Date   
Re: Audio pre-amplifier for microphone?

Paul KL7FLR
 

Paul,
Might this be what your looking for?  https://www.adafruit.com/product/1713

Paul
KL7FLR

Re: raduino crystal question

ashok.das81@...
 

Thanks KE7ER thats helps a lot.

Re: Audio pre-amplifier for microphone?

VK3HN
 

I bought one of these to experiment with, thinking there may be an op amp gain stage between the electret and the A pin (audio out). Unfortunately, there isn't. So unless you want a VOX, this module doesn't improve over an electret mic insert and a series resistor to the phantom DC supply. Note also that A has DC on it, there is no series capacitor. 

There is apparently a similar Arduino/breakout module, about the same size, with an on-board electret insert, that does have an op-amp gain stage, leading to an audio output.  This could replace the mic amp on a homebrew exciter.  I am not thinking of the SSM2167 modules which are another thing altogether.   If anyone knows where these are, please post a URL.

73 from Paul VK3HN.  

Re: Antuino manual

Jim Sheldon
 

OK, I'll check that.  The series 1N4148 on the battery line could also be open. I found the schematic.  Had trouble downloading from github but finally got it.  Thanks,
Jim

On Aug 22, 2019, at 9:22 PM, Ashhar Farhan <farhanbox@...> wrote:

Jim,
The SMD parts are assembled on a Panasonic pick and place. No chance of a reversed diode. What is, however, possible is that the DC connector, which is hand soldered, hasnt been soldered properly. Open up the box, unscrew the PCB and flow solder on the tabs of the DC connector from the component side. I covered this problem a while ago. 
A video manual is in the works. I finished a few yesterday, I will start posting th3 videos over the weekend.

73, f


On Fri 23 Aug, 2019, 6:17 AM Jim Sheldon, <w0eb@...> wrote:
That would be nice.  Mine works fine on the external power input but 6 brand new AA cells in the battery box (9.56V) wont even light it up.  I did check and have the 9+ volts on the PCB terminals but without a manual and current schematic I don't want to take it apart.  Not really a happy camper right now.  Farhan take note I suspect an open  or reversed diode but without a schematic I can trust, I don't want to destroy it accidentally.

Jim, W0EB 

 

On Aug 22, 2019, at 6:43 PM, John Norris <jlnorrisjr@...> wrote:

This may not be going to the right group.

Is there a manual available for the Antuino? My unit arrived today.

I thought I joined the Antuino group but I see the last posting I received was on 8/17.


John Norris
KI4UCN

Re: Antuino manual

Ashhar Farhan
 

Jim,
The SMD parts are assembled on a Panasonic pick and place. No chance of a reversed diode. What is, however, possible is that the DC connector, which is hand soldered, hasnt been soldered properly. Open up the box, unscrew the PCB and flow solder on the tabs of the DC connector from the component side. I covered this problem a while ago. 
A video manual is in the works. I finished a few yesterday, I will start posting th3 videos over the weekend.

73, f


On Fri 23 Aug, 2019, 6:17 AM Jim Sheldon, <w0eb@...> wrote:
That would be nice.  Mine works fine on the external power input but 6 brand new AA cells in the battery box (9.56V) wont even light it up.  I did check and have the 9+ volts on the PCB terminals but without a manual and current schematic I don't want to take it apart.  Not really a happy camper right now.  Farhan take note I suspect an open  or reversed diode but without a schematic I can trust, I don't want to destroy it accidentally.

Jim, W0EB 

 

On Aug 22, 2019, at 6:43 PM, John Norris <jlnorrisjr@...> wrote:

This may not be going to the right group.

Is there a manual available for the Antuino? My unit arrived today.

I thought I joined the Antuino group but I see the last posting I received was on 8/17.


John Norris
KI4UCN

Re: Antuino manual

Jerry Gaffke
 

From my post 71040:

There's an updated schematic in this July 26 2019 post from Farhan
along with a list of changes:    https://groups.io/g/BITX20/message/70551
As he states in that post, it all got archived here:
    https://github.com/afarhan/antuinov2.1
The previous version of the Raduino is found here, last updated in May of 2019:
    https://github.com/afarhan/antuino

Here's the manual:  http://www.hfsignals.com/index.php/antuino/
If the Bitx40 and uBitx are any indication, 
there won't be a better manual coming out until you write it.

Jerry, KE7ER



On Thu, Aug 22, 2019 at 05:47 PM, Jim Sheldon wrote:
That would be nice.  Mine works fine on the external power input but 6 brand new AA cells in the battery box (9.56V) wont even light it up.  I did check and have the 9+ volts on the PCB terminals but without a manual and current schematic I don't want to take it apart.  Not really a happy camper right now.  Farhan take note I suspect an open  or reversed diode but without a schematic I can trust, I don't want to destroy it accidentally.
 
Jim, W0EB 

Re: Antuino manual

Jim Sheldon
 

That would be nice.  Mine works fine on the external power input but 6 brand new AA cells in the battery box (9.56V) wont even light it up.  I did check and have the 9+ volts on the PCB terminals but without a manual and current schematic I don't want to take it apart.  Not really a happy camper right now.  Farhan take note I suspect an open  or reversed diode but without a schematic I can trust, I don't want to destroy it accidentally.

Jim, W0EB 

 

On Aug 22, 2019, at 6:43 PM, John Norris <jlnorrisjr@...> wrote:

This may not be going to the right group.

Is there a manual available for the Antuino? My unit arrived today.

I thought I joined the Antuino group but I see the last posting I received was on 8/17.


John Norris
KI4UCN

Re: Antuino manual

Curt
 

Check hfsignals website, and the files section of this group.

Antuino manual

John Norris
 

This may not be going to the right group.

Is there a manual available for the Antuino? My unit arrived today.

I thought I joined the Antuino group but I see the last posting I received was on 8/17.


John Norris
KI4UCN

Re: Bitx40 very loud, high-pitched, low frequency noise

SP9DEV
 

Thank you so much for your help Woody! I'll try to get my hand on a small ceramic cap and let you know if this resolved the problem. I'll also try to salvage the ferrite sleeve from an old cable. I'll also try to power the bitx using 8 AA batteries as a constant DC source to check if the problem is even related to the power supply. Hopefully 8 AA batteries will allow for at least a couple of minutes of RX operation.

Re: Isolate any jacks/controls from metal chassis? #ubitx

Jim
 

Used sticky back copper foil to line the plastic case on my SDRPlay. Worked well. Cleaned up some noise issues.

Jim
WA3APC

moderated Re: QST September 2019 pg42 to 47

Arv Evans
 

CAREFUL!



On Thu, Aug 22, 2019, 2:36 PM Dr. Flywheel <Dr.Flywheel@...> wrote:
Jack,

I just love educated responses that use Bullshit as an argument. What could be more reliable?

Cost of Books - See: https://www.debt.org/students/the-true-cost-of-college/
If, for example, you are majoring in architecture or engineering, you may need computer programs that an English or Education major won’t need. The national average for this category in 2017 was $1,100, but the cost of books is soaring every year so count on it going up from 8%-10% from year-to-year.


image.png
As much as you like to flatter yourself about the high loss rate of books "stolen" via file sharing services (torrent is one type), this type of traffic is almost negligible. Most torrent type traffic is PORN content. Empirical data that I received from ISP traffic pattern analysis indicates that about 93% of the file sharing protocols (in action) carry tagged PORN data. eBook tagged data traffic is almost not measurable in the grand scheme of things.

Good luck on changing the world. Now it is a competition between your high-value books (that apparently are not going to be published, due to lack of profitability) and what people are actually consuming en mass 24/7/365.

--Ron    N7FTZ



On Thu, Aug 22, 2019 at 11:20 AM Jack Purdum via Groups.Io <jjpurdum=yahoo.com@groups.io> wrote:
See below:
Jack, W8TEE

On Thursday, August 22, 2019, 1:48:25 PM EDT, Dr. Flywheel <Dr.Flywheel@...> wrote:


Everyone is entitled to their own opinion. The real question is what works in real life. Here are a few points to think about for people who insist on living in a virtual world:
  1. Many people use torrents to download books, in order to preview their content. Are you really saying that people only use torrent sites to preview books? Far and away most are using the site to get a free book and have no intention of paying for it regardless of its worth. To think otherwise is woefully naive. This is due to the fact that public libraries are limited in their ability to purchase and keep all the books in the world in their limited physical space. Do not assume that if someone downloads your book, they actually keep it forever. What difference can it possibly make whether they keep a free download book or not?
  2. I like previewing books prior to purchase. I also like physical books and my house is filled with them. I always purchase my books at bottom dollar, either "pre-owned" or "old stock". I use eBay, Amazon, B&N, etc for my purchase. As an author, you will not see a dime coming back to you through my purchase. However,  if you buy a used copy, at least someone bought the book and the author was paid for that copy. If you rip off a copy or someone gives you a file that contains the book, my guess is that copy has never been paid for.;
  3. Publishing for FREE has never stopped me from doing just that. If you are using the Internet, if you are using an Intel-based PC, if you are using Linux, if you are using an Android smart phone, if you are using WiFi technology, than you are using code, tools, and documents that I authored and/or contributed to maintain. I have never seen a dime coming back to me for my contributions, neither do I expect remuneration or royalties for my work. All of my work, including that in the Arduino Projects book is Open Source for both the hardware and software. So, in one sense I am paid for it, but in another I receive nothing for it. You're free to write what you want and disseminate it in whatever format you wish. However, publishers expect a return on their investment and I see nothing wrong with that.
  4. Many publishers act as a Mafia to squeeze a significant $$ by guarding the gates to publishing and physical distribution. When I went to college, my books cost between $3 and $10 each (Dover Edition). What is the justification for charging between $100 and $300 for a book used for educating university students and then changing the book edition every year to prevent resale of books (recycling)? There are many places where students can buy used books at reasonable prices. Perhaps one reason books are so expensive at university books stores is because publishers are getting ripped off by torrent sites. It could be a chicken-egg thing.
  5. Limiting information flow to the public will never work in today's world. the capabilities are there to distribute and share information by electronic means. This levels the playing field for all participants. The capabilities are orders of magnitude stronger than any laws on the books, as well as the ability to enforce such laws. Authors are better off being benevolent (open source) or offer their products at an enticing and fair price, or ask for voluntary pay from the consumer. There are already many people who take such attitude and being successful at dealing with reality. Do you get to determine "fair price"? Or perhaps the costs of development, editing, printing, binding, marketing, distribution and other costs play a more important part in determining a fair price. How do you know what my time is worth? Hint: You don't have a clue.
  6. Student debt in the U.S.A is already $1.48 TRILLION. great part of that is attributed to the cost of books Bullshit.. Someone is getting rich in this system and typically it is not the authors. Agreed, and torrent sites play a significant role.
 The world is constantly changing and sticking to old guns does not pay off. I suggest to stop whining and get on with your regularly scheduled programming...

--Ron   N7FTZ

On Thu, Aug 22, 2019 at 9:57 AM Jack Purdum via Groups.Io <jjpurdum=yahoo.com@groups.io> wrote:
This is an issue that hits home for me. One of my publishing companies has 3 people who's only job is to shut down torrent sites that allow free downloads of their books. Two years ago, they closed down over 2,000 sites that were downloading copyright material. They estimate that for every book I sell, three are downloaded illegally. We've even had universities point their students to these sites. It's impossible to stop them because the capital costs are little more than the cost of getting a domain name.

True, I'm out the royalties lost, but that's not the real cost of downloading/copying copyright material...regardless of the country's laws about it. The real cost are the books that don't come to the market because authors now know it's simply not worth the effort. If I were in it just for the money, I would have stopped writing around the turn of the century. We've even had readers on this site give the URL's of where my books can be downloaded free of charge. Since there is no way to stop them, my attitude now is: If you illegally download the book and read it, and decide it was worth it, then buy a copy of the book. I doubt there are many who follow this plan, but what else can an author do? It's a rock-hard-place situation.

Jack, W8TEE

On Thursday, August 22, 2019, 11:38:17 AM EDT, Arv Evans <arvid.evans@...> wrote:


The issue of posting something that might be under copyright does come up fairly frequently.
When this happens a lot of bandwidth is usually taken by those who charge in to protect the
copyright or patent, and not much ever comes of it.  Most do not know, or do not want to
admit, that for over half of the world copyrights and patents are irrelevant and are not enforced.
This makes it difficult or impossible to police violations in those countries.   Posting protected
material on a global forum like the BITX20 group seems to be a gray area because the person
posting the material may be in one of the unenforceable areas but the post can be read by
persons located in an enforceable area.  Best we can do is to ask that you do not post protected
material, and to remove those posts when it happens. 

Arv  K7HKL
_._


On Wed, Aug 21, 2019 at 11:00 PM kh6sky <kh6sky@...> wrote:
I have asked for permission from the ARRL to post an article from the early 60's and they refused to grant.  I am not optimistic about anything recent.  I have noted that QST authors sometimes post their articles on their own websites, for which I suppose they have permission, but don't know if it would be a work-around to go though the author and ask him to post it here.

Original firmware upload OK, CEC not so much - what am I doing wrong?

Kim Cary
 

On my no-mods-yet v5 µBitX when I upload the UBITXV5_CEC_V1.200_16P.hex I get 16 block symbols in the LCD upper row and no function or encoder response. When I upload ubitx_20._org.hex I get a functioning radio but I'm back to where I started.

What am I doing wrong?

How can I troubleshoot this?

moderated Re: QST September 2019 pg42 to 47

Gwen Patton
 

I took a course from the Mises Institute once on intellectual property. It wasn't until I was IN the class that I found out the professor was an IP contrarian. He didn't agree with copyright and intellectual property laws. I put up with his oh so libertarian claptrap for a couple of weeks, then told him I was dropping the course, because his opinion was that I didn't deserve anything for the effort I put into my own writing and artwork for my comic book and webcomic series.

People who go to THOSE lengths to justify stealing my work then trying to educate me as to why it wasn't really stealing are toads, and I told him so.

Gwen, NG3P

Re: Bitx40 very loud, high-pitched, low frequency noise

Woody
 

On 8/22/2019 20:15, SP9DEV wrote:

Would adding a very small capacitor (nano/pico order) help as well? Or would this be too small to make any difference?

And another question, does anyone know any MacGyver way to make something working as a ferrite sleeve? I don't have any right now and would like to test it as soon as possible.

One more thing....
A ferrite sleeve is useful for common mode RFI a higher frequencies, but has little effect on lower frequencies, like audio.  It provides a series inductance in the supply line, so more that one turn of a supply cable through the sleeve (if will fit) will be more effective than just one pass through.

Woody
--

Re: Bitx40 Fuses

Woody
 

On 8/22/2019 21:38, Donald wrote:
Jerry Gaffke, in post #44333, suggested using a 1/2A fuse for the main board, and using 2A or 3 A for the PA.
Any suggestions otherwise?

Perhaps a little over-kill, but...
That would provide the ultimate protection for the board, mostly by avoiding burning of circuit board traces in the event of a short.  As they say, silicon is faster to blow than a fuse ;)   Reverse polarity power can kill semiconductors, then (if they go shorted) blow the fuse. 

That is why a shunt power diode is useful in addition to a only fuse - to blow the fuse before the reverse polarity voltage reaches critical devices.  A series diode will stop the reverse voltage without blowing the fuse but will add about a 0.6 volt drop to the equipment.


Woody
--

moderated Re: QST September 2019 pg42 to 47

Jerry Gaffke
 

There is a racket going on with college textbooks.
These days you can wind up spending $300 on a required book for a class.
And there's various schemes to discourage a used market, kickbacks to
encourage the powers that be to choose specific textbooks, etc
Costs can be way more than $1k/yr.

Not true everywhere. 
Some schools make a policy of of using freely available material where possible.
And even make it possible to get credit by "attending" class online.
Worth considering when shopping for a University.

Generally speaking, I find it best to keep my nose clean with respect to obeying the law.
If you feel a law is wrong enough that it needs breaking, then go for it.
That can at times be an important civic duty.
But don't be surprised if there are consequences.

Regarding the ARRL and their grip on those copyrights, that's their privilege.
They seem enough of a force for mostly good that it is worth putting up with (YMMV).
Though if I spent 6 months on a project that I wanted made easily available
to amateurs worldwide, publishing in QST or QEX would not be my first choice.

Jerry, KE7ER


On Thu, Aug 22, 2019 at 02:05 PM, Ken Hansen wrote:
So textbooks cost $1K/year, tuition is $20K, and it's the TEXTBOOKS that are the problem?
 

Re: Bitx40 very loud, high-pitched, low frequency noise

Woody
 

On 8/22/2019 20:15, SP9DEV wrote:

Would adding a very small capacitor (nano/pico order) help as well? Or would this be too small to make any difference?

And another question, does anyone know any MacGyver way to make something working as a ferrite sleeve? I don't have any right now and would like to test it as soon as possible.

Piotr,
Lower value capacitors cannot hurt, but they are only useful for Very High Frequencies.  The type of capacitor (electrolytic,  ceramic, silver mica, etc.)  have different characteristics at different frequencies.   For example, tantalum electrolytic capacitors are typically useful at higher frequencies than aluminum electrolytic capacitors due to the lower ESR at high frequencies.  Lower capacitance ceramic or silver mica capacitors typically have lower ESR at high frequencies than do electrolytic ones.   For the very lowest ESR, "chip" (SMD) capacitors perform best.  This is because the lead wires on other capacitors add inductance in series with the capacitor, thus increasing the ESR.  In your case. it is doubtful that going below .01 uf will be helpful.

A physically small ceramic capacitor of .1 or .01 uf should be low enough to bypass anything less than VHF frequencies or very fast transient spikes.   Here is a reactance calculator that will give the effective series resistance (ESR) of a capacitor.  This is for an ideal capacitor and does not take into account lead length and the type (construction) of the part.
https://daycounter.com/Calculators/Reactance-Calculator.phtml

If you have any old computer cables, power supply cables, or similar that have a molded lump in the line, that is a ferrite sleeve.  Many times I have cut away the  molded plastic, pulled out the wire, and used them in my circuits.

 
Good luck!
Woody - KZ4AK

Google translate (maybe):
Kondensatory o niższej wartości nie mogą zaszkodzić, ale są przydatne tylko w przypadku bardzo wysokich częstotliwości. Rodzaj kondensatora (elektrolityczny, ceramiczny, mika srebrna itp.) Ma różne właściwości przy różnych częstotliwościach. Na przykład kondensatory elektrolityczne tantalu są zwykle użyteczne przy wyższych częstotliwościach niż aluminiowe kondensatory elektrolityczne ze względu na niższy ESR przy wysokich częstotliwościach. Kondensatory ceramiczne lub srebrowe miki o niższej pojemności zwykle mają niższą ESR przy wysokich częstotliwościach niż elektrolityczne. W przypadku najniższej ESR kondensatory „chipowe” (SMD) działają najlepiej. Jest tak, ponieważ przewody ołowiane w innych kondensatorach dodają indukcyjność szeregowo do kondensatora, zwiększając w ten sposób ESR. W Twoim przypadku. wątpliwe jest, aby pójść poniżej .01 uf będzie pomocne.

Fizycznie mały ceramiczny kondensator .1 lub .01 uf powinien być wystarczająco niski, aby ominąć cokolwiek mniejszego niż częstotliwości VHF lub bardzo szybkie przejściowe impulsy. Oto kalkulator reaktancji, który da efektywną rezystancję szeregową (ESR) kondensatora. Dotyczy to idealnego kondensatora i nie uwzględnia długości ołowiu oraz rodzaju (budowy) części.
https://daycounter.com/Calculators/Reactance-Calculator.phtml

Jeśli masz jakieś stare kable komputerowe, kable zasilające lub podobne, które mają uformowany guzek w linii, jest to tuleja ferrytowa. Wiele razy odciąłem uformowany plastik, wyciągnąłem drut i użyłem ich w moich obwodach.

--

Bitx40 Fuses

Donald
 

Jerry Gaffke, in post #44333, suggested using a 1/2A fuse for the main board, and using 2A or 3 A for the PA.
Any suggestions otherwise?

Re: Isolate any jacks/controls from metal chassis? #ubitx

Tom, wb6b
 

On Thu, Aug 22, 2019 at 09:54 AM, <jhowell39@...> wrote:
Electric guitar body cavities (pickup mounts, etc) often use a conductive copper tape for shielding
I bought a roll on Amazon some time back. The copper tape is handy.

One thing to note is: The tape claimed to have conductive adhesive. There was absolutely nothing conductive at all about the adhesive. 

I cut a hole in a piece of paper and stuck two pieces of the tape together so they only make contact through the 1/2 inch hole in the paper and I could not measure any resistance less than an open circuit.

If I stuck two pieces of copper tape together where they overlap (the edge of one going down the center of the other) then I measured a low resistance connection between them.

I believe in the case of the overlap, the rough edge of the copper tape where I cut it was making contact with the top of the copper foil I stuck it to.

I still like the tape, I just make sure I add some solder bridges across the overlapped layers. Even if the adhesive was conductive, probably not a good idea to rely on it for a solid electrical connection.

I've found this tape handy for adding big ground areas to prototype board projects, too.

Tom, wb6b