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Re: Quick digital mode question
¿ªÔÆÌåÓýLots of people do, but also very many do not. I have been using a Pi and a ?6 usb soundcard with leads directly to my ft891 with no issues at all. All of the input levels are controlled through the software sliders for the soundcard on the pi.Cheap and effective, but I was just concerned about the voltage on the ubitx mike. I think I have settled on a series capacitor to be on the safe side. Hope to be up and running on Monday!
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Re: Quick digital mode question
That surprises me. I always use a sort of psk interface, i. e. isolating transformer (to avoid ground loops), fixed attenuator (the signal from the sound card might be too strong for an mic input), volume potentiometer (to tailor the max output of the rig up to half of full output, to save finals and have a cleaner output) and blocking caps. Il 01/dic/2018 20:30, "Daimon Tilley" <daimontilley@...> ha scritto:
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Re: Quick digital mode question
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Re: Quick digital mode question
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Re: Quick digital mode question
¿ªÔÆÌåÓýThanks but there will be no transformer decoupling via signaling or similar, just straight from Pi to usb soundcard to rig.
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Re: Quick digital mode question
Gordon Gibby
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Re: Quick digital mode question
Daimon, I have not connected anything other than a mic and amp to the uBitx, however I have a lot of experience with both Arduino's and Raspberry Pi's. Both are susceptible to high voltage on their inputs (5 volt limit for most, 3.3v for some), and can be damaged if more is applied.? The dc available on the uBitx mic connection is over 8 vdc (limited by the cureent resistor).? I would strongly recommend you use a cap on both inputs and outputs to the uBitx (note there is already a cap on the audio out). Just my 2 cents Evan AC9TU? |
Re: Found one issue was Preamp question
Woody
¿ªÔÆÌåÓýDiscussed the cross-over issue to my
brother in law.? He was also perplexed, so did more research - and
found an answer.
Turns out, it is a "feature" of the LM358!?? The way the chip is designed to reach low output voltage, it can happen at low level audio levels.? The manufacturer should have a bold caveat in the datasheet.? This is mentioned in the TI datasheet, but buried down? on page 12.?? "For ac applications, where the load is capacitively coupled to the output of the amplifier, a resistor should be used, from the output of the amplifier to ground? increase the class A bias current and prevent crossover distortion. Where the load is directly coupled, as in dc applications, there is no crossover distortion." Now I know...? Woody? KZ4AK For more on this, see:? --------------------------------------------- On 11/28/2018 22:35, Woody wrote: More testing... Found something else that I didn't suspect.? Sure won't help audio quality!!! --
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Nextion 3.5 inch display software and firmware versions
Good afternoon all
I'm new to the group,?a friend? wants to upgrade his ubitx display to a Nextion 3.5 inch type. As far as I know his radio has no mods but he would like to add a S meter with the opamp solution. There's a lot of information on the site?with different software versions?so its hard to follow , could somebody suggest a software version and link for the Nextion display?and?Arduino code that will work with a unmodified radio.? Many Thanks in Advance Alan ?? ? |
I cant seem to find
LKNDAVE
hi all,
i am working a project that i want to use VK4PLN (VK4PP) RADUINOI2C ver. 1.0 i looked in the files section and through pages of files that are poorly described. for now i need the raduino i2c rotary 16x2 i2c sl5351 dds. it sure would be nice to know if there is a sketch that include the above and the other options on the board. i have been to nicks website and left empty. i love that board, thanks NICK please point me. TNX, DAVE N4LKN 73s |
Re: Consider the Bitx40, clean and cheap for 40m
bruce, you may replace the bi-directional amps by 3 transistor version and see the performance difference. ?A friend has indicated that noise level comes down. Even One could try with single dual gate mosfet per each direction. Thanks to the designer of simpleceiver. regards On Sat, Dec 1, 2018 at 6:19 PM Bruce MacKinnon KC1FSZ <bruce@...> wrote: Hi: |
Re: Consider the Bitx40, clean and cheap for 40m
Hi:
I'm also a fan of the BITX40/20 architecture and have had good luck on other bands.? One thing I did was to create a "mainframe" of the core of the design that starts right before the first mixer and ends right after the product detector/balanced modulator.? In my own experimentation it seems like 90% of the modification are happening in the "peripherals" around the core (different LC filters, different PAs, different bands, different audio/mic configurations, different software, different enclosures, etc.) so I am able to cover more ground without needing to re-build the inside of the inside every time. My core uses two SI5351 ports so the BFO is tunable just like the VFO making it easy to fool with different IFs, filter widths, etc.? I also based the chain on the W7ZOI TIA amp which seems to improve performance a lot.? So there is a bit of the uBITX design incorporated here I guess.? The crystal filter is on a daughter card for easy swap.? I'm using ADE-1 mixers on both sides which are easily/cheaply obtained on E-Bay.? Adjustable gain VFO/BFO buffers (ala N6QW LBS design).? The core is 100% symmetric so it's quick to build and test. 73s, Bruce KC1FSZ |
Re: Quick digital mode question
Gordon Gibby
¿ªÔÆÌåÓýI ?use series capacitors often, especially to avoid the transformer output shorting out the DC! 1 microfarad works usually
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Re: Nextion Display: Source ???
I have bought this from ebay and working ok with my ubitx ver.3. Regards? 73 Ricky? ( DV3RWR) On Sat, Dec 1, 2018 at 2:59 PM Snowist <uyelik@...> wrote: I trust Worldchips store in Ali???but they have 2.4 and 2.8 inch LCDs, removed 3.5 and higher from list. |
Quick digital mode question
Hi all,?
i am about to connect my Raspberry Pi via a usb souncdard to the uBitx. in relation to the mic out from the rig to the sound card - does the dc voltage present on the tip of the plug (for the electret mike) pose a problem? I am confused as to whether or not I should add a capacitor in line to block the dc? Should I, and would that even work? thanks. Daimon. G4USI. |
Re: RF power chain mods and improvements..
Andy,
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Don't grind weller bits as they are copper coated with iron (I think). Copper tips wear out quickly as the solder dissolves copper. Raj At 01/12/2018, you wrote: Hi Tim, |
Re: RF power chain mods and improvements..
Hi Tim,
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? ?That's an interesting sounding tip - thank you.? I'm fairly new to SMD and have just used the thin pencil tip on my Weller iron.? It's worked OK so far but there's likely plenty of room for improvement.? I'll see if I can get my hands on some different tips (or sacrifice one to the Dremel deities) and see how it feels.?? ? ?I use regular 60/40 solder and settled on 600-650 because I've been able to make joints quickly and not heat parts.? After a less than stellar 'success' rate soldering SI5351 chips last week, I'm beginning to wonder if I should get solder paste and a toaster oven.? hi hi ? ?73, Andy, KG5RKP On Sun, Nov 25, 2018 at 08:07 PM, Tim Gorman wrote: Andy, |
Re: Totally Absurd -- Farhan being questioned in a police station about doctored sat picture
Gosh! Never go against the Big Three!!! Glad to hear everything should be over!!! |