Date   
Re: Latest Build, Mods and results.

Jerry Gaffke
 

Pot RV1 on the uBitx varies output power.

VK2ETA came up with a way of using the shoulder of the 45mhz crystal filter to vary the output power. 
 https://groups.io/g/BITX20/message/46235
and wrote software to implement it:  https://groups.io/g/BITX20/message/50215
I believe this has also been incorporated into the KD8CEC firmware.
Requires no hardware mods.  This only works for SSB transmissions and not for CW,
though could be extended to CW if signal CW-KEY were injected into the second mixer instead of the first mixer.
No easily discernible change to the audio, though will be some variation in the audio response:
    https://groups.io/g/BITX20/message/50265
    https://groups.io/g/BITX20/message/50279

The uBitx.net site is getting rather large.  To say there's some sort of solution there
is becoming akin to saying there's a solution in one of the 52000 posts in this forum.
My best guess is that Dr Bill is suggesting an implementation involving a new PC board
controlled by extra pins from the Raduino to run some relays that select various 
preset attenuators.

There are plenty of other ways to do this, most involve hacking in some sort of attenuator.

Jerry, KE7ER


On Wed, Jun 13, 2018 at 07:14 am, K9HZ wrote:
Check uBITx.net.  Already there. 

 

Dr. William J. Schmidt - K9HZ  

 
On Jun 13, 2018, at 12:07 AM, brad martin <emclinux@...> wrote:

Isn’t there a pot that controls the output power? If so you could make a low power switch that is just adding a resistor in parallel or series depending on the circuit. I’m just walking and thinking here so don’t have the schematic easy to get.

Brad
On Tue, Jun 12, 2018 at 6:47 PM Nick VK4PLN <nickpullen@...> wrote:
Ah, too easy, I was hoping it was done via software and able to TX a much lower power carrier for tuning, not the full 15W...
Any ideas and thoughts?

 

 

Re: Latest Build, Mods and results.

brad martin
 

Just an idea, Ignore CW tone all together and focus of SSB.  Now if I understand right SSB output power is based on the audio in volume.  You yell into the mic you put out more power, you whisper you get less.  At least thats how its showing on my SWR meter and my power supply amp meter.  The CEC firmware can already do WSPR on its own with a push of the PTT button.  What if we implemented a tune feature that just produced a 700khz tone on SSB and you can vary the output power by simply (I assume) changing the output voltage/duty cycle of the tone.  Thinking it would go something like this, Change mode to tune, Push PTT to send a tone,  In the software it will change the duty cycle to generate 1W out on the band you are on.  On 40m that may be a 10% duty cycle where on 20m it may be 60%.

For me I am OK at best with hardware mods and a better coder.  Now off to clone CEC firmware repo to see if it can be done.

73,
Brad
KG5SPR

On Wed, Jun 13, 2018 at 11:25 AM, Jerry Gaffke via Groups.Io <jgaffke@...> wrote:
Pot RV1 on the uBitx varies output power.

VK2ETA came up with a way of using the shoulder of the 45mhz crystal filter to vary the output power. 
 https://groups.io/g/BITX20/message/46235
and wrote software to implement it:  https://groups.io/g/BITX20/message/50215
I believe this has also been incorporated into the KD8CEC firmware.
Requires no hardware mods.  This only works for SSB transmissions and not for CW,
though could be extended to CW if signal CW-KEY were injected into the second mixer instead of the first mixer.
No easily discernible change to the audio, though will be some variation in the audio response:
    https://groups.io/g/BITX20/message/50265
    https://groups.io/g/BITX20/message/50279

The uBitx.net site is getting rather large.  To say there's some sort of solution there
is becoming akin to saying there's a solution in one of the 52000 posts in this forum.
My best guess is that Dr Bill is suggesting an implementation involving a new PC board
controlled by extra pins from the Raduino to run some relays that select various 
preset attenuators.

There are plenty of other ways to do this, most involve hacking in some sort of attenuator.

Jerry, KE7ER


On Wed, Jun 13, 2018 at 07:14 am, K9HZ wrote:
Check uBITx.net.  Already there. 

 

Dr. William J. Schmidt - K9HZ  

 
On Jun 13, 2018, at 12:07 AM, brad martin <emclinux@...> wrote:

Isn’t there a pot that controls the output power? If so you could make a low power switch that is just adding a resistor in parallel or series depending on the circuit. I’m just walking and thinking here so don’t have the schematic easy to get.

Brad
On Tue, Jun 12, 2018 at 6:47 PM Nick VK4PLN <nickpullen@...> wrote:
Ah, too easy, I was hoping it was done via software and able to TX a much lower power carrier for tuning, not the full 15W...
Any ideas and thoughts?

 

 




--

Re: Latest Build, Mods and results.

Jerry Gaffke
 

That should work fine.

Take the filtered sidetone from the junction of R252, R253,  add a 10k pot from there to ground to attenuate that audio signal,
the attenuated signal goes through a switch and a series 1uF cap to the base of Q6.  Flip the switch on to enable this feature.
Only software change needed is to turn the sidetone on when tuning.  Adjust the pot for the desired power level during tune.
No additional Nano pins required.

Could do away with the pot, use two fixed resistors there to set maximum tuning power, and adjust the duty cycle
of the sidetone to reduce power under program control as you suggest.   The simple tone() function call currently used
is fixed at 50%, need to find some other way to create that tone.  Harmonic content of the tone would predominate
as duty cycle is reduced, but the RC filter at R250,251,252 should mostly take care of that.

Alternately, could use a spare Nano pin to drive a second RC filter that only injects its tone into Q6,
leaving the current sidetone  generator alone.  Then you can do without the extra switch.

Or create a tone using a smartphone app.
Or whistle softly into the mike.  

Lots of ways!

Jerry


On Wed, Jun 13, 2018 at 08:46 am, brad martin wrote:
Just an idea, Ignore CW tone all together and focus of SSB.  Now if I understand right SSB output power is based on the audio in volume.  You yell into the mic you put out more power, you whisper you get less.  At least thats how its showing on my SWR meter and my power supply amp meter.  The CEC firmware can already do WSPR on its own with a push of the PTT button.  What if we implemented a tune feature that just produced a 700khz tone on SSB and you can vary the output power by simply (I assume) changing the output voltage/duty cycle of the tone.  Thinking it would go something like this, Change mode to tune, Push PTT to send a tone,  In the software it will change the duty cycle to generate 1W out on the band you are on.  On 40m that may be a 10% duty cycle where on 20m it may be 60%.
 
For me I am OK at best with hardware mods and a better coder.  Now off to clone CEC firmware repo to see if it can be done.
 

Re: ubitx first power up

Latham, Chip
 

I am having transmitter problems with uBitx V3. Are there any test points and voltage and frequency values posted anywhere? Info would be very helpful. Output is so low I can’t measure it.

Thanks

N5FJK “Chip”

 

 

Re: Mobile operation (uBITX on car)

Peter Aiea
 

Interesting. Q : can the +5v pin on the Arduino nano be tapped for the mod instead of using a 7805?

On Jun 12, 2018 19:56, <david.parra@...> wrote:
Hi!

I remember a few weeks ago i read something about some problems with the AF amp and 13.8V power sources (shame on me, i can't find it again). It's safe to use a 13.8V source? I want to mount a ubitx on my car for mobile operation.

73 from Santiago de Chile,

David - CA3DPV


Re: Mobile operation (uBITX on car)

ajparent1/KB1GMX
 

I'd keep the audio and the digital power seperate so digital noises do not find their
way into the audio.   As is the digital 7805 runs warm so extra load is not helping
that.

Allison

Re: Learning Arduino

jazzymike
 

Hello Ken,
I also signed up for the course. Course starts on the June 18. Thanks for passing that info on to the group.

Mike, AA5EJ




Sent from my Verizon, Samsung Galaxy smartphone

-------- Original message --------
From: Paul Galburt - K2AYZ <galburt@...>
Date: 6/13/18 11:13 AM (GMT-05:00)
To: BITX20@groups.io
Subject: Re: [BITX20] Learning Arduino

Thanks, Ken

I signed up for the course. I have done Arduino programming but I am no ninja. I hope I can make 7AM :)

73,

Paul - K2AYZ

Unused pins

brad martin
 

Is there any unused pins in the stock raduino with the stock lcd screen other than a7. I’m looking for a digital pin preferably with PWM that’s unused. 

Brad

Re: Latest Build, Mods and results.

K9HZ <bill@...>
 

Digital power adjustment.  Several ways. 

 

Dr. William J. Schmidt - K9HZ


On Jun 13, 2018, at 9:55 AM, Roy Appleton <twelveoclockhigh@...> wrote:

What's already there????
 
Roy
WA0YMH

On Wed, Jun 13, 2018, 9:15 AM K9HZ <bill@...> wrote:
Check uBITx.net.  Already there. 

 

Dr. William J. Schmidt - K9HZ  


On Jun 13, 2018, at 12:07 AM, brad martin <emclinux@...> wrote:

Isn’t there a pot that controls the output power? If so you could make a low power switch that is just adding a resistor in parallel or series depending on the circuit. I’m just walking and thinking here so don’t have the schematic easy to get.

Brad
On Tue, Jun 12, 2018 at 6:47 PM Nick VK4PLN <nickpullen@...> wrote:
Ah, too easy, I was hoping it was done via software and able to TX a much lower power carrier for tuning, not the full 15W...
Any ideas and thoughts?

 

 

 

 

Re: Unused pins

Don, ND6T
 

Yes, indeed! D0 and D1. The information is found here. 73, Don

Re: Learning Arduino

Ken Frazer
 

Paul,
You don’t have to get up at 7:00, that is just the time that the course is first available. It is stored streaming that you can watch anytime that’s convenient for you.

Ken
KE5JCB

On Jun 13, 2018, at 9:13 AM, Paul Galburt - K2AYZ <galburt@...> wrote:

Thanks, Ken

I signed up for the course. I have done Arduino programming but I am no ninja. I hope I can make 7AM :)

73,

Paul - K2AYZ

Help needed.

Tom Cooper
 

I have a V3 uBITX and would like two resistance measurements from someone else's for comparison. 

I would like to know the power-off resistance to ground from a TX voltage connection and an RX voltage connection.

If you can oblige, many thanks!

Tom W1EAT

Ubix & case for sale

chris gress <Chrisg0wfh@...>
 

I am selling my Unix untouched kit and untouched case both boxed case came from sunil lakhani is red UK will ship to euro land if postage covered selling for what they cost me £123.27 post free in the UK contact chris g0wfh tel 07482429329
Email chrisg0wfh at gmail . com to much work and no time for the kit thanks chris

Re: Transmitter Mods

Rob Snow
 

I wanted to follow-up to the group with my experience with this mod.  It's fantastic, thank you Howard!  I lack any proper test gear outside of a cheap multimeter so signal reports are my test gauge and they have improved dramatically (FT8) on 20M and below.

The teepee was a bit of an adventure with my old eyes and shakes, but some +3.0 glasses and a splash of vodka helped things along.

73 Rob AG5OV


Parts info
Parts I sourced myself from DigiKey by trying to match Howard's parts, reading some and a bit of guessing.  I'd like to hear from someone more knowledgable if I picked decent ones.

Inductor:
MLF2012C270KT000
445-1064-1-ND
FIXED IND 27UH 5MA 1 OHM SMD

Cap
08051A271FAT2A
478-10391-1-ND
CAP CER 270PF 100V NP0 0805

Re: Transmitter Mods

Howard Fidel
 

Nothing wrong with your choices.

Howard

On 6/13/2018 9:46 PM, Rob Snow wrote:
I wanted to follow-up to the group with my experience with this mod.  It's fantastic, thank you Howard!  I lack any proper test gear outside of a cheap multimeter so signal reports are my test gauge and they have improved dramatically (FT8) on 20M and below.

The teepee was a bit of an adventure with my old eyes and shakes, but some +3.0 glasses and a splash of vodka helped things along.

73 Rob AG5OV


Parts info
Parts I sourced myself from DigiKey by trying to match Howard's parts, reading some and a bit of guessing.  I'd like to hear from someone more knowledgable if I picked decent ones.

Inductor:
MLF2012C270KT000
445-1064-1-ND
FIXED IND 27UH 5MA 1 OHM SMD

Cap
08051A271FAT2A
478-10391-1-ND
CAP CER 270PF 100V NP0 0805


Re: KD8CEC uBITX firmware 1.071 #ubitx

Michael Shreeve
 

I had that problem with another update at one time. The answer is calibration. For the most part you can bring everything into spec by adjusting the BFO (carrier oscillator)/ The object is to do the calibration as spoke of in HFsignals.com here . http://www.hfsignals.com/index.php/ubitx-tuneup/
This may be considered to be a "rough" calibration. After doing that, go to a sideband signal, for which you know the frequency, and whether it is upper or lower, set the correct ssb mode, go to calibration mode again, adjust the bfo. You should be able to clear it up . Then, go to WWV 10 MHz , or perhaps 15, and set the master clock again so the audio frequency and sound is the same regardless of whether your on upper or lower sideband. You'll then be on frequency. With correct sidebands. About the only thing you might need to do after that is set the BFO for sound has the  the correct tonal quality. Most of the time you will have adjusted it so has to much base.  

Re: KD8CEC uBITX firmware 1.071 #ubitx

Michael Shreeve
 

I've read Ian recommends manager for alignment. At least with his software. Not sure the instructions at hfsignals would work for Ians software, and using his instructions for alignment would be very important. 

How hot is too hot? #ubitx

Bo Barry
 

Anyone put their finger on the 7805 regulator on the randuino board?  13v in, 5v out isn't optimum for it. I attached a huge heatsink and now I can at least count to 10 with my finger on it. :)
Also I cut the red line in the USB cable so the power off switch worked on everything. As is, it was providing 5v from the PC, along with the 7805 regulator in the rig.
The tiny raspberry pi 5v fan seems to be working fine.
Bo W4GHV

Re: How hot is too hot? #ubitx

MVS Sarma
 

With 13.8V , perhaps the temperature goes high as 70 Celsius. It is always a good idea to sink the heat,.
it was manageable w/o heatsink at 12V but not 13.5 or 13.8.

Regards
MVS Sarma
 

On Thu, Jun 14, 2018 at 8:59 AM, Bo Barry <bobarr@...> wrote:
Anyone put their finger on the 7805 regulator on the randuino board?  13v in, 5v out isn't optimum for it. I attached a huge heatsink and now I can at least count to 10 with my finger on it. :)
Also I cut the red line in the USB cable so the power off switch worked on everything. As is, it was providing 5v from the PC, along with the 7805 regulator in the rig.
The tiny raspberry pi 5v fan seems to be working fine.
Bo W4GHV


Re: How hot is too hot? #ubitx

Skip Davis
 

Bo I found the same thing what I did was to add a 47 ohm resistor in the 12vdc into the regulator. I added it on the Raduino board and now I can hold my finger on the regulator without burning my finger. I just cut the trace from pin 15&16 on the Raduino and wired in a 1/4 watt resistor.

Skip Davis, NC9O 

On Jun 13, 2018, at 23:29, Bo Barry <bobarr@...> wrote:

Anyone put their finger on the 7805 regulator on the randuino board?  13v in, 5v out isn't optimum for it. I attached a huge heatsink and now I can at least count to 10 with my finger on it. :)
Also I cut the red line in the USB cable so the power off switch worked on everything. As is, it was providing 5v from the PC, along with the 7805 regulator in the rig.
The tiny raspberry pi 5v fan seems to be working fine.
Bo W4GHV