https://vk4pln.blogspot.com.au/2018/03/raduinoi2c-board.html

Jerry,

Would the following make sense then (software mods and Si5351 i2c bus address aside for now):

- $37 Elektor SDR board?

SDR board RF input connected after the first IF filter (or before?), uBitx Si5351 clocks #0 and #1 disabled (2nd IF and BFO off), 192kHz I/Q audio out to Teensy audio input with modded SDR software.

Tx chain as standard uBitx.

So many toys, so little time.

73, John (VK2ETA)

I did make progress by turning the audio down. Power dropped from 7 to 4 watts but the undesired dropped significantly and the desired increased. Then made a 500 mile FT8 contact with the 4 watts.

I just had the RF gain way down to watch the signals.
Anxious to have a nearby ham listen for them.

I plan to put some type meter on the audio input to the rig. It appears to be critical for digital modes at least.

Thanks for input. Bo W4GHV?

开云体育

Are you using stereo headphones? If you have a mono plug in the jack your shorting the audio to ground. You need to use a TRS plug in the jack supplied with the UBITX.

Allen?

I AM 70. I like the challenge...keeps me sharp.

I've decided I want built-in USB and the fear of RFI problems is a challenge I'm willing to take on. There are numerous RFI sources in the Raduino, from the 16 mHz clock, its harmonics and divided sub-harmonics, the I2C? bus and the SPI bus, plus 3 oscillators in the Si5351 and all their cross-talk intermodulation products.. It's an RFI jungle. At some point this has to be dealt with and running away from it won't eliminate the issue.

The Mega uses an ARM that also has no EEPROM if my memory serves, so you need either an extra part or a mechanism to use Flash for dAta storage. I think the latter is workable for this applicstion. Besides, I've seen no Mega boards in a Nano footprint except the Protoneer, which is $15 shipped. In that price range there are better alternatives. The $2.50 Pill is very compelling.

Regards
Joe

Update:

Things are happening fast and I'm trying to keep it straight in my old head. Is this list complete relative to the various "Raduino" versions available today ? I may have left some off....... Anyone happen to have a matrix of the various options ?? (silly question).

$$ is defined as the --estimated-- $ to implement on your uBITX (new "Raduino" board, new microcontroller, new display, new extra parts, etc). Open to corrections/clarifications.

No$$ is defined as only requiring a firmware load for the existing Nano microcontroller
Lo$$ is defined as <$30
Med$$ is defined as >$30 & <$90
Hi$$ is defined as >$90
??$$ is I don't know

73 Kees K5BCQ

1) Original "Raduino" with a Nano Ver ? (base Farahan started with and probably what most uBITX units have today). No$$
2) Upgrade to #1 ?? Ver ?? No$$
3) Upgrade original "Raduino" Nano with firmware by Ian Lee, KD8CEC. (called Ver? 4.3 today) No$$?
4) "RaduinoUMAX" with firmware by Mike Hagen, WA6ISP, (more I/O). Lo$$?
5) "Raduino Protoneer" (Arduino Zero Compatible Nano-ARM, uses SAM21 microcontroller). Who was/is working on this one ?
? ? ?Lo$$
6) "Raduino Pill" by Joe, W3JDR (uses a STM32F103 "Blue Pill" microcontroller, lots more I/O). Lo$$
7) "RAdI2Cino" by Jim Sheldon, W0EB, uses the Nano. Lo$$
8) "BITeensio", this is the new one by Jim Sheldon, W0EB, more info coming. ??$$
9) "JackAl" board this is the "will blow your socks off" design recently announced at FDIM by Jack Purdum, W8TEE, and Al??
? ? ?Peter,??AC8GY (all the capability you should ever want, uses a Teensy 3.6 microcontroller and will cost "a few $$ more" but
? ? ?has?VERY impressive capabilities which highly depends on the guys writing the firmware (as do?ALL?the others). Hi$$
10) "KB1OIQ" by KB1OIQ has I2C display, supports Keypad and voice?output suitable for low/no vision operators. ??$$
11) "Alison TBD" by Alison, KB1GMX, uses the Nano and has no rotary encoder, less or no menu, more buttons. ??$$

Evan, the WX labeled audio chips can blow out if the voltage going to them is beyond their tolerance? If you had the volume pot wires switched, then you may have blown out the chip as soon as you put power to the rig. I soldered a 6 volt regulator in the amp's supply line before I put power to it and it's been purring along nicely for almost two months. When they blow, most people are putting in a socket so they can replace the chip easier and there are a few good options discussed here on the board. So, that's the recommendation.
73, Dan? W2DLC?

There has been issues with the wire-up documents, and I haven't kept up with the changes, so I may be wrong here.
but it looks like your yellow and orange wires are swapped on the audio gain pot.
Some one that has their working uBITX in front of them, could probably be more help then I am at the moment.


The orange range wire from the audio connector should be connected to the to the wiper on the potentiometer and the yellow wire to the hot end of the potentiometer.

Regards,
Gary

If you need phase information for a digital ham mode you can generate IQ locally in the baseband audio signal from the uBitx with the Hilbert Transform. Like in those old telephone modems. There may be advantages to doing it at IF (like before an AGC).

That was my understanding, reading between the lines in Jack's post:
? ??/g/BITX20/message/49882
I could be wrong.

Much of what they are doing could be done in a form factor to match the current Raduino,
so it's easily swapped in.? As per the last paragraph here:
? ??/g/BITX20/message/49519?
?
It's very easy and fun to speculate about what can be done.
I've been thinking about an ARM based Raduino for the last year and a half:
? ??/g/BITX20/message/19340

But have so much fun figuring out how I would cram a spectrum analyzer and VNA
and oscilloscope and ... into that Raduino that I never get around to actually doing anything.
Much more difficult to successfully do something..

Jerry, KE7ER

Hey, I'm new here. I just finished assembling my ubitx, and I was disappointed to find there was no audio. I double checked all my connections, and everything seems to be wired correctly.

I saw somewhere that the "WX" branded TDA2822M chips are of lower quality than others, and mine is a WX. Might this be the issue??

Has anyone measured the bandwidth of the uBITX filter ???

I have tried it two ways. one with a SA/TG at the 12 mhz filter, and another by feeding in a audio tone from 200 hz to 2800 hz into the mic input from a function generator and using a wattmeter..? Both ways seem to give me a 3 to 6 db bandwidth of about 1600 hz.??

The receive audio seems ok to me, but several hams I talk to almost every day say the audio is not very good, like it is restricted.? I tried moving the BFO up and down about 100 hz at a time to get the best and they tune for the best signal from me incase the frequency is not exact.??

I did change to a Baofeng hand mic and the audio was somewhat better.? I am waiting on some parts to come in to repair a Shure desk mic to see how it sounds.? I am using a similar mic on my Icom 746pro.? I tried feeding my Drake L4B amp and getting around 150 watts out so the signal level is up the about the same as the Icom.? The audio did not seem to change when running the amp or not except it was stronger as it should be.

de ku4pt

That's the other way to do it.
This JackAl board is just sampling the audio that we normally hear when listening to the radio.

I'd call them both "SDR".
Some may disagree.

Jerry

Nope.

Often in SDR, they use the I and Q channels to retain information regarding
the phase of the local oscillator vs the incoming signal, this is then used
digitally in the computations to distinguish the signals above the local oscillator
from those that are below the local oscillator.

On the uBitx, we mix it with the local oscillator, then extract just the
upper sideband or the lower sideband in the analog domain using that?
narrow 12mhz crystal filter.? ?No need for that phase information.

Jerry

Yes Ron,

The SDR implementation needs an additional quadrature sampler, from reading the documentation the rest of the hardware is already there in the uBitx.

See?

73, John (VK2ETA)

Hello Bo,

Have you checked the volume level you are feeding the uBitx? The mic amp isn't expecting more than 40mV.

Also did you have any attenuation turned on the ICOM? The manual says it has settings for 10,20,30 dB attenuation. (I'm terribly curious if that's a hardware attenuator or software based. Looks to be hardware based according to the service manual. 10dB in tuner unit, 20dB in RF unit. Okay.)

I wonder if the spurs will go mostly away with 30dB ATT and checking that the sourdcard feed to the mic amp doesn't exceed 40mV.

The service manual says there is a 20dB voltage controlled attenuator to keep the ADC from getting swamped. Your two radios are so close I'm still sure the 7300 is showing you spurs due to close proximity.

Those are the first 2 things I would check.

73 de Jacob AG7CT

The Teensy 3.6 has a floating point unit and can do FIR filtering and more at that sample rate with the audio library.

So the IIR filters used here, which are at least an order of magnitude more CPU efficient, and should not be an issue for the Teensy 3.6.

One very interesting feature that opens up with this combination of CPU and library is the USB audio device emulation that would allow a computer to connect via USB for digital modes without a digital interface.

Plus the real possibility of on-board decoding and encoding of digital modes as well as built-in SDR.

Mind boggling and a hacker's dream that thing is.

73, John (VK2ETA)

I think I may be confused or missing something. Why use usb on blue pill. Like I have always used stlink or ftdi ? to program with . If using usb to communicate with could you not just cut the 5v trace on the board from the usb . ?I have been playing with the blue pill today trying it with cec ?firmware and run into errors with EEPROM ?and get. I have been reading of problems of this. I see that this is being worked on by STM, now whether it has been fixed I have not had time to check this out. The EEPROM ?routine Ian uses ?is very good I see it is being used in the new OEM firmware I have been reading about. Their have always been some quirks using STM processors on Arduino. Mxcube ?or attalis ?may be better option for programming.
Now this is just a thought for going with STM for my programming ability (or disability ) I will probably ?have to go with mega 2560 mini. I have had no problem getting ?Ian's ?firmware to compile on it. I like the STM idea but , hell, I'm ?almost 70, I don't ?need complication.
73's ?kn4ud


--
Allen ?Merrell