Keyboard Shortcuts
ctrl + shift + ? :
Show all keyboard shortcuts
ctrl + g :
Navigate to a group
ctrl + shift + f :
Find
ctrl + / :
Quick actions
esc to dismiss
Likes
- BITX20
- Messages
Search
|
Jim, glad to see CAT is supported (a requirement for me!).? Does this (re-)release of the Teensy 4 adaptor support v5 as well?? I thought from reading the TSW website that the answer is yes, but wanted to verify.? I see a lot of talk about v6, but I've got a v5...
Still percolating in my mind how I'm going to play with the Teensy audio board on this... :-) Rob KC4UPR |
|
Re: New uBITX Ver. 6 Assembled Today
Dave,
Thanks for the feedback and tutorial. I selected that antenna specifically because of the the no tuner claim. Unfortunately I think your snake oil call is on the money! That¡¯s the bad news. The good news is I can build a 40 meter dipole reasonably easily and get on the air at least on one band. That will be another days project. 73 Mick VA3EPM? |
|
Re: New uBITX Ver. 6 Assembled Today
Mick, An end-fed antenna at it's design frequency (where it is a 1/2 wave say at 7 MHz and thus about 66 feet long) will have a very high impedance at the feed point (one end).? You typically can't just hook it to your antenna jack, and expect to get any power into it.? The MFJ-1984 has a so-called matching transformer (more about that later). Various end fed feed arrangements are typically used, including 9:1 (or higher) transformers at the feed point.? That may help get the typically 1-2 thousand ohm impedance down to 100-200 ohms or so, which can get it in range of most "antenna tuners".? Also adding a counter-poise ("ground" line) there, to help stop RF from coming back down the outside of the coax shield, which can raise havoc with your rig.? Such a setup almost certainly will require a matching network ("antenna tuner") to match whatever impedance you are seeing from the antenna/transformer arrangement to your coax/transmitter. End-feds are popular with the QRP crowd, especially for portable operations, because you only need to have a single support (nearby tree) to throw the far end up into.? But care must be exercised in feeding such an antenna, because on the design frequency (and even harmonics) it will be far from the typical 50 ohm output of modern solid-state transmitters. Now, the MFJ-1984 is making some pretty wild claims for how well their end-fed antenna matches on practically all bands 40-10M WITHOUT A TUNER (WTF?) I call snake oil.? If it really does show a low SWR across all those bands, it likely has a 50 ohm or similar resistor in the housing across the feedline.? This will of course, give you a nice low SWR everyplace, but it will also dissipate most of your signal in that resistor, rather than radiating over the air.? There was an infamous shortened dipole that had a center insulator that was potted and shielded, making it difficult to see what was inside, even with X-rays.? Eventually, they were found out that the system had a big 50 ohm resistor in the center insulator housing, and thus, any band looked good, but it radiated very poorly. You may be able to hear well, in particular on 40M, because the signals on that band are pretty loud, and you can hear OK there with a severely compromised antenna.? But, it will be very frustrating, because most stations will not be able to hear you.? Compound that with running under 10W, and you will be very frustrated, indeed. Please start with a simple resonant (cut to frequency for that band) dipole antenna, center fed with 50 ohm coax.? You can use a 1:1 CURRENT balun at the feed point, if you want to stop antenna currents from coming back down the shield of the coax, but at the moment, that might considered an unnecessary complication.? Get it up in the air at least 30 feet or so, and try that on your setup. A simple resonant dipole is VERY?efficient, and say if you do this for 40M, you will be pleased with getting out and making contacts (especially on CW for QRP) out to several hundred miles.? At only 30 feet, it won't be a DX champ, because the angle of radiation will be somewhat high, but it will fine for closer in work. Hope that helps, 73, -- Dave, N8SBE
|
|
Re: compile error
Jack, W8TEE
"...be aware that the "Processor" needs to be? ATmega328P (Old Bootloader) with the more recent versions of the IDE" That's not always the case. It's most likely to occur with clones. You should try to compile with the default setting first. If it seems to lock when it's uploading the sketch to the microcontroller, then change to the "Old Bootloader" option. If that's the case, you will likely also need to make sure you've installed the CH340 device driver. Just search for "CH340 driver download" and run the program to install the driver. Jack, W8TEE
On Friday, January 10, 2020, 8:43:55 AM EST, Gary Anderson <gary.ag5tx@...> wrote:
In addition, for the Arduino IDE via the GUI, under File-> Preferences ? ? set to verbose by Clicking "compilation" box for "Show verbose output during" ? ? set "Compiler Warnings" to pull down "ALL". This will provide us with more, possibly useful details. Also make sure you have the "Arduino Nano" board selected under? Tools-> Board: ? ?(I sometimes forget at first to change this between projects) and be aware that the "Processor" needs to be? ATmega328P (Old Bootloader) with the more recent versions of the IDE Rgds, Gary -- Jack, W8TEE |
|
Re: compile error
In addition, for the Arduino IDE via the GUI, under File-> Preferences
? ? set to verbose by Clicking "compilation" box for "Show verbose output during" ? ? set "Compiler Warnings" to pull down "ALL". This will provide us with more, possibly useful details. Also make sure you have the "Arduino Nano" board selected under? Tools-> Board: ? ?(I sometimes forget at first to change this between projects) and be aware that the "Processor" needs to be? ATmega328P (Old Bootloader) with the more recent versions of the IDE Rgds, Gary |
|
Re: New uBITX Ver. 6 Assembled Today
Ashhar,
I draw .322 on RX and 1.47 Cw and shouting the loudest I can I draw about 1.5 amps at exactly 12 Vdc. I¡¯m running a new MFJ 1984 endfed antenna that is supposed to be tuned at the factory, however until I get an SWR meter I won¡¯t know for sure. 73 Mick VA3EPM? |
|
Re: #v5 Audio, Ground?
#v5
Hello Armando,
if it is an amateurradiokits.in then they do have an issue with the V5 board. I had to grind off the bump in the case ?right underneath the board with the headphone connector so it would not short out the speaker.? |
|
Re: New uBITX Ver. 6 Assembled Today
The Antuino from hfsignals is also well worth considering.
toggle quoted message
Show quoted text
It can measure the SWR of an antenna, and with an appropriate resistive attenuator it can measure the power output of a transmitter. Unlike any of the other instruments mentioned, it can measure very low level RF signals and can scan the entire HF radio spectrum looking for spurs and harmonics. So can be a spectrum analyzer of sorts (which the nanoVNA cannot do). The antuino should be easier to learn to use than a nanoVNA. The thing that makes the nanoVNA more powerful (and more difficult) is that it can measure resistance and reactance separately, rather than lumping them together as SWR does. Either the nanoVNA or the Antuino could be used for determining the passband of a filter, but the nanoVNA would also give you information about the phase difference between the voltage and current.. Jerry On Thu, Jan 9, 2020 at 05:35 PM, Jerry Gaffke wrote:
One trick I've used? is to see how hot a 50 ohm resistor gets, |
|
Re: #v5 Audio, Ground?
#v5
I remember reading posts that had the same issue.? It was traced to a clearance issue between the aux board and the v5 board.? When installed the 3.5 mm jack terminal was shorting out.? I would check that.
73 Evan AC9TU |
|
Re: Need to Calibrate the V6
#v6
That request would be best served by creating an "issue" here:
I've noticed that it reverts to default as well, and I agree it might be nicer to show the current value, rather than default every time, but these suggestions will get buried in the threads if they don't get acted on immediately, or logged somewhere like the issues page. Reed |
|
Re: compile error
Jack, W8TEE
It would help us figure it out if you pasted the error here, too, and detailed the IDE number, your Op System, and if you copied all of the files into the same directory. Jack, W8TEE
On Thursday, January 9, 2020, 9:57:34 PM EST, Bob Bennett via Groups.Io <bobsmacbox@...> wrote:
Anyone know how to overcome the EEPROM.put (CW_KEY_TYPE_temp_key) error that keeps coming up in my ubitxv6 compile? -- Bob NZ2Z -- Jack, W8TEE |
|
Relative Power indication on Nextion display
I¡¯m running the basic CEC software (not _S version) using the LM358-based S-meter sensor Ian offered on his site to drive the S-meter function on the Nextion display. To attempt relative power indication, I Incorporated the concept from his ¡°simpler¡± version (without the LM358), tapping off the antenna connector to provide input to the IC to approximate power level.
My hybrid version is producing appropriate output on the A7 line during both receive and transmit. ?However, while the Nextion display works fine during receive, it does not show any indication of the value (on A7) during transmit. ?Does the CEC software turn off the ¡°meter¡± feature during transmit? ?If so, is there a setting to change that, or a compile time declaration to make it active? Thanks. |
|
Re: New uBITX Ver. 6 Assembled Today
We need a more objective criterion ti assess what is happening. If the local radio ia picking up the modulation then the mic can't be a suspect. If the receiver is working then there is a negligible chance that the ssb tx ia busted. Rememeber that it was shipped working. Can you measure the power supply current? If you can, then measure how much it draws when you shout 'Haaaaaallow' into the mic. The current draw increase on 7mhz should be over 1.5A at peak. I hope you have used a matched antenna. - f On Fri 10 Jan, 2020, 7:06 AM Jerry Gaffke via Groups.Io, <jgaffke=[email protected]> wrote: One trick I've used? is to see how hot a 50 ohm resistor gets, |
|
Re: New uBITX Ver. 6 Assembled Today
One trick I've used? is to see how hot a 50 ohm resistor gets,
toggle quoted message
Show quoted text
Compare that to how hot a resistor on a variable voltage DC supply gets, vary the voltage till the heating is about the same then compute watts from V*V/R A diode RF probe is trivial to build, though involves a wee bit more math to interpret properly.. V*V/R = Watts, so V*V=Watts*R, and five watts into 50 ohms is sqrt(Watts*50ohms) = sqrt(5*50) = 15.8 volts rms. If the RF probe is peak reading, you will see 15.8 * 1.414 = 22.4 volts peak into a DC voltmeter. Many RF probe designs include a 4.7meg scaling resistor so it reads rms? on the assumption that the RF is a sine wave and the DVM has an input resistance of around 10meg. Those are some very large assumptions, I prefer to have it honestly tell me the peak voltage. Let's assume a 1n4148 diode has a forward drop of about 0.6 volts, a schottky Bat54s a drop of 0.2 volts. So errors get beyond 10% if below 6v peak for the 1n4148, or (6/1.414)*(6/1.414)/50 = 0.35 Watts. And errors get beyond 10% if below 2v peak for a Bat54s, or (2/1.414)*(2/1.414)/50 = 0.04 Watts. Taking that diode drop into account, the Bat54s can give useful results to well under a milliwatt. If you want an SWR meter that also shows power, consider Diz's $12 Tandem Match kit: ? ?? Item 18:?? If you want a full antenna analyzer, consider the nanoVNA and it's newer variants, as cheap as $40: ? ??/g/nanovna-users/messages?expanded=1 A steep learning curve, but very powerful. Jerry, KE7ER On Thu, Jan 9, 2020 at 01:50 PM, Alex Netherton wrote:
|
Mick
Bob Bennett
to navigate to use esc to dismiss