Re: Screen model. Explaim me
Gerard,
You can put a Nextion display with the KD8CEC software on the v6.? If you purchase the kit with the case, then the 2.8" Nextion can replace the 2.8" stock display and will fit with a little coaxing.
You can go to a larger display, as long as you either mill out the case window for the display to fit the larger size or put the entire kit in a different box.? The correct KD8CEC software will work with any model of uBITX.
As to using a larger ILI 9341 display, the larger screen takes more pixels and hence larger memory usage.? It is very possible if you go to a different micro controller like the Teensy.? There are adapter boards and software for that availble from the TSW web page:?
With either choice, you are removing and not using the stock display and substituting another one.? My choice is the Nextion, as there are a number of options currently available.? IF you are into coding, then the Teensy would be the way to go.? You could also check to see if the JackAl boards are available, as those have the Teensy and larger display options.
Just suggestions, you will need to research and moke your own choice.
73
Evan
AC9TU
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Re: No output power on
#v3
I haven't dug into this in depth, but I did test receive last night. Pumping 15 W into my loop with a borrowed Kenwood TS-2000 I was able to (faintly) hear my transmission in a dummy load. I suppose I could have stuck a piece of wire into a UHF connector and made a quickie vertical as well, but that was what occurred to me at the time. :)
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Hello
On the v3,v4,v5 we can put a Nextion and it works very well with the software of KD8CEC.On version 6, ai this time is not possible. It says you must have ILI9341.
See my if i am right When I look at the sales sites, they are only small screens. (2 or 3 inches) for ILI9341. Why?
Another curiosity I don¡¯t understand. If I zoom in on a screen called ili9341, I see an XPT4026 circuit. If I zoom, on screen (QVT-320_ILI 9341) that looks like the one. I have in home? (QVT-320), it is also the same circuit XPT 4026. An? only difference seems to be the connection. So, another question, is ILI9341 a connecting standard or something else?If we have the same circuit (XPT4026 on all models),Could we interface instead of a Nextion? I saw that we need to put a divider on several pins.
Here a beginning of talk about that:
/g/BITX20/topic/73277797?p=,,,20,0,0,0::recentpostdate,,,20,2,0,0&allview=1
I copy an excel file where i got some information
Well, it may be a lot of energy to put a screen a little bigger (it¡¯s square and not rectangular!)
But, this can be an interesting topic
cdt
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Re: Better choice quartz for 11.059 filter
Gerard,
No need to recalibrate.
The frequency at which the radio operates is determined by the 25mhz quartz crystal on the Raduino's Si5351.
Let us know if this works.
Jerry, KE7ER
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On Mon, Nov 2, 2020 at 06:36 AM, Gerard wrote:
Hello,
it's a good idea.
Confirm to me that there is no recalibration to do? and after that it remains to check that the 16 KHZ has disappeared on the sound .
Thank you
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Re: Better choice quartz for 11.059 filter
Hello,
it's a good idea.
Confirm to me that there is no recalibration to do? and after that it remains to check that the 16 KHZ has disappeared on the sound .
Thank you
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On Mon, Nov 2, 2020 at 03:26 PM, Jerry Gaffke wrote:
It might be possible to push the ceramic resonator enough by slipping a metal sheet?
of copper or aluminum
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Re: Better choice quartz for 11.059 filter
I think Evan has it right.
I hope Gerard has a Nano that is socketed to the Raduino, not soldered down like the early uBitx.
As I recall from a few years ago, putting a finger on the resonator pulled it away considerably.
It might be possible to push the ceramic resonator enough by slipping a metal sheet?
of copper or aluminum foil over the top of the resonantor with an insulating layer
of thin tape between the metal sheet and the board.? Grounding the metal sheet might
push it further.? Kapton tape would be idea, cellophane tape (Scotch tape) should work well enough.
I haven't tried any of this.
The Raduino comes with a $2 Nano clone using the CH340 chip for the USB-to-UART interface.
Not the $20 original Arduino design.? Here's a description and a schematic:
Note that there are pads for caps on each side of the resonator, but they are not used.
Those resonators are incredibly tiny, as are the pads for the caps.?
Might be easiest to simply swap out the Nano.
Jerry, KE7ER
On Mon, Nov 2, 2020 at 03:30 AM, Evan Hand wrote:
On Mon, Nov 2, 2020 at 03:38 AM, Gerard wrote:
You wrote: "push the 16mhz resonator over a few khz."
Gerard,
Some more explanation may be required.? The ceramic resonator is the "crystal" equivalent that is used for the Nano clock.? There is not an adjustment to change that in the firmware.? The change would be done on the Nano board by adding capacitors to the resonator leads.? Here is the link to the Nano schematic:
It would be adding capacitors to pins 7 and 8 on the ATMega328.? It would be a lower-cost risk than the filter replacement, but harder to do in the tight board space and pin spacing of the Nano.
Jerry,
Did I get it correct?? Also, have you tried adjusting the Nano frequency, and do you have any tips on how to do so?
For what its worth (FWIW)
73
Evan
AC9TU
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Re: Better choice quartz for 11.059 filter
Evan,
Thanks for the answer.
It¡¯s simple in fact, but handle the soldering iron well
cdt
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Re: Better choice quartz for 11.059 filter
On Mon, Nov 2, 2020 at 03:38 AM, Gerard wrote:
You wrote: "push the 16mhz resonator over a few khz."
Gerard, Some more explanation may be required.? The ceramic resonator is the "crystal" equivalent that is used for the Nano clock.? There is not an adjustment to change that in the firmware.? The change would be done on the Nano board by adding capacitors to the resonator leads.? Here is the link to the Nano schematic: It would be adding capacitors to pins 7 and 8 on the ATMega328.? It would be a lower-cost risk than the filter replacement, but harder to do in the tight board space and pin spacing of the Nano. Jerry, Did I get it correct?? Also, have you tried adjusting the Nano frequency, and do you have any tips on how to do so? For what its worth (FWIW) 73 Evan AC9TU
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Re: Better choice quartz for 11.059 filter
Gerard,
Here is an article on pulling crystal frequencies.??
The short answer is to use 1 or two capacitors to change the tuned circuit that is the crystal equivalent.? For the extreme case, you can use an LC circuit for larger shifts in frequency.? I have not done this, so it is all theory for me.
Sorry that it is in English, however, I do not speak French.
73
Evan
AC9TU
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Many thanks to all of you for your very interesting posts; it took me some time to reply since there is a lot of QRL for me.
I wll study each of the proposed solutions and I will perform some tests on my uBitx v5 rig.
In the meanwhile, i have one question to Jack and Al: Referring to your AGC circuit, I notice that Q205 - the npn part of the variable-gain amplifier - has no signal at its base since C203 is most probably a "do not install" part, marked as 0.00 uF. J309 is the voltage-controlled resistance, however the control signal is directly fed from uBitx IF (uBitx_IF_In), i.e. not coming from any peak detector. Please explain to me the functionality of that block; your design seems very interesting and simple and it deserves a good explanation.
73, George, SV1DEQ
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Re: Better choice quartz for 11.059 filter
Jerry,
You wrote: "push the 16mhz resonator over a few khz."
Before change quartz, or other and for my personal information.
I have tried several calibration, the 16 khz is always present.
How you do it to push the 16mhz resonator over few khz?
Is it on nano? if you can explain
thank's
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Re: Dummy Load Resistors & Motor Oil
hello,
on the other post, i have put that:
Here, dunny load in a?converse box with linseed oil
cdt
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Re: Dummy Load Resistors & Motor Oil
Most linseed oil is "boiled", which these days means it has chemical additives to make it polymerize faster.
Those drying agents create some nasty noxious fumes, as well as causing the spontaneous combustion of oil soaked rags.
The oil gives off heat when it polymerizes, a chemical reaction where it hardens into a kind of plastic.
Linseed oil is often used as a finish for wood.
We used maybe 20 gallons of "raw" linseed oil when creating our earthern floors.
The "raw" stuff does not have the drying agents, we "boiled" it in the traditional way by heating it to 110C (230F)?
and then immediately took it off the heat to cool.? Cooked the oil outside, watching the temps carefully.
According to this:??
the flash point is 222C (so vapors can burn but won't self ignite), auto ignition is 343C, boils at 349C.
I'd feel quite safe using raw linseed oil in a dummy load, but would avoid the "boiled" stuff.
If the oil does spill, the room will smell quite pleasant for years.
Just touch the can occasionally with a wet finger, cut power if it sizzles.
One of those microwave 50 ohm dummy loads bolted to 5 kilos of aluminum would probably work about as well.
As would WB9SBD's water and baking soda trick.
Jerry, KE7ER
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On Sun, Nov 1, 2020 at 06:49 PM, Dr. Flywheel wrote:
I caution against use of linseed oil. Once oxidized it can sponteously combust. With heat added this becomes even more dangerous. At one time I coated my cedar deck with linseed oil on a hot day. Later in the day I was surprised to find my deck smoking and one corner actually spontaneously began flaming in front of my eyes. Mineral oil is the only type of oil that is used in electric radiator type of heater and for a good reason...
?
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Re: Simple UBITX Test Set
The python code of my previous post works, but the first SWR computation is rather silly. I started with a formula for SWR given forward and reverse power, computed?power from the voltages.? Much easier to just use the voltages. So replace this python code:
? # Compute SWR from forward and reverse voltage readings
? sqprat = sqrt(vref*vref/(vfwd*vfwd));??
? swra = (1+sqprat)/(1-sqprat);
with this:
? # Compute SWR from forward and reflected voltage readings
? swra =?(vfwd+vref)/(vfwd-vref)
?
Here's the webpage from which the formulas for SWR from voltage and power readings came:
? ??
Formulas for computing s11 (the reflection coefficient) from antenna impedance, and then SWR from s11, are found here:
? ??
Jerry, KE7ER?
On Sun, Nov 1, 2020 at 08:16 PM, Jerry Gaffke wrote:
# Compute SWR from forward and reverse voltage readings
sqprat = sqrt(vref*vref/(vfwd*vfwd));??
swra = (1+sqprat)/(1-sqprat);
print(swra)
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Re: Simple UBITX Test Set
Attached is the schematic from? ?? Half of the transmitter's output voltage appears?between resistors R3 and R5.? R1 and the antenna form the other half of the bridge. D1 is a simple detector, it charges C1 with the peak voltage from that signal, so the meter sees half of the peak voltage from the transmitter. How D2 and C2 work is not so obvious, but they?detect the peak of the instantaneous difference in voltages across the bridge.? Those AC voltages can be up to 90 degrees out of phase if the antenna is purely inductive?or capacitive. In that part of the AC cycle where the left side of the bridge is more positive than the right side, current can flow through D2, charging cap C2. So the node between D2 and C2 has an AC component equal to the RF antenna voltage on the far side of C2, plus the DC component that C2 was charged with. The LPF of R8 and C4 removes the AC component so the right side meter can measure the peak of the difference voltage. For you python fans, here's my python code. Both print statements give exactly?the same value of?3.0170334337197553 This code uses python's complex number notation, the abs() function returns the amplitude of a complex value. ##################################
from math import sqrt
?
# Test computations of SWR for an arbitrary complex antenna impedance
Zant = 33 + 44j? ? ? ? ? ? ? # An arbitrary antenna impedance for a test case
?
# Compute the SWR by doing a circuit analysis of the SWR bridge
Vin = 1? ? ? ? ? ? ? ? ? ? ? # The peak transmitter voltage (value is arbitrary, it cancels out)
Zin =? (100+(50+Zant))/(100*(50+Zant))
V1 = Vin/2? ? ? ? ? ? ? ? ? ?# peak voltage at middle node on left side of bridge
V2 = Zant * Vin/(50+Zant)? ? # peak voltage at middle node on right side of bridge
vfwd = abs(V1)? ? ? ? ? ? ? ?# left side meter reading sees half of transmitter voltage
vref = abs(V1-V2)? ? ? ? ? ? # right side meter reading sees difference across bridge
# Compute SWR from forward and reverse voltage readings
sqprat = sqrt(vref*vref/(vfwd*vfwd));??
swra = (1+sqprat)/(1-sqprat);
print(swra)
?
# Compute s11 parameter from complex antenna impedance,then compute SWR
s11 = (Zant-50)/(Zant+50)
swrb = (1+abs(s11))/(1-abs(s11))
print(swrb)
##########################################
Note that transmitter power can be calculated from the left meter reading Vm1: ? ? Vrms =? (2*Vm1)/sqrt(2);? ?Power = Vrms*Vrms/50? This assumes that the antenna is replaced by a fourth 50 ohm resistor. A single DVM can be used to check the voltage at each meter position, making this an extremely cheap way to measure SWR. Most resistive SWR bridges only light up an LED, and you tune the? antenna for minimum brightness.? This can achieve a reasonably low SWR, but doesn't actually measure anything. Jerry, KE7ER
On Sun, Nov 1, 2020 at 06:29 PM, Jerry Gaffke wrote:
Would be good to include an SWR meter as part of a basic uBitx test set.
Here's a resistive bridge that I like:? ??
The two meters could be a single DVM that switches between the two positions.
They measure half of the voltage from the transmitter, also the voltage across the bridge.
I've written some python code given the two voltage readings, it can indeed compute
an SWR that agrees with an SWR calculated only from the assumed complex impedance
of the antenna.? A fourth 50 ohm resistor at the antenna port makes this a 8W dummy load.
From the forward voltage reading, we can get an accurate reading of transmitter power.
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Re: Better choice quartz for 11.059 filter
Ah, sounds right.
He might try moving the 16mhz resonator on his Nano
instead of going to the bother of building a new filter.
Jerry, KE7ER
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On Sun, Nov 1, 2020 at 06:58 PM, Evan Hand wrote:
on another thread Gerard had found a 16khz signal on the audio output of his rig with the 12MHz SSB filter. I went back and did the same test on my v4 board and found the same thing. I then checked my v5, it did not have the 16khz signal on it.?
That is one of the reasons that he is looking to swap out the 12MHz for 11.059MHz filter.?
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Re: Better choice quartz for 11.059 filter
What complaint is Gerard trying to fix? From this thread, I get the impression that he wants to move to an 11.059mhz IF so he can use newer firmware that was written for V5 and V6. ? ?? /g/BITX20/topic/77892249Moving to different IF crystals could be fun and educational, you will want a way to measure the passband of the completed filter and evaluate it for shape and attenuation. Modifying the source code of the new firmware for 12mhz would likely be easier. We had a few v3 and v4 uBitx users complaining of a strong audio hetrodyne anywhere they tuned, on all bands. ? ? /g/BITX20/message/40038It was determined that the fourth harmonic of the 12mhz BFO was beating against the third harmonic of the 16mhz processor clock.? The Nano on the Raduino has a 16mhz resonator, not a quartz crystal. The resonator can vary by 100khz, so only a few users were unlucky enough to have it fall into the 12mhz passband. The solution for v3 and v4 owners was to swap out the Nano, or somehow push the 16mhz resonator over a few khz. The permanent solution on v5 and v6 was to move the IF from 12mhz to 11.058mhz. The transmit spurs on the 15, 12, and 10 meter bands were due to distortion in the 45mhz amp creating a 90mhz second harmonic? that then mixed with CLK#2 to create a below 30mhz product. For example, when transmitting on 21mhz, CLK#2 is at 45+21=66mhz. And the 90mhz harmonic of 45mhz mixes with 66mhz to create a spur at 24mhz. These spurs were suppressed on v5 and v6 by cleaning up the 90mhz harmonic. ? ?? /g/BITX20/topic/28558651#62226Yes the 15,12,10 meter bands are not working very well for us at? this stage of the sunspot cycle. Jerry, KE7ER
On Sun, Nov 1, 2020 at 06:21 PM, Curt wrote:
you won't notice much difference on receive if you move the xtal frequency.? this change is to reduce the transmit spurious on certain bands.? and these bands are higher in the spectrum, and not working very well now.? the designer noted the impact of this change when the v5 was released - I suggest reviewing his notes to see if it is worth the effort for your use.?
73 curt
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Re: Better choice quartz for 11.059 filter
Curt,
on another thread Gerard had found a 16khz signal on the audio output of his rig with the 12MHz SSB filter. I went back and did the same test on my v4 board and found the same thing. I then checked my v5, it did not have the 16khz signal on it.?
That is one of the reasons that he is looking to swap out the 12MHz for 11.059MHz filter.?
73
Evan
AC9TU
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Re: Dummy Load Resistors & Motor Oil
I caution against use of linseed oil. Once oxidized it can sponteously combust. With heat added this becomes even more dangerous. At one time I coated my cedar deck with linseed oil on a hot day. Later in the day I was surprised to find my deck smoking and one corner actually spontaneously began flaming in front of my eyes. Mineral oil is the only type of oil that is used in electric radiator type of heater and for a good reason...
--Ron N7FTZ
Motor oil is slightly acidic.. .you don¡¯t want to use it. ? ? Motor oil might be good for high temperatures but what are its electrical properties? I believe most motor oils have a corrosion inhibitor, a wear inhibitor and some kind of detergent.? There are probably several other ingredients. I have never heard of anyone using motor oil for its dielectric strength.
From: "Steve Sawicki via " <ab2et@...>
To: [email protected]
Sent: Sunday, November 1, 2020 5:15:21 PM
Subject: Re: [BITX20] Dummy Load Resistors If you use the Linseed oil since it will with heat go "rancid" with use.
The better solution is to use the new ALL Synthetic motor oil, much better since it was designed for use in "High" Temperatures.
73's
Steve
AB2ET/4
--
¡_. _._
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Re: Simple UBITX Test Set
The discussion on dummy loads got me thinking of resistive SWR bridges.
Would be good to include an SWR meter as part of a basic uBitx test set.
Here's a resistive bridge that I like:? ??
The two meters could be a single DVM that switches between the two positions.
They measure half of the voltage from the transmitter, also the voltage across the bridge.
I've written some python code given the two voltage readings, it can indeed compute
an SWR that agrees with an SWR calculated only from the assumed complex impedance
of the antenna.? A fourth 50 ohm resistor at the antenna port makes this a 8W dummy load.
From the forward voltage reading, we can get an accurate reading of transmitter power.
In quantity on mouser, 50 ohm 2W resistors are $0.05 each,?
and 1n5711 diodes are $0.10 each.? Switching it in and out could be done
with jumpers on test pins.? The other parts are all a penny or two in quantity.
So we're at a total of about $0.50 in parts for an instrument that provides
a dummy load, an SWR meter, and measures transmitter power.
The remainder of the test set might be just some resistive attenuators?
and a diode RF probe.? So a total parts cost of $1 is not out of the question.
I believe the uBitx receiver can deal with an incoming signal approaching 0dBm,
A 0dBm signal is 0.224 volts rms, or 0.316 volts peak.
With microamp level diode currents, a shottky diode should conduct enough to make
measurements down below a 0.1 volt forward voltage, such low level measurements?
will only be accurate if corrected through the use of a calibration chart.
So a diode RF probe might be sufficient, though an AD8307 would be better.
AD8307's can be had for down around $0.30 each on eBay.
A Nano clone such as used on the Raduino should be able to send
at least a 2mhz and perhaps a 4mhz square wave out an IO pin.? A few resistors
could reduce this down to a calibrated 0dBm signal for injection into the receiver.
No need for an extra Si5351 output as a signal generator to drive the receiver
antenna port when doing a receiver check out.
Verifying that the 30mhz LPF and first mixer work properly across all bands
could be done?when checking out the transmitter in CW mode.
A basic test set such as described above is down around $1 total in parts.
A complete set of step by step instructions should be included.
It would be of considerable help to the many uBitx owners that come into the forum
wondering how to proceed when their rig doesn't work.
Having one well defined method of doing the measurements would make
troubleshooting via forum posts much easier.
Jerry, KE7ER
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Aurelia Fenderson-Peters
Gerard
George Metaxas (SV1DEQ)
