Date   

Re: Arduino Hangs

John (vk2eta)
 

Howard,

Good test with the 2nd nano. 

Since the si chip gets its 3.3v supply from the nano, did you check that the si chip had the proper supply voltage, just to make sure?

73, John


Re: Harmonics

ajparent1/KB1GMX <kb1gmx@...>
 

Every so often the attachments get dropped and #57222 posting suffered that.


On Thu, Aug 16, 2018 at 08:01 AM, ajparent1/KB1GMX wrote:
For an experiment I took the cut up board removed all the backside signals and front side 
paths and put the removed relays on the back and rewired the filters in with plain wires on the top.
With a simple layout change for the relays to a only one active and with one three filters due to
being only three relays for the 80/40/20 filters produced good low pass function without blow by. 
With four (4) it would switch all of them quite fine. One other feature is only 1 relay powered at
and time.  Photo of schematic added.


Re: Please advise

ajparent1/KB1GMX <kb1gmx@...>
 

Build it,  Allow room for possible fixes and don't get too wrapped around the axle.

Take it all in steps.  Some I suggest like pop and click are advised.  The mic
compression is good just don't crank the gain for more power.

Power leveling the verdict is out, there are fixes to make it less an issue
and they are simple.

With reasonable care and not forcing power its likely to be an issue.

A lot of the fixes and mods are "in process" and once cooked enough
you can go that path should you choose.

Allison


Re: Please advise

Howard Fidel
 

Mitchell:
The jury is out on the harmonic and spur fixes.
I have the parts for my power improvement mod if you want them.
I suggest assembling the uBitx as is and trying it out before doing any mods.

Howard


On 8/16/2018 12:27 PM, mitchellmichaelh@... wrote:
I have a new V4 ubitx and have purchased a larger display, new arduino for it and will purchase the vfo board.
Is there a place that list required and suggested mods. I am especially concerned about the harmonic problems and the leveling power output.
I if its still necessary be adding agc and microphone compression. Also I have a requirement to lower power when tuning a switch or button will be great.

The problem I have is there are so many posts from different authors that its very confusing.Especially which software etc.



Re: Sunday

Daniel Conklin <danconklin2@...>
 

Jack, I'm getting about 4 watts output with 13.8v the way I have it currently configured. It's driven with a 2n7000 MOSFET. I'm wondering if the uBiTX could benefit from this because it requires lower drive levels from the LO. 
Dan  W2DLC 


Please advise

mitchellmichaelh@...
 

I have a new V4 ubitx and have purchased a larger display, new arduino for it and will purchase the vfo board.
Is there a place that list required and suggested mods. I am especially concerned about the harmonic problems and the leveling power output.
I if its still necessary be adding agc and microphone compression. Also I have a requirement to lower power when tuning a switch or button will be great.

The problem I have is there are so many posts from different authors that its very confusing.Especially which software etc.


Re: Modular uBitx - "Ex: Harmonics"

Jerry Gaffke
 

The "off the rails" thing was me, not Jack.
I hope this nips the potential for another issue to argue about.

>  Well, at least everybody agrees to argue.

I rest my case.   ;-)


> Seems everyone did not understand my post.  The SDR radio does require a PC and a sound card. 
> But I meant that you could hook the STM card to that radio and there is software to decode the IQ and do psk31.


It's possible to do all the computations required for SDR
in a high end ARM processor (such as a Teensy with FP hardware).
No PC required.    OK, we can productively argue about that.

Jerry



On Thu, Aug 16, 2018 at 08:33 AM, ajparent1/KB1GMX wrote:
As to off the rails. yes, you spoke the truth.  


Re: Harmonics

Kees T
 

In reference to my earlier 6 LPF board post you can cut off the last 2 LPFs, clean up the board cut, and make it a 4 LPF board which measures only 64mm x 83mm.

73 kees K5BCQ


Re: Arduino Hangs

Howard Fidel
 

All:
I hooked up another Nano and checked the outputs at A4 and A5 and found they only went up to 3.5V. The one I put in the Raduino pulled up to 4.5 volts. I hooked up the first Nano just to the SCL and data lines for the SI chip and get the right signals from the Nano, but nothing happens with the SI chip. My conclusion is the SI chip and the new Nano I installed are both defective. I ordered a SI breakout board from Adafruit. I will test it first with the Nano that works and then install both into the Raduino. Hopefully after that I will be back in business with my uBitx.

Howard



On 8/16/2018 10:08 AM, Jerry Gaffke via Groups.Io wrote:
Wrong.
From page 252 of Atmel-8271-8-bit-AVR-Microcontroller-ATmega48A-48PA-88A-88PA-168A-168PA-328-328P_datasheet_Complete.pdf
dated 11-2015, section 24.9.5:
"Note that ADC pins ADC7 and ADC6 do not have digital input buffers, and therefore do not require Digital Input Disable bits."

This is why a stock uBitx sends CW if you power up without an external pullup on A6.

Jerry, KE7ER

On Thu, Aug 16, 2018 at 06:42 AM, Clark Martin wrote:
The “analog” pins, Arduino numbering A0-A7, are PORTC and can be used as digital IO or analog.  Any limitations (if any) area due to the Arduino development environment, specifically the pin I/O calls.

Clark Martin
KK6ISP



Re: Modular uBitx - "Ex: Harmonics"

ajparent1/KB1GMX <kb1gmx@...>
 

Jack,

It is and it isn't.  Context and presentation is everything.
As to different, you implied a MPU or PC is a must.  I said
it is not a must and provided  examples.

As to off the rails. yes, you spoke the truth.  If I point out you were
already off the rails, that is conveniently forgotten.   This is BITX
not SDR, at this point we have been off the rails for a while.   
So the semantic games and  protests are meaningless.

I really don't care if XYZ SDR uses a PC or not.  Ihat it does reuire one in
my mind is a flaw as its not a radio if and until the PC is operational as until
then it  has no features or function.

Allison


Re: BITX40 output power at 36 volts to the IRF510 #bitx40 #bitx40help

ajparent1/KB1GMX <kb1gmx@...>
 

>>Have a look at a 25 Watt amp by VK3XU at http://www.philipstorr.id.au/radio/seven/five/25%20Watt%20Amp.pdf
Looks a bit simpler to build than the WA2EBY amp.<<

It is simpler and doesn't work near as well.  Also it bets on the mosfets having
the same gate voltage threshold or a hand picked pair.  If they are not one will
run hotter and the 2nd harmonic output will be higher (cleans up with a filter).

Allison


Re: Modular uBitx - "Ex: Harmonics"

Jack, W8TEE
 

Allison:

You said my statement was "not totally true" when it was. In the second quote below, you imply that was my statement when in fact it was taken from the web site of the product being discussed. You then rambled on about something altogether different. Your statement about my quote was simply wrong and unwarranted. End of story, no more wasted bandwidth.

Jack, W8TEE


On Thursday, August 16, 2018, 11:11:24 AM EDT, ajparent1/KB1GMX <kb1gmx@...> wrote:


>>Except its not totally true.  I have two radios that do not even have a mcu and the
I and Q are processed as analog, they are high performing radios that are 
battery friendly.   Then again my Hallicrafters HT37 did it with tubes, and still does.<<

Jack, did you forget that item as the first paragraph.

And you double down with:

>>The I and Q signals must be provided/processed by external signal processing which could be a PC running Software Defined Radio software or a stand-alone digital signal processor <<

While it is absolutely true for that radio its not a absolute requirement.
Radios exist without a computer to do that! such as QRPlabs  QCX, The 4030 and few others.

My point being there is no requirent for a MPC to process I and Q and not any further off
the rails anymore than talking about SDR under the thread of HARMONICS.

Allison
Allison

 


Re: Modular uBitx - "Ex: Harmonics"

ajparent1/KB1GMX <kb1gmx@...>
 

r0n,

It is generally accepted as true.  How about this?
SOFTRock Ensamble, usually used with computer!  Since I wanted portable I built up
two analog processsors (Nee KK7B R2pro) pu them in the audio path and Arduino in 
the path to run the Si70s and user interface (vfos and switching and stuff not DSP).
The result is |SDR|  where software is hardwired analog, without a PC (or a PC
substitute like a Rpi ).

If you have I and Q baseband audio this can be done. 

Allison


Re: uBitX CW bandwith

Dennis Yancey
 

The filter from qrp guys works nicely. Can also give you some adjustable  gain so you don’t drive the Tda2822 too high.
--
72 and God bless
KD4EPG


Re: Modular uBitx - "Ex: Harmonics"

ajparent1/KB1GMX <kb1gmx@...>
 

>>Except its not totally true.  I have two radios that do not even have a mcu and the
I and Q are processed as analog, they are high performing radios that are 
battery friendly.   Then again my Hallicrafters HT37 did it with tubes, and still does.<<

Jack, did you forget that item as the first paragraph.

And you double down with:

>>The I and Q signals must be provided/processed by external signal processing which could be a PC running Software Defined Radio software or a stand-alone digital signal processor <<

While it is absolutely true for that radio its not a absolute requirement.
Radios exist without a computer to do that! such as QRPlabs  QCX, The 4030 and few others.

My point being there is no requirent for a MPC to process I and Q and not any further off
the rails anymore than talking about SDR under the thread of HARMONICS.

Allison
Allison

 


Re: Modular uBitx - "Ex: Harmonics"

W2CTX
 

Seems everyone did not understand my post.  The SDR radio does require a PC and a sound card.

But I meant that you could hook the STM card to that radio and there is software to decode the IQ

and do psk31.


The STM card has 4" color touch screen, USB ports, uSD card, sound ports, and even built-in microphones

all for about $55.


rOn

On August 16, 2018 at 1:16 AM Glenn <glennp@...> wrote:

I have one of these boards.  It requires a PC plus an external sound card.

There was talk of another board to replace the PC part and display etc, but I don't think anything has come of that.
glenn vk3pe


Re: Harmonics

ajparent1/KB1GMX <kb1gmx@...>
 

On Wed, Aug 15, 2018 at 11:34 PM, iz oos wrote:
Isn't the single relay switching in the Codan similar to the Ubitx? Maybe do these Nais relays isolate better the inputs and the outputs of the filters than those in the Ubitx?
Yes, somewhat, and no.  The Codan does use a single relay per band filter.  The NAIS relay is marginally better.
The layout is far better with much greater use of copper pour on the topside and as I earlier pointed out a lot
of vias used to stitch(connect) the top and bottom ground layers.  They get a great deal of isolation in the layout
and that gets them the attenuation required.  Note they are only one filter per relay.

A reminder:
The uBitx filters in isolation are good.  The relays are adequate.  The layout is entirely the issue.

For an experiment I took the cut up board removed all the backside signals and front side 
paths and put the removed relays on the back and rewired the filters in with plain wires on the top.
With a simple layout change for the relays to a only one active and with one three filters due to
being only three relays for the 80/40/20 filters produced good low pass function without blow by. 
With four (4) it would switch all of them quite fine. One other feature is only 1 relay powered at
and time.  Photo of schematic added.

What has not been tried is using K3 to switch in the 30mhz filter on TX to create cascade of 
30mhz low pass after the lower frequency ones.  I believe with the right values for the filter
that can work and with none of the KTx relays enabled the 30mhz filter is in place.

Allison


Re: Modular uBitx - "Ex: Harmonics"

Jerry Gaffke
 

Oh boy, another argument!
Allow me to jump in here uninvited .....

Looking back through the thread I see the stuff included below where things went off the rails.

I'd agree with W2CTX that an STM32F746NG based thingie is not a PC, and
is perfectly capable of being included in a rig I can still easily pick up with one hand.

On the other hand, an old gumper like me is amazed at the power of such a device,
considerably more capable than what a PC was back when PC's were a hot topic. 

Jack did pipe up that a high end Teensy could well do the DSP processing
required to create a stand-alone radio.  So he knows a PC is not required.

So it seems everybody agrees.
Well, at least everybody agrees to argue.

Jerry



On Wed, Aug 15, 2018 at 08:24 PM, W2CTX wrote:

The STM32F746NG is a board not a PC.  The raduino is a board.

https://www.st.com/en/evaluation-tools/32f746gdiscovery.html

On August 15, 2018 at 11:09 PM "Jack Purdum via Groups.Io" <jjpurdum@...> wrote: 

Still not a standalone system and requires a PC to process the signals. The cost's not bad if it were self-contained. 
 
Jack, W8TEE 
 
On Wednesday, August 15, 2018, 11:04:35 PM EDT, W2CTX <w2ctx@...> wrote:

Experimentally already exists in the form of code running in a STM32F746NG

driving https://www.hobbypcb.com/rs-hfiq.

 


Re: Sunday

Jack, W8TEE
 

Dan:

What kind of output are you getting and any idea of how efficient it is. (I know Class E supposed to be very good.)

Jack, W8TEE


On Thursday, August 16, 2018, 8:35:54 AM EDT, Daniel Conklin <danconklin2@...> wrote:


I have a 40 meter CW transceiver in a class E configuration with one IRF510. Works well.
I have seen some hams using class E for AM too, which is interesting to me. 
Dan, W2DLC 


Re: Modular uBitx - "Ex: Harmonics"

Jack, W8TEE
 

"Except its not totally true."

Gees, Allison, read what I said for once: I said the unit mentioned still required a PC, which it does. You then wander down some lane talking about other radios that don't require a PC, not the one I was referencing. I know there are SDR units out there that don't require a PC. Indeed, I have one (Elad Duo) which I like very much. Before you jump on my back for making an incorrect statement, it might be good to first see if the criticism is warranted. In this case, at least, it is not.

Jack, W8TEE


On Thursday, August 16, 2018, 10:23:23 AM EDT, ajparent1/KB1GMX <kb1gmx@...> wrote:


On Wed, Aug 15, 2018 at 08:09 PM, Jack Purdum wrote:
Still not a standalone system and requires a PC to process the signals. 
Except its not totally true.  I have two radios that do not even have a mcu and the
I and Q are processed as analog, they are high performing radios that are
battery friendly.   Then again my Hallicrafters HT37 did it with tubes, and still does.

Further, I have the software running on Rpi3b (39$) and a 7" touch screen (39$)
for about a year now.  Not even original work as that was done on a Pi2 by
someone else. 

If that was not enough Kees had SDRtogo some two years ago using a 32mcu
I think was the PIC32.

PC required designs are out there.  Many are rejecting that and want fully
self contained and the low cost MCUs are there that can do that.

Allison