Date   
Re: Digital BFO Mod: Terrible Audio! #bitx40help

Tim Gorman
 

Jerry,

Of course you are correct. I plead sleep deprivation at 3am and a
faulty memory. The low side is the one with the worst slope.

I have had a chance to go back and look at my notes since then.
According to my notes when I was building crystal filters show that
having the steepest slope on the high frequency side of the audio
provides the best bandwidth restriction in the received signal, ie.
cutting interference and noise. The low audio frequencies are typically
attenuated in the transmitter mic circuits by using lower value coupling
capacitors, i.e. high pass filtering. So the crystal filter is not as
important for attenuating the low frequencies in the received signal.

And you are correct about balanced modulators today. The filter doesn't
need to provide nearly the amount of carrier suppression as in the
"old" days.

I still believe Ashar has made the best overall choices in the way this
rig is designed.

tim ab0wr


On Fri, 16 Mar 2018 11:22:45 -0700
"Jerry Gaffke via Groups.Io" <jgaffke=yahoo.com@groups.io> wrote:

Crystal ladder filters tend to have a steeper skirt on the upper freq
side than on the lower freq side as Tim suggests. See fig 3
here:  https://www.arrl.org/files/file/QEX_Next_Issue/Nov-Dec_2009/QEX_Nov-Dec_09_Feature.pdf
Other than that, I disagree.

I'd say that unless other factors override this, the BFO frequency is
better off above the crystal filter to get maximum opposite sideband
rejection, using the sharper skirt on the upper side. This also
maximizes carrier suppression, though with a balanced modulator this
may not be a primary consideration.  Once you get rid of the opposite
sideband, you can shape the signal further with audio filters, though
this generally isn't needed.

With the 6 pole crystal filter on the uBitx, both skirts are fairly
sharp, much better than the Bitx40. So having the BFO above or below
the crystal filter works well enough.

A second consideration is that the local oscillators should be above
the intermediate frequency. On the uBitx, we have the VFO above the
45mhz first IF, for a 7.2mhz signal the VFO is 7.2mhz above 45mhz.
With the high side VFO, all VFO harmonics are up in VHF and beyond,
and products of those harmonics are more easily gotten rid of. 

On the uBitx, clk1 would best be 12mhz above the 45mhz first IF, to
create a 12mhz signal into the second IF.  However, on the uBitx we
have the further issue of Nano 16mhz and 12mhz oscillator
harmonics mixing with BFO harmonics, creating those audio tones the
some posts here have complained about, so we leave the BFO below the
12mhz crystal filter and use have clk1 above 45mhz for USB, below
45mhz or LSB.

Jerry, KE7ER

On Fri, Mar 16, 2018 at 01:00 am, Tim Gorman wrote:



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.

Re: Soldering gun or iron

 

No way I was going to leave this alone…

First advice, don’t listen to any ONE on this list, nor or any other list of any nature…never one….try it yourself…try multiple ways, and stick with what works for you.

So, with that said, here’s mine…

Get a temperature controlled solder station…that doesn’t mean 4 detents with 4 temps….that means 0 degrees to 700+ F with ability to pick your temp….as you always want lowest temperature that will work for the job….similar to radio….lowest watts out needed to do the job…but, with ability just like radio….to blast it when needed…and fast….

I have a solder station that is a replacement for the exact same model….one stolen back in 1995 (along with scope, NTSC generator, freq counter….everything except my fluke….I am still using it daily….from MCM (called something different now)….last I checked they started selling it again, as customers complained when it was discontinued. Cost when I checked last was about $70.  Tips got good back in the 90’s if you treat them right….I am using a tip from 1995 daily….very fine conical tip….will do almost anything….just slide up the barrel…

I recently bought one of these 2 in one hot air and solder rework stations….862D+….got mine for $49….most go from 60 to 65.  I broke the soldering iron (shame it worked great, but when it fell out the car, it snapped in half), found out the element isn’t ceramic, but is nichrome….and first replacement isn’t right)  the hot air works great, temperature tracks with a harbor freight thermocouple (so you know it has to be good)….my little builders group has been playing with this with manual pick and place, that is drivable….use a bicycle pump shell for z-axis, and steer with the T-handle, vacuum is a Tetra-whisper aquarium pump, and add a $30 USB camera (was daily special)…..a tube of MG solder paste, took off the nozzle and replace with smaller diameter nozzle off of empty flux refill bottle, and then used another of those empty bottle nozzles for the syringe pick up tube (luer lock) …..

if you want to see what we are doing go to Facebook Group: wecanhams 

this is latest with hot air/with no rework with pencil:


this one is a short video of the pick and place in action….with USB camera…I have made some improvements like 2 point clamps on the red tube and a recessed pick area...


Important to have a way to monitor the board temperature if you are using hot air or a reflow oven, and run a recognized heat profile…takes a little practice...


the latest hot air placement with no rework, paste was laid down with syringe, a little dab will do ya...


the rework station bolted down, before accessories added to new home. We are working with a lot of junk and recycled, up cycled junk.


Drivable Pick and Place in action, see the video on FB group



Our little builders group is having a blast with SMD’s….you should, too. 

Craig
KM4YEC


On Mar 16, 2018, at 6:36 PM, Michael Hagen <motdog@...> wrote:

Great Place for Solder and SMD Supplies!

72's Mike, WA6ISP

https://www.cmlsupply.com/


On 3/16/2018 3:27 PM, Roy Appleton wrote:
I don't do a lot of SMD projects and so I don't use a mask just manually apply the solder paste from a syringe that the paste came in. My advice is that you can't have too small a nozzle. In the attached photo I use the cone shaped one because the black one is too big. You'd be surprised how little paste you need before you make a big mess! My source for paste isn't available any more so don't have any suggestions but I'm sure it's not hard to find sources.

Roy
WA0YMH

On Mar 16, 2018 2:04 PM, "Christopher Miller" <djmalak2k6@...> wrote:
How do you apply the paste? I dont have a way to create a mask for a pcb. You also make a good point. If you have a heat gun you can use shrink wrap. Thats a great reason to get a hot air rework station with an iron.

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

VE1BWV audio pop fix - lost my sidetone

K4LXY
 

I implemented the audio pop fix suggested by Joe, VE2BWV (see uBitx.net).  It does pretty much eliminate the pop.  However, it also eliminates my cw sidetone.  (Note: I also have a 220uf cap as per Ashhar's suggestion; 470 created too much delay in the return to receive.)

I have a pot across R250 to allow me to adjust the sidetone volume.  If I turn it down to 0, basically eliminating R250, I get a bit of sidetone, but I'd much prefer to have more.  

I'd appreciate suggestions about how to keep this mod but get my sidetone back.

73 Howard K4LXY

Re: VE1BWV audio pop fix - lost my sidetone

K4LXY
 

Correction: I meant to say that I replaced R250 with a pot so that I could adjust sidetone volume.
Howard

Re: Finally finished boxing up my uBitX #ubitx

K4LXY
 

Looks good, Mike.  How are you liking the 2073 replacement?  I am thinking of putting a regulator in for the TDA, but it would be easier to just replace the IC if the 2073 works OK.  
I too have a SCAF in the audio line and it makes a huge difference on CW (I'm using the Hi-Per-Mite).  
As you may note from my earlier message, I implemented an audio pop fix today that works but eliminates the sidetone.  I want my sidetone back!

73
Howard K4LXY

Re: Shipped, me too

John Scott
 

Received my package 3/16/2018.  It was held up in customs for an extra 12 hours (according to the tracking).
Unit # is 928/3 ( I think) the slash could be a 1 but I doubt it. And at the end of the numbers there is an upside down U...
Now the fun begins.
If you want to extend the display - I used a ribbon cable that was an old hard drive interface cable.  It was only 6" long and I used a double row 90 degree pins for the connection to the rarduino  board itself.  Let me know if you want to see some pictures and I will see if I can send them.. :-)
John
KK5VH

Re: Shipped, me too

John Scott
 

Ooops forgot my email address:
KK5VH@...

John

Re: Finally finished boxing up my uBitX #ubitx

Tim Gorman
 

Mike,

Nice. Did you line the box with copper or just left the plastic as is?

tim ab0wr

On Sat, 17 Mar 2018 06:05:16 -0700
"Michael Aiello" <n2htt.mike@...> wrote:

After about 8 weeks of working on it slowly, a few minutes at a time,
I've finally finished boxing up my uBitX and it's now up and running
FB. The box and mic holder are 3d-printed from a design I found on
Thingiverse and remixed a bit.
I've made a few mods along the way:

* replaced failed WX TDA2822 with a NJM2073D pin-compatible chip
* rewired power to put fuse ahead of protective diode
* added QRPGuys keying adapter
* upgraded firmware to KD8CEC v1.01
* increased mic gain by added 47 ohm resistor across R63

I'm primarily interested in CW, so I tried out my NesCAF switched
capaacitance audio filter with the rig -it works great! The NesCAF
was built from a kit years ago, and has been languishing on a shelf,
but it will get used now daily. I've had a lot of fun with this
little rig already just putting it together, I'm looking forward to
getting on the air with it a regularly. 73, Mike N2HTT

Re: Finally finished boxing up my uBitX #ubitx

 

Howard,

 I too have been using the 2073 with much better audio and no more distortion over load at low volume. Got mine from a 1991 tape player :-)


--
David

 N8DAH
Kit-Projects.com

Re: VE1BWV audio pop fix - lost my sidetone

Ashhar Farhan
 

Place the FET on the OTHER side of the R70.
- f

On 17 Mar 2018 7:52 pm, "DrZ" <zehrhj2@...> wrote:
Correction: I meant to say that I replaced R250 with a pot so that I could adjust sidetone volume.
Howard

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

Gordon Gibby
 

Can you give a little more specifics on how you found the receivers were different?


On Mar 15, 2018, at 17:07, Sajid Rahum via Groups.Io <zs735@...> wrote:

Go for Quansheng uv-r50.  Far far better than Baofeng

https://www.aliexpress.com/store/product/New-for-Ham-Radio-Fan-Upgrade-2000mAh-Long-Standby-5W-QUANSHENG-TG-R50-Dual-Band-VHF/2841090_32830410473.html?spm=2114.12010608.0.0.232c3cf77LeGqp

I ordered two of these.  I have Baofeng UV-82 side by side.  Day night difference between receivers.

Re: VE1BWV audio pop fix - lost my sidetone

 

BITX40 or uBITX you must disclose, we are sworn to secrecy!

At 17/03/2018, you wrote:
I implemented the audio pop fix suggested by Joe, VE2BWV (see uBitx.net). It does pretty much eliminate the pop. However, it also eliminates my cw sidetone. (Note: I also have a 220uf cap as per Ashhar's suggestion; 470 created too much delay in the return to receive.)

I have a pot across R250 to allow me to adjust the sidetone volume. If I turn it down to 0, basically eliminating R250, I get a bit of sidetone, but I'd much prefer to have more.

I'd appreciate suggestions about how to keep this mod but get my sidetone back.

73 Howard K4LXY

Re: VE1BWV audio pop fix - lost my sidetone

 

Only 10 Ohms load, Try R70 = 1K or even 10K.

Raj


At 17/03/2018, you wrote:
Place the FET on the OTHER side of the R70.
- f

On 17 Mar 2018 7:52 pm, "DrZ" <zehrhj2@...> wrote:
Correction: I meant to say that I replaced R250 with a pot so that I could adjust sidetone volume.
Howard

uBITX Low Power Output

WA9GQT@...
 

I removed the bad U1 TDA2822 and installed the new TDA2822 in an IC socket.  Receiving great again. Now I am troubleshooting low power 
output.  Only getting 2 watts maximum power on 30 meters drawing 0.88 A.  Even though I can only get maximum power of 2 watts on 30m,
I did make a contact with KE4COH, Bryan in Lancaster, SC. 
He gave me RST 449 but copied me solid with my 2 watts into a dipole.  I checked
power output on 80
meters and getting 4 watts out at 1.03 A.  Any troubleshooting help would be appreciated. 
Thanks,
73, Rod WA9GQT


Re: Soldering gun or iron

Fr Richard R <rickocr2005@...>
 

Well....... with all said and done..... this is what I finally decided to purchase for my beginning setup:

a simple set up for this beginner...... trying to keep things inexpensive for the time being.

Now to find the time to begin with the build.

thanks to all for your advice.  I am sure I will be looking at past emails in the group as I start!!

73 and God Bless

Fr Richard
WB8YXF




On Saturday, March 17, 2018, 9:43:42 AM EDT, Craig Thibodeaux <km4yec@...> wrote:


No way I was going to leave this alone…

First advice, don’t listen to any ONE on this list, nor or any other list of any nature…never one….try it yourself…try multiple ways, and stick with what works for you.

So, with that said, here’s mine…

Get a temperature controlled solder station…that doesn’t mean 4 detents with 4 temps….that means 0 degrees to 700+ F with ability to pick your temp….as you always want lowest temperature that will work for the job….similar to radio….lowest watts out needed to do the job…but, with ability just like radio….to blast it when needed…and fast….

I have a solder station that is a replacement for the exact same model….one stolen back in 1995 (along with scope, NTSC generator, freq counter….everything except my fluke….I am still using it daily….from MCM (called something different now)….last I checked they started selling it again, as customers complained when it was discontinued. Cost when I checked last was about $70.  Tips got good back in the 90’s if you treat them right….I am using a tip from 1995 daily….very fine conical tip….will do almost anything….just slide up the barrel…

I recently bought one of these 2 in one hot air and solder rework stations….862D+….got mine for $49….most go from 60 to 65.  I broke the soldering iron (shame it worked great, but when it fell out the car, it snapped in half), found out the element isn’t ceramic, but is nichrome….and first replacement isn’t right)  the hot air works great, temperature tracks with a harbor freight thermocouple (so you know it has to be good)….my little builders group has been playing with this with manual pick and place, that is drivable….use a bicycle pump shell for z-axis, and steer with the T-handle, vacuum is a Tetra-whisper aquarium pump, and add a $30 USB camera (was daily special)…..a tube of MG solder paste, took off the nozzle and replace with smaller diameter nozzle off of empty flux refill bottle, and then used another of those empty bottle nozzles for the syringe pick up tube (luer lock) …..

if you want to see what we are doing go to Facebook Group: wecanhams 

this is latest with hot air/with no rework with pencil:


this one is a short video of the pick and place in action….with USB camera…I have made some improvements like 2 point clamps on the red tube and a recessed pick area...


Important to have a way to monitor the board temperature if you are using hot air or a reflow oven, and run a recognized heat profile…takes a little practice...


the latest hot air placement with no rework, paste was laid down with syringe, a little dab will do ya...


the rework station bolted down, before accessories added to new home. We are working with a lot of junk and recycled, up cycled junk.


Drivable Pick and Place in action, see the video on FB group



Our little builders group is having a blast with SMD’s….you should, too. 

Craig
KM4YEC


On Mar 16, 2018, at 6:36 PM, Michael Hagen <motdog@...> wrote:

Great Place for Solder and SMD Supplies!

72's Mike, WA6ISP

https://www.cmlsupply.com/


On 3/16/2018 3:27 PM, Roy Appleton wrote:
I don't do a lot of SMD projects and so I don't use a mask just manually apply the solder paste from a syringe that the paste came in. My advice is that you can't have too small a nozzle. In the attached photo I use the cone shaped one because the black one is too big. You'd be surprised how little paste you need before you make a big mess! My source for paste isn't available any more so don't have any suggestions but I'm sure it's not hard to find sources.

Roy
WA0YMH

On Mar 16, 2018 2:04 PM, "Christopher Miller" <djmalak2k6@...> wrote:
How do you apply the paste? I dont have a way to create a mask for a pcb. You also make a good point. If you have a heat gun you can use shrink wrap. Thats a great reason to get a hot air rework station with an iron.

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

Re: VE1BWV audio pop fix - lost my sidetone

K4LXY
 

Opps - uBitx

Re: Soldering gun or iron

Christopher Miller
 

This looks pretty good for the initial setup. It has tweezers even. One thing I would still recommend is the metal tip cleaner. It might just be the leaded solder, but I find the sponges dont clean the tip as well. Plus you shock the tip by sticking it in relatively cold water.

Chris
KF4FTR

Re: Finally finished boxing up my uBitX #ubitx

 

Looks great Mike, glad you got the audio fixed. I received my NJM2073D chips last week but haven't needed them yet, maybe never. I really like the compact box you used.

Joel
N6ALT

Re: Low power output on ubitx

Mike R.
 

Hi Conrad and thanks for the reply.
I just shootgunned and replaced Q90 with a non-smd part and have exactly the same problem.
So replacing Q90 doesn't seem to be the cure.
In reading the posts I see where 12v on the collector of Q90 could be a bad thing. I get 11.7v on the collector,
3.7v on the base, and almost 3v on the emitter. I'm thinking I might have an issue further down the transmit chain.
The 12v I'm seeing on the collectors of Q92,93,96,and 97 are concerning as Glen's measurements has them at 2.8v.

Re: Soldering gun or iron

David Wilcox
 

If you plan on ANY rework (removing parts from a scrap rig or parts you soldered in in error) forget the solder sucker in that set.  I have tried many different ones over the years and found them not effective.  If you don't want to invest in a real solder vacuum removal device get some solder wick of different sizes and a bottle of rosin flux.  Dip the wick in the flux, heat it up by the part you are removing and little by little the wick actually wicks up the solder until it is 95% removed. Then with a little heat on the remaining legs of whatever you are removing you can lift it off or out of the holes in the board.  I have been doing that for years with great success.  Then remove the excess flux with 91% rubbing alcohol available at any drug store.

Have fun.

Dave K8WPE

On Mar 17, 2018, at 11:35 AM, Fr Richard R via Groups.Io <rickocr2005@...> wrote:

Well....... with all said and done..... this is what I finally decided to purchase for my beginning setup:

a simple set up for this beginner...... trying to keep things inexpensive for the time being.

Now to find the time to begin with the build.

thanks to all for your advice.  I am sure I will be looking at past emails in the group as I start!!

73 and God Bless

Fr Richard
WB8YXF




On Saturday, March 17, 2018, 9:43:42 AM EDT, Craig Thibodeaux <km4yec@...> wrote:


No way I was going to leave this alone…

First advice, don’t listen to any ONE on this list, nor or any other list of any nature…never one….try it yourself…try multiple ways, and stick with what works for you.

So, with that said, here’s mine…

Get a temperature controlled solder station…that doesn’t mean 4 detents with 4 temps….that means 0 degrees to 700+ F with ability to pick your temp….as you always want lowest temperature that will work for the job….similar to radio….lowest watts out needed to do the job…but, with ability just like radio….to blast it when needed…and fast….

I have a solder station that is a replacement for the exact same model….one stolen back in 1995 (along with scope, NTSC generator, freq counter….everything except my fluke….I am still using it daily….from MCM (called something different now)….last I checked they started selling it again, as customers complained when it was discontinued. Cost when I checked last was about $70.  Tips got good back in the 90’s if you treat them right….I am using a tip from 1995 daily….very fine conical tip….will do almost anything….just slide up the barrel…

I recently bought one of these 2 in one hot air and solder rework stations….862D+….got mine for $49….most go from 60 to 65.  I broke the soldering iron (shame it worked great, but when it fell out the car, it snapped in half), found out the element isn’t ceramic, but is nichrome….and first replacement isn’t right)  the hot air works great, temperature tracks with a harbor freight thermocouple (so you know it has to be good)….my little builders group has been playing with this with manual pick and place, that is drivable….use a bicycle pump shell for z-axis, and steer with the T-handle, vacuum is a Tetra-whisper aquarium pump, and add a $30 USB camera (was daily special)…..a tube of MG solder paste, took off the nozzle and replace with smaller diameter nozzle off of empty flux refill bottle, and then used another of those empty bottle nozzles for the syringe pick up tube (luer lock) …..

if you want to see what we are doing go to Facebook Group: wecanhams 

this is latest with hot air/with no rework with pencil:


this one is a short video of the pick and place in action….with USB camera…I have made some improvements like 2 point clamps on the red tube and a recessed pick area...


Important to have a way to monitor the board temperature if you are using hot air or a reflow oven, and run a recognized heat profile…takes a little practice...

<28958739_2035568706459771_6244662275475505152_o.jpeg>

the latest hot air placement with no rework, paste was laid down with syringe, a little dab will do ya...

<29244570_2041142825902359_574099065751470080_o.jpeg>

the rework station bolted down, before accessories added to new home. We are working with a lot of junk and recycled, up cycled junk.

<28336400_2021687984514510_1756727514447237923_o.jpeg>

Drivable Pick and Place in action, see the video on FB group

<smdpnplib.png>


Our little builders group is having a blast with SMD’s….you should, too. 

Craig
KM4YEC


On Mar 16, 2018, at 6:36 PM, Michael Hagen <motdog@...> wrote:

Great Place for Solder and SMD Supplies!

72's Mike, WA6ISP

https://www.cmlsupply.com/


On 3/16/2018 3:27 PM, Roy Appleton wrote:
I don't do a lot of SMD projects and so I don't use a mask just manually apply the solder paste from a syringe that the paste came in. My advice is that you can't have too small a nozzle. In the attached photo I use the cone shaped one because the black one is too big. You'd be surprised how little paste you need before you make a big mess! My source for paste isn't available any more so don't have any suggestions but I'm sure it's not hard to find sources.

Roy
WA0YMH

On Mar 16, 2018 2:04 PM, "Christopher Miller" <djmalak2k6@...> wrote:
How do you apply the paste? I dont have a way to create a mask for a pcb. You also make a good point. If you have a heat gun you can use shrink wrap. Thats a great reason to get a hot air rework station with an iron.

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

<28958739_2035568706459771_6244662275475505152_o.jpeg>
<smdpnplib.png>
<28336400_2021687984514510_1756727514447237923_o.jpeg>
<29244570_2041142825902359_574099065751470080_o.jpeg>