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Re: Low Power Output for Hendricks BitX20A - Watt meters and Scope readings do not agree....
#bitx20
Very weird, your math looks right to me.
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Could be a bad scope probe, have you tried more than one probe? Could be a bunch of bad scope probes. You have 4 measurements saying around 5 Watts and one saying 12 Watts. My bet is that it is around 5 Watts. And that since the 10x probe works, the scope is doing fine. If your scope is one that attempts to read the switch and scale the 1x vs 10x readings for you, could be that the?scaling feature is hosed. Not much going on in a scope probe: ? ?? In 1x mode, my cheapo scope probes show about 100 ohms from probe tip to BNC center pin, that 100 ohms might be there to prevent massive currents when I do something really stupid. In 10x mode, it's 8.9 meg. In both cases, it is almost certainly driving a 1 meg load inside the scope, just like the link above says. ? Would be interesting to replace your 1x probe with a short piece of coax. Or maybe just a twisted pair of hookup wire. Keep it below a meter in length to avoid trouble with reflections at 14mhz. Then try adding a 9meg series resistor, see if it behaves properly as a 10x probe. Jerry On Thu, May 17, 2018 at 09:13 pm, ab2ts wrote:
What am I missing? |
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Re: rough draft of how to connect BITX to PC for digital modes wiki
Joe Puma
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On May 17, 2018, at 9:08 PM, atouk <atouk@...> wrote:
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Re: share your BITX success stories
Yup, I have no idea why they come mounted sticking out the side.
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If you wish, once flipped you can keep that LM7805 cool by soldering the tab to the Raduino ground plane, though somebody once pointed out that the heat will cause the 25mhz oscillator to drift a bit more. A 25 to 50 ohm 1/2 watt resistor, perhaps on the bottom of the uBitx, in series with? that 12v line into the Raduino will reduce the heat at the Raduino. On the Bitx40, it was necessary to add caps on that 12v line to keep LCD updates on the Raduino from getting into the 12v rail of the main board and creating hash in the receiver. I've added a diode on the Raduino board between the incoming 12v pin and the LM7805, after first cutting that trace.? Provides reverse polarity protection, which the LM7805 does not. Also, when powering the Raduino from the USB cable during downloads, that 5v goes back through the LM7805 and powers the radio, which is ok I guess if you want to? listen to the SW bands while downloading but seems it might cause trouble. On Thu, May 17, 2018 at 07:54 pm, ajparent1/KB1GMX wrote:
Flipped the 5V regulator around so it doesn't hang off, my case needed that bit of space for a really |
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Re: Mic doesn't work in bitx40
#bitx40
I cant see any attachment. Just google and you will see what they look
like.
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Check your polarity of connection. At 17-05-18, you wrote: Thank you for your reply.. |
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Re: uBitx diagnostic document from Facebook group
#ubitx
Thanks to?Ufi Auttorri for creating this guide. It was certainly a lot of work to do this.?
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Low Power Output for Hendricks BitX20A - Watt meters and Scope readings do not agree....
#bitx20
I solved my stability problem for the Hendricks Bitx20A ?kit by applying the?Martiens mod. ? ? Now I need to resolve a low power output problem. ? I had been just calculating the power output from my peak to peak O-Scope readings with a 10x probe. ? However I notice that while I had 70 VPP on the scope with the 10x probe ( ~ 12.2W = (70^2)/400 ); my wattmeters both read a much lower 4 to 6 watts. ? My wattmeters are a NorCal QRP Club watt meter and a Heathkit HM-9 QRP Wattmeter. ? I am driving the microphone input with a 600 Hz phase shift sine wave oscillator.
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Re: Raduino not working 0 Volts on Pin 6 (red wire)
#ubitx-help
#ubitx
I am (unfortunately) counting in from the right, so my pin numbering?
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is reversed from that shown at? ? On Thu, May 17, 2018 at 09:02 pm, Jerry Gaffke wrote:
I've got my uBitx Raduino totally unhooked from the wiring harness and the uBitx board, |
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Re: Raduino not working 0 Volts on Pin 6 (red wire)
#ubitx-help
#ubitx
Yup, this one has been hard to follow.
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Let's keep this thread going, seems a fine title for it. Doing a search for "Rogier", I find these: /g/BITX20/message/47715 /g/BITX20/message/49091 /g/BITX20/message/49445 /g/BITX20/message/49496 /g/BITX20/message/49518 I'm assuming all his posts have been signed "Rogier". It seems he still has the original firmware installed, the Raduino worked at first,? but now it powers up with a display of "LSB A : 7150.000" and fails to respond to the function button or the encoder or the PTT switch. He also reports that? ? "There is 0 volt on pin 6 (red wire for the funktion button) to ground on the yellow wire (pin 4) or common ground on the chassis." His iMac does not see the Raduino when hooked up with a USB cable, but then? that's not unusual.? Many possible reasons for this. ? ########################### I've got my uBitx Raduino totally unhooked from the wiring harness and the uBitx board, laying flat on my desk.? Have a USB cable to a laptop to power up the Raduino. Using a corner mounting hole of the Raduino for ground, I see 4.6 volts on the first four pins in from the right on the top connector (ENCA, ENCB, FUNCTION, PTT). The 5'th is ground, so I see 0 volts there. The 6'th is 5 volts, and I see 4.7 or so because of a diode drop in the Nano. The 7'th and 8'th are analog pins without pullups, so are pretty much undefined. Be very careful when probing the 6'th pin that it does not get shorted to adjacent pins by the probe, but if you see around 4.7 volts there that will verify that the meter is set up correctly. If the Function button pin is low and the others high, could be there is something like a piece of wire or a glob of solder on the Raduino that is shorting it to ground.? With power off, how many ohms from the Function button pin to ground?? I see several mega-ohms. A shorted function button will put it into calibration mode, and it may be waiting for the function button to be released before updating the display. If all four of those pins on the right side are low, that suggests more serious trouble. Perhaps the flash program in the Nano got corrupted?? (I doubt it!) Perhaps the IO cells into the Nano got blown? (Not all four!) I'm betting the other three pins are high, and the Function button pin is getting shorted low somehow, and thus hanging up the processor. ? Jerry, KE7ER On Thu, May 17, 2018 at 07:37 pm, Gary Anderson wrote:
Rogier has a few threads open on his problems.? Casually, hard to keep up with where he is at the moment. |
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Re: Mic doesn't work in bitx40
#bitx40
Thank you for your reply.. And the 1uF polar capacitor, also behaving weird. The positive side is show the same exactly voltage with the output from 4.7KOhm resistor. But the negative side always show 1.4Volt, even when the mic is connected or not. Please help me. Thank you |
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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. |
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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 |
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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. |
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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 |
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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 |
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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. |
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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, |
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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? |
Raj vu2zap
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