Re: Bitx40 very loud, high-pitched, low frequency noise
Fun fact, when I start to touch and move around the brown wire from volume control knob, I can hear local FM radio station.
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Eyesight prohibits finishing uBitc ver 4
Cant see well enough to finish
Ubitc ver 4 mounted in chassis along with auto tuner and power supply. Switches and jacks installed. Includes pc oscilloscope and RF tap for use with oscilloscope.
?search uBitx on ebay
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Bitx40 very loud, high-pitched, low frequency noise
Hi! I've just finished assembling my Bitx40, and when I turn on the radio, I hear a terribly loud noise (link to listen below). The radio works fine, because I can hear some operators behind that noise, but I cannot tune the radio loud enough to hear them properly, as the noise is extremely loud even on the smallest volume. I don't really know what's happening gere. Any help?
The noise: https://www.youtube.com/watch?v=1j0ywo45N7I
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Ivan
cool stuff.? remember that 4.7 k resistor you installed?? find the 'outside' of the resistor - and arrange a push button connection to ground.? the Raduino reads the voltage created at the 'inside' of this resistor (you can see it then with a DVM) to command the rig to transmit a CW signal.? the outside of course goes to where a key jack is located (whether you installed one or not -- this push button can exist simultaneous with a key jack).?
Curt
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Hi Friends !
My name is Ivan and i'm a happy owner of a V4 microbitx. I'm not using CW mode in my Microbitx but i would like to add a switch in the front panel to send the cw tone in order to tune.?
If someone can give me a hand i will appreciate?
KN4TOU?
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Those filters are 25 MHz wide NOT 25kHz
On Tue, Aug 20, 2019 at 9:42 AM kh6sky < kh6sky@...> wrote: You could use one of these inexpensive ($5 ebay) Texscan LC filters for a 70 MHz IF and it might go well. These are 25 kHz wide at the 1 dB points and I have not seen a curve but the data sheet says "sharp skirts".??
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You could use one of these inexpensive ($5 ebay) Texscan LC filters for a 70 MHz IF and it might go well. These are 25 kHz wide at the 1 dB points and I have not seen a curve but the data sheet says "sharp skirts".??
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thank you but if i change the frequency to 60 mhz or more i have to change the value of the capacitors and the number of turns?
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You could just make LC filters as well. A triple tuned filter should do the trick. While you are at it, change the 1st IF from 45 Mhz to 60 MHz or beyond.
- f
hello i have finished building the ubitx CM2KMK version and i have problems with the 45mhz crystal filter. the only filters i have in my inventory are the following--
22M03? ? ? ?45,1mhz? ? ?from a motorola GM300
49S10B? ? ?49,95 mhz? ?from a kenwood TK760
FL-210? ? ? ?21,8 mhz? ? ? ?from Icom M59
I have tested all of them by changing the frequency acording to each crystal in the source code.The best results so far i get with the 21.8mhz filter FL-210.
iI think the problem is matching the impedance with the two coils L5 and L7 i used 12 turns on T37-6 .
Please if someone have any documentation about the filters or knows what impedance they have i wil be very thankfull.
Thanks in advance ! 73de yo4huj
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Yes a low amperage fuse for now. There are many linear power supplies well under 10 amps on the planet, likely you can find one at what you in the UK refer to as a rally.
I have a little mfj switching supply, and I imagine some have homebrewed one similar.
Enjoy your build.
Curt
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Mark, interesting...I really know nothing about the legacy as this v5 is my first ubitx, but not my first home built rig.
I can't imagine a corrrectly designed filter would have a 3db or greater insertion loss, perhaps using wrong values by experimenters on earlier version could cause this. I suspect Allison is correct with just a wrong part in my filter.
In-circuit measurement isn't easy, I may try to use my vna on it to check it's transfer function, or just unsolder a few and measure..
Thanks all!
Brad
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On Mon, Aug 19, 2019 at 06:26 AM, Jack Purdum wrote:
but this article looks like it could help:
What an interesting site. The site that host the article you linked: Has a lot of interesting projects and articles. It is amazing how well the experimenter/maker/hobbyist world is doing, with so many sites devoted to technology for experimenters. The projects now days were just science fiction dreams 30+ years ago. Tom, wb6b
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hello i have finished building the ubitx CM2KMK version and i have problems with the 45mhz crystal filter. the only filters i have in my inventory are the following--
22M03? ? ? ?45,1mhz? ? ?from a motorola GM300
49S10B? ? ?49,95 mhz? ?from a kenwood TK760
FL-210? ? ? ?21,8 mhz? ? ? ?from Icom M59
I have tested all of them by changing the frequency acording to each crystal in the source code.The best results so far i get with the 21.8mhz filter FL-210.
iI think the problem is matching the impedance with the two coils L5 and L7 i used 12 turns on T37-6 .
Please if someone have any documentation about the filters or knows what impedance they have i wil be very thankfull.
Thanks in advance ! 73de yo4huj
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thank you very much now i understand. 73 all the best
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Thanks.? This is exactly what I was looking for.? If I dive in, i'll go V5.
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I think that you need to answer that question for yourself.? If you go back and read some of the threads in this group for Spurs and Harmonics, you will see that there are a number of modifications that you would need to make to bring the version 3 (v3) into FCC compliance.? So if you like to modify things, the v3 will give you a lot of opportunities beyond adding things.? You may also be equipment challenged to verify if you have tamed the spurs, any second receiver with some measurement system should be able to help with the harmonics, or just use SSB and not CW.
There are also comments about key clicks and audio issues with the v3 on this group.
If you want to learn allot and jump into kit modding, get the v3.? If you want to build a fairly compliant semi kit and add improvements of functionality (touch screen, AGC, S meter, ect..), buy the new v5.? Your choice.
FWIW
73
Evan
AC9TU
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Yes, order the v5 board and get the latest and greatest. There were a number of worthwhile improvements between v3 and v5.
I'm having a lot of fun with my v5 uBITX.
73,
Doug K4DSP
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On Mon, Aug 19, 2019 at 11:14 AM, Jon Schumacher wrote:
Greetings,
I read the article in this months QST.? I am intrigued and am
contemplating making an order.
BUT!!!
I have a friend who likes to build kits.? He bought a version 3 kit and
a box to go with it a year or 2 ago and never touched it. He offered it
to me for a great price.? I am leaning towards just getting the latest
and greatest.
Any thoughts??
Jon - N8UL
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Greetings,
I read the article in this months QST.? I am intrigued and am contemplating making an order.
BUT!!!
I have a friend who likes to build kits.? He bought a version 3 kit and a box to go with it a year or 2 ago and never touched it. He offered it to me for a great price.? I am leaning towards just getting the latest and greatest.
Any thoughts??
Jon - N8UL
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The only weak spot I see is the ADC chain.? It¡¯s 14 bits but while the spec says there are two¡ there is actually only one and its muxed.? But it can resolve differential signals because of the way it¡¯s set up. ? ?
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From: [email protected] [mailto:[email protected]] On Behalf Of Jack Purdum via Groups.Io
Sent: Monday, August 19, 2019 8:04 AM
To: [email protected]
Subject: Re: [BITX20] Help #arduino? As many of you probably already know, PJRS, the makers of the Teensy family, just added the Teensy 4.0 and it is a beast! Some features include: ¨C ARM Cortex-M7 at 600 MHz
¨C 1024K RAM (512K is tightly coupled)
¨C 2048K Flash (64K reserved for recovery & EEPROM emulation)
¨C 2 USB ports, both 480 MBit/sec
¨C 3 CAN Bus (1 with CAN FD)
¨C 2 I2S Digital Audio
¨C 1 S/PDIF Digital Audio
¨C 1 SDIO (4 bit) native SD
¨C 3 SPI, all with 16 word FIFO
¨C 3 I2C, all with 4 byte FIFO
¨C 7 Serial, all with 4 byte FIFO
¨C 32 general purpose DMA channels
¨C 31 PWM pins
¨C 40 digital pins, all interrrupt capable
¨C 14 analog pins, 2 ADCs on chip plus more. Paul was very careful when he selected his Beta testers for it, and most were frequent contributors to his Forum and the authors of major libraries. They been beating on it for almost a year, so I think the core should be pretty stable. The footprint is actually smaller than the 3.6 and the cost is, too...$19.95. It's overkill for many projects, but the depth of that resource pool opens a whole new world in many arenas! On Sunday, August 18, 2019, 11:20:55 PM EDT, Evan Hand <elhandjr@...> wrote: The short answer is yes, if you add the screen features you want to the Arduino firmware.? I am not aware of any such firmware available.? There is also a shortage of I/O in the stock Raduino.?
I would suggest that you first look at the Nextion display work that can be found here:??
Dr. Lee has written software and screen designs to work with the Nano that came with the uBitx.? With all the added features, there is very little room for more modifications in the Nano code.? You do need to purchase a Nextion display with touch screen capability.?? Be sure to verify the screen size and the enhanced version with touch capabilities to work with the KD8CEC software.? I used both the 2.4 and 3.2 inch enhanced versions.? Available from multiple vendors.
There is the also JackAl add on board that did change the processor to one with more memory and speed.? That is available here:?? This has higher capabilities, at a higher price.? Be sure to note that the listed price for the board does not include every thing that you need to make it work.
You can go the route of converting the Nano code to a larger/more powerful processor like the Teensy on the JackAL board or other newer Arduino based system.? Regardless, that will be a significant effort.? Would be curious to see any results that you come up with.
73
Evan
AC9TU -- ¡_. _._
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MadRadioModder