Re: uBITX AM BCI Filter
#ubitx
Hello Nick,
This is looking very good.
I will try a quick version tomorrow with T68-6 toroids (the smallest size I have handy) in the antenna circuit just to see how much attenuation I get. I am using the same circuit as yours and re-calculated the turns for the T68-6.
If that works I will order some small T30-6 toroids and do the same a you.
Please let me know the results when you wire yours up. I will keep you informed of my results.
All the best,
73, John (VK2ETA)
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I believe you will find that the front and rear panels for these cases are isolated electrically from the rest of the cabinet. They nestle into the plastic rim around the front and the back.?
If you want an RF proof enclosure you will have to run a ground wire from the panels to the rest of the case.?
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Re: Found another case for the Ubitx
I have one on back order. I have the smaller one and I just can¡¯t get the ubitx in it. However it is a nice case so I backordered the bigger one
Bob
W5rkm
On Jan 31, 2018, 5:34 PM -0600, wishbone_aaa <dlmock@...>, wrote:
Looks like this would be a good candidate.
https://www.circuitspecialists.com/metal-instrument-enclosure-la-6.html
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Re: Software support Request for Full QSK BITX40
If the IRF510 gate is driven hard with a square wave, it switches fine at 7mhz and beyond, showing a nice square wave
for drain voltage (0-24v) and drain current with troughs all the way to zero.? That's with a 50 ohm antenna load, supply at 12v.
If the antenna port impedance is 10000 ohms at 7mhz, those drain and antenna port voltages roughly double,
and drain currents are kept fairly small.? ? I assume the lack of major voltage spikes is because
there remains some drain current in the troughs?due perhaps to miller effect capacitance
If the antenna port impedance is 10000 ohms at 7khz, the simulation shows
the kilovolt spikes I'd expect from a flyback transformer.
??
Quite curious.
But I think I'm ready to start playing with the uBitx, as the push-pull final there should be more predictable.
Jerry
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On Wed, Jan 31, 2018 at 03:32 pm, Jerry Gaffke wrote:
So T7 does indeed behave like a flyback transformer at slow speeds, but at 7mhz the IRF510
stays on to where that coil current always has somewhere to go, T7 behaves more like a forward transformer.
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Jack, I am using the serial connection. No drivers needed. ? v/r Fred W4JLE ? ?
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From: [email protected] [mailto:[email protected]] On Behalf Of Jack Purdum via Groups.Io
Sent: Wednesday, January 31, 2018 14:48
To: [email protected]
Subject: Re: [BITX20] Nextion Display? Are you running the Nextion from the STM32? No driver issues?
From: Dr Fred Hambrecht <w4jle@...>
To: [email protected]
Sent: Wednesday, January 31, 2018 2:13 PM
Subject: [BITX20] Nextion Display ? I may be late to the party, but I have just discovered the NEXTION?display. I am using it on my BitX. What makes it really neat is the software that can be downloaded from the manufacturer's site. It takes all the pain out of graphics programming. I have also replaced the UNO with an STM32 as in addition to the normal stuff I have added a GPS module to display time/location/grid square data as well as using the 1PPS to do a continuous correction to the SI oscillator. The higher resolution allows calculating the SWR etc with much finer gradations.? I will be adding a filter board from a CODAN that will allow all band operation.(bought for $12.00 on EBay). Amazing what is available to the?homebrewer today! ?
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Re: Fixing a blown Raduino board
Bernie:
Usually a "ticking" noise is caused by communication
between the chip and the LCD. It may not be that, however.
Anyway it is a kind of "normal" RFI from a uPC. Usually it can be
eliminated with proper wire dressing or shielding. Most uBITX'ers
have used shielding on extension cables for the LCD because
that is when they hear it.
john
AD5YE
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Re: Found another case for the Ubitx
Got one on backorder for my third uBITX. ?uBITX should ship pretty soon so I hope the case backorder doesn't take too long too. ?I've used the smaller versionsions of this case on other projects and it's really nice to work with but the aluminum front and back panels are really soft aluminum so be careful drilling holes and cutting the LCD window.
Jim Sheldon, W0EB
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Re: UPLOAD FIRMWARE IN RADUINO
What are those lights on the nano anyway? And do I need them?
There are usually 4 leds on the nano. They are usually in a row and
labeled "RX TX PWR L".
The RX and TX lights are connected to the lines that connect both the USB
interface and the ATMega628P. They connect to TX0 and RX0. They are very
useful as their flashing shows that communication is taking place during an
upload. Likewise, if RX flashes once and then not again during an upload,
there is a communications problem. Usually they are red and green; some may
be orange. Messing with them will probably mess up RX0 and TX0. It is
best to leave them alone. They are always out (low) with no serial communication
to the chip. If they stay on, something is wrong...
PWR refers to a direct connection to the voltage regulated 5v line. It is NOT
connected to the input voltage, whatever that may be. It is an indication that
the board has power either from Vin or USB. That is all it does. It is usually
red though I have seen many orange lights. It is useful, but it could be eliminated,
I guess.
L is connected to D13. It is a good light and should not be disconnected. If the
ATMega has a bootloader (which it should in a nano) this will flash three times
when the reset button is pushed and released. That is not guaranteed because
earlier versions of the bootloader did not show themselves through D13. And
if the ubiquitous Blink program is loaded, it will falsh D13. That alone makes it
a good light to retain. It is your "diagnostic visual indicator".
Anyway, that is what those leds do.
Hope this helps.
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Found another case for the Ubitx
Looks like this would be a good candidate.
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Re: Software support Request for Full QSK BITX40
Gary,
Simulating just the IRF510 and T7, minimal load, driving the gate hard with a 0-10v square wave,
I see spikes to several kV as current through the IRF510 shuts off, but only if I slow the square wave down enough.
The simulation gets kind of weird with a load of 10k ohms or more
At 7mhz the IRF510 stays on, even in the troughs, even though the gate pin goes to zero volts.
I haven't looked at the model for the IRF510, but all it would take is resistance going into the gate?
and miller capacitance from drain to gate to account for this.
So T7 does indeed behave like a flyback transformer at slow speeds, but at 7mhz the IRF510
stays on to where that coil current always has somewhere to go, T7 behaves more like a forward transformer.
Jerry, KE7ER
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On Wed, Jan 31, 2018 at 01:26 pm, Jerry Gaffke wrote:
With no load at the antenna port, the simulation shows an IRF510 drain current that stays near the quiescent 100ma
with perhaps 20ma pk-pk of RF riding on top of it.? (An initial spike that I'm ignoring here, as we would be increasing?
drive at audio rates.)? ? The drain current never goes toward zero, even when Q13 is driven with 400mv pk-pk.
Gate voltage is quite distorted, but does get down to 1.2v which should be enough to shut down the IRF510.
I'd guess that as the IRF510 shuts down the drain voltage rises, the gate-drain capacitance causes the gate voltage to rise,
and so the IRF510 continues to conduct.? ? ?When operating more slowly the IRF510 does indeed shut down as Vgs rises.
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Re: Spare/replacement part
As for T2 remove it from the board and check if the insulation has been removed from all leads. I have seen cases where one lead of coil still had the insulation causing an intermittent connection such as you have described.
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Jerry,
?You can do a ESP32 Widora Air for about $12 with free shipping.?? The ESP32 packs quite a punch in I/O, memory, and processing.? That and Bluetooth and WiFi.?? The Widora particular package is about the same as the STM32 device you're talking about.?
73, Michael
KM4OLT
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On Wed, Jan 31, 2018 at 01:32 pm, Jerry Gaffke wrote:
Scratch that.
The STM32F103C8 has a measly 64kbytes of flash, 20kbytes of ram.
For megabytes, you'll have to shell out $5 for the RasberryPi-zero.
. . .
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Jack,
?The Nextion display only uses a serial port.? Software is written on the processor on the display to change the display contents based on data sent back and forth on the serial port.??? This allows in this case the external processor to deal with data a processing and letting the display itself to handle graphics content.?
73, Michael
KM4OLT
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On Wed, Jan 31, 2018 at 11:48 am, Jack Purdum wrote:
Fred:
?
Are you running the Nextion from the STM32? No driver issues?
?
Jack, W8TEE
?
?
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Re: Audio gone on new ubitx
Have you checked Q71? Try removing it. Go to CW mode and see if you get the CW side tone
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Re: Audio gone on new ubitx
Try a firmware reload?? Also check
connections between board and raduino, and raduino and display.
M
On 1/02/18 10:17 AM, Erik Hokansson wrote:
I
do have 12v at pin 2.. I was able to key up the P tt and use a
keyer to transmit...they key word there is "was"..now the display
just reflects the u bitx version and stays there?
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Re: uBITX Firmware (CEC) 0.30 released (Test version).
#ubitx
Ian should have a guide available shortly to explain his software enhancements as a release version is almost there.? You are using the beta 0.34 version. ??
At top left is the frequency of the other VFO, not currently in use.? So if you have VFO A in use this is VFO B frequency.? The middle section shows the step value on the encoder, and the right hand shows the key type - Iambic A, Iambic B or Straight Key.
I am finding the IF shift helpful, and I like being able to adjust the frequency step value by holding in the butto for about 2-3 seconds.
Mike
On Thu, 1 Feb 2018 at 9:27 AM, Je < emilus@...> wrote: Congratulations to the author at first glance seems OK. But what is the 14.150k on the first line of the display?
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Re: Spare/replacement part
Check to see if coils are touching any smts. One of my bitx coils was soldered to a resistor, I guess during final assembly it was up against it and got hot enough to stick. I¡¯m going one by one checking missing parts, bad solder joint, etc.
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On Jan 31, 2018, at 13:33, Michael Davis < maddmd818@...> wrote: T2 on my Bitx40 is intermittent. By that I mean, if I nudge it my receiver cuts out, if I move it, it comes back on. I have re-soldered the circuit board connections and have removed T2 from an old Bitx40 board. The leads are short and before I attempt to unsolder the bad T2, I though I'd ask if there is a way to buy a spare. I am going to examine the connections more closely with my computer microscope first. Is T1 identical to T2? Any others on the board identical. Thanks
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Scratch that.
The STM32F103C8 has a measly 64kbytes of flash, 20kbytes of ram.
For megabytes, you'll have to shell out $5 for the RasberryPi-zero.
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On Wed, Jan 31, 2018 at 12:14 pm, Jerry Gaffke wrote:
I'm currently playing with a "Blue Pill", has the STM32F103C8, $2 on ebay
? ??
Has the M3 core at 72mhz,? 64meg of flash, 20meg of ram, 12bit ADC.
Otherwise much like like the Nano, IO is primarily 3.3v with some 5v tolerant pins.
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Re: Software support Request for Full QSK BITX40
Gary,
With no load at the antenna port, the simulation shows an IRF510 drain current that stays near the quiescent 100ma
with perhaps 20ma pk-pk of RF riding on top of it.? (An initial spike that I'm ignoring here, as we would be increasing?
drive at audio rates.)? ? The drain current never goes toward zero, even when Q13 is driven with 400mv pk-pk.
Gate voltage is quite distorted, but does get down to 1.2v which should be enough to shut down the IRF510.
I'd guess that as the IRF510 shuts down the drain voltage rises, the gate-drain capacitance causes the gate voltage to rise,
and so the IRF510 continues to conduct.? ? ?When operating more slowly the IRF510 does indeed shut down as Vgs rises.
Jerry
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On Wed, Jan 31, 2018 at 09:40 am, Jerry Gaffke wrote:
One major conundrum:?
When the Bitx40 IRF510 turns off and the magnetic field collapses that energy needs some place to go,
the induced emf in T7 will create voltage spikes that rise as high as it needed till it finds a load,?
perhaps arcing across the transformer.? But my LTSpice simulation of the Bitx40 final with no load
shows no such spike, the output voltage remains pretty much determined by the turns ratio
as if T7 were a straight up forward transformer.
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Re: Audio gone on new ubitx
I do have 12v at pin 2.. I was able to key up the P tt and use a keyer to transmit...they key word there is "was"..now the display just reflects the u bitx version and stays there?
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Bob McMillan
Jim Sheldon
Michael Monteith
James Lawrie