Re: Modular uBitx - "Ex: Harmonics"
The reason Raspberry Pis are so inexpensive is they take advantage of the price advantage of using basically the same processor that is used in hundreds of millions of radio transceivers, already. (smartphones)?
So, a Raspberry Pi finding its way back into another transceiver (uBITX) does not seem too far of a stretch. Not necessarily for SDR I/Q processing, but running digital modes in a small radio package is a good thing. Also, there are some audio/microphone compressor/equalizer software packages that can run under Linux that might improve your SSB transmit audio without needing to add an additional analog compressor board (albeit a second USB sound adaptor).
On the RFI noise front, I found a metal case for the Pi that will go inside the bigger transceiver case.?
I like?Allison's idea of using Android tablets as a controller for the uBITX. I'm, also, looking into running a web server on my Raspberry Pi so I can operate my uBITX from either an iPhone or Android (without installing an App). Possibility borrowing a little from the web interface of OpenWebRX. ?Some browsers may be capable of sending realtime audio back to the uBITX. I'm looking at the protocol that supposedly allows this.?
I've seen some commercial HF radios that let users send/receive text messages from their Smartphones. That, on Ham Radio, would certainly attract a new younger group of Amateur Radio operators to the hobby.
Tom, wb6b
?
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I am using a metal box but it is powder coated and so not a good ground.? The instructions recommend a heavier ground wire from the power ground to the main board.? I did this and also ran a ground wire to the ground tabs of all the sockets and the yellow lead to complete the grounding.? Pretty sure that grounding is not a factor.? Just finished reading up on how to upgrade.? I am looking forward to hear if you have solved the CW issue with your upgrade.? Good luck.? Jeff
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Re: Wow... 15 volts in and a bunch out..
Cool. Yes, it can safely work at that
temp. Some people have put a resistor in series to reduce the
temp, but the heat sink is easier. The resistor is a good idea if
you are much closer to the power limit.
Howard
On 8/18/2018 9:31 PM, Kevin Rea wrote:
toggle quoted message
Show quoted text
Ok, i just put one
on it.
on it's datasheet, looks like it can operate up to about 257
degrees?fahrenheit, so at 135 degrees it seems safe.
kevin
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Re: Wow... 15 volts in and a bunch out..
Ok, i just put one on it.
on it's datasheet, looks like it can operate up to about 257 degrees?fahrenheit, so at 135 degrees it seems safe.
kevin
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Farhan gives a hint on the uBitx description to consider adding a second crystal filter at a lower IF. It would involve retuning the bfo and selecting it. I would imagine its been done by someone. 73 curt
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Re: Modular uBitx - "Ex: Harmonics"
Gordon
Those Chinese boards look pretty good.?
Hang in there.? We are all pulling for you.
Arv
_._
On Sat, Aug 18, 2018 at 7:14 PM Gordon Gibby < ggibby@...> wrote:
Regarding my external relays idea : ?The Chinese boards arrived, and I believe the digikey parts also.... then I had to go to the emergency room with incredible abdominal pain that turned out to be gallbladder stone induced pancreatitis. ? I¡¯m still in the
hospital, ?much better, now to have the gallbladder out Monday. ? ?
Then maybe I can get back to this and many other projects.? Group Builds of uBitx¡¯s ?at my house today had to be canceled of course. ? Getting old is tough but the alternative is less desirable?
Gordon.?
On Aug 16, 2018, at 22:01, ajparent1/KB1GMX < kb1gmx@...> wrote:
Arv,
I have a laptop using a Rpi3b and a 10inch screen (not touch) with a real
keyboard and mouse with a steampunk sorta look.? With a stereo usb
dongle IT runs Fldigi, gsdr and a few other useful things like Xlog under
Raspian (linux).? Noise has not been an issue.? Its mostly all wood so
its not shielded.? Power drain is pretty low with the display backlight down.
The asus Tinker board is faster and uses more power, heck 1.8GHZ,
2gb ram and all that. No Noticeable noise
Android tablets work, the smaller ones with quad cores are ok for this too
and it could be the whole front panel for a radio at cheap prices.? I have
two for that.?
Allison
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Re: Modular uBitx - "Ex: Harmonics"
Regarding my external relays idea : ?The Chinese boards arrived, and I believe the digikey parts also.... then I had to go to the emergency room with incredible abdominal pain that turned out to be gallbladder stone induced pancreatitis. ? I¡¯m still in the
hospital, ?much better, now to have the gallbladder out Monday. ? ?
Then maybe I can get back to this and many other projects. ?Group Builds of uBitx¡¯s ?at my house today had to be canceled of course. ? Getting old is tough but the alternative is less desirable?
Gordon.?
On Aug 16, 2018, at 22:01, ajparent1/KB1GMX < kb1gmx@...> wrote:
toggle quoted message
Show quoted text
Arv,
I have a laptop using a Rpi3b and a 10inch screen (not touch) with a real
keyboard and mouse with a steampunk sorta look.? With a stereo usb
dongle IT runs Fldigi, gsdr and a few other useful things like Xlog under
Raspian (linux).? Noise has not been an issue.? Its mostly all wood so
its not shielded.? Power drain is pretty low with the display backlight down.
The asus Tinker board is faster and uses more power, heck 1.8GHZ,
2gb ram and all that. No Noticeable noise
Android tablets work, the smaller ones with quad cores are ok for this too
and it could be the whole front panel for a radio at cheap prices.? I have
two for that.?
Allison
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Re: Wow... 15 volts in and a bunch out..
7805 5 volt regulator for the Arduino.
Adding a small clip on heat sink is? good idea.
On 8/18/2018 8:58 PM, Kevin Rea wrote:
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Show quoted text
so far, the hottest thing i have found is that large transistor
that sticks out the side of the raduino, on the front side of the
unit, don't know
what that part is for, possibly audio ?? anyway, i monitor it at
about 135 degrees fahrenheit.
kevin
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Re: Wow... 15 volts in and a bunch out..
so far, the hottest thing i have found is that large transistor that sticks out the side of the raduino, on the front side of the unit, don't know
what that part is for, possibly audio ?? anyway, i monitor it at about 135 degrees fahrenheit.
kevin
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Re: #ubitx. Increasing power output
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Re: #ubitx. Increasing power output
On Sat, Aug 18, 2018 at 08:58 AM, David Nelson wrote:
Bo you got a place holder but no photo? kc2ipx
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Wow... 15 volts in and a bunch out..
So, I thought I would try just 15 volts straight into the rear power connector..
wow.. 30 watts ssb on 20 meters into a dummy load.
i have three temp monitors on it to see what all the areas do, so far nothing really hot..
kevin
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On Saturday, August 18, 2018, 10:39:46 AM PDT, George Baumann <georgehbaumann@...> wrote:
Think this is what he posted! /g/BITX20/album?id=67452Indeed it is ...Sorry, I should have made it clearer ...Also a folder there for T9,? Just in case Working on dumping another for T11, after I get the finals balanced best I can (minimize 2nd harmonic)
Jim ab7vf
_._,_._,_
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So this 1db flat gain and power from the reference?? I¡¯m sure it can be done by doing some compensation at the gate¡ ? 
? ?
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From: [email protected] [mailto:[email protected]] On Behalf Of ajparent1/KB1GMX
Sent: Saturday, August 18, 2018 1:39 PM
To: [email protected]
Subject: Re: [BITX20] #bitx40help BITX40 LSB Winlink ? MadRadioModeler,
Actually the Miller capacitance (drain to gate) of the RD16HHF is about in the same
(about half that of IRF510).? The RD15VHF1 is a VHF part and has even lower?
reverse Capacitance than RD16HHF.? Compared to MRF137, not impressive
just cheaper.
You are however right, that if badly designed it can be come significant.
The most common issue is to assume the input of the MOSFET is infinite
and it is, at DC only!? ?At RF its a complex series capacitance, resistance
and inductance.? That also means the driver circuit must deliver RF to a
complex load that is typically reactive (capacitive to about 180pf).? It
also requires maintaining gate circuit impedance low enough so that
the Drain-Gate capacitance is not a negative feedback of uncontrolled
significance (miller effect).??
If one designs using IRF510 and treats it like a RF part an amp like I have
in my hands that is flat gain and power (1db) from 2 to over 30mhz at 10W
is not only possible but also is well behaved with excellent stability.? An
example of this is the work of IK4AUY (and others).?
Look at the picture at?
What to I mean by treated as an RF part?? The IRF510 has significant gain
to well past 70mhz.? Its power out is the product of power delivered to the
gate and?can easily exceeds 13db even at 50mhz.? So hanging it on full
length leads for example is a really bad thing to do.? That means treating
it like a VHF device.? The board has to be made just like one would?for any
high power amp.? That means wide traces (not barely 30mils), ample
grounding and?large numbers of vias (stitching) to link topside ground
the back side ground.
It helps to have a driver that doesn't go flat on its face at mid HF.? After all
Its hard to amp up 100mW when your expecting more than 400mw or so.
Failure to do so with any device with gain at VHF usually results in instability,
low gain, and parts sensitivity.??
Allison -- ¡_. _._
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Hello,
Havent posted on here in several months, long story short; due to illness, family drama, lack of time i am considering parting with the following items for trade or cash. Please note i have do desire to make money from these item... just recoup a little of what i spent.
1. ?First Release uBitx - Dec 17
2. ?Second Release ubitx - Feb 17 ?
3. ?One maybe two Bitx40s - Same time frame
4. ?All extra Radino VFO kits bought (4-5)
5. ?Whatever extra chips i bought new to playwith for radios (audio amps, compressor chips, a few additional Sis VFO based boards, a few other Sis type clock generator I2c based clock chips, etc.
All uBitx kits and Bitx40 kits were only opened for inventory, none assembled or tested. Any additional items also new. I have several ATmega328p mini boards i can through in, most Sparkfun or Adafruit. These have headers soldered and tested. You will need usb to serial adapter to connect and i may even through in a few Teensy 3.1/3.2 boards as well.
I also have several better grade NPN and PNP transistors i bought to swap out on the kits.
As stated not looking to make money just recoup a little, and would prefer to trade for other working excellent condition old AM Marine Radio or Radios.
If interested please contact me directly, i think you can or reply to this post. It maybe a day or two before i check this post, and ill send picks if you want them.
Thanks,
Jim
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Re: Use of BitX40 for WSJT-X
You can just edit it in the sketch .
On Sat, 18 Aug 2018 at 19:59, Jack Margolis <jmargolis9@...> wrote: Greg,
Can one just edit the Raduino to change the frequencies from the 40 meter band to the 20 meter band, or do you need a new sketch?
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Re: Use of BitX40 for WSJT-X
Greg,
Can one just edit the Raduino to change the frequencies from the 40 meter band to the 20 meter band, or do you need a new sketch?
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Re: ubitx troubleshooting help - low power after irf510 replacement
Here's a thread and a quote for part of it, that I found on the web about them,
Quality of Tada parts is always an issue. I may speak for the developers and PCB suppliers present here that build a lot of prototypes and most of us had issues with diodes, JFETs and Op Amps from Tayda where the prototyping failedbecause of these parts.
The only things I buy from them are the Alpha pots as they are still ok.
LEDs have been ok but not the RGB types.
You can also buy resistors and caps but dont expect the values you order. Always meassure them.
I you look close you see that the leads are very thin compared to parts sourced from other sources.
MLCC caps are ok but not really cheap. Electrolytics are ok too but you need to check the meassurements in the datasheet -if they have one. They are usually not the smallest
Milled IC sockets are ok. Pin headers not, they are hard to solder in.
Do not expect to see the same parts when ordering now and 4weeks later.
You can but standard OpAmps or Digital ICs like TL072 or CD40106 but nothing that is usually very expensive from other sources. You will get what you pay for? 
If I need high quality parts in a short time I use Mouser but ai will order in quantities and therefore they are cheap for me.
I have a local electronics online store here in Germany for small orders- but compared to Mouser their shipping rates piss me off more if you look at the numbers you get and the shipping you pay for.
Nichicon is a good source for small electrolytic caps.
73, Mark
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Re: UBITX won't key--- solved
Joe
Not a problem.? We have all been there and done that.? My comment was more about the
trolls who latch onto others problems and amplify the seriousness.
Some have bemoaned the fact that uBITX and the BITX40 do not have the same level of
documentation as QRP-Labs products, but they actually fit a different audience.? Hans is
working on top-of-the line kit ideas with proprietary software where Farhan has produced an
experimenter's kit that relies on on-line support via the discussion group.? Actually Hans
(QRP-Labs) and Farhan (HFSignals) are friends and may at least subconsciously be avoiding
stepping on each others toes with identical products.?
Not sure what might be different? but my Debian Linux and Arduino IDE seems able to
automatically determine which boot-loader it might be working with and automatically do
the right thing.? However, it is good to note on-line that some may have different results.
Now that I have said that, I may have jinxed it and my next download will fail!? 8-)
Arv
_._
?
On Sat, 18 Aug 2018 11:13:22 -0600
"Arv Evans" <arvid.evans@...> wrote:
Hi Arv, I put my dunce cap on and go sit in the corner. :-)
It's just that I worked 2 days trying to figure out this
keyer problem, and the frustration grew to where I had to
blame the parts. The only advice I got was check for
5v to 0v transistion, which was there, yet the keyer
still didn't work.
BTW, I googled and searched for Arduino nano not syncing,
but not one link led me to "use the OLD BOOTLOADER".
I suppose I'm guilty of relying on Google Search to do my
work for me.... but it does work most of the time. :-)
Now that I read the Arduino Nano manual, I see it prominently
mentioned there.
I wonder why the uBITX dosn't ship with the KD8CEC software upgrade
to begin with? It was a good learning experience, but shouldn't
the keyer work right out of the box?
The uBITx is a pretty solid toy, an experimenter's dream toy,
but I think it sadly lacks in clear documentation.
The KD8CEC documentation however, is first rate.
Maybe it's meant to be that way, to force us into the learning process.
After all, this did make me learn about the Arduino IDE and
the Nano, so that made it all worth the time.
Joe
>Way too often we are quick to blame the part(s) for being defective when it
>is just an
>operator mistake.? Others reading these posts are also very quick to blame
>problems
>on "clone" hardware or "made in....." parts.? Sometimes it is more
>productive to take a
>step back and review what has been done or said that led up to the
>problem.? It is
>difficult to find someone who has never made a mistake or misread (or
>failed to read)
>the instruction manual.
>
>Arv
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MadRadioModeler,
Actually the Miller capacitance (drain to gate) of the RD16HHF is about in the same
(about half that of IRF510).? The RD15VHF1 is a VHF part and has even lower?
reverse Capacitance than RD16HHF.? Compared to MRF137, not impressive
just cheaper.
You are however right, that if badly designed it can be come significant.
The most common issue is to assume the input of the MOSFET is infinite
and it is, at DC only!? ?At RF its a complex series capacitance, resistance
and inductance.? That also means the driver circuit must deliver RF to a
complex load that is typically reactive (capacitive to about 180pf).? It
also requires maintaining gate circuit impedance low enough so that
the Drain-Gate capacitance is not a negative feedback of uncontrolled
significance (miller effect).??
If one designs using IRF510 and treats it like a RF part an amp like I have
in my hands that is flat gain and power (1db) from 2 to over 30mhz at 10W
is not only possible but also is well behaved with excellent stability.? An
example of this is the work of IK4AUY (and others).?
Look at the picture at?http://ik4auy.xoom.it/article_4_english.htm
What to I mean by treated as an RF part?? The IRF510 has significant gain
to well past 70mhz.? Its power out is the product of power delivered to the
gate and?can easily exceeds 13db even at 50mhz.? So hanging it on full
length leads for example is a really bad thing to do.? That means treating
it like a VHF device.? The board has to be made just like one would?for any
high power amp.? That means wide traces (not barely 30mils), ample
grounding and?large numbers of vias (stitching) to link topside ground
the back side ground.
It helps to have a driver that doesn't go flat on its face at mid HF.? After all
Its hard to amp up 100mW when your expecting more than 400mw or so.
Failure to do so with any device with gain at VHF usually results in instability,
low gain, and parts sensitivity.??
Allison
|
MadRadioModder
James Lawrie
Marc Jones