Date   

Re: Audio AVC

Adrian Chadd
 

You wouldn't even need to do that; you can just drop the gain by say 1/4 or so immediately in software and get ready for another interrupt. If the gain is still above the analog comparator level you'll soon get another interrupt and soon drop the gain another 1/4. The microcontroller side response would be effectively instantaneous assuming no-one disables interrupts. Analog comparator interrupts are good for hacks like that.

Once it's not triggering the comparator anymore you can take your time bringing the AGC back up.


-adrian


On Wed, 24 Apr 2019 at 11:32, Hasan Murtaza <hasmanean@...> wrote:
Oh for a fast attack, you probably want to use an analog comparator (some microcontrollers have them) that triggers an interrrupt, which switches a mosfet on to either shunt in a low values resistor or something until the AGC loop filter has time to decide how much gain is needed. 

Hasan


Re: FOR SALE

Ben WB5QAL/6
 

May I see some pictures?  Can I program it in place or does one have to remove the board to reach the connector?

--
Ben Weiss
Clearlake, CA

On Apr 24, 2019, at 11:45 AM, Michael Goins, k5wmg <wmgoins@...> wrote:

uBitX upgraded with 3.2" Nextion Display and agc, red commercial cabinet with internal speaker, needs12v at about 3 amps with low standby power. This is a V3 board with the kd8cec v1.1 software. No mic but will include a mike connector and any condenser mike will work with it. The touch-screen display is very cool and essentially self- explanatory. 

Bought within the last month and simply will now not have time to play with it. Photos as needed. Complete ready to run radio. Firm on price. $250 shipped.
    
Mike, k5wmg


Re: First ubitx lsb contact!

Kelly Mabry
 

Yessir, Ron! I have spent time in Durham, NC some years back. We will definitely be looking for you. I have a few things to do for the new shack, but i definitely  will be active starting next month. 
73, 
Kelly K5AID 


Re: First ubitx lsb contact!

ronmhauser@...
 

Congratulations Kelly.  Like you, I had never made a single contact QRP.  My commercial radio is an old Kenwood TS830.  I haven't turned it on in the three weeks since I got my uBitx running.  I'm having a great time making contacts and not telling people ... or telling them after a rag chew ... that I'm running 7 watts.  : )    You are in my sweet spot, we will have to listen for each other (I'm in western NC with good geography and easy skip to AR).  Keep on buiding!

73
--Ron
K0EIA


FOR SALE

Michael Goins, k5wmg <wmgoins@...>
 

uBitX upgraded with 3.2" Nextion Display and agc, red commercial cabinet with internal speaker, needs12v at about 3 amps with low standby power. This is a V3 board with the kd8cec v1.1 software. No mic but will include a mike connector and any condenser mike will work with it. The touch-screen display is very cool and essentially self- explanatory. 

Bought within the last month and simply will now not have time to play with it. Photos as needed. Complete ready to run radio. Firm on price. $250 shipped.
    
Mike, k5wmg


Re: Audio AVC

Hasan Murtaza
 

Oh for a fast attack, you probably want to use an analog comparator (some microcontrollers have them) that triggers an interrrupt, which switches a mosfet on to either shunt in a low values resistor or something until the AGC loop filter has time to decide how much gain is needed. 

Hasan


wsprnet results, wsjt-x, and calibration success --> world domination V4 #calibration #firmware

Don - KM4UDX
 

Hello all. So after living with non-trivial frequency/calibration error, I finally found my boy-bits and went back to reading everything ever written on uBITX calibration (with CEC firmware and memory manager).  The result was extraordinary levels of fear and confusion. 

In desperation, I finally said "foo it",  calculated the error ratio @ 10.00 mhz, multiplied that ratio by the base calibration number to get ~~-5000, then added -5000 in MM, and hit reboot.  Then went to wsjtx's freqcal mode to measure my  new error relative to 3.330 (-7Hz) and 10.00 (-18Hz) reference signals. I was now close enough that I didn't want to touch anything. But I did. And every time I tried to reduce the error further by tweaking the calibration numbers, everything got worse. So I quickly realized I was as close as a mere mortal could aspire. 

But I did run the complete freqcal process in wsjtx, and that process reduced my uBITX freq error to like 1hz or less in wsjtx.  That wsjtx is wicked. If anyone wants help with uBITX wsjtx freqcal mode, I'm your dude.  
 
Here are my wsprnet results using my humble V4 uBITX.  Without any real effort other than stumbling in the dark, and GREAT help from fellow hams and wonderful persons Ding, KA8BRK, and Dan W3BU, I am ranked ~155 in 2 way WSPRnet spots after only a few days of auto band hopping. NEVER did I expect my little uBITX to get to Australia  and Antarctica.  All hale the mighty uBITX.

Don
km4udx


 


Re: Kit projects AGC install

Kelly Mabry
 

Hi! No worries on the email thing. I replied to your there, but here in open forum might be a better method of reaching me. Bless you brother.

73,
Kelly K5AID





Sent from my Verizon, Samsung Galaxy smartphone

-------- Original message --------
From: "KE2GKB via Groups.Io" <tkeller@...>
Date: 4/24/19 10:18 AM (GMT-06:00)
To: BITX20@groups.io
Subject: Re: [BITX20] Kit projects AGC install

Thanks for the response!
Kelly I just responded to your email, again apologies for the delay.
I have paraphrased below.

The only addition I have as of moment is that the castellations that you are soldering to the trace have copper on the bottom. Apply as little heat as needed, they make a solid joint easily. The solder should just start to come up the cup. It does not need to reach the top of the board. 
A decent example is in this picture 

73
KE2GKB

On Wed, Apr 24, 2019, 5:02 AM Playthatbeat Mrdj <playthatbeat303@...> wrote:
position the board and mark with a sharpie the spots where You need to expose copper below, then use a small flathead screwdriver, or anything small, flat and hard to scrape away the coating and expose the copper.. You don't need to use much force, just take Your time and get a good strip exposed at each spot. You don't want a sharp point for this, just a hard object. Then tin both the AGC board and the exposed spots with solder, and the rest should just be a matter of adding enough solder to make a good bond, once You have the AGC board aligned in place. Maybe use some masking tape to hold it in place if You have big fingers..

I agree that a dremel is not the way to go. they are the Uzi of power tools. look cute, but are utterly useless, unless you like damaging Your fingers and making lots of noise.


--
Tim Keller - KE2GKB
https://shop.kit-projects.com


Re: Adding SOTABEAMS LASERBEAM-VARI Digital Variable Audio f\Filter Module to Your BITX/uBITX

Dennis Zabawa
 

This document supplies additional information for linking a microcontroller with a SOTABEAMS, VariBeam (VB) module for use with a BITX/uBITX.
 
You can access this file at the URL:


Re: Kit projects AGC install

Kelly Mabry
 

Well, Playthatbeat Mrdj...that quote defines my experience when adapting my front panel board for a keyer.

"I agree that a dremel is not the way to go. they are the Uzi of power tools. look cute, but are utterly useless, unless you like damaging Your fingers (and boards) and making lots of noise."


I might just hang that on the wall of my shack...


Re: First ubitx lsb contact!

Kelly Mabry
 

I like that Richard!! I used to work for GenCorp Aerojet in Iuka, MS. Our peogram  Manager was out of Redstone Arsenal in Huntsville AL. Thiokol hated me due to all the rework I made them do on nozzle instrumentation. I became an expert on Mil specs and contract requirements. All our measurements were in inches.. 
Ok enough off topic!  Thanks for the trip down memory lane.. 

73,
Kelly K5AID 


Re: First ubitx lsb contact!

Joe Puma
 

Kelly that’s great. I live in NY and with my end fed half wave antenna that tops off at 35 feet I am able to talk to Florida easily on 20 meters. Last week when we had some slight solar activity I made a contact with Italy on 20 meters,
well the guy couldn’t hear me too well on the uBitx so I jumped on my 100w radio to complete the contact. He did hear something on the uBitx. 

My uBitx has been modded for a more even power level. On 20 meter I can do 14watts. On 80 it’s 12watt 


Joe
KD2NFC 


On Apr 24, 2019, at 2:54 AM, Kelly Mabry <kmabry2007@...> wrote:

Haha i should have said miles... up to this point, i had not truly worked qrp. The satisfaction of building it, then operating it is awesome. Thank you all for collaborating with me on this project. Your suggestions and advice illustrates what I love about this hobby. So, just few things left to do before I build.... another one. Lol. Well i need to install the AGC mod from kit projects.

73,
Kelly K5AID 


Re: First ubitx lsb contact!

Jerry Gaffke
 

The US put a man on the moon with a mix of metric and imperial:
    https://www.reddit.com/r/askscience/comments/39f8im/did_nasa_use_the_metric_system_when_we_landed_on/
But that doesn't always work out so well:
    https://www.wired.com/2010/11/1110mars-climate-observer-report/

I was thinking 175 megaparsecs

Jerry, KE7ER


On Wed, Apr 24, 2019 at 09:29 AM, RICHARD wrote:
The US put a man on the moon using INCHES !


Re: Audio AVC

bobolink
 

Here is my Arduino IDE dual core esp32 audio framework. Mainly just tone generation. I did fir filters with but haven’t uploaded them.
Audio Framework
Many libraries work but the esp32 unlike other Arduino processors, doesn’t like to spend a lot of time in interrupt routines (I guess because of rtos). I had to rewrite the “Talkie” library because of the interrupt handling.
Talkie

wm6h


Re: Kit projects AGC install

digger AB3XU
 

Just so it doesn't get missed, don't forget that the one trace needs to get cut open.


Re: First ubitx lsb contact!

Laddie <laddie2@...>
 

Its not our fault, back in grade school "they said, we would convert to metric before adulthood". I'm 64 and still waiting! Blame the British, imperial kings feet, arms digits and all.

----- Original Message -----
From: "RICHARD" <k6kwq@...>
To: "BITX20" <BITX20@groups.io>
Sent: Wednesday, April 24, 2019 12:29:40 PM
Subject: Re: [BITX20] First ubitx lsb contact!

The US put a man on the moon using INCHES !

Sent from Mail<https://go.microsoft.com/fwlink/?LinkId=550986> for Windows 10

________________________________
From: BITX20@groups.io <BITX20@groups.io> on behalf of Dexter N Muir <dexy@...>
Sent: Tuesday, April 23, 2019 11:05:08 PM
To: BITX20@groups.io
Subject: Re: [BITX20] First ubitx lsb contact!

175m? Barely a city block. 175 mi more like it, 285km! I really despair of US clinging to Imperial measure, when it butchers English language - Metric (NOT METERIC!) is so much easier: 300/f for w/l.
73 de ZL2DEX


Re: First ubitx lsb contact!

RICHARD <k6kwq@...>
 

The US put a man on the moon using INCHES !

 

Sent from Mail for Windows 10

 


From: BITX20@groups.io <BITX20@groups.io> on behalf of Dexter N Muir <dexy@...>
Sent: Tuesday, April 23, 2019 11:05:08 PM
To: BITX20@groups.io
Subject: Re: [BITX20] First ubitx lsb contact!
 
175m? Barely a city block. 175 mi more like it, 285km! I really despair of US clinging to Imperial measure, when it butchers English language - Metric (NOT METERIC!) is so much easier: 300/f for w/l.
73 de ZL2DEX


Re: Kit projects AGC install

KE2GKB
 

Thanks for the response!
Kelly I just responded to your email, again apologies for the delay.
I have paraphrased below.

The only addition I have as of moment is that the castellations that you are soldering to the trace have copper on the bottom. Apply as little heat as needed, they make a solid joint easily. The solder should just start to come up the cup. It does not need to reach the top of the board. 
A decent example is in this picture 

73
KE2GKB


On Wed, Apr 24, 2019, 5:02 AM Playthatbeat Mrdj <playthatbeat303@...> wrote:
position the board and mark with a sharpie the spots where You need to expose copper below, then use a small flathead screwdriver, or anything small, flat and hard to scrape away the coating and expose the copper.. You don't need to use much force, just take Your time and get a good strip exposed at each spot. You don't want a sharp point for this, just a hard object. Then tin both the AGC board and the exposed spots with solder, and the rest should just be a matter of adding enough solder to make a good bond, once You have the AGC board aligned in place. Maybe use some masking tape to hold it in place if You have big fingers..

I agree that a dremel is not the way to go. they are the Uzi of power tools. look cute, but are utterly useless, unless you like damaging Your fingers and making lots of noise.


--
Tim Keller - KE2GKB
https://shop.kit-projects.com


Re: Raduino reinforcement, 3d printed

_Dave_ AD0B
 

I printed these for club members with ubitx radios. I don't usually print black. It does terrible outside without being painted. Summer sun will melt it in 5 minutes.

I have had an Anet A8 printer. Paid 153 for it 3 years ago. It isn't expensive to get into. Have 2000 hours of printing out of it. Maybe a couple of dozen rolls of filament. Have tried ABS but didn't like the warm up time. With ABS the bed needs to get to 100 degrees, and the parts seem more likely to warp when cooling so I print with PLA. Be aware that printing 3d is not like printing on a sheet of paper. There are a 100 reasons to fail. It can be from a poorly designed object or a mechanical issue with the filament, dirt or the machine. Just ask anyone who has one. Mine will print happily for a couple hundred hours or more and then something goes haywire and needs to be adjusted. It takes about 40 minutes to print even a small part like the raduino bracket.

The real fun isn't the printing but the designing. I use Fusion360, a professional grade software that is available with a free license for the hobby and small business designer. The trick with designing something is that it should be easy to print. I use Repetier Host as a slicing software. Have tried several others but this usually sets up the print best.

Once you figure out what you can make you will be amazed. Take a look at thingaverse.com and you might get an idea. It isn't just for radio but most any component that is in a non hot location can be designed. All around our farm we have printed parts and brackets. Go to the hardware store trips have been greatly reduced.


Re: Audio AVC

Jack, W8TEE
 

We did all that and more with the JackAl board, but it's based on the Teensy 3.6 controller, which isn't cheap. We selected the Teensy because of its excellent audio processing library and still think that was the best choice...at the time. Since then, the ESP32 libraries have expanded, so that's probably a viable alternative.

Jack, W8TEE



On Wednesday, April 24, 2019, 9:05:01 AM EDT, wb8lga <cbeener@...> wrote:


Yes I agree ESP32 is up for the Job. When we get Time I'm going to use one for DSP audio filter.  SSB/CW. and a AGC that controls the RF Attenuator .and move the S-Meter/DSP to it also.

The ESP32 has enough power to run it all with no other micro's needed.

WB8LGA

Charles


On 4/23/2019 2:18 AM, MadRadioModder wrote:

Wow!  Jack is an ESP32 convert!

 

 

From: BITX20@groups.io [mailto:BITX20@groups.io] On Behalf Of Jack Purdum via Groups.Io
Sent: Monday, April 22, 2019 9:04 PM
To: BITX20@groups.io
Subject: Re: [BITX20] Audio AVC

 

Exactly. Consider the ESP32 with 1.3Mb of flash, 350Kb of SRAM, all scooting along at 240Mhz at a price of around $6. It also has two DAC ports. While the DAC ports are only 8 bit, it's better than no DAC. Also, you can program the ESP32 from within the Arduino IDE. So far, I haven't found any libraries that don't work with it. Oh, it also has builtin WIFI and Bluetooth.

 

Jack, W8TEE

 

On Monday, April 22, 2019, 9:37:05 PM EDT, Jerry Gaffke via Groups.Io <jgaffke@...> wrote:

 

 

Doing AGC in software would incur added delay, especially with an i2c pot on our beloved little Nano.
We want to keep the attack time as short as possible.
Would be fun to try, perhaps using one of the small ARM processors with fast embedded ADC and DAC capabilities.
Jerry


On Mon, Apr 22, 2019 at 05:45 PM, Hasan Murtaza wrote:

Technically the simplest circuit (for some people) would be a software solution. Send the amplified output to a diode plus capacitor in a peak detector configuration. The capacitor voltage will be a quasi DC signal proportional to the maximum value of the signal. Read it into the arduino via an ADC pin. 

So far, component count =2.

Next replace the collector resistor in the class A common emitter amplifier with a digital potentiometer. Control the pot resistance (and hence the transistor amplification) with a digital output pin of the arduino. Write some software to set the gain based on the measured peak output voltage.

Total parts count is 3. 

If you sample the audio voltage directly you can do even fancier tricks like computing rms value or histograms etc.

Hasan


Virus-free. www.avg.com

--

…_. _._