Re: #ubitx. Great EFHW group on Facebook
Most, if not all, of the design information presented on that FB group is simply wrong. The gimmicky transformer that is advocated works well only with truly resonant half wave wires and only on the bands on which the system is resonant. And even then it is not nearly as good as a simple LC tuner. The reason that group keeps going and propagating their rubbish is they systematically exclude and block anyone who produces actual data that refutes their ridiculous claims. Read the EFHW trail here and you will be much better informed than if you rely on those videos and the group chat.
WA8TOD
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Re: Odd Raduino, How do I Connect it?
#bitx40
I think Arne has a BitX40 and the confusion is that the wire up instructions say to connect the 5-pin connector to the Raduino, but there no longer is a 5 pin header to match. Instead, HFSignals is currently shipping the same physical Raduino package for both the BitX40 and the uBitX, just with different software loaded. So, to answer the question, use the 5 pins closest to the blue pot to connect to.
=Vic=
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Re: Right-sided relay harmonic attempted fix for v3/4 ubitx
Warren thanks,
I googled around and discovered I'm not the only one trying to prototype things with tiny chips. So, thanks for pointing the Adafruit one out. I'll order the Adafruit one or see what Digi-Key has.
Tom, wb6b
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Re: Right-sided relay harmonic attempted fix for v3/4 ubitx
Jim
You might want to look at these Adafruit breakout boards. They are great for prototyping with QFNs.
WA8TOD
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Re: Right-sided relay harmonic attempted fix for v3/4 ubitx
Gordon,
"the uBitx is mounted on a PLASTIC upturned Dollar Tree desk organizer"
Well it looks good, anyway. I'm a fan of dollar tree stuff myself.
I have to take the long path and build a SA first, then I'll try the heavy metal and straps approach on my uBITX. Even if it improves things, it may or may not be enough. Then I'm going to see if the 15V suggestion actually improves the TX chain gain, without making a bunch of mods to improve the gain running at lower voltages, like 12v. And make sure it is a good solution, not one that leads to overdriving things and creating more spurious emissions. (I'll put a 9v regulator on my audio amplifier IC, before I go cranking up the voltage to the whole uBITX).?
I like the added relays approach, it should work. It is one of the simpler and doable solutions offered on these forums.
Tom, wb6b
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Re: Harmonics measured by Warren. How bad?
I don't agree at all with that pragmatic rule. A transmitter has to have a clean output. Your TV may be interfered if it has an external low quality and high gain amplifier which is saturated by out of band signals whatever clean is your TX. On the other hand your TV may not be affected but you may produce QRM everywhere on the HF which,depending on propagation conditions, can be heard thousands miles away.
hi
i am rather mystified as to how the American ham test his rig to meet fcc requirements for -43 db
does he have to have a spectrum analyser
in the uk ofcom is rather more pragmatic - if you are not causing interference then your rig is ok.
i test mine by looking at my tv for interference. if my tv is not interfered with then my neighbours are almost certainly not.
73 de terry gm4dso
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Re: Harmonics measured by Warren. How bad?
Hi Terry,
Now that we know about it, I suppose people should do what they can to mitigate it.
But I do wonder if, for us to build own equipment, only those who invest in thousands of dollars of lab equipment will be able to certify their creations and participate in the hobby (other than buying gear from established manufactures). That would be unfortunate.?
It sounds like the UK regulations are much more sensible and realistic.
Maybe the market will respond with low cost test equipment solutions allowing hams to make more of these kind of measurements (less than the cost of an antenna analyzer). That would be good with or without regulations, and advance the state of the art.
Tom, wb6b
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Re: Harmonics measured by Warren. How bad?
Hi Allison,
"However most are run at such low loaded?Q they are not very useful for harmonic control"
Very good, a second and even better reason for not relying an L antenna tuner to help with harmonics.
Tom, wb6b
?
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Re: Harmonics measured by Warren. How bad?
hi
i am rather mystified as to how the American ham test his rig to meet fcc requirements for -43 db
does he have to have a spectrum analyser
in the uk ofcom is rather more pragmatic - if you are not causing interference then your rig is ok.
i test mine by looking at my tv for interference. if my tv is not interfered with then my neighbours are almost certainly not.
73 de terry gm4dso
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Re: Right-sided relay harmonic attempted fix for v3/4 ubitx
No, the uBitx is mounted on a PLASTIC upturned Dollar Tree desk organizer. ? Sorry!
Gordon
On Aug 27, 2018, at 23:01, Tom, wb6b < wb6b@...> wrote:
toggle quoted message
Show quoted text
By the way, my tiny attenuators arrived.?
Maybe I'll try solder paste, bare wires, a hot air rework station and the scotch tape?trick outlined by Ian, kd8cec.
<Attenuator PE43711A.jpg>
Tom, wb6b
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Re: Harmonics measured by Warren. How bad?
On Monday, August 27, 2018, 4:01:33 PM PDT, ajparent1/KB1GMX <kb1gmx@...> wrote:
you need a two tone source and that can be just a few trasistor and I think Elecraft sells a small one. 2T-gen 2-Tone Test Oscillator? looks like 80$ DK7IH has the one I built on his website ..Need to add 2 switches to shown schematic to cutoff each oscillator individually to set levels ..2 transistors 6 caps some resistors 2 pots ...fiddle with the caps to get freq right ....Not 80$
Jim
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Re: Nextion 3.2 for CEC 1.097
#ubitx
There is no simple way to scale in the Nextion editor.? Basically any images must be exported, scaled (or remade) and then replaced in the editor.? None of the page elements would line up so they would all have to be resized and moved.? You can click and drag various page elements to move and resize each one, but when lining and sizing things up to the pixel, you pretty much have to enter values into x,y,w and h. Also, some things like height in waveform don't scale up very well as how it is displayed is based on the data the Nextion screen is receiving from the arduino.? It's almost as much work as designing it from scratch.? You are basically remaking the gui for each screen size.
Darren
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Re: Right-sided relay harmonic attempted fix for v3/4 ubitx
By the way, my tiny attenuators arrived.? Maybe I'll try solder paste, bare wires, a hot air rework station and the scotch tape?trick outlined by Ian, kd8cec.  Tom, wb6b
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Just looking for some insight.? See attachment for details.
Mike
K5ESS
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Re: sub-harmonic mixer BITX harmonics and spurs
it would make them horribly worse. i am back to the bench today and i hope i can figure out a few fixes for these soon.
- f
On Tue, Aug 28, 2018 at 1:12 AM, Arv Evans <arvid.evans@...> wrote: I wonder if anybody has considered using sub-harmonic mixers in BITX, and
what the effect might be on harmonics and spurs?
Arv
_._
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Re: Right-sided relay harmonic attempted fix for v3/4 ubitx
Gordon,
Thanks for sharing your information so far and the pictures of your setup. Looks like real metal under your uBITX, bolted to the corners, so satisfies the bee in my bonnet about that.
As a digital guy, I know about bit buckets-- I've never seen an RF bucket before this.
Tom, wb6b
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Re: #ubitx. Great EFHW group on Facebook
barry
No offense.? It is all part of the game we play as ham radio operators.? Sometimes we take it
a bit too serious, and sometimes not serious enough.??? 8-)
Easiest way to find things that have been discussed earlier is to log into and
use the message search capability to find lists of messages about a particular topic.?
Arv
_._
On Mon, Aug 27, 2018 at 6:21 PM Bo Barry < bobarr@...> wrote: Been skipping them, thinking I was the cause of it started.? Wrong I guess.
But since I'm 100% sold on my no tuner MyAntennas EFHW I'm reluctant to read anymore about it. ?
Too anxious in tuning up the rig.
Sorry if I offended.
PS I'm interested in Farhan s earlier comments on power improvement but can't find it. In May I believe.
I'm happy with my v4 and went back to my v3 which is a bit puny.? I haven't put the socket pins in it and some 2222A's are on order.? I'm interested in tinkering with the other simple mods he had. The Q90 mod is beyond my patience even tho I have a microscope, etc.? Links appreciated in case I can't find them, if you have them handy. ? I think the topic was more power on 10 meters
. Thanks Bo?
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Howard, do you still have the 3 parts you were offering? I accumulated another v3 and thought I would try them.
Bo W4GHV
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Re: #ubitx. Great EFHW group on Facebook
Whoops, I found it! C81, R83, R261, R262 mods? ?and some by Howard ? for added 33uH and 220pf caps
Going to study them after I do the 2222A thing. 73, Bo
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Re: Odd Raduino, How do I Connect it?
#bitx40
All of them.
Those pins to the left match the uBitx V3 and V4 board socket.
Allison
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Vic WA4THR
Darren VE3XLT