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Re: Ideas for AM, NB FM Demod and CW filter board
Alison, My main interest was in demodulation. With its full HF coverage lack of proper AM detector seems a major feature lacking in the rig. NBFM comes as bonus with this chip. TDA1220 has an internal? AGC for AM. I feel simple addition of this add on board will? make uBitx a very fine Gen coverage Rx.? FM can be done possibly shift the BFO to 15MHz? phase modulate and triple it for decent deviation and modulation index and pass the signal thru 45MHz filter up reverse. As you rightly say cost and complexity will go up and we still wont be able to beat a Baofeng and a 2nd hand 817 will be a better option. With the new Ver 4 boards and connectors across the 12MHz filter I foresee people trying out parallel CW xtal filter mod soon hence thought about a plug in board. 73 Rahul VU3WJM |
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Re: Ubitx Noob help
#ubitx-help
You should have a red wire that is not connected on the audio connector.? There is a purple wire on the other connector will be a purple wire that is not connected.?? When wiring up the power connector, I would connect the red and brown together at the switch.? This is made so that if you want to , you can apply more voltage to just the final transistors for more power. One other thing, there is no fuse.? I used an inline fuse holder on the power wire with a 4 amp fuse.? You could probably use a 3 amp fuse and be ok, but mine has been modified and draws slightly more current. 73 de ku4pt On Tue, May 29, 2018 at 1:26 PM, <davedt1e@...> wrote: Hello.? Nice to meet you all and thanks for all the contributions you all make here. |
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Re: The new uBITX boards are here
¿ªÔÆÌåÓýHello to the group, I'm new here and just placed an order for the uBTIX kit two days ago. I forgot to pay the extra $10 for express shipping, so looks like another 3 to 4 weeks before I start having fun.? I'm reading about a new uBITX board. Will the kit that I ordered have the new board? I also would like to receive any suggestions and recommendations to help me get started and understanding the technology behind the uBITX.? Thanks in advance for all your help. Mike, AA5EJ? Irmo, SC Sent from my Verizon, Samsung Galaxy smartphone |
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Ubitx Noob help
#ubitx-help
Hello.? Nice to meet you all and thanks for all the contributions you all make here.
I'm new to this so please forgive my ignorance.? I've almost completed my Ubitx but have a couple of noobie questions that I'm hoping someone will answer for me. Off of the audio connector I'm left with a red wire.? Is this supposed to go somewhere? When wiring up my power switch,...Should I connect both the red and brown (the PA I believe) wires to the leg that runs to the switch? Everything else seems pretty clear so far. Thanks. |
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Re: Ideas for AM, NB FM Demod and CW filter board
Trust Rahul to discover these chips! The TDA1220 appears to be a winner. The simple alternative is a super regen at 45 mhz... - f On Tue, 29 May 2018, 22:49 ajparent1/KB1GMX, <kb1gmx@...> wrote: if the board does 10W SSB then am will be about 2.5W, not so much on that. |
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Re: Ideas for AM, NB FM Demod and CW filter board
if the board does 10W SSB then am will be about 2.5W, not so much on that.
The bands I see AM on or are 160, 75 and 40M and rarely on 10M but 2.5w will not cut it.? Generating? AM in a SSB system requires doing low level AM adding parts. For FM you need to cut back on power as it 100% duty cycle.? The only place I see any? HF FM activity is 10M, the rest is VHF and up.? That and a way to modulate one of the oscillators.?? Adding AM and FM to a ubitx is a bad way to go.? For AM RX you could use a chip but then you need agc. Listening to AM without AGC is really poor.? ?Some AM/FM RX chips exist but they must be upstream of the 12mhz?filter (too narrow for both am and FM as you need a 6-8khz wide filter for that. The uBitx is well developed for SSB and CW why make for costly and complex for modes not often used and?might make for a better separate low cost radio.? Now using it with a transverter to get SSB on VHF and UHF is simple and a good match. For FM work on those bands (2m and UHF) there are so many cheap radios that do that well enough so don't bother.? Here a BaoFeng is under 30$ and does everything I can want at 5W and it fits in my bag. Can it be done, yes the FT817 and IC703 prove it can.? Inexpensively not so much. I'd expect doing that would turn the board form a 110$ to a 200++ very quickly. Also with used FT817s out there for about 400$ (they do 6,2 and 432 as well) as all mode cost and compliance with regulator agencies becomes an issue. Allison |
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Re: A steal for Arduino Experimenters
Vince Vielhaber
Banggood's customer service isn't exactly top notch. I ordered something that came without a power cord and contacted their CS dept. The response was to send them pictures. Pictures of what? An empty spot on my desk where a cord would've been? A power strip with an empty outlet? Fortunately I had a cord here that worked (it wasn't a standard PC style cord) so I just dropped it but I'm a lot more careful of what I buy from them.
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For the price I just don't expect it to be 100%. I ordered a crimper in a plastic case. The case was all busted up when it arrived. Didn't even bother contacting them, just taped it up and left it at that. Vince. On 05/29/2018 04:38 AM, David Wilcox via Groups.Io wrote:
I bought the Elegoo starter kit for $30.00 and it came with a little CD --
Michigan VHF Corp. |
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Re: I would like to chat with someone that has set there ubtx up with a raspberry pi and is using fl digi,
Bo Barry
I have mine with an attached 5" display working good with FT8 and maybe fldigi. Short term memory shot at 78.
I'll fire it up today and take some notes. I'm using the handy usb sound card with a short extension cable AND a volume control. If you don't have one I'll send you one. I bought too many. The 5" display is a bit "tough", I recommend 7" or a big display.? Bluetooth kb& mouse ?and touch screen. We'llget U going soon!? Bo W4GHV since '54 |
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Re: Receive FM Radio Station
#bitx40
If you don't have a scope, perhaps you have or can borrow a receiver that can tune those oscillators in.
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The oscillators are an unmodulated carrier, so best if the receiver is in SSB mode so you can year a tone. But an AM receiver can be used, it should go quiet as you get near the signal. If you have a 12mhz crystal filter for the IF, the BFO should be 2 or 3 khz below 12mhz. Jerry On Tue, May 29, 2018 at 01:34 am, Raj vu2zap wrote: First check if your VFO and BFO are working correctly. |
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Re: The new uBITX boards are here
Tnx dave. This is a community effort as you know. I was helped with kicad by bhatnagar who is on this group. - f On Tue, 29 May 2018, 22:31 David Robertson, <kd1na363@...> wrote: Ashhar, |
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Re: The new uBITX boards are here
David Robertson
Ashhar,
I just wanted to comment on your Micro BITX kits in general.? In showing your circuit boards to some engineering friends of mine, they, and I, were impressed with the layout and workmanship of your boards. Considering the price of your kits the circuit design is superb, improvable but superb. I Have 2 of your mBITX kits and have really enjoyed putting them together and operating them. I am seriously considering ordering one of your new boards. Good job for you and all your crew! Keep up the good work! 73 Dave KD1NA |
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Re: A steal for Arduino Experimenters
The 8mhz clock is an RC oscillator inside the ATmega328, no external crystal or resonator required.
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Not very accurate, will wander about with temperature. But can be trimmed via flash bits if it winds up at a spot that interferes with the radio somehow. On Tue, May 29, 2018 at 07:26 am, Joel Caulkins wrote: Oh, I forgot to add that we can make the ATmega328 even easier by eliminating the 16Mhz crystal and the two 22pf caps, and use the internal 8Mhz clock which runs a si5351 and OLED display just fine with no noticeable difference. |
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Re: Ideas for AM, NB FM Demod and CW filter board
Mr Farhan did a great job of designing the uBITX and keeping the price as low as it is.? I doubt it could be done, but I would like to see something along the same line that has NBFM? and maybe AM and a CW filter in it for less than $ 200 USD shipped.? Just wish that I had the skills to do things like this. I had two reasons to get this rig.? One was to play and modify it, the other is to drive some VHF/UHF converters from the Ukrain that are selling for less than $ 100.?? de ku4pt On Tue, May 29, 2018 at 12:35 PM, Rahul Srivastava via Groups.Io <vu3wjm@...> wrote: Hi! |
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Re: RF power chain mods and improvements..
A good compromise might be to use external LPF's in the antenna coax when
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operating on seldom used bands such as 160m,30m,17m,12m. Recode setTXFilters() to use the the LPF for the next band up.? The downside is that some will inevitably cheat by not adding the external LPF for the lesser bands, and be emitting harmonics almost as strong as their fundamental.? Perhaps the stock code should not support those bands, so you have to willfully? hack the code and have some idea what you are doing before they are enabled. Or perhaps a message to the display nagging the operator to add that external filter. Jerry, KE7ER On Tue, May 29, 2018 at 09:27 am, ajparent1/KB1GMX wrote: To go 3.5 to 30mhz is a problem for engineering as they |
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Re: I would like to chat with someone that has set there ubtx up with a raspberry pi and is using fl digi,
It has been discussed here before.
I have a RPi3b running FLdigi and its ok with a external usb sound card and a FTDI RS232-3v3 serial cable. the serial cable provides DTR keying(externa or PTT)? for my Tentec 6n2 rig and the sound card with isolation transformers handle the audio.? NOTE use the RPi 3 or higher and make sure you max the clock for the version as FLdigi use a lot of the CPU.? Also tune Linux for minimum process activity so FLdigi has sufficient resources.? Try to not use software modem or pWM as it s resource intensive the external sound card I use were cheap USB stereo units 7-8$ off Amazon. I'd use the exact same interface for the uBitx as it works fine with my all of my HB SSB radios and the kd1jv 20M SlopBucket, KNQ7A as well. Allison |
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Re: Oscillation problems Bitx20a
Several things:
The IRF510 is a very good RF device in that it achieves a lot of gain and at respectable power. That translates to about 16dB in the HF range with 50 -200ma of bias.? That also means keeping it away from the low power part of the amplifier chain preferably a straight line from input to output.? I usually cut the drain lead off the IRF510 at the case and use the tab (with suitable lug and insulators) for connection.? That allows the input Gate to be further from the output? Drain and the source lead to be as short as possible with mounting the transistor to a heat sink that is grounded (use insulators and thermal grease). List that as tribal tricks. Other considerations is that power conductors can propagate signals to places not desired so by pass well (to excess). If the input circuit or output circuit is not well controlled for impedance the high gain devices (includes the drivers and before) will become oscillators.? The resistor to the gate of the IRF510 should be kept to a low value such as 47 ohms.? Also keep the toroids well apart as despite claims they do couple to the one next to it, just not as well as open coils will. Dead bug means short leads are a very good practice! Allison |
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Re: Instruction Manual needs revision
#ubitx
Too bad the pictures aren't clickable (for enlarging). Only the schematic gets bigger 73? K5KDT On Tue, May 29, 2018 at 10:04 AM W7PEA <patrick@...> wrote: Yes! There's a wiki on doing a vanilla buid I started for the same reasons you mention.??/g/BITX20/wiki/uBITX-Assembly |
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Banggood front panel template
brad martin
Figured I would share my design of the front panel of the Banggood () that I have seen a lot of people using.? Im not a graphic designer or a designer of any sort so please edit this as you like or see fit and contribute your edits as you want.? Currently the basic design of this is that the uBITX mainboard, raduino, and LCD all just drop in.  |
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Re: A steal for Arduino Experimenters
I find the Arduino clones easy enough, but the CH340 trips up lots of folks, especially those with a Mac.
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Doing away with or disabling the CH340, then coming in with a UART through D0,D1 allows a choice of the various USB-to-UART devices, perhaps FTDI or CP2102.? Having D0,D1 come to the front panel at a stereo 3.5mm jack allow D0,D1 to be used with a keyer paddle when not used for CAT or firmware downloads.? No need to mess with getting a USB cable into the Arduino. Having the USB-to-UART a separate cable assembly allows an easy UART loopback test of the host port before trying to mess with talking to an Arduino.? And if using it for CAT, a UART at 9600 baud is going to be a lot easier to filter out RFI cruft from than a 12mhz USB port. I don't think this is a slam dunk either way, it's nice to be able to plug a USB cable into an Arduino and not worry about obtaining some other thingie to put between your PC's USB port and the Arduino. Just presenting an alternate view here.? Glossary: The Nano and Protoneer are particular flavors of Arduino processor boards, and the Raduino is a board built by? hfsignals that has a Nano mounted on it plus a display and the si5351 to create our local oscillators.? CAT is an acronym for "Computer Aided Transceiver", where you use a desktop/laptop/RasberryPi to control your amateur radio transceiver instead of twiddling all the knobs and switches on the transceiver. RFI is Radio Frequency Interference.? USB is what comes out of that little rectangular port of your laptop (Universal Serial Bus), and it not Upper SideBand in this context.? UART is Universal Asynchronoous? Receiver Transmitter, a fairly primitive and easy to debug way of moving data around that predates USB by about 40 years.? D0,D1 are two generic digital pins on the Arduino that also connect to the Arduino's internal UART hardware.? The CH340 chip on the Nano listens to the USB interface from your laptop, translates it into UART signals that get presented to D0,D1 through two 1k resistors, the resistors allow you to talk to D0,D1 from some other device besides the CH340 such as a CP2102 or FTDI cable assembly of your choosing when the CH340 is not being used. Jerry, KE7ER On Tue, May 29, 2018 at 07:58 am, Jack Purdum wrote:
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