So Mark and I are having the exact same no receive problem. I've reprogrammed my nano thinking maybe something was amiss but that didn't help. Mark replaced his 5351 board including the nano with a known good part and now his works. Is there any way to replacement for these boards? ?There's no way I can replace the smd 5351 chip which I believe to be the culprit. ? Brian
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Re: Changing frequency display
Thanks Dr Fred. I have never messed with the raduino. Changing a sketch scares me. I do need to learn more about how to read the file/sketch save the file and modify the file.
Maybe I didn't explain my simple method very well. Part 1. A 25-50 ohm resistors in series with each outer potentiometer tab to green and another resistor in series to yellow. That would prevent the fast frequency change from engaging (I assume), since the center/violet would never "see" a direct (low or 0 ohms resistance) connection to either yellow or green raduino point. Part 2. A momentary push button switch from the center/purple pot tab to the raduino yellow wire and another to the raduino green wire. This would replicate the full turn, 0 ohms, of the pot CW or CCW. No ground to any of these connections (on purpose anyway) Simple? Work? I hope so. Part 3. A 3 turn or 10 turn pot? We'll see, stay tuned.
Sent from Mike's iPad WA1MAD
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On Fri, Mar 17, 2017 at 01:28 pm, Nathern Priddy wrote: I used a 100 MHz scope to measure the peak voltage across a 50W Bird dummy load.? The peak voltage is about 10 volts which equates to about 1 W of output power.? I had a friend listen to my signal and he said it was clear but very weak.
Any suggestions about where to look?
?
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I just completed my BIT40X and can only get about 1 Watt of RF out.? I turned the bias adjust pot fully clockwise and read a current of about 200 ma from the power supply.? The instructions say it shoud be near zero ma and increase as you turn the pot counterclockwise.
I used a 100 MHz scope to measure the peak voltage across a 50W Bird dummy load.? The peak voltage is about 10 volts which equates to about 1 W of output power.? I had a friend listen to my signal and he said it was clear but very weak.
Any suggestions about where to look?
The receiver portion works just fine on 40 meters.? Having no AGC will take a little getting used to.? Hi Hi
Barry - K5VIP
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Re: Rotary Encoder and latest sketch
I just uploaded:
and
which are the rotary encoder articles I wrote for QRP Quarterly. Perhaps those will help.
Jack, W8TEE
From: N7PXY <hickspj467@...>
To: [email protected]
Sent: Friday, March 17, 2017 3:11 PM
Subject: [BITX20] Rotary Encoder and latest sketch
I am very confused. I find several sketches and many references to using an encoder for tuning. Is there a set of complete instructions for installing an encoder (where to hook it up to which raduino pins etc.) and can someone point me to the latest sketch that incorporates code to operate the encoder? I am very shaky and inexperienced with Arduino IDE and programming and need some hand holding.
PJH
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Hello,
This email message is a notification to let you know that a file has been uploaded to the Files area of the [email protected]
group.
File: PurdumRotaryEncodersRevisited.doc
Uploaded By:
Jack Purdum
Description:
The second rotary encoder article that features Fast Tune for frequency changes.
You can access this file at the URL:
/g/BITX20/files/PurdumRotaryEncodersRevisited.doc
Cheers,
The Groups.io Team
|
Hello,
This email message is a notification to let you know that a file has been uploaded to the Files area of the [email protected]
group.
File: PurdumEncoderArticle.doc
Uploaded By:
Jack Purdum
Description:
The first of two articles on using a rotary encoder with an Arduino Nano or similar controller.
You can access this file at the URL:
/g/BITX20/files/PurdumEncoderArticle.doc
Cheers,
The Groups.io Team
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I finally got the high side vfo code working by removing c91, c92. I found if left in place the vfo did not work above ~10MHz. So if anyone is planning on using the commented out USB code in the original file you will probably need to do the same. Raduino bfo is now working, LSB sounds great but still need to test USB. Also still works well down on 75m.?
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Rotary Encoder and latest sketch
I am very confused. I find several sketches and many references to using an encoder for tuning. Is there a set of complete instructions for installing an encoder (where to hook it up to which raduino pins etc.) and can someone point me to the latest sketch that incorporates code to operate the encoder? I am very shaky and inexperienced with Arduino IDE and programming and need some hand holding.
PJH
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I need to explain. I have a TBI, that sometimes causes me to need something reexplained in a different way. Also I have cerebral palsy, so my son would be building the kit for me. I haven't the coordination/skill Todo it.
What I hope to find is a qrp TX/RX that can do digital if helped by a signalink and/or raspberry pi.? Is this a good fit for the bit x 40? Or would the more complex softrock or another design be a better choice on a budget? Kg7owo...Soon to be extra class :-)
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inexpensive...simply.....yet very functional......mostly great fun!!!!
On Mar 16, 2017 3:30 PM, < pierre@...> wrote: Hi Rafal,
No you have not missed anything and you are not the first to notice the short comings of the design, Allison KB1GMX has also done a very nice analysis of the Bitx design with suggestions as to how it might be improved (of course with some added complexity).
The Bitx is like most things a compromise design (to keep it simple) and yes the single transistor amps and crystal filter have a Zin/Zout of about 200 ohms while the mixers are 50 ohm so there is mismatch and some performance lost.
Also Farham has noted that for better IP3 performance at 40m the first Rx RF amp should probably be disabled but then if you are using your Bitx in the field with a simple wire antenna strung up in a tree the extra gain is probably makes things a little easier.
Yes the Bitx could be better but then it would become more complex, so the trade-off.
Regards,
Peter VK1XP
On 17-03-2017 06:41, Rafa? Lichwa?a wrote:
I plan to build BITX40 TRX, so I've read the project description and
analyze the circuit. As it is well described on the web page, there
are single transistor amplifier stages which have the following
input-output impedance translation:
Rout = (Rfeedback * Remmiter) / Rinput
In all stages there are Rfeedback = 1.1k (two 2.2k in parallel from
both amplifier directions) and Remmiter = 10R.
That means we have the following impedance translation:
Rout = 11000 / Rin
So now, analyzing the circuit starting from the 50R antenna, we have
the following impedances:
antenna: 50R
LPF-input: 50R
LPF-output: 50R
1st AMP-input: 50R
1st AMP-output: 220R (after translation)
diode MIXER(assuming equal impedances on each port): 220R
2nd AMP-input: 220R
2nd AMP-output: 50R (after translation)
Xtal BPF-input: 50R
Xtal BPF-output: 50R
3rd AMP-input: 50R
3rd AMP-output: 220R (after translation)
AND.....
now there is PI-attenuator (-3.85dB) with both 220R shunt to GND and
22R in series.
That means this attenuator is designed for 50R input/output impedance
- it does NOT match 3rd AMP output impedance which is 220R!
Did I miss something or I've just misunderstood the circuit design?
Best regards,
Rafal SP3GO
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Re: Letting the smoke out
Dr Fankinstein would be proud KD8CGH <rkayakr@...> wrote: !!!!!!?? It's alive !!!! It was a burned trace. I traced the voltage and saw 13.7 at L8 and 7-9 at T7.? I soldered a jumper on the back of the board from L8 to T7 pin 6 and now I have 13.7 volts at the Drain and reasonable RF output measured by my power meter into my dummy load. Thanks for the help.
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Re: Changing frequency display
Craig,
you would need greater resolution when you want the tuning range to cover
the entire 40m band (instead of just a 50kHz segment).
currently:
single turn pot => 300 degrees rotation => 1000 steps =>0.3 degree/step
tuning range 50kHz => 50,000 kHz/1,000 steps = 50Hz/step
If we want a tuning range of 400 kHz (8x larger range), then the step size
would be 400Hz per step, which is too much (not enough precision).
It wouldn't help to just use a multiturn pot in this case because there
are still only 1,000 steps.
In order to keep the 50 Hz/step you would need 8,000 steps instead of
1,000, so eight times more steps. More steps means greater resolution. We
need 3 additional bits in order to have 8 times more steps.
For 3 additional bits we need to take 4^3=64 samples and take the average
of them (oversampling).
With 3 bits greater resolution, so 8,000 steps, in combination with a
10-turn pot, we would have 10 turns x 360 degrees / 8,000 steps = 0.45
degrees/step, which is 50% better than we currently have, while the tuning
range would span the entire 40m band!
But as I said I have never tried this - perhaps the tuning mechanism will
become too slow when it needs to take 64x more samples to determine the
pot position. Then a rotary encoder might indeed be easier and perhaps
cheaper too!
73, Allard PE1NWL
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Re: calibration routine fixed (raduino v1.0.2)
I figured out the problem. ?I had the Sparkfun board selected. ?It is fixed now and your fixes to the sketch worked to get the calibration corrected. ?
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Re: Changing frequency display
Good afternoon Michael, ? Much easier to do it in the sketch. With your method the switch has to be a break before make or you stand a chance of creating a short if the pot is at the +5 volt end and you simply push the ground end switch shorting the +5 to ground and letting all the smoke out of the 5 volt regulator. I have mine setup to use a second pot to select the step size and can select 1, 10, 100, 1000 or 10000 Hz steps. This could also be done with a button switch to step through the various steps. For some ideas look at Marcus's sketch. (A redo of his QEX article). He has some great ideas I have stolen. Mine has a GPS module attached and displays Time and Grid square as well as counting the oscillator during the one second GPS signal and automatically correcting the Si5153. $20 for a GPS module and adding 4 wires. I am looking at removing the pots and going with a rotary encoder and using the switch on the encoder to select step size. I am not a programmer, but have become adept at swiping code sections of other people's sketches. ? V/R?????????????????????????????????????????????????????????????????????????????????????? ? Fred W4JLE ? ? ?
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-----Original Message-----
From: [email protected] [mailto:[email protected]] On Behalf Of Michael Davis
Sent: Friday, March 17, 2017 9:23 AM
To: [email protected]
Subject: Re: [BITX20] Changing frequency display ? I am about to make a tuning mod. I will add a 27-50 ohm resistor in series to each side of the tuning pot (yellow and green) That will prevent the pot from fast tuning at either end of travel. I will add 2 momentary buttons from the pot. One violet to yellow, the other violet to green. If my understanding of the tuning method is correct, this will exclude the control from doing anything but changing frequency in its normal range. When I want to step up, just push the U button, down press the D button, essentially having a sort of band range control over the desired frequency. I also plan on using a 10 turn, or a 3 turn 10k linear pot. Obviously using a multi turn pot makes the button mod a real necessity. No more getting close to the end of pot tuning travel then "ooops' the frequency starts taking off. Thoughts? ? Sent from Mike's iPad WA1MAD ? ? ? ? ? ?
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Brian Lewis, I replaced the SI5351 board that has the Raduino on it with one from another BITX40. ?It is now receiving. ?I've got some 25mHz crystals coming and I'll see if mine is bad. ?Also in the midst of reprograming the Raduino with the latest sketch. ?But it was the original SI5351/ Raduino set up that was causing the problem of no signal and any signal there was, was muffled and distorted. ?I suspect that is your problem also. Mark W5MCU
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Re: 12vDC wiring and hookup
I use a separate switch DPDT ON-OFF-ON switch. In one position you feed 12V to both the main board and the final, in the other on position I feed 19.8 volts to the final and 12 volts to the board as follows: Switch contacts ? 1?????????? 2 3?????? ???4???? ?Rear of switch view. 5?????? ???6 ? Connect 12V ?from power supply to 1,2 and 5 Connect pin3 ?to power for the board (PWR1) Brown wire Connect pin 4 to final power (PA-PWR) brown wire Connect pin 6 to Final voltage. (In my case 19.8V) ? When the switch is in the center off position no voltage is fed to any circuit. In the down position 12 volts is fed from pin 1 to 3 powering the board and via pin 2 to pin 4 sending 12 volts to the final. In the up position pin 5 feeds 12 volts to the board and the final voltage on pin 6 is fed to the final. (Remember when the switch is in the down position the upper contacts are connected and vice versa.) This allows me to select either high or low power. ? V/R Fred W4JLE ?
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From: [email protected] [mailto:[email protected]] On Behalf Of Crippen81@...
Sent: Friday, March 17, 2017 8:00 AM
To: [email protected]
Subject: [BITX20] 12vDC wiring and hookup ? I am pacing the house waiting for my Bitx40 to arrive (we. Should be mere days away now) and looking over the build plans. I am looking for some clarification on the 12v power. From the power jack do you run direct to the volume pot for on/off and then distribute to the board or are all the connections made in parallel?? If you parallel the connection wouldn't that keep power flowing into parts of the board after other pieces (via the on/off volume pot) had been turned off?
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Re: Letting the smoke out
!!!!!!?? It's alive !!!! It was a burned trace. I traced the voltage and saw 13.7 at L8 and 7-9 at T7.? I soldered a jumper on the back of the board from L8 to T7 pin 6 and now I have 13.7 volts at the Drain and reasonable RF output measured by my power meter into my dummy load. Thanks for the help.
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Re: Changing frequency display
Adding momentary switches to both ends of the potentiometer would be a simple and frugal alternative to holding the pot at either 0 or 10k ohms. Another approach would be to use a rotary encoder and Jack's code. Why does anyone want greater resolution on SSB? Or is it just an exercise in programming for the fun of it?
Confused in Illinois
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Re: Wiring the EP sockets
On 3/17/2017 7:47 AM, richard kappler
wrote:
that doesn't work switch it to 5. I don't like that
as much because it requires making a QSO. Which would you do in
my position?
regards, Richard - W2KAP
But that's the fun part! And then you can get an audio and signal
report. Win-win!
Jonathan - KK6RPX
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lee hyde
Allard PE1NWL
Bob Benedict, KD8CGH
Craig Wadsworth