderate speaker volumes.
You would need two resistors for a voltage divider, and maybe waste
500 ma through them to keep the voltage moderately well regulated.

Good spot for an LM7805.

On Thu, Mar 15, 2018 at 07:10 pm, Ashhar Farhan wrote:


One could use a voltage drop resistor. The higher the current draw,
lower would be the voltage to the TDA2822
 

Re: Blew the irf510's up, substituted irfp260's in there place... #ubitx-help

Ghericoan
 

I have a two amp fuse inline. How do you tell if it is oscillating?

And a really bad swr is what I am guessing killed the irf510's.
--
----------
N5WLF, Greggory (or my nickname, Ghericoan)
General Class, Digital Radio Hobbyist

Re: Soldering gun or iron

David Wilcox
 

If you belong to a club or have even one ham radio buddy.  All of us who have been in the hobby for a while have upgraded and our older but still good soldering devices are just sitting there.  Last year at our annual radio club swap I finally parted with a Heathkit adjustable soldering pencil that I had had since college and another similar soldering pencil that I had retired when I upgraded.  They are usually Free if you just ask.  Free is good, especially getting started.  AND there are many hams like me who if we know of your need will just give you lots of stuff including ham magazines just to get them out of our shack. Don't be afraid to give your location and need.  We are brothers in this fraternity.

Dave K8WPE

On Mar 15, 2018, at 1:56 PM, Fr Richard R via Groups.Io <rickocr2005@...> wrote:

Thank you, sorry about such an incomplete question and being so nooby......

limited budget, not sure about future kits, we'll see how this one goes.  I used to use a Soldering Gun a long long time ago...... I have a very low wattage iron someplace that I thought I was going to use for a small kit, though never did.......

so an iron is better that a gun...... and I will just probably get an inexpensive one on Amazon as I am also getting a cable, some new STTDA2822M's and a couple of LM7809CT to prepare for a possible bad TDA2822!










On Thursday, March 15, 2018, 1:47:51 PM EDT, Doug W <dougwilner@...> wrote:


Kind of like asking what car you should buy or shovel or rifle or whatever.  We can be much more helpful if you know your goals.  Are you on a limited budget and this is the only thing you plan to ever build and need the cheapest way to just get this done or do you have so much spare cash you light Cuban cigars with $100 bills and want the best tools that will last for generations?
Personally my go to iron is a supposedly 60w adjustable pencil type iron that I keep planning to upgrade but I like it and it gets the job done.  I have this one https://www.amazon.com/gp/product/B00Y9UW2XA  that was around $15.  It isn't available anymore but there are tons of similar Chinese ones on Amazon.  While you're at it I would suggest picking up one of the copper scrubby looking tip cleaners.

Re: Soldering gun or iron

David Wilcox
 

I think this was intended as a tongue in cheek joke. Don't even consider it for construction of todays small radios. It works great for soldering coax connectors to a coax or maybe to a circuit board in a non QRP project. I still use my 250 w Weller soldering GUN occasionally in working on big things as in the tube sets of yesteryear.

Dave K8WPE

On Mar 15, 2018, at 6:15 PM, Joe Puma <kd2nfc@...> wrote:

I used to watch my grandfather repair tube TV’s with this one.
On Mar 15, 2018, at 4:48 PM, Vince Vielhaber <vev@...> wrote:

I have a small butane torch (harbor freight) that comes just before the propane torch.

Vince.



On 03/15/2018 01:59 PM, Jerry Gaffke via Groups.Io wrote:
Yes, a temperature controlled pencil iron with a fine tip would be a
good choice for working on these rigs.
That and some strong reading glasses and bright work light.

I still have the 140W gun that I built tube gear when in my teens.
Use it occasionally when soldering up large chunks of metal, perhaps
when using
12 gauge house wiring for an inductor. Beyond that, it's the propane torch.

Jerry


On Thu, Mar 15, 2018 at 10:47 am, Doug W wrote:

Kind of like asking what car you should buy or shovel or rifle or
whatever. We can be much more helpful if you know your goals. Are
you on a limited budget and this is the only thing you plan to ever
build and need the cheapest way to just get this done or do you have
so much spare cash you light Cuban cigars with $100 bills and want
the best tools that will last for generations?
Personally my go to iron is a supposedly 60w adjustable pencil type
iron that I keep planning to upgrade but I like it and it gets the
job done. I have this one
https://www.amazon.com/gp/product/B00Y9UW2XA that was around $15.
It isn't available anymore but there are tons of similar Chinese
ones on Amazon. While you're at it I would suggest picking up one
of the copper scrubby looking tip cleaners.
--
Michigan VHF Corp. http://www.nobucks.net/ http://www.CDupe.com/
http://www.metalworkingfun.com


<image1.jpeg>

Re: Officially done with my uBITX!

Andy Wragg
 

Hi Joel,

Great work there, a couple of requests/questions if I may.

Firstly, what's the weight of the finished assembly?
Secondly, could we have some gut shots?
Third - did you mount the LCD screen still connected to the Raduino?

I'm guessing the PTT button is mounted on the body of the mic somewhere.

73's
M6UAW

BITX QSO Afternoon/Night, Sunday, March 18, 3PM/7PM Local Time, 7277 kHz in North America, 7177 kHz elsewhere

John P
 

BITX QSO Afternoon/Evening, Sunday, March 18, 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

New file uploaded to BITX20@groups.io

BITX20@groups.io Notification <BITX20+notification@...>
 

Hello,

This email message is a notification to let you know that a file has been uploaded to the Files area of the BITX20@groups.io group.

File: ubitx_I2C2L_V3_00R.zip

Uploaded By: Jim Sheldon

Description:
W0EB/W2CTX latest firmware release for I2C equipped uBITX transceivers. Old file deleted and reposted with bug fixes. This version works on ANY I2C enabled Raduino card with an I2C 2 line x 16 character display if you follow the instructions and works especially well on our "RadI2Cino" card (available from W0EB - email via the email listed on QRZ please, not on the group forum for details on the RadI2Cino) This is the TWO line display version with fully implemented CAT and interrupt driven CW - swappable paddle selection, Iambic A and B keyer modes. Completely rewritten alignment mode that has proven to be quite accurate as well. Third try - this one includes the already compiled hex file.

You can access this file at the URL:
https://groups.io/g/BITX20/files/ubitx_I2C2L_V3_00R.zip

Cheers,
The Groups.io Team

New file uploaded to BITX20@groups.io

BITX20@groups.io Notification <BITX20+notification@...>
 

Hello,

This email message is a notification to let you know that a file has been uploaded to the Files area of the BITX20@groups.io group.

File: ubitx_I2C4L_V3_00R.zip

Uploaded By: Jim Sheldon

Description:
W0EB/W2CTX latest firmware release for I2C equipped uBITX transceivers. Old file deleted and reposted with bug fixes. This version works on ANY I2C enabled Raduino card with an I2C 2 line x 16 character display if you follow the instructions and works especially well on our "RadI2Cino" card (available from W0EB - email via the email listed on QRZ please, not on the group forum for details on the RadI2Cino) This is the FOUR line display version with fully implemented CAT and interrupt driven CW - swappable paddle selection, Iambic A and B keyer modes. Completely rewritten alignment mode that has proven to be quite accurate as well. Third try - this one includes the already compiled hex file.

You can access this file at the URL:
https://groups.io/g/BITX20/files/ubitx_I2C4L_V3_00R.zip

Cheers,
The Groups.io Team

Re: Officially done with my uBITX!

 

Hi Andy,

The radio weighs 2 pounds. I did not leave the display mounted to the main board as it would make the display not centered and too low on the front panel. I built a short flat extension cable out of a female and male header. You are right about the PTT switch, it's mounted in the pen housing on a small piece of perf board. And lastly here are some pics of the guts.

Joel
N6ALT

Re: Officially done with my uBITX!

Jeffrey Peters <dek9jp@...>
 

Very nicely done!

Where was your cabinet from?

Thank you, Jeff K9JP

On Fri, Mar 16, 2018 at 9:39 AM, Joel Caulkins <caulktel@...> wrote:
Hi Andy,

The radio weighs 2 pounds. I did not leave the display mounted to the main board as it would make the display not centered and too low on the front panel. I built a short flat extension cable out of a female and male header. You are right about the PTT switch, it's mounted in the pen housing on a small piece of perf board. And lastly here are some pics of the guts.

Joel
N6ALT




--
Not all of me will die - - - The good I do will live forever.  <><

Re: Officially done with my uBITX!

 

Hi Jeff,

After three attempts at different enclosures, I settled on this one from China. https://www.ebay.com/itm/123008133070?ViewItem=&item=123008133070 It is built very well and super light. Only 4 screws hold the whole thing together yet it is very strong and rigid. Very ingenious.

Joel
N6ALT

Re: Raduino oscilators. 33mhz and 57mhz. Documentation says one thinng, but this is what I measured.

Michael Shreeve
 

Very happy with the way this question was handled by our group. Thanks again to Jerry (and others) , taking their time to make available  elaborate explanations which hopefully make sense to programmers and non programmers alike. I must say that a non programmer might not ever know that the 33 and 57 MHz oscillators had been switched (at least some of the explanations would lead you to believe that) except by hands on measurement of the actual radio. Hands on is a good thing. Thanks guys.  

Re: The issues of the TDA2822

 

Hi All,

I have blow TDA2822 WX version also during press CW key. I find another replacement from local and can get only TDA2822L version. 
now I have replace it and use without any problem.

73 E29AHU
Choke

On Wed, Mar 14, 2018 at 1:19 AM, Rahul Srivastava via Groups.Io <vu3wjm@...> wrote:
Hi!

Farhan already knows this story of mine regarding 2822's. Recently I made a simple  low noise receiver. Seeing the specs and after a nice discussion with Farhan I used this chip. Bought 10 pcs of them ie 5 each from 2 different shops locally, read as typical far east device manufacturer unheard of.

2 created virtual short and the holy smoke, 2 of them had lot of hiss, 1 was very peaceful silent , dead silence, rest of them had low gain AF level whatever. I had an old original St chip about 10 years old in my junk box I installed it and everything became fine..

Moral of the story :  Lot of sub standard stuff is out there these days.

73

Rahul VU3WJM


Re: Raduino oscilators. 33mhz and 57mhz. Documentation says one thinng, but this is what I measured.

Michael Shreeve
 

And yes Don, looking forward to our next 80 meter QSO. Its so much fun to see just how well this radio does. Conversations on Sunday AM with folks in Portland, Reno, the bay area, all over the west , crystal clear, barefoot, and amazing !

Re: Popped Audio Chip #ubitx

Bill KC5SB
 

When mine blew it took R75 out at the same time.  You might check surrounding components under magnification. 

Re: Officially done with my uBITX!

Jeffrey Peters <dek9jp@...>
 

Thank you Joel,

I just placed an order.  Yes, I saw the wonderful design and simple way to have everything attached and secure.

Thanks again for your help and kindness.

73, Jeff K9JP

On Fri, Mar 16, 2018 at 10:06 AM, Joel Caulkins <caulktel@...> wrote:
Hi Jeff,

After three attempts at different enclosures, I settled on this one from China. https://www.ebay.com/itm/123008133070?ViewItem=&item=123008133070 It is built very well and super light. Only 4 screws hold the whole thing together yet it is very strong and rigid. Very ingenious.

Joel
N6ALT




--
Not all of me will die - - - The good I do will live forever.  <><

Re: Soldering gun or iron

Christopher Miller
 

Thats true, Farhan is correct that is the most important factor. Keeping the tip clean and tinned, as well as having the tip be quality is in my experience as well the most important as well. I believe the second should be temperature control. If you are going to buy a 100$ iron you might as well get a rework station? I checked again and tips and elements of the station are available. The PID loop cycles a couple times a second and works.

Its true I put through hole kits together with garbage but having a proper iron / station improved my work a lot. 

If a person will be doing work reasonably regularly paying 60-70 for a decent station with smd growing in popularity makes sense. You can salvage parts by using the hot air gun and tapping them to get the surface tension of the leaded solders surface tension to pull the part in to place.

Chris