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Re: Asking for help solving a Hendricks kit BitX20 PA oscillation problem
I replaced both BS170¡¯s and solved the bias current problem. ??I re-soldered both T1 & T2. ??That may have been a contributor. ?I ended up using a 470 ohm resistor across their drains instead of the 1k resistor. ?Now all is very very stable. ???Currently trying to do a final alignment. ?Hoping that will fix my power output problem which is currently limited to about 4.2 Watts. |
Re: rough draft of how to connect BITX to PC for digital modes wiki
I had the wrong link for the FTDI cable.? It should be ? Also worth noting, you could probably save on shipping to order your parts from less suppliers than I did.? This wasn't the top of my project list so I just kept adding parts on to orders for other things as I thought of it.
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Re: share your BITX success stories
Well took it out of the box and wired up the connectors and all and having on the bench spread out.
haven't measured power in any exacting way for at 11V I see 6W at 7mhz.? Receives well. I then installed my mod for the audio amp to run it at 8V regulated.? It works.? Only one part used an lm7808. Changed the resistor on the back of the LCD from 100ohms to 330 to damp down the brightness a bit. Adjusted pot on the back of Raduino for better contrast. Flipped the 5V regulator around so it doesn't hang off, my case needed that bit of space for a really good encoder. Next step is the bias on Q70 its sitting at 1.6V way too low for good overload results. 16k resistor will fix that. After that replace q90 with 2n2222A and then check the bias it seems to be at higher current than needed. At this point I'll break for an order of a dozen MPSH10 and some other RF parts to try. The case, no matter what they say the drillin and blastin is the work: While waiting I'm working the fitment of the case and the various parts.? ?Other things that will need to be on the panel is the power led, some form of metering?for received signal strength and relative TX power (bargraph but not on LCD).? Mic jack, headphone, and antenna jack are? on the front panel along with LCD and power switch.? Then we have audio level and rf-gain.? All this goes in an area 8.x inches by 2.25 inches. It has the potential for being cramped if I use the larger tuning encoder.? ?The display eats panel space too. plodding on.. Allison |
Re: Raduino not working 0 Volts on Pin 6 (red wire)
#ubitx-help
#ubitx
Rogier has a few threads open on his problems.? Casually, hard to keep up with where he is at the moment.
He has shared more information than is contained in this thread. I usually _try_ to look a threads I've responded to, to see if progress is made or if additional inputs? / coaching might be helpful. I can see how using non threaded email, one might not understand this perspective. So, please if you have an issue where others are trying help. Please stay on the same thread e.g. subject line.? Easier for others taking their time to try an help. |
Re: Using IRF530 outputs and 2N3553 drivers in ubitx
Rahul Srivastava
I have often thought of using the IRF's in common gate mode to avoid gate capacitance issues. Never came across such a design, gain would be slightly low but should have better stability and better high freq performance after all it was done all the time with tubes. Rahul VU3WJM |
Re: ND6T AGC implementation for uBIT-X
The AGC and Pop Fix boards have both been redone and are already at the board house. Copies of the new ones are in the "Files" section.....as before.? Some of the changes were very slight but it will make for a better board and more reliable fix .....provided that nothing else got hosed.?
That wattmeter board may work quite well at lower power levels just as long as you have a 30dB span (1mW to 1W, 5mW to 5W, etc) . Testing yet to be done. 73 Kees K5BCQ |
Re: Why I bought a uBITX
While a soldering iron and a screw driver is all you need to setup the ubitx, i would encourage everyone to experiment with testing and measuring. A resistive swr bridge is just three resistors and a transformer. An RF voltmeter is a diode and a capacitor. An HF oscillator is a one evening project. Raduino, with a different firmware can be a programmable signal gemerator and a voltmeter too. Each of these kind of projects will enhance your understanding and bring immense joy to your hobby.?? - f On Fri, 18 May 2018, 00:46 Jerry Gaffke via Groups.Io, <jgaffke=[email protected]> wrote: I haven't seen a lot of flames here regarding imprecise measurements. |
Re: Raduino Questions for Bitx40
Then board seems alright. It looks like some raduino wire is grounded?that shouldnt be grounded. Check your wiring carefully against the wiring diagram at HF Signals. - f On Fri, 18 May 2018, 04:04 Thomas Erwin, <terwin3486@...> wrote: Greeting, |
Re: uBITX Wireup Diagrams on the HF SIGNALS WEBSITE ARE WRONG!!
#ubitx
#ubitx-help
What you are missing are some resistors plus these comments from the Raduino source code file? ubitx_keyer.ino:
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* CW Keyer
?*
?* The CW keyer handles either a straight key or an iambic / paddle key.
?* They all use just one analog input line. This is how it works.
?* The analog line has the internal pull-up resistor enabled.
?* When a straight key is connected, it shorts the pull-up resistor, analog input is 0 volts
?* When a paddle is connected, the dot and the dash are connected to the analog pin through
?* a 10K and a 2.2K resistors. These produce a 4v and a 2v input to the analog pins.
?* So, the readings are as follows :
?* 0v - straight key
?* 1-2.5 v - paddle dot
?* 2.5 to 4.5 v - paddle dash
?* 2.0 to 0.5 v - dot and dash pressed
?*
?* The keyer is written to transparently handle all these cases
?*
So there is one wire into the Raduino, but the voltage on that single wire says if you have nothing going on, the straight key is pressed, or the dot or dash paddles are pressed. Very clever. Unfortunately, it doesn't work very well.? A little bit of dirt in your straight key contacts and the resistance there can be enough that the Raduino things it's a dot paddle press. Here's a hardware fix, your key tells a fet to turn on, which in turn switches the resistor network: ? ?? Some of the newer firmware releases have ways around this problem also.?? Jerry, KE7ER On Thu, May 17, 2018 at 06:02 pm, Alan Shapiro wrote:
How can the plugged in paddle work when only the tip (or ring) and ground of course,are connected?? Don't both tip and ring have to be wired?? What am I missing? |
Re: ND6T AGC implementation for uBIT-X
Yup, that would work.
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I'm thinking of something useful for detecting low level RF when trying to figure out why the transmitter is putting out 1 Watt instead of 5Watts. But the scaling resistors in front of your AD8307 could be adjusted as needed. I was also thinking that if the AGC or pop fix boards needed to be redone, you might squeeze in pads for an AD8307. Nik has an AD8307 on his Raduino: ? ?/g/BITX20/message/42237 Did anyone try it? Was it quiet enough to be useful? Jerry, KE7ER |
Re: A friendly suggestion for Farhan.
I made a mag loop for 40 and am working on the homemade capacitors remote tuning mechanism. I started with an arduino and servo, and now going KISS with a DC 0.6 RPM motor, momentary rocker switch, PWM driver to slow it down more, and a field strength meter to use instead of a SWR meter. I once said before the uBITX was released I wouldn't mind assembling and winding the toroids myself like other kits are. And I too stock parts. Woodworkers stock wood, machinists stock metal, we all stock things for our hobbies as we chose to enjoy it. It's an investment in our continued enjoyment, as well as a convenience. Who likes to wait 6 weeks to start a project?
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Re: Using the uBitx with FT8
By the way, thanks Doug for taking the time to post your work on doing this. I'll very interested in doing the same thing! Roy WA0YMH On Thu, May 17, 2018, 7:46 PM Doug W <dougwilner@...> wrote: I just posted how I did it.? There are many other ways but this should get you started.? /g/BITX20/message/49561 |
Re: rough draft of how to connect BITX to PC for digital modes wiki
¿ªÔÆÌåÓýI followed a similar approach.? Mounted a 4 port usb hub inside the case.? One port for the radiuno, one for a 6 buck usb sound dongle, two free for future use (rtl dongle for panadapter and maybe a pi0 for for something in the future). I also used an Easy-Digi board simply because I prefer to have the radio as electrically isolated from the computer as possible.? The advantage of the USB sound dongle is that the radio gets it's own dedicated audio in and out channels. This way I can have WSJT-X running and not lose my main PC audio. ? Disadvantage?? I used an unpowered hub that puts a load on a single USB port with the RTL dongle plugged in.? I'll change that later. The only thing I had to do to tame the audio is to put a 330 ohm resistor across the output side of the audio out (dongle mic in) to make the volume adjustment smoother. I run the CEC software to control freq changes and transmit from
WSJT-X via CAT control through Onmi-Rig. On 5/17/2018 8:45 PM, Doug W wrote:
It seems almost every day (or hour) someone has a question about connecting their radio for digital modes.? Following are my cobbled together notes that if the group deems worthy could be the start of a wiki page on the topic.? My concern is my use of a TRRS jack might be too specific, but at least this is a place to start.? Your feedback is welcome. |
Re: uBITX Wireup Diagrams on the HF SIGNALS WEBSITE ARE WRONG!!
#ubitx
#ubitx-help
How can the plugged in paddle work when only the tip (or ring) and ground of course,are connected?? Don't both tip and ring have to be wired?? What am I missing?
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Re: Using the uBitx with FT8
I just posted how I did it.? There are many other ways but this should get you started.? /g/BITX20/message/49561
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rough draft of how to connect BITX to PC for digital modes wiki
It seems almost every day (or hour) someone has a question about connecting their radio for digital modes.? Following are my cobbled together notes that if the group deems worthy could be the start of a wiki page on the topic.? My concern is my use of a TRRS jack might be too specific, but at least this is a place to start.? Your feedback is welcome.
---------------- There are many different ways to pair your radio¡¯s audio and ptt circuits with a computer to work digital modes.? This is not a discussion of all the different ways.? This is how I did it.? Most of the information is readily available if you search this list and online. I'm using an Easy Digi kit for switching PTT and isolating Rx audio.? I found the loss was too high on the Tx side so I'm going right from the sound card to the rig for Tx but I will describe using both sides of the Easy Digi below.? I set up my radios with a mono jack for the speaker and TRRS for mic/PTT and corresponding cables on the Easy Digi so everything is interchangeable.? I'm using a USB sound card and an FTDI cable.? I have the sound card and FTDI cable plugged into a small unpowered USB hub with the Easy Digi hot glued on top with the cables all hot glued for strain relief.? It is ugly as sin but sits out of sight and works.? There are links below to all the parts I used. Pop the cover off the USB sound card and desolder the two audio jacks.? Cut two pieces long enough to go from the sound card to the Easy Digi off the mono cable.? It is 6¡¯ long, you have plenty to spare and it is good shielded cable.? Solder the cables where the jacks were and route them out the holes in the case where the jacks were.? Now solder those cables to the corresponding spots on the Easy Digi.? Mic from the sound card to Audio to PC on the Easy Digi and speaker on the sound card to Audio from PC.? Now solder the audio cable with plugs to the Easy Digi board.? Audio to your radio¡¯s speaker via the mono cable and Mic to your radio¡¯s mic via the 4 conductor cable if doing it like I did.? The last connections are from the FTDI to the Easy Digi and the Easy Digi to your ptt.? Cut the RJ45 connector off the FTDI cable and connect the following cables to the Easy Digi, Black to DIG GND, Green to DTR and Brown to RTS.? Those are the only wires you will use in that cable.? Now connect PTT HI on the Easy Digi to your PTT wire and PTT GND to your PTT ground.? Both of these are also part of the 4 conductor cable.? Now plug the FTDI cable and USB sound card in the USB hub and connect the hub to your computer.? If you are using Windows, your machine should set both up without issue.? Connect the mono jack to your radio's speaker jack and the TRRS plug to your TRRS jack or however you have your mic and ptt connected. Assuming you are using WSJT-X, in settings under the radio tab select RTS for PTT method and whatever port the FTDI adapter cable shows up on.? With a dummy load connected to your radio click the Test PTT button several times to make sure it toggles Tx on and off on your radio. One last very important thing.? The heat sinks on the IRF510¡¯s are sized for casual voice and cw work not the full blast usage of digital modes.? Make sure you have a plan to deal with the heat.? There are many other posts on heat sink ideas.? I have found even a little air flow from a small fan makes a huge difference.
? Easy Digi
https://www.jameco.com/z/PJ31640-3-5mm-4-Conductor-TRRS-Panel-Mount-Phone-Jack_2201607.html
https://www.amazon.com/gp/product/B01J4G00MI -- Doug AC9RZ |
Re: ND6T AGC implementation for uBIT-X
The diode detector could be dead-bugged.
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Better might be pads for an AD8307 on one of those boards someday. On Thu, May 17, 2018 at 04:07 pm, Jerry Gaffke wrote:
? A schottky diode plus C's and R's to build a diode RF detector, cost another dime, display to a DVM or perhaps the Nano's A7 |