Re: i2c signal meter/analyser/dsp/cw decoder
Vic and Sourav, thank you for posting this as I have the exact same problem... thank goodness for this forum!
73,?
Kelly K5AID?
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Re: i2c signal meter/analyser/dsp/cw decoder
To get? those extra buttons and some other updated features like the CW speed arrows on the main screen you need to update the Nextion GUI. Look for "UBITX_Nextion_GUI_V3.zip"
=Vic=
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Re: ubitx v5 down: IRF510 heatsink very hot immediately after turning on the radio
#ubitx-help
#ubitx
I really like the idea of taking the antenna connection and jumper to each of the inputs to the IFs, That is a low cost white noise signal generator.? Let us know how that test goes.
73
Evan
AC9TU
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Re: ubitx v5 down: IRF510 heatsink very hot immediately after turning on the radio
#ubitx-help
#ubitx
There is another thread on Groups.io that follows a similar problem.? The pictures of the clock signals as taken on TP12, 15 and 18 are on this post: /g/BITX20/message/63509When you get your test probes, verify the signals at the above test points with your new scope. Note that the above is for a v4 board, so the frequencies are different.? Amplitudes and frequencies are the key.? Remember that the above is for a v4 board with a 12 MHz BFO and crystal filter instead of the 11.059 MHz of the v5.? Otherwise should be close. You might want to skim through the full thread.? Again, it was on a v4 board, but other than audio changes and first IF transistor replacements for better frequency response, they are mostly the same board.? The voltage measurements that are on this sight should be a good starting point. At this point, I would start measuring voltages starting with R18 and R38 to verify that the IF sections are getting powered.? Then test around the transistors and compare to the test document for the v3 board that you have.? Small changes around Q10, 11 and 12 could be because of the part change for those 3 transistors.? Key is to verify that the transistors are in an operational state (usually around a .7 volt Base to Emitter voltage drop, and current flow through the device measured on the output resistor - I=E/R).? A useful tool is a signal generator.? There are a number of kits and China imports that can be useful for a relatively low cost.? I went higher scale and bough a Koolertron on Amazon for $140.? There are lower cost units that will do the job. Good luck on finding your issue. 73 Evan AC9TU ?
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Re: ubitx mobile in a car
Mobile antennas are what they are. I am not an expert on these as well. But I have noticed that putting a board for Manhattan style homebrew stuff (say 30*20cm) on the roof and soldering this board to the outer of the feedpoint the swr changes (my eyes can't see? the RF and the radiation pattern except for the visible spectrum, yet). The rational of this is to have a better ground when using a magnet mount. The large copper plate an the roof is like a large capacitor so that the RF at HF flows as if they were soldered. Diamond sells a magnet plate similar to this at Wimo.com, I simply took the idea and experimented a bit.
Il 15/apr/2019 21:08, "Lawrence Galea" < 9h1avlaw@...> ha scritto: Hi, Many moons and moons ago, i remember seeing a write-up if I remember correctly in QST, about someone experimenting to get better efficiency while operating mobile.
What he did was to get two whips, one attached to the front bumper where it was fed with coax, the other was attached to the rear bumper and? tuned by a series variable capacitor to the rear bumper.
The two whips were bent over and their tips connected together to form a sort of continuous whip from the front to the rear of the vehicle.
He claimed that it was more efficient which it should considering that it was quite longer, at least double the normal length, than a normal mobile whip.and if iI remember correctly there were no loading coils with their inherent losses.
Naturally it would be better for NVIS considering that it was more horizontal than vertical.
One can visualize this setup if one looks at? a military vehicle where the whip is bent over the vehicle for NVIS propagation, but in the case I mentioned the whip (two joined whips) was tuned making the vehicle part of the system and working like a sort of loop.
One problem with modern vehicles is that they have a lot of fibre parts unlike the old vehicles where everything or nearly everything was metal, but maybe someone can try it and let us know about the result.
Hope this helps.
Regards
On Mon, Apr 15, 2019 at 5:56 PM ajparent1/KB1GMX < kb1gmx@...> wrote: The reality of mobile ops is they antennas used will be inefficient for bands below 20mhz.
Reason is loading coils are a required thing to tune out the reactance of a short antenna.
There is no way around that.?
FOr 20M antenna efficiency is about about 8ft tall will be reasonable about 33% as its pretty
close to 1/2 size.? Center fed is about the best.
For 40M its about 1/4 size and allowing for the fact that cars are a terrible counterpoise for
the antenna so efficiency under 10% are the norm.? IF you can tolerate a taller than 8ft
antenna that helps, center loaded is best.? Do not use an antenna tuner as you at the wrong
end of the cable.? Its best if the tuner is at the base of the antenna.
K0BG has a very complete site on how to get the best out of a mobile antenna.
I run 40M mobile QRP using KNQ7A or FT817 and the antenna is a cheap 40M 8ft
centerfed whip?with mods.? The mods are a 9 turn 1-inch dia coil from the base to
ground to load the antenna.? Then the antenna itself has the longest whip section
possible at the top and is tuned by removing some of the plastic shrink and removing
turns to keep it as long as possible.? This is more efficient than shortening the whip
to tune it.? Its good for about 30khz either side of where tuned.? ? Using a tuner to
get more bandwidth results?in?a significant loss in efficiency as they antenna is then
untuned. I verified this with a field strength meter.? However those antennas are
cheap (about 20$) and I can carry two (one for 7163, and 7250) in the bed of the pickup.??
Ignition noise it a problem with the car/truck... fix it and then you hear the other near you.
Allison
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Re: ubitx v5 down: IRF510 heatsink very hot immediately after turning on the radio
#ubitx-help
#ubitx
Also Q90 could be shorted base to emitter, this is the first driver stage and is in the RX/TX path if bad it will short both incoming and out going signals to ground. Check at TP2 at the junction of L1/C80 and K1 if you have a very low level of signal on CW keyed and it goes away on the other side of C80 then Q90 may be bad.
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On Apr 15, 2019, at 22:30, Curt via Groups.Io < wb8yyy@...> wrote: Jens
Great progress all around. As I remember your failure was sudden, maybe no smoke or odor. Losing both transmit and receive, I am thinking it might not relate to PA failure. I have jumped to wrong conclusions myself before.
Given local oscillators seem to be okay,? perhaps try a jumper wire from the antenna connector to the first mixer, bypassing a lot of stuff. Taking same to the lower frequency xtal filter should receive radio noise and any kind of signals at that frequency.? let's not rule out all that heat opening up a previously good connection on or off the board. By bypassing all those relays with a jumper takes them out of the matter. I hope you find its something simple or at least isolate it.
Others were on a similar wavelength.
Curt
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Re: ubitx v5 down: IRF510 heatsink very hot immediately after turning on the radio
#ubitx-help
#ubitx
Sticking an antenna at the input to the various amplifier stages of a receiver
is a good way to debug, not much in the way of tools required.
Start at the audio power amp and work back, the noise should get louder with each stage.
When it doesn't, you have figured out the stage in which the problem is found.
Atmospheric noise, power line hum, your neighbor's wall warts,
automotive ignition systems, there's plenty of signal to hear at most any frequency.
Unfortunately.
Here's a video where Farhan shows how on a Bitx40, but this technique works fine on a uBitx too.
? ?
The wire he has is just an antenna, maybe three or four feet long, connected to nothing.
Jerry, KE7ER
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On Mon, Apr 15, 2019 at 07:30 PM, Curt wrote:
Given local oscillators seem to be okay,? perhaps try a jumper wire from the antenna connector to the first mixer, bypassing a lot of stuff. Taking same to the lower frequency xtal filter should receive radio noise and any kind of signals at that frequency.
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Re: ubitx v5 down: IRF510 heatsink very hot immediately after turning on the radio
#ubitx-help
#ubitx
Jens
Great progress all around. As I remember your failure was sudden, maybe no smoke or odor. Losing both transmit and receive, I am thinking it might not relate to PA failure. I have jumped to wrong conclusions myself before.
Given local oscillators seem to be okay,? perhaps try a jumper wire from the antenna connector to the first mixer, bypassing a lot of stuff. Taking same to the lower frequency xtal filter should receive radio noise and any kind of signals at that frequency.? let's not rule out all that heat opening up a previously good connection on or off the board. By bypassing all those relays with a jumper takes them out of the matter. I hope you find its something simple or at least isolate it.
Others were on a similar wavelength.
Curt
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Re: Homebrew li-ion battery pack into ubitx
18650 cells from laptop batteries.? I'm planning on using this to power my uBitx.? 4S3P pack I just built. I haven't sealed it all up with Kapton tape yet.??
Yes, and one can score some nice LiPo cells from a cordless drill?battery pack?and get a charging controller for the intended voltage (12v, 16v, etc) on eBay with separate leads to sense each 4v step of the battery pack for balanced charging.
Ted
K3RTA??
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Jens
sorry about your malady.? since there are only a few changes from v3 to v4 to v5, I would start with that data.? the largest change in biased parts between them is the audio amplifier.? all the other major parts - PA, driver, bidirectional amplifiers are the same or very similar.? as you find anything suspicious in your measurements, list members can help if you post the data to your other thread.?
overheating - do check the regulators first to see what they are doing.? I will go check out that thread.?
Curt
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Re: Finally started construction
#ubitx
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Re: Finally started construction
#ubitx
Bob
if you still have more after supplying Russell, I would be interested in a batch - sorry your email is not at QRZ hence the traffic here.? I am curious is these are the shielded ones from TDK that Raj recommends?? did they help your rig improve spurious on the upper bands, if you happen to know?
73 Curt WB8YYY
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I found the following diagnostic guide for the uBitx V3: /g/GCBG/attachment/105/0/uBitxTroubleshooting%20manuala.pdfUnfortunately I have not been able to find such a document for the uBitx V5. If such a document does not yet exist - it would be great if somebody with a working uBitx V5 could take the measurements and update the uBitx V3 document. Thank you, -jens PS: My uBitx V5 is correctly broken (both for RX and TX) due to overheating and I need to know the expected voltage levels for the uBitx V5 'measure points' in order to isolate the problem. More on this investigation can be found in the following thread: /g/BITX20/topic/ubitx_v5_down_irf510/31026083?p=,,,20,0,0,0::recentpostdate%2Fsticky,,,20,2,0,31026083
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Re: ubitx v5 down: IRF510 heatsink very hot immediately after turning on the radio
#ubitx-help
#ubitx
Hi Evan,
An update on the investigation:
1) Radiuno tests:
I was able to buy a used Tektronix 2465 oscilloscope over the weekend for a very good
price and could get started with proposed Raduino clock generator test:
Observations:
- All 3 signals are being generated with the expected frequencies,
- CLK#2 and CLK#1 signals are sawtooth shaped,
- CLK#0 looks very different (pls. see the picture on Google photos),
- Frequency range for signals seem to be ok: CLK#2 varies with when I change
bands or tune within a band, CLK#1 varies based on the 'mode' selection (USB or LSB).
CLK#0:
CLK#1: https://photos.app.goo.gl/1GcupVPLvr7UqjyB8
CLK#2: https://photos.app.goo.gl/tzNNQJNFtaNXQTUs9
Note: The reason CLK#0 looks so different could be related to my home made 1:1
probe (I expect regular 100Mhz probes to arrive in the next few days). Based on the
screenshots for some of the measurements, it seems the home made probe work better
with higher frequencies.
Conclusion:
Raduino seems to work.
2) Audio amplifier tests:
I repeated the 'inject an audio signal' test: I connected the audio signal to VOL_H (instead of
VOL_M) this time and GND.
Observation:
The signal was perfectly audible, volume could be controlled via the potentiometer.
Conclusion:
Audio amplifier seems to work.
3) Q74 test:
Resistence measurements of this MOSFET need to wait until I get the 100Mhz probes with a finer tip -
the measurement points are tiny.
Thank you for your support,
-jens
PS: It would be great to have 'reference' oscilloscope screen shots for all of the measurement points
of the uBitx v5.
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Hello Sascha.
Thank you for keeping us informed and posting the videos.
Some ideas:
1. For my capacitor tuning (L-network, not a loop) I use an RC servo. The cheap SG90 servos (less than $2 on eBay) will do 180 degrees rotation in fact and the angular accuracy is good enough. Less noise but still not silent either. But you can drive the capacitor shaft directly since there is no need for gears and therefore it is easy to make a tiny sound proofing box for them. RFI into the servo was fixed with a simple toroid for the control cables just at the servo entry. If wanted you could cut power to the servo with a mosfet to save energy (a few milliamps) when not moving.
2. For tuning, you can use CW and reduce power by using Ted's method (see /g/BITX20/message/67662).
You would need to change the cat_lib.ino library a little. For example you could create an AM mode in the CatSetMode method that sets an AM flag to use later in the CatSetPTT method.
In the CatSetPTT method on a PTT ON command, if AM mode flag is set, you could use a startTx(TX_CW, 0) followed by cwKeydown();
On a CAT PTT OFF command just reverse with cwKeyUp(); followed by stopTx();
That's the logic I use for my tuner.
That way you don't need to change the loop tuner's code.
Hope that helps,
73, John (VK2ETA)
?????
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Re: Finally started construction
#ubitx
I have a bunch of those inductors.? I can send 10 if you send me a sase and a dollar bill.? If you want to use PayPal, it's $1.70.? My address is good on QRZ.? I'll give you the PayPal info if you want it.
73, Bob. W7HNV
My XYL purchased an Ubitx for me late last year. It is a V4. Board. I had time to start on the recommended fixs this weekend. I have replaced the relays with the Axicoms. Does anyone in the U.S. have the SMD inductors for L5 and L7 for sale? I hope to put this in a pelican style case with a tuner and power source to use for portable ops. Thanks to everyone here for their vast wealth of knowledge. I have learned so much about these radios and electronics in general reading this board.
Russell Ward W8ARD
Columbus Ohio
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Ha! I saw the reply about the "circular firing squad" someone else posted too - LOL.
Jim
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------ Original Message ------ From: "W2CTX" <w2ctx@...> To: [email protected]Sent: 4/15/2019 1:03:50 PM Subject: [BITX20] Nextion Saga Now don't flame me guys....
Reading all these questions about what build goes with what Nextion size and
what options are supposed to be activated reminds me of Abbot and Costello -
Who's on First.
rOn
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Re: Kit-Projects ND6T Ubitx AGC
Lee I sent it over. The updated instructions are in the same download area on the kit-projects website. -- David
?N8DAH
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Re: ubitx mobile in a car
Hi, Many moons and moons ago, i remember seeing a write-up if I remember correctly in QST, about someone experimenting to get better efficiency while operating mobile.
What he did was to get two whips, one attached to the front bumper where it was fed with coax, the other was attached to the rear bumper and? tuned by a series variable capacitor to the rear bumper.
The two whips were bent over and their tips connected together to form a sort of continuous whip from the front to the rear of the vehicle.
He claimed that it was more efficient which it should considering that it was quite longer, at least double the normal length, than a normal mobile whip.and if iI remember correctly there were no loading coils with their inherent losses.
Naturally it would be better for NVIS considering that it was more horizontal than vertical.
One can visualize this setup if one looks at? a military vehicle where the whip is bent over the vehicle for NVIS propagation, but in the case I mentioned the whip (two joined whips) was tuned making the vehicle part of the system and working like a sort of loop.
One problem with modern vehicles is that they have a lot of fibre parts unlike the old vehicles where everything or nearly everything was metal, but maybe someone can try it and let us know about the result.
Hope this helps.
Regards
On Mon, Apr 15, 2019 at 5:56 PM ajparent1/KB1GMX < kb1gmx@...> wrote: The reality of mobile ops is they antennas used will be inefficient for bands below 20mhz.
Reason is loading coils are a required thing to tune out the reactance of a short antenna.
There is no way around that.?
FOr 20M antenna efficiency is about about 8ft tall will be reasonable about 33% as its pretty
close to 1/2 size.? Center fed is about the best.
For 40M its about 1/4 size and allowing for the fact that cars are a terrible counterpoise for
the antenna so efficiency under 10% are the norm.? IF you can tolerate a taller than 8ft
antenna that helps, center loaded is best.? Do not use an antenna tuner as you at the wrong
end of the cable.? Its best if the tuner is at the base of the antenna.
K0BG has a very complete site on how to get the best out of a mobile antenna.
I run 40M mobile QRP using KNQ7A or FT817 and the antenna is a cheap 40M 8ft
centerfed whip?with mods.? The mods are a 9 turn 1-inch dia coil from the base to
ground to load the antenna.? Then the antenna itself has the longest whip section
possible at the top and is tuned by removing some of the plastic shrink and removing
turns to keep it as long as possible.? This is more efficient than shortening the whip
to tune it.? Its good for about 30khz either side of where tuned.? ? Using a tuner to
get more bandwidth results?in?a significant loss in efficiency as they antenna is then
untuned. I verified this with a field strength meter.? However those antennas are
cheap (about 20$) and I can carry two (one for 7163, and 7250) in the bed of the pickup.??
Ignition noise it a problem with the car/truck... fix it and then you hear the other near you.
Allison
|
I would recommend first using the standard display to insure that the main board works.? I was able to position the 3.2" nextion display opening such that the standard display could be seen through the hole for testing.? This way you know where to look for any issues that come up at first.? The KD8CEC software is GREAT, however you add a number of other potential issues with version compatibility that are best tackled AFTER any bugs are worked out with the stock parts you are going to keep.? You also get a feel for how the radio sounds and operates first, then add the "extras" later.
The above is my opinion based on my experiences.? Yours may be different.
73
Evan
AC9TU
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Vic WA4THR
Skip Davis
Jim Sheldon
N8DAH