Date   
Bitx 40 - My Raduino doesn't look like the others #bitx40 #radiuno #bitx40help

Jim Miller
 

I'm wiring up my newly unboxed BitX40 and the back of my Raduino (adruino uno) does not look like the website http://www.hfsignals.com/index.php/2017/11/23/wiring-up-the-bitx40/

I've attached two photos, and what I _think_ is correct?

Anyway, I would appreciate it if I could get some confirmation before I potentially release the magic smoke.


Thanks,
Jim

Re: UbitX I2C GPIO Breakouts?

AA9GG
 

I managed to get a few free samples of the PCF8574N from TI.  It is an I/O expander I2C - 8bits in a 16DIP package.  It is basically the chip used on the I2C LCD piggyback boards. I keep you posted.

On Thu, Apr 19, 2018 at 12:03 PM, Gerry Hull <gerry@...> wrote:
Understood.  I’m wanting to put transverters in my ubitx; would love to control the I/O switching, as well as have the display show the transverted frequency. So, these would not be signals that needed to be switched rapidly.   I would not use it to key CW, but I might use these I/Os for a keying sequencer.

Gerry, W1VE



On Thu, Apr 19, 2018 at 12:45 PM Jerry Gaffke via Groups.Io <jgaffke=yahoo.com@groups.io> wrote:
Could work fine.
The library to speak i2c is already getting loaded for the si5351.

Primary issue I see is that i2c links take a millisecond or so,
vs under a microsecond for direct access of an IO pin.
At some point as we load up the Nano with i2c peripherals, it will get bogged down.
This applies to i2c displays as well.
Hasn't been an issue yet.

Another possible issue is that the common i2c bus provides an easy way
for RFI and birdies to find their way into the receiver.

Jerry, KE7ER


On Thu, Apr 19, 2018 at 09:28 am, Mark Kesner wrote:
Looks like a great idea to me.  I googled the mentioned boards and there is a lot of info on how to use these.  Sparkfun has breakout boards for a similar device for $5 as well as examples and links to the library, etc.

I guess it depends on the firmware you are using and whether there is room to load the library. (?)

Thanks!

Mark
KC4GIA




--
Paul Mateer, AA9GG
Elan Engineering Corp.
www.elanengr.com
NAQCC 3123, SKCC 4628

Re: Replacement for the blown tda2822

Doug W
 

Ron,
A quick glance at BITXmap.com shows there are more ZLs than you might think.  Although it looks like Christchurch would make you the first from the South Island.

Re: uBITX shipping time

Doug W
 

On Thu, Apr 19, 2018 at 11:50 am, <hotrod541@...> wrote:
What software is best to install?
The rig ships with a perfectly functional sketch installed.  I recommend you get it all put together and fully tested before trying any of the other sketches or modifications floating around.

Re: Tx frequency selection for FT8 on BITX40 running Allard's sketch #bitx40

Tim Gorman
 

I believe you are transmitting an audio tone through a SSB transmitter.
If your freq dial is set to 7.074.000 and you are sending a 1khz audio
tone you will actually be transmitting on 7.075.000 (i.e. 7074000 +
1000).

tim ab0wr

On Thu, 19 Apr 2018 06:33:56 -0700
"Doug W" <dougwilner@...> wrote:

On Thu, Apr 19, 2018 at 03:09 am, Vic WA4THR wrote:


There may be a misunderstanding of how the digital modes work with
today's computer software.
Thank you for the reply but your answer does not address the
question.  I have a clear understanding of the receive function which
you describe quite well.  The question was are you transmitting right
on 7.074.000 or are you offsetting that at all?

Franken-uBitx (no Raduino, and apologies to Mary Shelley :-)

Mark Pilant
 

Never one to take the easy road, I thought I'd share my progress so far
with building up my uBitx. I call it my "Franken-uBitx" because it is
made up from a lot of different parts I had laying around. :-) :-)

So far, my Franken-uBitx consists of the following:
1) An unchanged uBitx main board (no Raduino used)
2) An Adafruit 2050 3.5 inch (320 x 480) TFT touchscreen
3) An Adafruit 2045 Si5351 Clock Generator Breakout board
4) Meduino Mega2560 Pro Mini board

as the major assemblies.

The software started out as the TFT_uBitx sketch by VU2SPF and VE1BWV.
I then made various changes to the code:
1) To more easily support the Meduino board (2 row pin headers
instead of single pins; but the board is about the size of an
Uno)
2) Support the TFT display
3) Support the encoder

Some of the other changes I have made (or am planing to make) are:
1) Added a socket for the TDA2822 chip
2) Separate fuses for the uBitx board and PA
3) Separate On/Off switch (and power on LED) and traditional
(shaft) sized volume control
4) Separate 5V regulator (with plus and minus power buss) to
power the Meduino, display, and Si5351 boards

All of this in a Hammond box I had around.

Right now, the sketch works with a nice touch screen interface as well
as all the clock frequencies generated. The next major step is to wire
up the 5V regulator and power buss. Then it is really nothing more than
connecting everything up. Then some final testing before getting on the
air.

In addition, I'll be documenting all of this (with pictures) for anyone
else to borrow from :-)

Oh yes, I also have another uBitx I plan to leave pretty much stock except
for changing the 2 line display to a 4 line display. That way I'll have
an easy way to do A / B comparisons.

Hopefully my project will add to the pool of things for others to try :-P

73

- Mark N1VQW

Re: Replacement for the blown tda2822

riparry@...
 

Hello Dex, There doesn't seem to be many ZLs building the uBitx so wonder if we could link up? I am in Christchurch 03 3389021
Cheers
Ron ZL3VX

Re: show your mic

Ashhar Farhan
 

What do you know! Mine is uglier than yours. 


On Thu, 19 Apr 2018, 22:53 Bill KC5SB, <blmerideth@...> wrote:
Here's mine.  I made it from an old 9 volt flashlight.

Re: proof readers needed for KD8CEC firmware manual

Vince Loschiavo
 

Rod

ill give it a go..

vince
n2aie

Re: uBITX shipping time

hotrod541@...
 

Ordered on March 14th and was delivered on 4-19-2018, 3 days after being notified by DHL.  Now if the case would come I will be happy person.  I need to download the construction manual, if I can find it.  What software is best to install?

Re: Transmitter Mods

Jerry Gaffke
 

The parallel resonance helps us to a point, though an ideal inductor would generally be better.
For example, if the inductor is self resonant at 14mhz, we'd see much more power out on 20m
than we see on 10m.  I'd prefer to keep gain vs freq somewhat controlled and predicatable.

The caps are easier to add, easier to obtain, have a higher self resonance:
    https://electronics.stackexchange.com/questions/193608/self-resonance-frequency-for-mlcc-capacitor
Maybe add 220pF caps across all six of the 22 ohm emitter resistors, and forget the inductor?
Then add a variable cap somewhere around Q90 that can be tweaked to give the flattest response,
that setting may vary given your particular 2n3904 transistor characteristics. 
 
But the inductor in series with the negative feedback is a good idea.
If this can all be done with just 3 extra components and get good enough results across
the different uBitx's out there, I'm fine with that.

One other issue:
As Henning notes in post 45035, the chokes L8 and L9 are best wound on a single core:
See the discussion below figure 4 on this webpage, where he discusses how the bifiliar
approach works, though he does not discuss the individual choke solution:
    http://ludens.cl/Electron/mosfetamps/amps.html
I was seeing significantly worse results in how the uBitx final worked compared
to the WA2EBY final in my LTSpice simulation, could be due to these chokes.
    https://groups.io/g/BITX20/topic/9615903
I may have to play with that further, not obvious to me how or if the individual chokes
at L8, L9 would impact the results..

Jerry, KE7ER


On Thu, Apr 19, 2018 at 11:00 am, Jerry Gaffke wrote:
Good question.
It's a parallel resonance:  
    https://www.everythingrf.com/community/what-is-self-resonant-frequency

Re: ubitx is available for $109, there are a3 catches

M Garza <mgarza896@...>
 

You will receive a message from PayPal with a tracking number when it ships.  They are running 4 to 6 weeks behind.

Marco - KG5PRT 

On Thu, Apr 19, 2018, 8:14 AM RMV <W8RMV@...> wrote:
Ashhar Farhan,
Made my payment weeks ago.  Haven't heard anything aside from the Paypal payment notification.  Do I ever get a confirmation from you/uBITX prior to shipment?
Thanx - Bob W8RMV

Re: Transmitter Mods

Gordon Gibby <ggibby@...>
 

Aha!!! 

Thanks.  Didn’t realize it was parallel. 

Much appreciated.  Learn something every day!

Gordon




On Apr 19, 2018, at 14:00, Jerry Gaffke via Groups.Io <jgaffke@...> wrote:

Good question.
It's a parallel resonance:  
    https://www.everythingrf.com/community/what-is-self-resonant-frequency



On Thu, Apr 19, 2018 at 10:55 am, Gordon Gibby wrote:
How is a series resonance 30,000 ohms?   
 
I’m kind of dumb, but I thought at series resonance , reactive components cancel and all that is left is the tiny ohmic resistance of the wire. 
 
What am I missing?
 

Re: Transmitter Mods

Jerry Gaffke
 

Good question.
It's a parallel resonance:  
    https://www.everythingrf.com/community/what-is-self-resonant-frequency



On Thu, Apr 19, 2018 at 10:55 am, Gordon Gibby wrote:
How is a series resonance 30,000 ohms?   
 
I’m kind of dumb, but I thought at series resonance , reactive components cancel and all that is left is the tiny ohmic resistance of the wire. 
 
What am I missing?
 

Re: Transmitter Mods

Gordon Gibby <ggibby@...>
 

How is a series resonance 30,000 ohms?   

I’m kind of dumb, but I thought at series resonance , reactive components cancel and all that is left is the tiny ohmic resistance of the wire. 

What am I missing?

Thanks

Gordon



On Apr 19, 2018, at 13:22, Howard Fidel <sonic1@...> wrote:

Gordon:
Very high, about 30 K. It actually helps us.

Howard

On 4/19/2018 1:03 PM, Gordon Gibby wrote:

​I found some on digikey with a self resonaance 40 Mhz or higher....


probably does matter.   At the self resonant point the series impeane will be very low....




From: BITX20@groups.io <BITX20@groups.io> on behalf of ohwenzelph via Groups.Io <Ohwenzelph@...>
Sent: Thursday, April 19, 2018 12:59 PM
To: bitx20@groups.io
Subject: Re: [BITX20] Transmitter Mods
 
does it matter that most 27uH inductors seem to have a self resonant frequency below 28MHz?


Re: ubitx is available for $109, there are a3 catches

K5ESS
 

No

 

From: BITX20@groups.io [mailto:BITX20@groups.io] On Behalf Of RMV
Sent: Thursday, April 19, 2018 8:15 AM
To: BITX20@groups.io
Subject: Re: [BITX20] ubitx is available for $109, there are a3 catches

 

Ashhar Farhan,
Made my payment weeks ago.  Haven't heard anything aside from the Paypal payment notification.  Do I ever get a confirmation from you/uBITX prior to shipment?
Thanx - Bob W8RMV

Re: show your mic

Bill KC5SB
 

Here's mine.  I made it from an old 9 volt flashlight.

Re: Transmitter Mods

Howard Fidel
 

Gordon:
Very high, about 30 K. It actually helps us.

Howard

On 4/19/2018 1:03 PM, Gordon Gibby wrote:

​I found some on digikey with a self resonaance 40 Mhz or higher....


probably does matter.   At the self resonant point the series impeane will be very low....




From: BITX20@groups.io <BITX20@groups.io> on behalf of ohwenzelph via Groups.Io <Ohwenzelph@...>
Sent: Thursday, April 19, 2018 12:59 PM
To: bitx20@groups.io
Subject: Re: [BITX20] Transmitter Mods
 
does it matter that most 27uH inductors seem to have a self resonant frequency below 28MHz?


Re: Transmitter Mods

Howard Fidel
 

That is a good question. In our application, the impedance is still high, it just becomes more capacitive then inductive. If you look at the impedance plot, the resonance is about 20 MHz, but the reactance at 30 MHz is still 2000 ohms, so the gain goes up. On the 15 meter band, it looks like 30K ohms, so the amp runs open loop.
The bottom line is that the design is not that robust to begin with, and what I have made is a patch. I would never have designed the signal path myself this way. I would have use an opamp to drive the transformer to replace everything from C80 to T10.
The fix works, and has been validated by others. It would be smaller, probably not cheaper, but robust.

Howard

On 4/19/2018 12:59 PM, ohwenzelph via Groups.Io wrote:
does it matter that most 27uH inductors seem to have a self resonant frequency below 28MHz?


Re: Tx frequency selection for FT8 on BITX40 running Allard's sketch #bitx40

Gerry Hull
 

Hi Doug,

Agreed.  I operate remotely from the Yukon as VY1AAA a lot... when on FT8, it generates Big pileups.  Those people who understand how to use split in FT8 get through faster.  Technique is still important.

I’m excited to try FT8 on the uBitX (which arrives Friday) from the home QTH in NH.  10w + FT8 has provided many DXCC in short order.

Gerry W1VE


On Thu, Apr 19, 2018 at 11:32 AM Doug W <dougwilner@...> wrote:
Thanks Gerry.  Interestingly enough I did some searching on the topic of operating FT8 in split mode.  Turns out it is a hotly contested topic in certain circles with very strong opinions on both sides.  I think it is time for me to shift from theoretical to practical and leave the details to the guy with the medal from Sweden.