Problem with demaged BITX40
My second bitx40 came damaged. I found the broken T4 transformer wire, and I fixed it. TRX transmits but with weak power but I leave it to fix later. Unfortunately the reception is still poor but when I touch my finger the L3 ?of bandpass filter, reception is greatly improved, you can see it here . As I watch the coil bandpass filter seems that L2 has more turns than L1 and L3, it is similar to VFO L4. And here my question is how many turns on which core have the L1, L2, L3 bandpass filter coils and what are the characteristic data of the VFO L4 coil. I could unwrap a few turns of L4 to get L2 ( or L3, or L1 ) - it looks like L4 has the same core and same wire diameter ....
best regards
Tom
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Actually heard a station working a VK prefix, and I could just make out his reply. Nearly worked P33 Cyprus, but had to go off and do other things.
Lets start a DX challenge. So my 1st one is 1423km.
Phil-G7BZD
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I want to build the BITX40 with an enclosure that can house a battery. I am hoping that a 12v/7a or 12v/5a battery will be sufficient for a few hours of RX and TX. Is there any recommendations for the amp hours in a battery? What is the minimum amp hours I should consider?
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Perhaps the calibrate wire got shorted (to the 12v heatsink on the IRF510?) and blew the IO cell. ?Perhaps that IO cell is inside the mega328 ?in the Raduino's Nano is now sinking lots of extra current, dragging down the main 12v supply. ?The low 12v supply could cause problems with the audio amp. ?That's about the only reason I can see for these two problems to show up simultaneously.
On Sun, Mar 26, 2017 at 06:09 pm, College Professor Simon Thompson wrote: Everything was working until I tried to calibrate the Bitx40. I grounded the red wire from the Raduino, the calibration routine launched, I zero beat the received frequency, disconnected the ground path. And then the radio stated to motorboat, and the screen will not stop displaying "Calibration: Set to Zero Beath: XXXX" and then the message changes to "Calibration: Set Offest: XXXX," and then the radio starts motor boating and there is a shrill tone coming out of the speaker. I disconnected everything, the reloaded the sketch and library, and reconnected everything, but the same message comes up when I restart it.
?
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Re: How to contact Ashar to purchase a new Raduino/SI5351 board
Did you try teamhfsigs@... ?
That is the contact address included in the related paypal
messages..
I have not tried it though.
Bjorn
On 2017-03-27 17:31, Mark Underkofler
wrote:
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Does anyone know how to contact Ashar for the purchase of a
replacement Raduino/SI5351 board? ?My original BITX40
Raduino/Si5351 board never functioned. ?I purchased another
BITX40 kit and used the Raduino/SI5351 board in the 2nd kit to
make sure that was the problem. ?It was, and now I'd like to get
a new Raduino/SI5351 board to use in the radio I 'stole' the
board from.
Any suggestions would be appreciated.
Mark Underkofler W5MCU
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How to contact Ashar to purchase a new Raduino/SI5351 board
Does anyone know how to contact Ashar for the purchase of a replacement Raduino/SI5351 board? ?My original BITX40 Raduino/Si5351 board never functioned. ?I purchased another BITX40 kit and used the Raduino/SI5351 board in the 2nd kit to make sure that was the problem. ?It was, and now I'd like to get a new Raduino/SI5351 board to use in the radio I 'stole' the board from. Any suggestions would be appreciated. Mark Underkofler W5MCU
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Re: Bitx40 low volume oscillation squeal
To eliminate the audio squeal, try rearranging wires. ?Twist pairs that go together. ? Route all wiring away from the Raduino board. ?Neatly bundle unused wires and put them away from the wiring that is in use. ?This worked for me.
TW
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Interesting. When I put a scope on my Nano, it reads HIGH without a digitalWrite() call, which prevents the pin from floating. That said, mine is a clone, so perhaps there is a difference. As a rule, I do usually follow an INPUT_PULLUP for pinMode() with a digitalWrite(), but do that as a documentation courtesy. I'd be interested to know what someone sees with a "real" Nano.
Jack, W8TEE
From: DJ2AG <ya_duck@...>
To: [email protected]
Sent: Monday, March 27, 2017 10:41 AM
Subject: Re: [BITX20] Calibration route
Unfortunately the Arduino Digital Pin Tutorial is somewhat misleading ?in that it highlights the Pullup setup for older Arduino Versions in a box and only describes in the text how to do it the new way. The correct way to enable internal pullup, as Jack has written is:? pinMode(CAL_BUTTON, INPUT_PULLUP); but it has to be followed by a digitalWrite(CAL_BUTTON,HIGH); to actually connect the internal?pullup resistor to 5V.
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For hardware designed around a pin having a pullup with a
specific purpose, an additional external pullup is preferred to
counter programming error or other issue.? One less chance for a
typo to create havoc.
On 3/27/2017 10:41 AM, DJ2AG wrote:
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Unfortunately the Arduino Digital Pin Tutorial is somewhat
misleading ?in that it highlights the Pullup setup for older
Arduino Versions in a box and only describes in the text how to
do it the new way.
The correct way to enable internal pullup, as Jack has written
is:?
pinMode(CAL_BUTTON, INPUT_PULLUP);
but it has to be followed by a
digitalWrite(CAL_BUTTON,HIGH);
to actually connect the internal?pullup resistor
to 5V.
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It's not all that complicated to make sure you are programming the correct code into the Raduio.. ?I believe good working code similar to what got shipped with the kit can be found at ? ? and described in the thread ?/g/BITX20/topic/4479273? ? Make a minor change to the sketch, in this case perhaps the calibration message: ? ? ?old: ? ?printLine1("Calibrating: Set"); ? new:?printLine1("Calibrate: Set");
Compile and upload to the Raduino. ?If you see the new message, then you know the program is getting successfully loaded.
Weird that the Arduino's have occasional reports here of corrupted flash, and need to be reprogrammed. ?On most microcontrollers I've dealt with in the past this never comes up. ? Since Simon is not seeing a high of 5v ?on the calibrate wire, perhaps that wire got shorted to something and it blew the io cell. ?If so, and if adding a 1k pullup resistor from the calibrate wire to 5v does not help, I would try moving the calibrate pin in the Raduino sketch: ? ? old: ?#define CAL_BUTTON (A2) ? ? new: ?#define CAL_BUTTON (A0) and use the black wire on the 8'th pin of the connector for calibrate instead of the red wire on the 6'th pin.
Jerry, KE7ER #define CAL_BUTTON (A2) #define CAL_BUTTON (A2)
#define CAL_BUTTON (A2) #define CAL_BUTTON (A2)
Essentially, I think when you disconnected everything and reloaded, You either did not reload,
or you reloaded the same hex file as before.
?
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Unfortunately the Arduino Digital Pin Tutorial is somewhat misleading ?in that it highlights the Pullup setup for older Arduino Versions in a box and only describes in the text how to do it the new way. The correct way to enable internal pullup, as Jack has written is:? pinMode(CAL_BUTTON, INPUT_PULLUP); but it has to be followed by a digitalWrite(CAL_BUTTON,HIGH); to actually connect the internal?pullup resistor to 5V.
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Re: extra surface mount component
Well there you go! :-)) :-)) Roy,
WA0YMH
On Mar 27, 2017 9:19 AM, "Jerry Gaffke via Groups.Io" <jgaffke= [email protected]> wrote: I sent an email off to hfsigs asking about that extra SMD cap.? The answer: ?I should join the Bitx20 group and my technical queries will be solved.
On Sun, Mar 26, 2017 at 04:16 pm, Jerry Gaffke wrote:
This has been reported previously: ?/g/BITX20/topic/smd_cap/4525885 I don't remember any resolution to this issue. Might be worth an email to ? ? hfsigs @ gmail dot com My guess is this is a part to improve performance, but that most of us are running without it.? Likely safe to continue with checkout while this is sorted out. I assume this part was in the bag, and not some part that got chipped off the board by rough handling during shipment.? My board had C107 chipped off. Jerry, KE7ER
?
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Re: extra surface mount component
I sent an email off to hfsigs asking about that extra SMD cap. ?The answer: ?I should join the Bitx20 group and my technical queries will be solved.
On Sun, Mar 26, 2017 at 04:16 pm, Jerry Gaffke wrote: This has been reported previously: ?/g/BITX20/topic/smd_cap/4525885 I don't remember any resolution to this issue. Might be worth an email to ? ? hfsigs @ gmail dot com My guess is this is a part to improve performance, but that most of us are running without it. ?Likely safe to continue with checkout while this is sorted out. I assume this part was in the bag, and not some part that got chipped off the board by rough handling during shipment. ?My board had C107 chipped off. Jerry, KE7ER
?
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If you want to activate the internal pullups on the Arduino, you would use:
? ?pinMode(CAL_BUTTON, INPUT_PULLUP);
to activate that mode. The options for the second argument in the function call are: INPUT, OUTPUT, and?INPUT_PULLUP. If you use INPUT, it explicitly disables the internal pullups.?
Jack, W8TEE
From: Darryl Harvey <darryl@...>
To: [email protected]
Sent: Monday, March 27, 2017 2:18 AM
Subject: Re: [BITX20] Calibration route
Hi,
"Tie High" means - via a resistor connect this wire to +5V.
Red Wire -----C---- RESISTOR ----------- +5V
Then the junction between the red wire and resistor (Where the "C" is above) is the location you connect to GROUND to set calibration mode.
?
I just checked the code, and it should have the internal pullups active so in theory shouldn't need an external pullup;
| pinMode(CAL_BUTTON, INPUT); | | digitalWrite(CAL_BUTTON, HIGH); | ? |
but I would still add a pull-up to be sure as you are having problems.
?
The Red wire you are grounding. Connect this to a resistor (anything above 1K will do) and the other end of the resistor goes to the 5v rail.
Red Wire --------- RESISTOR ----------- +5V
?
The 5v rail can be found on the raduino board. ?
See the circuit attached and note the location/pins of the +5V signal on the connectors, this is what you want to tap into at anyone of those available pins..
?
I dont have one in front of me to show you a physical location.?
Possible locations to pickup +5V;
- LCD Display connector - Pins 2 or 15
- Controls connector - Pin 3
- Arduino Nano - Pin 12
- The output of the voltage regulator could also be a good option)
Hope that helps
Darryl
?
?
?
On 2017-03-27 04:52 PM, College Professor Simon Thompson wrote:
Hi Darryl
?
Please tell me precisely how I am to do this.
?
What pin do I connect to the 5 v rail? What does “tie it high” mean? Where is the 5 v rail? What resistor (resistance and wattage) should I use??
?
It would be helpful if you could describe the procedure step by step.
On Mar 26, 2017, at 10:39 PM, Darryl Harvey < darryl@...> wrote:
To elaborate on this topic;
Source: ?
What you have is called a?Floating?pin. Digital Input pins are very sensitive to change, and unless positively driven to one state or another (High or Low), will pick up stray capacitance from nearby sources, like breadboards, human fingers, or even the air. Any wire connected to it will act like a little antenna and cause the input state to change. And I mean any wire, the trace on the board, the wire to the breadboard, the breadboard pin, even the metal pin of the IC itself.
This is refereed to in the Arduino reference page:
If the pin isn't connected to anything, digitalRead() can return either HIGH or LOW (and this can change randomly).
If you look at the?:
This also means however, that input pins with nothing connected to them, or with wires connected to them that are not connected to other circuits, will report seemingly random changes in pin state, picking up electrical noise from the environment, or capacitively coupling the state of a nearby pin.
Often it is useful to steer an input pin to a known state if no input is present. This can be done by adding a pullup resistor (to +5V), or a pulldown resistor (resistor to ground) on the input, with 10K being a common value. There are also convenient 20K pullup resistors built into the Atmega chip that can be accessed from software. These built-in pullup resistors are accessed in the following manner.
pinMode(pin, INPUT); // set pin to input digitalWrite(pin, HIGH); // turn on pullup resistors
These weak pull resistors force the input pin state into a known state, and are easily overwritten by stronger input voltages, like a direct connection to ground or +5v.
?
So tie it high (Via a resistor) to the 5V rail.
?
Rgds,
Darryl
?
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Congrats Phil !? It would be a fun exercise to have folks post the distance covered in their first contact with the BitX.? Mine was a bit over 600 miles (1000 km), quite a thrill to see this little board covering those distances!
73,
Kevin - N8DLP
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We used to say “fuses are for sissies”. LoL? Have fun guys, it’s a toy!
?
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The wiring directions on the hfsigs website are correct when they call for the orange wire of the 5-PIN connector to go to +12 volt power (through the on/off switch).
My now painfully obvious mistake was made by using the orange wire of the 8-PIN CONNECTOR.? This wire is not used at all, and in fact goes directly to a pin on the processor chip.? When 12 volts is applied to this orange wire the chip gets
a nice hole burned through its case, and much smoke exits.
Kevin
N8DLP
This email is intended only for the use of the party to which it is addressed and may contain information that is privileged, confidential, or protected by law. If you are not the intended recipient you are hereby notified that any dissemination, copying or
distribution of the email or its contents is strictly prohibited. If you have received this message in error, please notify us immediately, by replying to the message and deleting it from your computer. WARNING: Internet communications are not assured to be
secure or clear of inaccuracies as information could be intercepted, corrupted, lost, destroyed, arrive late or incomplete, or contain viruses. Therefore, we do not accept responsibility for any errors or omissions that are present in this email, or any attachment,
that have arisen as a result of e-mail transmission.
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What are the values of the capacitor to be used in the filter for 80 meter . I dont want to by the filter because qrn and grm is very high in our location . Thanks in advance . Vu2rjw Soundar
On Mar 27, 2017 7:13 AM, "Ryan Flowers" < geocrasher@...> wrote: Yep, a filter bypass is dirty, but it works! I'll be using a QRP Labs 80m filter. I think I have devised a way to make it very easy to insert into the circuit with nothing but a switch to choose the filter. I need to do some experimenting though. I'll post information when I have it. The stock LPF should be okay though since the next harmonic when running the vfo down to 3.8-3.99mhz should be over 8mhz, which is above what he LPF lets through.?
--
Ryan Flowers KC7RYS?
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Re: Bitx40 low volume oscillation squeal
Still no luck in resolving my "squeal".
So far, I have removed C113 across pins 1 and 8 of the LM386 in order to
reduce it's gain. Big improvement to audio, at least to my ears.
The "squeal" at low audio levels existed before I removed C113 and
persists after removal.
I have now tried three different 10K pots - the two that were included
with the kit and a third new 10K pot (linear taper).
I have now tried three different small speakers, two are 4 ohm and the
third is marked 8 ohm.
And for good measure, combinations of these different 10K pots and
speakers.
All of this to no avail - I still get a "squeal" i.e. oscillation at
very low volume level for about five degrees or so of pot rotation from
full counter clockwise position turning clockwise to a higher volume
setting.
The "squeal" i.e. oscillation, disappears once the control has been
turned past this very low volume setting.
I am using a good quality HP / Agilent lab power supply and have tried
another with the same reuslts.
Still at a loss. There is something I don't quite understand about the
why of this behaviour. I guess it's back to basics and to prototype the
circuit to see if I can replicate the behaviour and if so then what I
need to fix it.
News at 11.....
cheers, Graham ve3gtc
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On 3/27/2017, "Michael Davis" <maddmd818@...> wrote: I was going to mention speaker impedance. Mine did oscillate with a 4 ohm speaker, but not 8 ohm. I believe you said that there was no oscillation before removing the capacitor. Try adding an 8-16 ohm resistor in series with the speaker, or try a 16 ohm speaker, to see if the circuit change somehow affected what the audio amplifier load will be happy with.
Sent from Mike's iPad WA1MAD
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Re: Trouble With Alternate Audio Inputs (BITX40 Module)
Are you using screened audio leads or simply two wires? If you are not using screened wired between the source you are using and the mic input you are courting all sorts of problems. Regards Lawrence
On Mon, Mar 27, 2017 at 4:02 AM, <bruce@...> wrote: Hi: I'm trying to feed some different audio sources into the BITX40 mic input.? The stage that I'm feeding the BITX40 has an isolation transformer (pictured below) and some other components that provide RFI suppression.? The stage also has a capacitor to block the DC bias that is provided by the BITX40 (I have not cut out the bias resistor in the radio). ? For some reason when I key the rig there is an oscillation that puts the rig into full RF output.? When I switch back to the supplied electret mic everything is fine. ? I am testing on battery power to rule out any supply issues and I have also shorted the input side of the isolation transformer to rule out any problems with earlier audio stages. ? Obviously, my issue is related to the differences between the supplied electret capsule and the audio stage that I am using to drive the radio.? I'm not very experienced with audio circuit design. Two questions: 1. Does anyone have the actual data-sheet for the microphone capsule that is shipped with the BITX40 module?? It would be good to have some details on impedances, etc. 2. Has anyone come up with pre-amp/audio interface that works well with the BITX40? This is what I have right now: 
Thanks and 73s, Bruce KC1FSZ
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atouk
Soundararajan Ra.