Date   

Re: minimum supply voltage

Jerry Gaffke
 

The board is designed to operate at 12v.
I doubt it will work very well at 6v.

That said, in answer to your question, an LM2940-5 has a lower dropout voltage than the LM7805:
  http://www.ti.com/lit/ds/symlink/lm2940c.pdf
  http://www.ti.com/lit/ds/symlink/lm340.pdf

The "Dropout Voltage" at the bottom of page 5 of the LM2940c datasheet says worst case at 1 Amp is 1 Volt.
But the Raduino pulls far less than 1 Amp, likely well under a half volt.  So would work with 5.5v going in.

Near the bottom of page 6 of the second datasheet above (covers both LM340 and LM7805)
it says the "Dropout Voltage" is "typically" 2 volts at 1 Amp, they don't give a worst case.
Will probably be less than 2v since the Raduino is not pulling much current, but you'd be on very
shaky ground if trying to feed it only 6v.

Jerry, KE7ER


On Thu, Apr 26, 2018 at 09:35 am, vajra guru wrote:
Have received my uBITx but haven't started assembling yet... I was thinking along similar lines, using 6V to power the board, and using 24V for the PA... Does it make sense to change out the 7805 voltage regulator for something different to make this work? Thx, Calvin VE3EIT


Re: No PTT

Jerry Gaffke
 

That's how we all learn!

Might be time to place an order for a new Nano such as one of these, the first one comes with the Mini-B USB cable:
    https://www.banggood.com/ATmega328P-Arduino-Compatible-Nano-V3-Improved-Version-With-USB-Cable-p-933647.html?rmmds=buy&cur_warehouse=CN
    https://www.banggood.com/ATmega328P-Nano-V3-Controller-Board-Compatible-Arduino-p-940937.html?rmmds=buy&cur_warehouse=CN
    http://www.oddwires.com/nano-3-low-cost-arduino-compatible-assembled-and-with-cable/
With Banggood, selecting the "CN" warehouse means it is shipped from China, they also have US and UK warehouses for some items.
There are cheaper sources, though I don't mind giving an established vendor an extra dollar
on the assumption that they do a better job of quality control, might save me a day of hair pulling.
I suggest you get two or three Nano's, they are very fun to play with.

Once you can download firmware to the Nano using the step by step instructions provided in this forum,
it is very easy to make minor adjustments to example programs and have the Nano do new tricks.
It may take some time to get a host computer set up with the Arduino IDE, and configured to
talk to the Nano over a USB cable.  But it is a very valuable and useful learning experience.
Even if your Nano did not blow, you would want to do this so you can upgrade the firmware
to some of the newer and better uBitx firmware described in this forum.

Make sure you get a good Mini-B USB cable for your Nano.
Many such cables only have power and ground wires for charging a cell phone perhaps, no data lines.

Some folks have been socketing the Nano when they add it to the Raduino
so it's easier to swap the next time it blows.

The Nano is easier to program than a ZX81, I had one of those back in the early 80's.
Best of all, with the Nano you won't need to find a cassette tape deck that still works.

Jerry, KE7ER


On Thu, Apr 26, 2018 at 09:26 am, Geoff Theasby wrote:
It is entirely possible that 12 volts has been inappropriately applied. I did find the odd wiring error.
It was working, briefly, immediately after 'tune up'. So I have no doubt it was shipped in working order.  
I shall apply your idea for pull-up resistors (Tomorrow - I am rather tired now)


Re: ND6T AGC implementation for uBIT-X

 

Ditto, size 1206 SMD would be nice.

Joel
N6ALT


Re: ND6T AGC implementation for uBIT-X

Kees T
 

I figure a bare PC board could be sent in the USA for $1. postpaid....... and a complete kit of parts for $3. postpaid as long as it can be mailed in a letter envelope and we avoid PayPal fees.  

73 Kees K5BCQ


Re: Let the magic smoke out of my bitx40

Allard PE1NWL
 

On Thu, Apr 26, 2018 at 10:13 am, <davesters@...> wrote:
I think I am going to increase the delay in the stepping. So I can keep up with it better.
You can easily increase the delay at line 70:

49// Function Button
#define CLICK_DELAY 1500          // max time (in ms) between function button clicks


Re: minimum supply voltage

Jack, W8TEE
 

I thought the input voltage (e.g., 7V) had to be at least 2V greater than the output voltage (5V), or is that only for buck converters. (Software guy here...not hardware.)

Jack, W8TEE


On Thursday, April 26, 2018, 12:35:48 PM EDT, vajra guru <vajraguru99@...> wrote:


Have received my uBITx but haven't started assembling yet... I was thinking along similar lines, using 6V to power the board, and using 24V for the PA... Does it make sense to change out the 7805 voltage regulator for something different to make this work? Thx, Calvin VE3EIT

On Thursday, April 26, 2018, Skip Davis via Groups.Io <skipnc9o=yahoo.com@groups.io> wrote:
Sarma, if we look at setting up the uBITX for a minimal supply voltage operation we will need to also include minimal dropout regulators to the RF amplifier stages too. Then the resistors values will need to be recalculate for all stages to maintain the gain throughout the bidirectional RF amplifiers. This sounds like an interesting idea try.

Skip Davis, NC9O 

On Apr 26, 2018, at 01:20, Mvs Sarma <mvssarma@...> wrote:

We need to study the minimum voltage needed for relay operation. If we can change the relays to5V type, and use a LDO regulator on raduino, we can work at 6V battery for the rig except that we may have to provide higher voltage for the HF linear  final section. May be, the bias arrangements of the pre-amp, driver and power amp need to be tweaked.

regards
 sarma
 vu3zmv

Regards
MVS Sarma
 

On Thu, Apr 26, 2018 at 12:24 AM, Matthew Stevens <matthew@...> wrote:
Apologies if this has been answered before, but I can't find it anywhere. I know the max recommended supply voltage is 15v. But, what is the minimum recommended? I have a 9.9v lithium pack I was thinking about re-purposing for a /p power supply.

73

--
- Matthew nj4y






Re: Let the magic smoke out of my bitx40

_Dave_ AD0B
 

Thank you so much for the concise list of instructions. I had most of it figured out but obviously had not figured out that I didn't need need the red wire.

I actually blew out a second arduino when I touched the function button with the unit turned off. Must have had a cap discharge, the display went on for a second and the second nano quit. 

As a precaution I put a 1k resistor between the ground and the function switch. 

I think I am going to increase the delay in the stepping. So I can keep up with it better. Would like to try a ten turn pot. 

Am learning ditties so that will be implemented later on. 
Regards 
Dave
K0MBT


Re: Let the magic smoke out of my bitx40

Allard PE1NWL
 

On Thu, Apr 26, 2018 at 06:52 am, <davesters@...> wrote:
I like this version of the firmware. I put in switch to calibrate the frequency, no more poking a bare wire into the power supply connection. I also added a function switch.
Glad you like the software!
Actually with this software you no longer need the red 'calibrate' wire (or switch) at all. The same calibrate function can also be accessed via the SETTINGS menu (keep the Function Button pressed for 3 seconds):

   SETTINGS menu:
   1 short press: Set the 4 scan parameters (lower limit, upper limit, step size, step delay)
   2 short presses: Set the 6 CW parameters (key type, auto-space, touch sensitivity, semi-QSK on/off, QSK delay, sidetone pitch)
   3 short presses: LSB calibration
   4 short presses: USB calibration
   5 short presses: Set VFO drive level in LSB mode
   6 short presses: Set VFO drive level in USB mode
   7 short presses: Set tuning range parameters (minimum dial frequency, max dial freq, tuning pot span)
   long press: exit SETTINGS menu - go back to NORMAL menu

73 Allard PE1NWL


Re: ND6T AGC implementation for uBIT-X

Jonathan
 

I was wondering the same thing.  I'd like a bare PCB for this mod too.

-Jonathan


Re: minimum supply voltage

_Dave_ AD0B
 

I have powered the bitx40 with a 3 cell lipo. Never dropped it below 11.4. 


Re: minimum supply voltage

vajra guru
 

Have received my uBITx but haven't started assembling yet... I was thinking along similar lines, using 6V to power the board, and using 24V for the PA... Does it make sense to change out the 7805 voltage regulator for something different to make this work? Thx, Calvin VE3EIT


On Thursday, April 26, 2018, Skip Davis via Groups.Io <skipnc9o=yahoo.com@groups.io> wrote:
Sarma, if we look at setting up the uBITX for a minimal supply voltage operation we will need to also include minimal dropout regulators to the RF amplifier stages too. Then the resistors values will need to be recalculate for all stages to maintain the gain throughout the bidirectional RF amplifiers. This sounds like an interesting idea try.

Skip Davis, NC9O 

On Apr 26, 2018, at 01:20, Mvs Sarma <mvssarma@...> wrote:

We need to study the minimum voltage needed for relay operation. If we can change the relays to5V type, and use a LDO regulator on raduino, we can work at 6V battery for the rig except that we may have to provide higher voltage for the HF linear  final section. May be, the bias arrangements of the pre-amp, driver and power amp need to be tweaked.

regards
 sarma
 vu3zmv

Regards
MVS Sarma
 

On Thu, Apr 26, 2018 at 12:24 AM, Matthew Stevens <matthew@...> wrote:
Apologies if this has been answered before, but I can't find it anywhere. I know the max recommended supply voltage is 15v. But, what is the minimum recommended? I have a 9.9v lithium pack I was thinking about re-purposing for a /p power supply.

73

--
- Matthew nj4y






Re: No PTT

Geoff Theasby <geofftheasby@...>
 

Hi Jerry,

It is entirely possible that 12 volts has been inappropriately applied. I did find the odd wiring error.

It was working, briefly, immediately after 'tune up'. So I have no doubt it was shipped in working order. 

I shall apply your idea for pull-up resistors (Tomorrow - I am rather tired now)


Thank you again,
Geoff

On 26 April 2018 at 15:38, Jerry Gaffke via Groups.Io <jgaffke@...> wrote:
You are correct, the encoder switches are wired to the two pins on the upper right
of the Raduino.

This is really weird.
The "LSB A 7.150" suggests the Raduino is mostly working correctly.
We've seen Nano input cells get blown like this, but usually happens when somebody
wires something up wrong and maybe puts 12 volts on a Nano pin somehow.
I believe the Raduino gets checked out before leaving hfsignals.

You might try adding 4.7k pullup resistors (anything between 1k and 10k will do)
from each encoder signal to the Raduino's 5v rail.
So add a resistor at the 8 pin connector on the front of the board from the pin on the
upper right at the 8'th pin location (has a black wire, one of the encoder signals)
to the 6'th pin in from the right (has a green wire, tied to 5 volts.
Add another resistor from the second in in from the upper right (brown wire, 
second encoder signal) to the 6'th pin in (green wire, 5 volts).
This might fix the problem with the encoder if all that is failing is the Nano's
internal 30k pullup resistors, but the Nano's input buffers are still ok.

You can extract unused wires from the cable harnesses by pressing
the retaining clip of the pin through the hole in the white connector shell
while tugging gently on the wire.  That avoids any possibility of wires flying
around and touching things they should not.  Alternately, put tape over the
ends of all unused wires.

Anything you do to make this thing work is not cheating in my book.
Good luck!

Jerry


On Thu, Apr 26, 2018 at 06:36 am, Geoff Theasby wrote:
Set up as before, reads "LSB A 7.150". No voltage detected at the pins in question. Checking with the ohmmeter (Raduino switched off) at the encoder shows continuity on-off-on-off as the knob is turned. Both pins similar, but out of phase of course. 
So, no volts from Raduino. (Display facing up, using the two pins at extreme right)



ND6T AGC implementation for uBIT-X

Kees T
 

It appears that the ND6T implementation of an AGC fix for the uBIT-X is a winner. 

He describes a simple X-Acto knife cut PC board for layout. Is anyone thinking of providing a small 2 sided PC board w/wo all the parts ?

73 Kees K5BCQ


Re: No PTT

Jerry Gaffke
 

You are correct, the encoder switches are wired to the two pins on the upper right
of the Raduino.

This is really weird.
The "LSB A 7.150" suggests the Raduino is mostly working correctly.
We've seen Nano input cells get blown like this, but usually happens when somebody
wires something up wrong and maybe puts 12 volts on a Nano pin somehow.
I believe the Raduino gets checked out before leaving hfsignals.

You might try adding 4.7k pullup resistors (anything between 1k and 10k will do)
from each encoder signal to the Raduino's 5v rail.
So add a resistor at the 8 pin connector on the front of the board from the pin on the
upper right at the 8'th pin location (has a black wire, one of the encoder signals)
to the 6'th pin in from the right (has a green wire, tied to 5 volts.
Add another resistor from the second in in from the upper right (brown wire, 
second encoder signal) to the 6'th pin in (green wire, 5 volts).
This might fix the problem with the encoder if all that is failing is the Nano's
internal 30k pullup resistors, but the Nano's input buffers are still ok.

You can extract unused wires from the cable harnesses by pressing
the retaining clip of the pin through the hole in the white connector shell
while tugging gently on the wire.  That avoids any possibility of wires flying
around and touching things they should not.  Alternately, put tape over the
ends of all unused wires.

Anything you do to make this thing work is not cheating in my book.
Good luck!

Jerry


On Thu, Apr 26, 2018 at 06:36 am, Geoff Theasby wrote:
Set up as before, reads "LSB A 7.150". No voltage detected at the pins in question. Checking with the ohmmeter (Raduino switched off) at the encoder shows continuity on-off-on-off as the knob is turned. Both pins similar, but out of phase of course. 
So, no volts from Raduino. (Display facing up, using the two pins at extreme right)


Re: ubitx-VE1BWV/VU2SPF TIPS

Rob Bleumer <Bleumer@...>
 

Could you tel me where you got the TFT display  or the spec's.
Thanks!
Rob PA0RBL


Let the magic smoke out of my bitx40

_Dave_ AD0B
 

Just had put in  the allard software  and was making an adjustment on the calibration. 
I had not put in a calibration switch so I was touching the red wire to ground. After a few trials I inadvertently touched it to the 13v input. The display stayed on for a second then then got crinkled and stopped displaying data.

It had blown the nano. I had a new nano in my drawer so I cut off the original nano and pulled the pins one at a time. To make it easier to swap. I put in a socket on the driver board. Mounted the new nano to the other side and soldered the pins on the opposite side so that the orientation was maintained. 

I like this version of the firmware. I put in switch to calibrate the frequency, no more poking a bare wire into the power supply connection. I also added a function switch.


Re: Protoneer Nano-Arm #ubitx

Jack, W8TEE
 

It is not a drop-in replacement. It would be a mistake to put 5V on any of the pins, although the internal regulator can handle it. Also, even something as simple as printing "Hello World" is a little different:
void setup(){
  SerialUSB.begin(9600);
  while(!SerialUSB){
    ;
  }
}

void loop(){
  SerialUSB.print("Hello World");

Note the use of the SerialUSB object instead of just Serial. Also, like the Arduino Due and Zero, you need a "while spin" for the COM link to establish itself. Most things are the same, but you should expect a few gotchas along the way.

Jack, W8TEE

On Thursday, April 26, 2018, 9:38:03 AM EDT, W2CTX <w2ctx@...> wrote:


A friend of mine did not think this is a "drop-in" replacement. 

I checked the pin-out and looks like SDA and SCL are different?

I also wonder if being 3volt rather than 5volt chip is a problem?


Correct me if I am wrong.


rOn



Re: Protoneer Nano-Arm #ubitx

W2CTX
 

A friend of mine did not think this is a "drop-in" replacement. 

I checked the pin-out and looks like SDA and SCL are different?

I also wonder if being 3volt rather than 5volt chip is a problem?


Correct me if I am wrong.


rOn



Re: motherboard photo #bitx40help #bitx40

SaMa photo SaMa photo
 

Thanks William
but this is not the bitx40 card

Sergio


Re: No PTT

Geoff Theasby <geofftheasby@...>
 

Hi Jerry & John,

Set up as before, reads "LSB A 7.150". No voltage detected at the pins in question. Checking with the ohmmeter (Raduino switched off) at the encoder shows continuity on-off-on-off as the knob is turned. Both pins similar, but out of phase of course. 
So, no volts from Raduino. (Display facing up, using the two pins at extreme right)

Regards
Geoff

On 26 April 2018 at 12:19, John <vk2eta@...> wrote:
Hello Geoff,

Yes Jerry's point is quite right. You will need to setup the Arduino development program in any case to reprogram the new Nano.

So you may as well do that now and load the diagnostic software to check if your Arduino is working as expected or not.

I will get that software ready tomorrow regardless, because I think it should be a tool available to the kit builders.

Let us know what you find in the mean time.

All the best,

73, John