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Re: Conflicting information
Actually those two sources are not in conflict. ?Both are correct. ?Both talk about the Raduino, which is the small PCB with the mini USB connector (the display, the nano, and the SiLabs oscillator chip). ?The Wiki doesn't talk about the rest of the BITX40, which should remain powered off. ?Pat's article does mention "The raduino should be attached to the usb port configured earlier and the Bitx powered OFF"
You can't program the Nano on the Raduino without powering it up -- that happens when you plug the USB cable into your computer. ?But the BITX 12 volt power supply should remain off. 73, Bob, WB4SON |
Re: Foreign orders
#w8tee
Jack Purdum
These are good ideas. I'll investigate this further...thanks!! Jack, W8TEE From: Graham <planophore@...> To: [email protected] Sent: Wednesday, May 31, 2017 5:32 PM Subject: Re: [BITX20] #W8TEE Foreign orders
Jack, a couple of thoughts, 1) put your design on oshpark as a shared project. Others could then order (in multiples of three) at a reasonable price. 2) contact Hans Summer G0UPL ( I seem to recall he is a member of this group) who runs he may have some good ideas on how to better do what you are trying to do. Either way, your commitment to providing these boards at a reasonable cost is commendable Cheers, Graham ve3gtc On 2017-05-31 19:30, Jack Purdum via
Groups.Io wrote:
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Re: Conflicting information
It doesn't matter either way.? The Arduino can be powered externally while the USB interface is connected, or it can get it's power from the USB port.? Both modes of operation are supported. 73 KE0KKM On May 31, 2017 4:45 PM, "John P" <j.m.price@...> wrote: Hi Everyone! As you can see I just joined this group this morning at the recommendation of a friend. |
Conflicting information
John P
Hi Everyone! As you can see I just joined this group this morning at the recommendation of a friend.
I'm just finishing up a BITX40, which is the first think I've done in Ham Radio in the last 20 years or so. I found 2 articles on here?describing how to upload software into the Raduino; one by Pat Griffin in the messages list, and one in the WIKI section. Pat's article says the Raduino should be powered off when connecting it to the computer via the USB port (which I tend to think is correct), while the WIKI article says the BITX should be powered on. Hopefully someone with the capability to do so, can correct whichever one is wrong. -- John - WA2FZW |
Re: Spurious RF at beginning of transmission
Photo of TX Burst response is here:?/g/ Incidentally I posted a photo of the output spectrum as well.? Right at the US FCC limit of no spur more than 43 dB below the carrier.: ?/g/BITX20/photo/6276/1?p=Name,,,20,1,0,0 73, Bob, WB4SON |
Re: Foreign orders
#w8tee
Graham
¿ªÔÆÌåÓýJack,a couple of thoughts, 1) put your design on oshpark as a shared project. Others could then order (in multiples of three) at a reasonable price. 2) contact Hans Summer G0UPL ( I seem to recall he is a member of this group) who runs he may have some good ideas on how to better do what you are trying to do. Either way, your commitment to providing these boards at a reasonable cost is commendable Cheers, Graham ve3gtc On 2017-05-31 19:30, Jack Purdum via
Groups.Io wrote:
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Re: Spurious RF at beginning of transmission
Folks have been reasonably certain of that on Bitx rigs for about 15 years now. ?A simple fix for the kerchunk into the headphones when entering receive was recently posted here, and there have been many others. ?The transmit kerchunk you describe has not been addressed so much. ?Easier to fix now that we have the Raduino, could shut down the Si5351 VFO buffer at CLK2 until that kerchunk is over with. ?Though 60ms is a rather long time, if using VOX that timeout I'm suggesting could easily clip off something significant. ?Let us know when you find a better fix.
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On Wed, May 31, 2017 at 02:07 pm, Bob wrote: the burst of RF is coming directly through the balanced mixer which is unbalanced for about 60 mS due to the microphone amplifier stage being switched on for transmit. ? |
Re: Spurious RF at beginning of transmission
Arrghh -- sorry, phone call and I hit the wrong button.Continuing ...
When the radio goes into TX, that cap has to charge up via R127 -- which takes a LONG time. ?During that time, Q12 is also powering up and C122 has been sitting at zero volts, so it starts charging as well. ?This is the response of the Microphone Amplifier to the rising edge of the TX signal -- and the net result is that the Balanced Mixer (T4/D15/D16) is knocked out of balance until the amplifier stabilizes. ?The result of that is a spurious RF transmission that looks like the one I have attached as a file. ?The RF rises almost immediately to about 5-8 watts, within 5 ms drops down to about 3 watts, builds back up to 5-8 watts in another 5 ms, then slowly decays over a period of 60 ms decays down to close to zero. ?(All of this observed with the PTT line held). That's pretty much the equivalent of a DOT at 20 WPM. ?You can hear that TX burst clearly on a monitor receiver. When sending CW that initial burst may be masked by the first element as long as the speed is slow enough (< 20 WPM). Since the unintended RF burst is caused by the transient response of the stage being powered up, a more optimal solution would be to keep that stage powered at all times, but shunt the audio to the base of Q12. ?Reducing the size of C124 would help shorten the burst. 73, Bob, WB4SON |
Re: Encoder
¿ªÔÆÌåÓýI got 10 ea.? WITH Threaded Bushing on eBay for less than $10.? BUT, you have to WAIT!? Probably 4 Weeks on some Chinese orders. I am using a non threaded one temporarily in the meantime.On 5/31/2017 2:01 PM, Bruce Harvey
wrote:
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Spurious RF at beginning of transmission
Ashhar Farhan VU2ESE's BITX40 is an amazing QRP SSB Radio and has set an unbelievable price-performance point. ?And many folks are adding new bells/whistles every day (like Allard and Jack). ??I've been working with a friend of mine, Willy W1LY, and his BITX40. ?Willy had installed the version 1.13 software from Allard and the HW modifications needed for CW. ?We have both noticed some interesting RF behavior when the radio first enters TX, even when on LSB (just PTT, with no audio). |
Re: W8TEE TFT/VFO Board from FDIM talk
¿ªÔÆÌåÓýThanks Ken,
Just what? want. On the encoder,? was thrown by the threaded shaft part.? On looking at pictures, now I see, some bushings are not threaded.? Guess I needed the word "bushing"? :-) 73, Bruce On 2017-05-31 5:52 PM, Ken wrote:
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Re: Raduino_v1.13 with scan function released
Yes, I think you got it. ?But better than adding a trim cap at C103 is to hook up the Raduino's CLK0 to replace the analog oscillator entirely, like the uBitx is doing for the BFO. ?Allard says he is looking into supporting this in a future sketch. ?This would allow the Nano to flip the BFO freq depending on if you want USB, LSB or CW, transmit or receive. ?All of those can affect where we might want the BFO placed, in addition to where the crystal filter happens to be centered on your rig. ?What's more, driving the BFO from CLK0 allows us to tune your CW carrier through the filter's range, and figure out what the shape of the filter is by monitoring the power of the outgoing CW carrier.
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For now, if all you care about is sufficient drive when transmitting CW, I suggest you just put in a 10k resistor (instead of Allard's original 47k). On Wed, May 31, 2017 at 01:11 pm, John Smith wrote: Is this a little bit more about what Peter was saying about "the relationship between the BFO crystal and the crystal filter bandpass"? ? |
Re: W8TEE TFT/VFO Board from FDIM talk
forgot the encoder 73 Ken On Wed, May 31, 2017 at 4:22 PM, Bruce Harvey <bharvey@...> wrote:
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Re: W8TEE TFT/VFO Board from FDIM talk
73 Ken VA3ABN On Wed, May 31, 2017 at 4:22 PM, Bruce Harvey <bharvey@...> wrote:
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Change from TX offset to RX offset in future code versions?
I've been working with a friend of mine, Willy W1LY, and his BITX40. ?Willy had installed the version 1.13 software from Allard and the HW modifications needed and was happily working CW. ?He very carefully calibrated the radio and chose a 600 Hz CW offset. ?Even so he noticed a problem on transmit. ?If he set the display of his BITX40 to 7.039.0 MHz, he noticed that his signal was reported as 7.038.4 on the spotting networks. ?It appeared that the CW Offset was being applied on transmit rather than receive.
The reference point for amateur transmissions is the transmit carrier frequency. ?That is what is entered into one's log. ?That's all the regulatory agencies care about -- - what your transmit frequency is. ?You would look at your display frequency and write that down. ?So if the display says 7.039.0 MHz that is what you log and that should be the transmit frequency. However, in the case of 1.13 firmware, that is not the case. ?the CW_OFFSET is applied at TX time. ?The following three lines of code show that CWoffset is set to the CW_OFFSET (established at calibration time), the frequency is then set to the display frequency plus that offset by setFequency, and the PTT switch is activated. ? ? ? CWoffset = CW_OFFSET;
? ? ? setFrequency(frequency);
? ? ? digitalWrite(TX_RX, 1); // activate the PTT switch - go in transmit mode
?
When the transmission is completed (the timer expires), the code sets the radio back into RX, then clears out CWoffset, and sets the frequency back to the dial frequency (with no offset).? ? digitalWrite(TX_RX, 0); // release the PTT?switch - go back to receive mode
? ? CWoffset = 0;
? ? setFrequency(frequency);
?
This is actually the opposite of what should ideally be going on. ?As it stands now, the TX Carrier frequency is not what the user is expecting, and it means that spotting networks are off.Maybe there is some reason like code size that the TX offset is used, but to get the BITX40 on the same page with other radios, to have their frequency display agree and their spots to be accurate, changing to RX offset would be best. 73, Bob, WB4SON |
Re: W8TEE TFT/VFO Board from FDIM talk
¿ªÔÆÌåÓýOn 2017-05-27 4:57 PM, Jack Purdum via
Groups.Io wrote:
KY040 (threaded shaft) encoders Hi guys, I've been trying to locate an Arduino Mega 2560 Pro Mini board source that is available to Canadian buyers. Any suggestions would be appreciated. Also, I haven't found a KY040 (threaded shaft) encoder. Other than that I think I have the other parts located and ordered. Bruce, VE1II |
Re: Raduino_v1.13 with scan function released
Jerry, you said "That variation is due to how the BFO lands on the edge of the crystal filter, so different rigs wind up with different drive levels into the IRF510."?
Is this a little bit more about what Peter was saying about "the relationship between the BFO crystal and the crystal filter bandpass"? I am just starting thinking about this stuff, and so far it seems necessary to have a trim cap at C103 to adjust for best audio power and quality. And now something similar for CW BFO frequency. Would this help Allard with his efforts on CW?? Here is the link to Peter's post on the subject of "Improved Audio Hack. ?/g/BITX20/message/27222 |