Re: CW Offset does NOT work on Raduino_v1.14.1 for BITX40
Sockets are good when you need them, but otherwise they are just dozens of extra potential points of failure. ?Especially for somebody operating portable at the beach, the slightly corrosive salt air could tarnish those connections.. ?I'd like to see the Si5351 on the Bitx40 board so it's just a few wires from Bitx40 to the processor+display of our choosing, no need for a 30 pin connection from Nano to Raduino. ?The Nano is just one of the many processors that we might want to use with the Bitx40.
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On Wed, Jun 14, 2017 at 07:55 pm, Jeff wrote:
It is only $3 but I sure would like to know the thought process of not putting it in a socket
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Re: CW Offset does NOT work on Raduino_v1.14.1 for BITX40
Here's the datasheet for the processor used on the Nano: ?
On page 365, they spec an absolute maximum of voltage on an IO pin of VCC+0.5, if VCC is at zero then the maximum voltage is 0.5v. ?Beyond that, you may damage the device.
They also spec an absolute maximum current into that IO pin of 40ma.
I was cautioning against hooking up the 78L05 directly to a Nano IO pin because we would be exceeding both of these specs by quite a bit if we have the Bitx40 powered up and the Raduino not powered up, or perhaps not yet powered up due to a few milliseconds delay in charging up a cap somewhere, or have a failed regulator on the Raduino, or a flaky connector somewhere.. ?You will blow an IO pin unless you pay attention to this sort of thing.
This case is a bit unusual in that we would have been driving that IO pin from a voltage source capable of hundreds of ma (the 78L05 datasheet says at least 100ma while holding it within spec near 5v, but it could give much more). ?If it's just a regular signal going into the Nano from some peripheral chip, they generally don't drive more than 10ma into a dead short to gound, and the Nano IO pins can live through that. ?With that 10k series resistor that Allard recommends in his notes between the 78L05 and the Nano's A0, the current is limited to 5v/10k = 0.5ma, which is far less than the Nano IO pin's 40ma max, so most of the 5 volts from the 78L05 will be across the resistor, the voltage from A0 to ground would be just a fraction of a volt.?
Jack wrote:
> ?Admittedly, my memory's not what it used to be, but I don't remember anyone
> ?blowing an Nano I/O pin. I'm sure there have been some who somehow
> ?connected 12V directly to an input pin but, to me, that's a $3 lesson that they needed to pay.?
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Re: CW Offset does NOT work on Raduino_v1.14.1 for BITX40
Yep I blew up one as well when I had it just wired up and laying on the workbench and I just repaired another one with the same problem. It is only $3 but I sure would like to know the thought process of not putting it in a socket. I know it probably saved a few cents but when I was cutting out the original one it sure didn't seem to be worth it at the time.
Jeff
N9ARZ
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Re: CW Offset does NOT work on Raduino_v1.14.1 for BITX40
Back in January I experienced a short with one of the loose wires and the metal heatsink. Jerry knew how to fix the rough tuning that resulted from the short. The A6 tuning pin was conducting current instead of sencing input. The solution was to change to A7 for tuining, both the wiring and code. There might have been 3 more who had something similar happen. It also wiped the Raduino code, just left it running blink. It,s all back there if you want to look for it.
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Re: CW Offset does NOT work on Raduino_v1.14.1 for BITX40
Admittedly, my memory's not what it used to be, but I don't remember anyone blowing an Nano I/O pin. I'm sure there have been some who somehow connected 12V directly to an input pin but, to me, that's a $3 lesson that they needed to pay.?
Jack, W8TEE
From: Jerry Gaffke via Groups.Io <jgaffke@...>
To: [email protected]
Sent: Wednesday, June 14, 2017 7:10 PM
Subject: Re: [BITX20] CW Offset does NOT work on Raduino_v1.14.1 for BITX40
The reason to go with the output of the 78L05 was because it swings between 0 and 5v, which is the range acceptable to the Nano. But looks like we want two resistors to do that properly. Perhaps the 10k series resistor ?from 78L05 to the Nano is not absolutely needed, but we've seen enough blown Nano IO pins here that I would definitely include it in case the 12v TX line goes high but the Raduino is not powered up for some reason. Might be more straightforward to instead sense the 12v TX line using a resistive divider of 20k and 10k in series,? with 12v TX into the top of the 20k, bottom of the 10k to ground. The join between the 20k and 10k goes to the Nano's A0 input. The 78L05 is not involved. So the Nano sees 12v * 10k/(20k+10k) = 4v when TX is at 12v, otherwise 0v. Your choice, either this or the two 10k's on the 78L05, either should work just fine. ? Jerry On Wed, Jun 14, 2017 at 03:53 pm, Jerry Gaffke wrote:
Adding a 10k load to the 78L05 will not affect bias to the IRF510 gate.
The 78L05 can supply between 0 and 100ma while maintaining a constant 5v at the output.
That 10k resistor will draw an extra ?5v/10k = 0.5ma.
Jerry, KE7ER
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Re: CW Offset does NOT work on Raduino_v1.14.1 for BITX40
Sounds good.
The reason the Bix40 is so popular is that it gives great performance with?
very few parts. ?Your approach is in line with that philosophy.
Keep it simple wherever we can.
Jerry, KE7ER
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On Wed, Jun 14, 2017 at 04:36 pm, Allard PE1NWL wrote:
So before overreacting and advising everyone to add extra resistors I'd
like to hear if there are any other builders having similar issues
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At this point in time, there are approximately 156 markers on the map. What is the estimate number of BITX40's sold? Judging from previous conversations about serial numbers and batches, I would guess at about 4,000 sent out, and some folks buying more than one. I would venture a guess that we are only seeing the currently active group members who bothered to make their mark. But wow, is this the biggest game of Marco Polo, or what? For people in other parts of the world who wonder what I am talking about, Marco Polo is a swimming pool game. Sometimes I also hear it in Walmart.
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Re: CW Offset does NOT work on Raduino_v1.14.1 for BITX40
Yes, sensing the 12V from the TX/RX line is also an option.
But I'm still a bit reluctant as I'm not completely convinced yet that we
anyway need a two-resistor solution.
The elegantly simple one-resistor method has worked fine in all cases so
far (at least that I know of). So far only one builder (ja9mat Hidehiko)
reported that in his case it didn't work reliably.
As he mentioned that his radio was still in an experimental setup
situation (perhaps with long or loose wires, poor ground connections,
etc.), there is still a possibility that his problem will disappear once
everything is properly built together and wired correctly.
So before overreacting and advising everyone to add extra resistors I'd
like to hear if there are any other builders having similar issues, and if
Hidehiko-san's problem disappeared after he has properly wired everything.
73 Allard PE1NWL
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Re: CW Offset does NOT work on Raduino_v1.14.1 for BITX40
The reason to go with the output of the 78L05 was because it swings between 0 and 5v, which is the range acceptable to the Nano.
But looks like we want two resistors to do that properly.
Perhaps the 10k series resistor ?from 78L05 to the Nano is not absolutely needed,
but we've seen enough blown Nano IO pins here that I would definitely include it in case
the 12v TX line goes high but the Raduino is not powered up for some reason.
Might be more straightforward to instead sense the 12v TX line using a resistive divider of 20k and 10k in series,?
with 12v TX into the top of the 20k, bottom of the 10k to ground.
The join between the 20k and 10k goes to the Nano's A0 input.
The 78L05 is not involved.
So the Nano sees 12v * 10k/(20k+10k) = 4v when TX is at 12v, otherwise 0v.
Your choice, either this or the two 10k's on the 78L05, either should work just fine.
?
Jerry
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On Wed, Jun 14, 2017 at 03:53 pm, Jerry Gaffke wrote:
Adding a 10k load to the 78L05 will not affect bias to the IRF510 gate.
The 78L05 can supply between 0 and 100ma while maintaining a constant 5v at the output.
That 10k resistor will draw an extra ?5v/10k = 0.5ma.
Jerry, KE7ER
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Re: CW Offset does NOT work on Raduino_v1.14.1 for BITX40
Adding a 10k load to the 78L05 will not affect bias to the IRF510 gate.
The 78L05 can supply between 0 and 100ma while maintaining a constant 5v at the output.
That 10k resistor will draw an extra ?5v/10k = 0.5ma.
Jerry, KE7ER
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On Wed, Jun 14, 2017 at 03:37 pm, Allard PE1NWL wrote:
Couldn't it have some effect on the IRF150 bias setting? Do we perhaps need to check/realign the bias after adding the 10K resistor?
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Re: BITX operator map is now locked down
Sadly, I was sure it would wind up that way. I think we all
appreciate that you want it to be owned collectively but it is too
much work to ask you to keep downloading the latest .kmz. So if you
have a few people available to add folks I think that is the best
you can do. It is a great idea and I think will encourage more
contacts. Is there a way to place a note on the page directing folks
how to get signed up? I'd be happy to help add folks if needed.
Jonathan - KK6RPX
On 6/14/2017 3:26 PM, Doug W wrote:
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Once again someone
who didn't understand the map and didn't take the time to ask for
help or RTFM blew it up.? I have been manually downloading the kmz
randomly so we are restored as of about 2:30 pm central time.?
Until we come up with a better solution, the map is locked down
and only I can edit.? As always, I am happy to add anyone
manually.? Just email me at KD9CYF at gmail dot com or reply
here.? I think I can add editors so if you are interested and have
a general understanding of google maps let me know if you want to
help.? I really liked the idea of full access for everyone but
this thing is getting messed up about every other day making it
useless.? I want this to be ours not mine.
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Re: CW Offset does NOT work on Raduino_v1.14.1 for BITX40
All, many thanks for all of your thoughts and comments. I tend to agree with Jerry that probably the easiest and most reliable way to improve the situation would be to just add a 10K resistor at the ouput of the 7805. I believe the most convenient place for the resistor would be to solder it across C150. I haven't tried this yet, what do you think? Couldn't it have some effect on the IRF150 bias setting? Do we perhaps need to check/realign the bias after adding the 10K resistor?  73 Allard PE1NWL
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BITX operator map is now locked down
Once again someone who didn't understand the map and didn't take the time to ask for help or RTFM blew it up.? I have been manually downloading the kmz randomly so we are restored as of about 2:30 pm central time.? Until we come up with a better solution, the map is locked down and only I can edit.? As always, I am happy to add anyone manually.? Just email me at KD9CYF at gmail dot com or reply here.? I think I can add editors so if you are interested and have a general understanding of google maps let me know if you want to help.? I really liked the idea of full access for everyone but this thing is getting messed up about every other day making it useless.? I want this to be ours not mine.
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Re: CW Offset does NOT work on Raduino_v1.14.1 for BITX40
Now Jerry, how'd you know I was going to come over here and read this thread about CW?
For my digital upgrade I will be using serial PTT rig control in Fldigi. A year ago I made the CW keying circuit found in the Fldigi Manual and added a relay module for solid sounding keying of the radio. And I hope this new control scheme work equally as well. Check out this link for the VOX style CW keying circuit. It does require a particular balance of combined volume controls (side tone on radio out, received signal, output tone on right....).
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On Wed, Jun 14, 2017 at 10:58 am, Jerry Gaffke wrote:
John Smith:
> I already have right channel PTT circuit in the form of the Fldigi CW keying circuit
If all I wanted was a simple way to drive the Bitx40 for CW, I'd add an extra 10k resistor and skip all the FLdigi stuff.
If you already have the FLdigi stuff somehow dealing with this PTT thing, that's great.
Jerry, KE7ER
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I ordered two Bitx40 over the weekend?and had delivery by?DHL.? They were here this morning.? I have ordered a lot of things in the past, even overnight, it was as fast as anyone could hope for.? Thx.
I also need picture and information for ordering cases for these radios.? I do want to be able to add the additional things.? I do not want a huge case to add them, just what is needed.
If anyone could offer any information about a good case kit for this latest kit and the most up to date add-ons, ( like the AGC and so on ).? I would surely be mighty appreciative.? It is ok to email me direct too.
Ron
KJ4FFG
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Re: CW Offset does NOT work on Raduino_v1.14.1 for BITX40
Thanks Allard, PE1NWL.
OK all, Yes because my situation is still in experiment ballkack.
So the perfect grounding and casing to avoid the stray capacity will be good.
ja9mat Hidehiko.
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Re: WANTED VK3YE LED LDR AGC diagram
Yes thats it, take the red wire from the 3 way socket and connect it to the input, output from AGC then goes to AF pot.
Think thats part of the fun, most is words from e-mails, bits of info from the forum, some good stuff on here, and theres at least 3 pages on Facebook. Plus it got some of us, experimenting again.
Plenty of help from others for me, never programmed a Raduino... so had help there. So nice to try and help others along the way. Cannot wait to get mine cased, but that could take a while.
Phil - G7BZD
On Wed, Jun 14, 2017 at 9:45 PM, M0LHT <m0lht.huw@...> wrote: i will use the heat shrink once its in the box and wired up ( after i show it flashing away and working).
where abouts did you connect yours too. do i take the audio from the board where the volume control socket is and fit it in-between the socket and the volume control pot.
as your probably aware this is my first time building and adding without instructions.
Huw?
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Re: WANTED VK3YE LED LDR AGC diagram
i will use the heat shrink once its in the box and wired up ( after i show it flashing away and working).
where abouts did you connect yours too. do i take the audio from the board where the volume control socket is and fit it in-between the socket and the volume control pot.
as your probably aware this is my first time building and adding without instructions.
Huw?
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Re: WANTED VK3YE LED LDR AGC diagram
I used a piece of heat shrink tubing over the LED/LDR, so its nicely confined and the LDR only sees the flashing of the LED, Level of flash is only low, although I think it depends on the LDR and the LED combination. Coupled with the RF gain, it becomes a fantastic RX to listen too. 3 pots + tuning pot so far. AF, RF, AGC and tuning.
Yours looks good, take it, all functions, having it adjustable I think maybe overkill, but without trying one will not know.
Phil - G7BZD?
On Wed, Jun 14, 2017 at 9:03 PM, M0LHT <m0lht.huw@...> wrote: so here it is Phil one board nearly finished. Thank you for your assistance. i haven't fitted the audio 10k trim pot i will need to shop around or hunt in the depths of a junk box for that part. i assume its just to tweek the volume to a reasonable level.
so the next question is where to fit the wires to the board.
I've put the pictures as files as they where massive.
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Re: WANTED VK3YE LED LDR AGC diagram
so here it is Phil one board nearly finished. Thank you for your assistance. i haven't fitted the audio 10k trim pot i will need to shop around or hunt in the depths of a junk box for that part. i assume its just to tweek the volume to a reasonable level.
so the next question is where to fit the wires to the board.
I've put the pictures as files as they where massive.
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Jeff
Allard PE1NWL
Hidehiko Komachi - JA9MAT
