Re: Question: Why do you call "AGC" a simple automatic antenna "attenuator" in this forum?
#ubitx
#ubitxv6
Some of the old vintage radios and amplifiers are real hunks of steel compared to what we use today but never forget that we won wars with those old relics. Also, some are still used today; when I worked at two Army Depots, some of that old stuff was refurbished and sold/given to foreign allies to use in their military even though we had quit using it here in America. And they were happy to get it.
Many of us can remember using the old vintage transmitters for ham radio usage as well as adapting them for antenna tuners, etc. Wartime antenna components are still in operation today by many hams.
Will some of the stuff that we buy today endure like that wartime equipment? I wonder but maintenance today is not what it was back then. If some ham's equipment goes sour, the item is often thrown away (or set on a back shelf) and a new one bought and this is often a distinct improvement over what they had used before. Technology has improved but the oldtimers' willingness to repair is not what it was in years past mainly because something 30-40 years old is not going to give us what the new stuff will give us ... so why bother? Back then, though, it was not done for pleasure along, repairs were done because it was necessary to get back on the air.
Out with the old and in with the new is the way more in common today.
Bob ¡ª KK5R
On Friday, November 20, 2020, 7:39:31 PM EST, IW4AJR Loris <lorisbollina@...> wrote:
There was no standardization in the old magazines! P1 stands for Potentiometer 1 nothing more!
Come on ... a little imagination doesn't hurt !!! ... look at those scoundrels who made electronics 50 years ago went to the moon even if they hadn't standardized and codified the mind ... sometimes the imagination does much more than beautiful presentations!
Cheerful guys! so soon we will remove the trouble ... more than old we do not become ... then even these boring chatter of old fools will end!
73 de IW4AJR Loris
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Re: Question: Why do you call "AGC" a simple automatic antenna "attenuator" in this forum?
#ubitx
#ubitxv6
There was no standardization in the old magazines! P1 stands for Potentiometer 1 nothing more!
Come on ... a little imagination doesn't hurt !!! ... look at those scoundrels who made electronics 50 years ago went to the moon even if they hadn't standardized and codified the mind ... sometimes the imagination does much more than beautiful presentations!
Cheerful guys! so soon we will remove the trouble ... more than old we do not become ... then even these boring chatter of old fools will end!
73 de IW4AJR Loris
|
Re: Question: Why do you call "AGC" a simple automatic antenna "attenuator" in this forum?
#ubitx
#ubitxv6
Hello Darrell ...
But what do you want to expect from a magazine from 40 years ago? ... symbols and diagrams were often drawn by hand by inexperienced people then passed to printing without controls ... they were not all electronics professionals! come on ... have a little imagination!
Hello from IW4AJR Loris
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Re: WARNING: Promotional offer
Jack, please post a short/brief summary of the book's general features such as what it deals with and the goal of the book. This is for 1) those who would like to see what the book is about (that may have forgotten) and, 2) for the benefit of new people to this forum that may not know what this is about.
The title of the book and how to contact Amazon (link) regarding the book would also be appreciated. Amazon probably has a review of the book that may also be very useful.
Thanks.
Bob ¡ª KK5R
On Friday, November 20, 2020, 10:32:11 AM EST, Jack, W8TEE via groups.io <jjpurdum@...> wrote:
All:
I feel badly about the font size error that occurred in my Beginning C for Microcontrollers book, especially since you bought the printed book before it was hardly even reviewed. As it turns out, this error was totally my fault and not KDP's. The new book has increased the font size from 8 to 12-point and I have also added an index, which makes it more usable as a reference. As a result, the page count has increased from 380 to 475 pages. The narrative is virtually unchanged, except for the addition of the index.
I wrote to KDP to see if I could get the mailing addresses of the people who bought the book. For reasons I can understand, that request was denied. So, here's the deal:
1. Rip off the front cover of the book and three pages from somewhere near the middle of the book. 2. Mail the pages and cover with a check for $10 (or you can use my PayPal account--email me privately) to me at my address as given in QRZ.com. Be sure to include your address where the new book should be sent.
In return, I will mail you a new book to replace the one you just destroyed. I need you to post mark your return pages on or before Dec 5, 2020. The offer dies at midnight on Dec. 5th, 2020. On Dec. 6, I will order enough books to replace those who have ordered new ones. It seems to take Amazon about 14 days to get the books to me. Add in the Holiday mail rush, and it may take a little longer. After they arrive, I will try to mail the new book to you as quickly as I can.
It's an imperfect solution to a nettlesome problem, but the best I can come up with. For those who think I'm doing this to make money, I can assure you that, by the time I pay my cost for printing the new book (which increased by more than 20%) and the cost to mail it back to you, I will be losing money on the deal. Still, it's the right thing to do.
I do appreciate your support.
Jack, W8TEE
P.S., Read the three pages from the center of the book before you mail them back!
-- Jack, W8TEE
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Re: Question: Why do you call "AGC" a simple automatic antenna "attenuator" in this forum?
#ubitx
#ubitxv6
This gives more detail re the rheostat...
On Friday, November 20, 2020, 9:56:20 AM EST, Gareth Evans via groups.io <headstone255@...> wrote:
This goes back to the early days of electricity in the mid 19th C, well before
J J Thomson discovered the electron. (Not sure which one? of the million
trillions he found!? :-)? ? )
It was not then known exactly what was a flow of electricity and it was thought to
be a stream of some sort.? Now, I'm not a student of the Classics, and it is 53
years since I did Latin at school, but I believe that Rheus was Ancient Greek
for a stream, so Rheostat is a stream controller in much the same way
that Thermostat is a temperature controller.
Also from that same period of time, a Rheofore is a length of wire!
73 de Gareth G4SDW
On Fri, Nov 20, 2020 at 11:38 AM, Bob Lunsford wrote:
>
>? A settable resistor with two terminals is usually called a rheostat.
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Re: Alternative Calibration Procedure uBITx v6
Yeah, I tried that too, but as you saw, the audio frequency changes from minute to minute. The carrier is constant. It's also stronger.
73,
Mark
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Re: Question: Why do you call "AGC" a simple automatic antenna "attenuator" in this forum?
#ubitx
#ubitxv6
AGC systems are not difficult to figure out or implement. ?The math behind a useful RF AGC has been around for at least 9 decades. ?The Hycas system is just a modern restatement of older applications. ?
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On Nov 20, 2020, at 3:44 AM, Ashhar Farhan <farhanbox@...> wrote:
? AGC is a feature and attenuation is a function. Automatic Gain control can work using an electronically controlled attenuation in the signal chain or by using variable gain amplifiers somewhere in the chain. the golden rule of good signal processing is to control the gain as early in the signal chain as is possible. The best gain control is to put variable resistor right at the antenna terminal. The reason is very simple: the amplifiers down the chain have to handle weaker signals and weaker signals mean better fidelity. An audio AGC in a conventional superhet where most of the gain is in the IF stage will overload even on a moderate signals due to the distortions in IF amplifiers. Picture this, there is the lowest level signal that the receiver can resolve, this is set by the bandwidth and the noise figure of the receiver. The? highest signal that the receiver can resolve without distorting is determined by the IIP3 and the phase noise of the local oscillator. The range of signals between the minimum discernable signal and the loudest signal that the receiver can handle without noticeable distortion is your dynamic range. Now, consider what happens if you switch on a 10 db attenuator between the antenna and the receiver. the MDS (minimum discernable signal) has to be 10 times more powerful and on the other hand, the signal level at which the distortion starts to show is also up by 10 db. In effect, to borrrow?Rob, NC0B's words, the dynamic range is a moveable window that can be shifted up or down with attenuators. Most receivers are too sensitive for HF bands. For instance, the ubitx is too sensitive for 40 meters, the atmospheric noise is 100 times more powerful than the internal noise (noise floor) of the receiver. This is wasted dynamic range. if we had thrown in a 20 db attenuator, we would hear exactly the same signals as before but our dynamic range would have been 100 times more. Dynamic range doesn't only apply when you are contesting or having a neighbour who transmits 1000 watts, it is a measure of how sweet the receiver sound is as well. So, why is ubitx so needlessly sensitive? That is, because it is meant to work from 10 meters to 80 Meters. That sensitivity will be needed when the 15 meter opens up in a few years from now. RF attenuation does remain the best place to control the gain, even for an AGC system. The challenge is to build a smoothly varying attenuator that doesn't need any active devices. Active devices in wide open receivers like the ubitx can severally compromise the receiver performance.? I am planning to do a video to explain who careful gain distribution is the key to a good radio design. - f On Fri, Nov 20, 2020 at 9:38 AM TD < dlee@...> wrote: > "what component is P1" ?????
I figured it was a pot but never seen that symbol used before.
---
Darrell Lee
Advanced Data Systems, Inc.
2801 Wade Hampton Blvd.
Suite 115-153
Taylors, SC 29687
864-230-9626 | dlee@...
On 11/19/2020 01:15 PM, IW4AJR Loris wrote:
> Hello TD ...
>
> "what component is P1" ?????
>
> maybe it is simply a resistive trimmer or a potentiometer ???? perhaps
> !!! HAHAHAHA
>
> don't tell me you don't know what P1 is because I don't believe it!
>
> this diagram is just an example of how a simple dynamic compressor
> with a handful of passive components can be made, how to insert it and
> where to insert it in the ?BITX is something you have to decide,
> study it a bit and look at the diagram of the part receiver of the
> ?BITX (from the volume potentiometer to the speaker) and see if you
> need it as an input to the BF amplifier (LM386) or if you want to
> insert it in parallel with the output before the headphone jack.
>
> hi TD ... good job! greetings from IW4AJR Loris
>
>
> Links:
> ------
> [1] /g/BITX20/message/83812
> [2] /mt/78337317/4392615
> [3] /g/BITX20/post
> [4] /g/BITX20/mutehashtag/ubitx
> [5] /g/BITX20/mutehashtag/ubitxv6
> [6] /g/BITX20/editsub/4392615
> [7] /g/BITX20/leave/defanged
--
¡_. _._
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Re: Question: Why do you call "AGC" a simple automatic antenna "attenuator" in this forum?
#ubitx
#ubitxv6
Some apparently thought?that P1 referred?to PI, as in Raspberry Pi, or the? symbol used to represent a mathematical constant.? ?8-)
Arv _._
Hi,
Until I see an individual schematic I guess that "P1" is "plug number
one". Maybe that is my grey hair (or what is left of it). Schematics
that I have would label that "VR1". If you happen to see that on a
schematic, now you know what it is.
73,
Bill? KU8H
bark less - wag more
On 11/20/20 3:24 AM, Raj vu2zap wrote:
> A variable pot is shown with an arrow. A pot that is adjusted once and set
> is called a preset and is shown with a short line instead of arrow.
>
>
>
> At 20/11/2020, you wrote:
>>> "what component is P1" ?????
>>
>> I figured it was a pot but never seen that symbol used before.
>>
>> ---
>> Darrell Lee
>> Advanced Data Systems, Inc.
>> 2801 Wade Hampton Blvd.
>> Suite 115-153
>> Taylors, SC 29687
>> 864-230-9626 | dlee@...
>
|
Thanks Jerry,
Concerning the tx, we are not working on ham bands. We'll use an
experimental license (if it works ok without the SSB filter), in order
to carry the wideband experiments.
Rafael
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On 11/11/20 10:17 PM, Jerry Gaffke via groups.io wrote: Rafael,
Bypassing the SSB filter would make the receiver be wideband,
but you would lose single signal reception.? You will hear signals on
both sides of?the BFO, not just one side as you do with the filter in
place.
Try it, just tack a wire from one side of the filter to the other,
from header CW-1 pin 1 to header CW-2 pin 1 in the uBitx v6 schematic.
Could be educational.
Could even be useful, allowing one to quickly tune across the band
when looking for signals.
Bypassing the SSB filter when transmitting would create an illegal
wideband transmission
on the HF bands.
Jerry, KE7ER
On Wed, Nov 11, 2020 at 11:53 AM, "Rafael Diniz"
<rafael@...> wrote:
Hi everybody,
I bought two ubitx v6, and now I'm waiting them to arrive. One
question
about wideband operation - if I bypass the SSB filter, could I get a
clean 15kHz wide operation?
Thanks,
Rafael PU2UIT
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Re: Alternative Calibration Procedure uBITx v6
I¡¯ve used that method also, that works too. ? It also takes the advantage of taking the measurement down to audio frequencies. ?
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On Nov 20, 2020, at 15:23, AndyH <awhecker@...> wrote:
?I like it!? Simpler than the method I've been using! I tune to WWV, then hit the WWV Wikipedia page to see what frequency audio tone is broadcast that minute.? I use the WSJT-X waterfall to track the audio tone. 73, Andy On Wed, Nov 18, 2020 at 09:12 PM, Mark Erbaugh wrote:
Following the calibration procedure for my v6, I had trouble zero beating a carrier, so I tried a modified approach that seems to work better for me. With the radio in LSB mode, I tuned 1 kHz above WWV at 5 MHz. WWV's carrier thus creates a 1 kHz tone. I used a program with an audio waterfall (I used FLDIGI) and adjusted the uBITx's tuning calibration until the tone was at 1 kHz.
73,
Mark
|
Re: Alternative Calibration Procedure uBITx v6
I like it!? Simpler than the method I've been using!
I tune to WWV, then hit the WWV Wikipedia page to see what frequency audio tone is broadcast that minute.? I use the WSJT-X waterfall to track the audio tone.
73, Andy
toggle quoted message
Show quoted text
On Wed, Nov 18, 2020 at 09:12 PM, Mark Erbaugh wrote:
Following the calibration procedure for my v6, I had trouble zero beating a carrier, so I tried a modified approach that seems to work better for me. With the radio in LSB mode, I tuned 1 kHz above WWV at 5 MHz. WWV's carrier thus creates a 1 kHz tone. I used a program with an audio waterfall (I used FLDIGI) and adjusted the uBITx's tuning calibration until the tone was at 1 kHz.
73,
Mark
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Re: SWR meter with second arduino
Gerard,
I am not familiar with the multi-display modes.? I would assume that each has an I2C address that is configured as part of the Nextion programming.? This is guesswork on my part.
I would assume that the size of the screen does not matter other than the .tft or .hmi file that is needed to program it.? I am sure that there is only one version of the Nano code to work with the multiple Nextion displays.
73
Evan
AC9TU
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Re: SWR meter with second arduino
Evan,
OK
Look here, i like colors on the second Nextion
An other tft file?
My idea is to have main screen on a future 5" nextion, and use the actual 3.2" to sea swr or scan?. Don't know if possible?
I was able to sell electronic components on E.. Y to buy the future 5". Lol.
I also receive an Automatic antenna tuner in kit of Ukraine (Less 15 days). Model of N7DDC. (Also wiyh my E..Y solds to pay it.!!
There is also a small screen.
So, some work to do
cdt
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Re: SWR meter with second arduino
Gerard,
I have not built the SWR/Power meter into a uBITX, so cannot help there.? I have done the research on using two Nextion displays and found this in the past:
I have not built this either, only providing links that I know.
73
Evan
AC9TU
|
WARNING: Promotional offer
All:
I feel badly about the font size error that occurred in my Beginning C for Microcontrollers book, especially since you bought the printed book before it was hardly even reviewed. As it turns out, this error was totally my fault and not KDP's. The new book has increased the font size from 8 to 12-point and I have also added an index, which makes it more usable as a reference. As a result, the page count has increased from 380 to 475 pages. The narrative is virtually unchanged, except for the addition of the index.
I wrote to KDP to see if I could get the mailing addresses of the people who bought the book. For reasons I can understand, that request was denied. So, here's the deal:
1. Rip off the front cover of the book and three pages from somewhere near the middle of the book. 2. Mail the pages and cover with a check for $10 (or you can use my PayPal account--email me privately) to me at my address as given in QRZ.com. Be sure to include your address where the new book should be sent.
In return, I will mail you a new book to replace the one you just destroyed. I need you to post mark your return pages on or before Dec 5, 2020. The offer dies at midnight on Dec. 5th, 2020. On Dec. 6, I will order enough books to replace those who have ordered new ones. It seems to take Amazon about 14 days to get the books to me. Add in the Holiday mail rush, and it may take a little longer. After they arrive, I will try to mail the new book to you as quickly as I can.
It's an imperfect solution to a nettlesome problem, but the best I can come up with. For those who think I'm doing this to make money, I can assure you that, by the time I pay my cost for printing the new book (which increased by more than 20%) and the cost to mail it back to you, I will be losing money on the deal. Still, it's the right thing to do.
I do appreciate your support.
Jack, W8TEE
P.S., Read the three pages from the center of the book before you mail them back!
-- Jack, W8TEE
|
SWR meter with second arduino
Hello,
I was looking at this documentation for my information and I have a doubt about the connection.
Look at the comments..
So my question is, what¡¯s the right connection?
On the original arduino (the one I call the master) or on the 2nd (the one I call the slave)?
Some body have build it?
Second question, it seemed to me to have seen that we could connect a 2nd Nextion with this second nano. (Example to display the swr only)
I can¡¯t find this doc, unless I¡¯ve revered?
cdt
|
Re: Alternative Calibration Procedure uBITx v6
Hello,
If you inject a signal of 15mhz near the antenna by radiation (Mid 0 to 30MHZ) and watch the beat up to 0 at the oscilloscope just before the SSB filter (or After the 45mhz filter), you must be well calibrated too.
I did it like that.?After that, we have to calibrate the BFO.
Is that a good method for you?
For me, it's work fine
cdt
|
Re: Question: Why do you call "AGC" a simple automatic antenna "attenuator" in this forum?
#ubitx
#ubitxv6
This goes back to the early days of electricity in the mid 19th C, well before
J J Thomson discovered the electron. (Not sure which one of the million
trillions he found! :-) )
It was not then known exactly what was a flow of electricity and it was thought to
be a stream of some sort. Now, I'm not a student of the Classics, and it is 53
years since I did Latin at school, but I believe that Rheus was Ancient Greek
for a stream, so Rheostat is a stream controller in much the same way
that Thermostat is a temperature controller.
Also from that same period of time, a Rheofore is a length of wire!
73 de Gareth G4SDW
toggle quoted message
Show quoted text
On Fri, Nov 20, 2020 at 11:38 AM, Bob Lunsford wrote:
A settable resistor with two terminals is usually called a rheostat.
|
On Mon, Nov 16, 2020 at 01:17 PM, lu7yw wrote:
https://www.youtube.com/watch?v=uvukDHvMoXE
There is not enough information here to give any answers. It may help if you details of exactly which UBITx board, which s-meter solution , and which firmware, you are using. Include versions of software.? The more details the better. ? -- Dennis WC8C
|
Re: Question: Why do you call "AGC" a simple automatic antenna "attenuator" in this forum?
#ubitx
#ubitxv6
Hi,
Until I see an individual schematic I guess that "P1" is "plug number one". Maybe that is my grey hair (or what is left of it). Schematics that I have would label that "VR1". If you happen to see that on a schematic, now you know what it is.
73,
Bill KU8H
bark less - wag more
toggle quoted message
Show quoted text
On 11/20/20 3:24 AM, Raj vu2zap wrote: A variable pot is shown with an arrow. A pot that is adjusted once and set
is called a preset and is shown with a short line instead of arrow.
At 20/11/2020, you wrote:
"what component is P1" ????? I figured it was a pot but never seen that symbol used before.
---
Darrell Lee
Advanced Data Systems, Inc.
2801 Wade Hampton Blvd.
Suite 115-153
Taylors, SC 29687
864-230-9626 | dlee@...
|
Bob Lunsford
Mark Erbaugh
MadRadioModder
Gerard