Re: JackAl System Preview
I m also interesting for price + shiping JackAl board!? 9a3xz,Mikele
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Re: uBitx has a bit too crispy / semi-distorted audio even on low signal levels
#ubitx
#ubitx-help
You may be attacking the wrong problem. If I interpret the description of the audio correctly, "crispy" may be audio that has significantly suppressed lower frequencies. I encountered this problem as soon as I fired my V4 uBitx. I found out that the problem was related to the output of the 1st mixer (45 MHz) falling too close to the edge of the IF filter. In my case it was about 2500 Hz. If you are using the CEC software you can verify the symptom by adjusting the IF SHIFT frequency. After figuring out the real problem and adjusting the oscillator frequency, I am getting very good audio and much increased receiver sensitivity.
--Ron? ? ?N7FTZ?
The distortion is caused by improper biassing the final transistor pair. There will be
no distortion by taking audio from volume pot.
Raj
At 30-09-18, you wrote:
>Would taking audio from the wiper of the vol pot on the v4 not just amplify the distortion? Or will this be bypassing the audio??
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Re: JackAl System Preview
Please add me to purchase your kits thanks?
KE7GO steve
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Re: The Triple Scratch-Built BITX Club
Not I. I am a paint by number when it comes to electronics. Someone else designs, provides assembly instructions of a working project, that I can follow, then I will build and hope that it works. Hope that I don't have bad solder joints, this has never happened, or put diodes in backwards, this has happened with my first HF rig kit from Heathkit. An Elmer checked my work, found the problem, corrected it and returned kit radio to me. I am an operator. I might be too old to grasp how to make the magic work. I have tried to learn for over 30 years but it doesn't stick in my brain cells. I am better at computer hardware and programming. Terry - KB8AMZ Brimfield Twp, OH USA EN91hd Linux User# 412308, Ubuntu User# 34905,?PCARS#78, NAQCC#6668, QRP-ARCI#8855, SKCC#14195
On Wed, Sep 26, 2018 at 5:14 AM Bill Meara via Groups.Io <n2cqr= [email protected]> wrote:
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So if I buy say the Adifruit cable with the built in FTDI and download the driver, then I can download direct to the Nextion with the 4 pin connector instead of the sd card?
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Thanks N5KBP for the concise explanation.'
Can I now download the ino file from gitHub, make changes and overwrite what I have put in with the hex Loader?
Thanks Mike, I have already downloaded the latest uBit-x with the hex method and successfully used the micro-sd card.? I'm not familiar with FTDI, but will look it up
I noticed that people have their call letters on the screen.? Is this something you have to add in the Nextion simulation software and re upload?
Andy KM4TRT
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Re: Modified Baofeng Mic on BitX40 with AmateurRadiokits.in case
I used a Baofeng mic on my ubitx. Just cut off the connector and fit a 3.5mm stereo jack. Gnd for ptt can use the same gnd as the mic element.
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Re: Modified Baofeng Mic on BitX40 with AmateurRadiokits.in case
I run a stock mic on a normal stereo 3.5mm jack. The PTT and mic are on the same neutral.
Perhaps you should drill another hole to get your 2.5mm receptacle to fit or put a washer on the receptacle that is loose.?
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Re: uBIT and antenna connector and Nextion 7"
Hi Tom,
On a 160 meter mail list there are hams who report using RG6 - 75 ohm TV cable - on that band in their DXing station at full legal power of 1500 watts (and maybe a little more) without issues. Just go ahead and use whatever you have. This if HF, not microwaves.
73,
Bill KU8H
toggle quoted message
Show quoted text
On 09/30/2018 04:59 AM, Tom, wb6b wrote: I'm beginning to like SMA cables and connectors more and more. For my
short cable runs such as from transceiver to tuner or dummy load I use
short SMA cables and SMA to BNC, SO239/PL259 and F connector adaptors.
It is a great way to hook just about anything to anything. For things I
build, I now mostly use SMA. I'm thinking about replacing the two pin
antenna connector on the uBITX board with an SMA. Although for the short
length from the board to the current BNC connector, the individual wires
twisted together is probably just fine.
I live at a resort town and before I made a trip down the mountain and
bought some 50 ohm coax cables, I used 75 ohm (supposedly high grade)
coax cable available at the hardware store. It seemed to work well, but
I was making an adaptor by splicing the 75 ohm coax to a SMA cable
(before I received the SMA to F adaptors) and found the 75 ohm coax
cable has aluminum wire for the shield braid. The center conductor may
be copper clad steel. None-the-less it did work. For significantly
higher power transceivers the power handling capacity of the TV 75 ohm
coax (and the SMA cables) would be an issue.
Tom, wb6b
--
bark less - wag more
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Re: uBIT and antenna connector and Nextion 7"
75¦¸ cable will work well at HF.
On Sun, Sep 30, 2018 at 10:04 AM Rich < admin@...> wrote: That's perfect thank you. I'm not going into the 50 Vs 75 ohm debate other than to say that I am using 75 cable with an impedance transformer on my current rig. Works exceptionally well with an SWR of 1.2 on a home brew slim Jim on 2m. I get 75 ohm cable for free before anyone starts accusing lol.
That's possibly not going to work with HF variance of wavelengths, so I'm either going to have to pay for cable or come up with something else ?
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Re: uBIT and antenna connector and Nextion 7"
WF65 is also the same physical size as CLF200, so thank you for that.? I have an abundance of gear to do pretty much anything then. Perfect.
Now just to wait for the screen and mic connector to arrive.. oh and finish off building my new 3d printer for the enclosure lol
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Re: uBitx has a bit too crispy / semi-distorted audio even on low signal levels
#ubitx
#ubitx-help
The distortion is caused by improper biassing the final transistor pair. There will be
no distortion by taking audio from volume pot.
Raj
toggle quoted message
Show quoted text
At 30-09-18, you wrote: Would taking audio from the wiper of the vol pot on the v4 not just amplify the distortion? Or will this be bypassing the audio?
|
Re: uBitx has a bit too crispy / semi-distorted audio even on low signal levels
#ubitx
#ubitx-help
Would taking audio from the wiper of the vol pot on the v4 not just amplify the distortion? Or will this be bypassing the audio??
|
Re: uBIT and antenna connector and Nextion 7"
I'm beginning to like SMA cables and connectors more and more. For my short cable runs such as from transceiver to tuner or dummy load I use short SMA cables and SMA to BNC, SO239/PL259 and F connector adaptors. It is a great way to hook just about anything to anything. For things I build, I now mostly use SMA. I'm thinking about replacing the two pin antenna connector on the uBITX board with an SMA. Although for the short length from the board to the current BNC connector, the individual wires twisted together is probably just fine.?
I live at a resort town and before I made a trip down the mountain and bought some 50 ohm coax cables, I used 75 ohm (supposedly high grade) coax cable available at the hardware store. It seemed to work well, but I was making an adaptor by splicing the 75 ohm coax to a SMA cable (before I received the SMA to F adaptors) and found the 75 ohm coax cable has aluminum wire for the shield braid. The center conductor may be copper clad steel. None-the-less it did work. For significantly higher power transceivers the power handling capacity of the TV 75 ohm coax (and the SMA cables) would be an issue.
Tom, wb6b
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Re: uBIT and antenna connector and Nextion 7"
I work in the satellite TV industry in the UK, so yeah... Coax is definitely not an issue.?
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Re: uBIT and antenna connector and Nextion 7"
Different co-ax only matters if it's part of the radiating antenna. Feedline (e.g. to tuner or other matching network) not so much. Once the antenna gets close enough to resistive at whichever value, it matters little. If you have co-ax coming out your ears, it's handy as part of a dipole - broadens the resonant range.
73 de ZL2DEX
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Re: uBitx has a bit too crispy / semi-distorted audio even on low signal levels
#ubitx
#ubitx-help
Then of course there's using the existing circuit with a couple more diodes in the base circuit to drive power transistors Darlington-fashion with emitter resistors of 0.05 ohms - and a duplicate circuit driven anti-phase? to the 'earthy' side of the speaker. Real advanced, but totally basic - and all from the junk-pile! Go burst your eardrums with Hi-Fi at your leisure!
<sarcasm off>
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Re: uBIT and antenna connector and Nextion 7"
That's perfect thank you. I'm not going into the 50 Vs 75 ohm debate other than to say that I am using 75 cable with an impedance transformer on my current rig. Works exceptionally well with an SWR of 1.2 on a home brew slim Jim on 2m. I get 75 ohm cable for free before anyone starts accusing lol.
That's possibly not going to work with HF variance of wavelengths, so I'm either going to have to pay for cable or come up with something else ?
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Re: uBitx has a bit too crispy / semi-distorted audio even on low signal levels
#ubitx
#ubitx-help
and basic audio-amp practice: measure that standing current by the voltage across either or both emitter resistors. Report your finding of the V or I for cleanest audio here and a consensus will quickly be shown that can quickly be set in any rig - maybe with that preset measured could indicate a default value that can be pre-installed (factory mod?). It may vary per speaker impedance / ouput transistor type / emitter resistors value, giving more audio to taste. Honestly, has no-one any audio experience? That basic circuit is infinitely extensible!
73 de ZL2DEX
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Re: uBitx has a bit too crispy / semi-distorted audio even on low signal levels
#ubitx
#ubitx-help
If this is about uBitx V4 then you need to do the audio mod. Some boards may be overly distorted!
Cut the track between D15 and D16 and solder the center and one end lead of a 100 Ohm preset.
I use a bourne10 turn.
Set the trimmer to 0 ohm and switch on. Now slowly increase preset till distortion vanishes and the
audio volume will increase. This should happen about mid point. Do not advance it too much as you
will have hot output transistors.
Raj
toggle quoted message
Show quoted text
At 30-09-18, you wrote: Hi
THX. Because i will use stock volume control delivered with uBitx, I will disconnect VOL_MID from volume control and connect it to IN from external amp.
Martin, OK5MCA
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Terry Morris
_Dave_ AD0B
Raj vu2zap