Date   
Re: Volume potentiometer choice

Lawrence Galea
 

Logarithmic 

On Sat, Mar 11, 2017 at 9:47 PM, <mcfortner@...> wrote:

I think I have everything I want/need to customize my radio, so I'm about ready to assemble it.  However, I am wondering, what would be a better volume potentiometer, a linear or logarithmic?  I have a 1/4 inch linear potentiometer with built in on/off switch here, but would a log control work better?  Or is it all just a matter of personal preference?  

Michael KA3X


Re: New to programming raduino

Michael Hagen
 

Message with link to PDF document on Programming

https://groups.io/g/BITX20/message/22618


Try to get a blink example working first.  Do THIS FIRST.  You must be able to program a simple program before going further.

They are selected in the Examples left hand menu.  Don't skip this learning step!


Then next step would to be add Libraries required for Raduino.

Then find a Bitx40 file that you want to try and see if it will compile without mistakes.

Then keep trying and ask questions when you get stuck.  We have all been there.

73s

Mike, WA6ISP

Re: Volume potentiometer choice

College Professor Simon Thompson <nwccenglishprofessor@...>
 

Right. I must have read something about the tuning pot. Sorry for the misdirection.

On Mar 11, 2017, at 1:14 PM, Jerry Gaffke via Groups.Io <jgaffke@...> wrote:

Logarithmic for a volume control.  Linear works, but the low end will be touchy to adjust.  The response of human hearing to sound intensity is pretty much logarithmic.  Just google "hearing logarithmic".   However that tuning pot really needs to be linear.

Jerry, KE7ER

On Sat, Mar 11, 2017 at 12:54 pm, College Professor Simon Thompson wrote:

I think someone earlier said a linear taper port will work better. You could check the list.
 


Re: Replacing the 7805 on the Raduino so something that does not get so hot

Michael Hagen
 

You are asking for help on something with a completely different subject?

Here is a link to programming document.

https://groups.io/g/BITX20/message/22618


There is a PDF file, save it so you can find it again.  It is hard to find in these posts.

I saw it yesterday, and still had problems finding it.

Keep Truckin!

73s

Mike, WA6ISP


Re: Spurious output.

Brian
 

Visually the transformers look OK. That's why I ask whether anybody else has measured this before going any further.

Re: Replacing the 7805 on the Raduino so something that does not get so hot

Master Ice <special@...>
 


I have to disagree there .
I use a 12V/5V buck/boost converter in my BITX and in other builds of mine.
As long as you follow sensible construction and wiring practices and layout, I have had no noise problems whatsoever.
 
Slim
----- Original Message -----
Sent: Saturday, March 11, 2017 7:54 PM
Subject: Re: [BITX20] Replacing the 7805 on the Raduino so something that does not get so hot

The switching mode regulators are invariably noisy. that's the main reason to avoid them.

MVS Sarma had a suggestion, we can remove the backlight LED out of the regulator and directly feed it with a resistor from 12v. that should significantly bring down the power consumption from the 7805

- f

On Sat, Mar 11, 2017 at 9:59 PM, <motdog@...> wrote:

Hi,

I would try a resistor in series to the 7805, I have used really small and cheap ones from Mouser.  Usually 1 watt, they are like 0.4" long and $0.10.

Up the resistance until the voltage at the 7805 meets requirements.  Probably 8V will be enough.  Or put a 7809 in front?

The other thing, put a TO220 big regulator on it.  Also, if you have an LCD with back light, connect it to 12V thru a bigger resistor to take

the current out of the small regulator.  That is usually 50 ma or so.  You could maybe add a second regulator just for the LED back light, it is current you are setting, not voltage.

The switching version my not be good in a radio!  May have some nice birdies!

I never use the regulator built into Nano Arduinos, it is so cheap to put a TO-220 one external?

I have blow up the ones on the Nanos,  Nano is my favorite, I have used several of them in projects. eBay for a few bucks.


73s

Mike, WA6ISP



Virus-free. www.avast.com

Re: Replacing the 7805 on the Raduino so something that does not get so hot

Allard PE1NWL
 

Steve,
please read Jerry's reply to the same question you posted in another thread:
https://groups.io/g/BITX20/message/23228?p=Created,,,20,1,0,0
It explains pretty well how you can get it working.
Good luck, 73 Allard PE1NWL

Re: Replacing the 7805 on the Raduino so something that does not get so hot

Jerry Gaffke
 

Good luck.

On Sat, Mar 11, 2017 at 12:20 pm, Steve Barlow wrote:

Ash hat

 

Re: Volume potentiometer choice

Jerry Gaffke
 

Logarithmic for a volume control.  Linear works, but the low end will be touchy to adjust.  The response of human hearing to sound intensity is pretty much logarithmic.  Just google "hearing logarithmic".   However that tuning pot really needs to be linear.

Jerry, KE7ER

On Sat, Mar 11, 2017 at 12:54 pm, College Professor Simon Thompson wrote:

I think someone earlier said a linear taper port will work better. You could check the list.

 

Re: Volume potentiometer choice

College Professor Simon Thompson <nwccenglishprofessor@...>
 

I think someone earlier said a linear taper port will work better. You could check the list.

On Mar 11, 2017, at 12:47 PM, mcfortner@... wrote:

I think I have everything I want/need to customize my radio, so I'm about ready to assemble it.  However, I am wondering, what would be a better volume potentiometer, a linear or logarithmic?  I have a 1/4 inch linear potentiometer with built in on/off switch here, but would a log control work better?  Or is it all just a matter of personal preference?  

Michael KA3X


Volume potentiometer choice

Michael
 

I think I have everything I want/need to customize my radio, so I'm about ready to assemble it.  However, I am wondering, what would be a better volume potentiometer, a linear or logarithmic?  I have a 1/4 inch linear potentiometer with built in on/off switch here, but would a log control work better?  Or is it all just a matter of personal preference?  

Michael KA3X

Re: Replacing the 7805 on the Raduino so something that does not get so hot

Steve Barlow <swbarlow55@...>
 

Ash hat
Sorry to but it but I need some info
Myself and others have received bitx40 with the blink programme in the Arduino
Now I am a novice with this device and I have been told to just load the Bitx 40 sketch and all will be fine
But it is not
I am going wrong somehow
Can someone give me the exact process and files to get this thing working
It has now been going on for 6 days and I am no nearer
I am busting a gut to get on air with the radio so as you can imagine it is very frustrating
Would be grateful for any assistance
Thanks
Steve

On Sat, 11 Mar 2017 at 19:55, Ashhar Farhan <farhanbox@...> wrote:
The switching mode regulators are invariably noisy. that's the main reason to avoid them.

MVS Sarma had a suggestion, we can remove the backlight LED out of the regulator and directly feed it with a resistor from 12v. that should significantly bring down the power consumption from the 7805

- f

On Sat, Mar 11, 2017 at 9:59 PM, <motdog@...> wrote:

Hi,

I would try a resistor in series to the 7805, I have used really small and cheap ones from Mouser.  Usually 1 watt, they are like 0.4" long and $0.10.

Up the resistance until the voltage at the 7805 meets requirements.  Probably 8V will be enough.  Or put a 7809 in front?

The other thing, put a TO220 big regulator on it.  Also, if you have an LCD with back light, connect it to 12V thru a bigger resistor to take

the current out of the small regulator.  That is usually 50 ma or so.  You could maybe add a second regulator just for the LED back light, it is current you are setting, not voltage.

The switching version my not be good in a radio!  May have some nice birdies!

I never use the regulator built into Nano Arduinos, it is so cheap to put a TO-220 one external?

I have blow up the ones on the Nanos,  Nano is my favorite, I have used several of them in projects. eBay for a few bucks.


73s

Mike, WA6ISP


Re: Flutter fix (raduino v1.0.3)

Allard PE1NWL
 

Hi Al,

Thanks for your suggestion for further code improvement.
I haven't yet tried this but I will certainly have a look at it.
73, Allard PE1NWL

Re: Replacing the 7805 on the Raduino so something that does not get so hot

Ashhar Farhan
 

The switching mode regulators are invariably noisy. that's the main reason to avoid them.

MVS Sarma had a suggestion, we can remove the backlight LED out of the regulator and directly feed it with a resistor from 12v. that should significantly bring down the power consumption from the 7805

- f

On Sat, Mar 11, 2017 at 9:59 PM, <motdog@...> wrote:

Hi,

I would try a resistor in series to the 7805, I have used really small and cheap ones from Mouser.  Usually 1 watt, they are like 0.4" long and $0.10.

Up the resistance until the voltage at the 7805 meets requirements.  Probably 8V will be enough.  Or put a 7809 in front?

The other thing, put a TO220 big regulator on it.  Also, if you have an LCD with back light, connect it to 12V thru a bigger resistor to take

the current out of the small regulator.  That is usually 50 ma or so.  You could maybe add a second regulator just for the LED back light, it is current you are setting, not voltage.

The switching version my not be good in a radio!  May have some nice birdies!

I never use the regulator built into Nano Arduinos, it is so cheap to put a TO-220 one external?

I have blow up the ones on the Nanos,  Nano is my favorite, I have used several of them in projects. eBay for a few bucks.


73s

Mike, WA6ISP


Re: PCB uBitx -working on it-

Jim Smith <zx97lite@...>
 

Awesome,and thru hole too!

Pete  WB9FLW

Re: Spurious output.

Ashhar Farhan
 

Your RF mixer might be defective, check that the two transformer windings are not shorting.

-- f

On Sun, Mar 12, 2017 at 12:45 AM, Jerry Gaffke via Groups.Io <jgaffke@...> wrote:

Well, never been a question for me anyways.  Other's have asked if a sine wave VFO might be better.  I'm convinced a square wave into the diodes is ideal.  You could make a case for a sine wave being better if it's to be transported around a radio by a big random jumble of 2 foot long wires.   Better still is to just use coax.


On Sat, Mar 11, 2017 at 10:20 am, Jerry Gaffke wrote:

There never has been a question.

 


Re: Spurious output.

Jerry Gaffke
 

Well, never been a question for me anyways.  Other's have asked if a sine wave VFO might be better.  I'm convinced a square wave into the diodes is ideal.  You could make a case for a sine wave being better if it's to be transported around a radio by a big random jumble of 2 foot long wires.   Better still is to just use coax.


On Sat, Mar 11, 2017 at 10:20 am, Jerry Gaffke wrote:

There never has been a question.

 

Re: Spurious output.

Jerry Gaffke
 


The image from the 4'th VFO harmonic, transmit or receive, can be cured by running the VFO at 19mhz, not 5 mhz.  (We've discussed receive images from this fourth harmonic previously, hadn't occurred to me that it would also affect transmitting.)  The analog vfo is not stable enough for this, but the Raduino is plenty steady.  Only issue is you would then be on the upper sideband.  Can get back to lower sideband by moving the BFO down in frequency about 3khz, perhaps by just adding capacitance at C103, though it may take more extreme measures to 3khz with the crystal BFO oscillator.  A much better solution is to use the first channel of the Si5351 to drive the BFO, and hack the Raduino sketch to put it at about 11.970mhz.  (Use the BFO scheme from the new uBitx schematics.)   With the Si5351 driving the BFO, we can now easily switch between USB and LSB, and put the carrier right in the middle of the filter when transmitting CW (by unbalancing the modulator, much like the uBitx unbalances the first mixer), this also allows much easier calibration procedures that scale properly to other bands.

> Is there a conclusion

There never has been a question.  Diode ring mixers are comutating mixers, should be operating as switches.  Square wave is best.  If you were to feed them with a pure sine wave, the diodes would be passing through their transition region very briefly, and they would either be conducting or not conducting anyway.  A square wave approaches the ideal of switching the diodes instantaneously and simultaneously, a sine wave only adds to the crud coming out off the mixer.  If still curious, see my rant here:  https://groups.io/g/BITX20/message/22521

Jerry, KE7ER


On Sat, Mar 11, 2017 at 09:51 am, <vk4bap@...> wrote:

I am using a BITX40 with Raduino. The only changes have been around the mic amp and getting rid of the tuning noises. This is related to the rx birdie just below 7.2MHz, which annoys me but I can live with that. However if I transmit on 7.15MHz I can measure an upper sideband signal at 7.4MHz which is only about 33dB down. This is the 4th harmonic of the vfo mixing with the 12MHz IF.

Can anyone with modern test gear confirm this? I would love to have a Rigol but have to make do with a receiver and switched attentuators. I am measuring the level across the R136 pot with no power applied to the IRF510. Twin-T af oscillator into the mic input.

Does the square wave from the Raduino make this worse than using a clean sine wave from the analogue vfo? Is there a conclusion as to whether a diode mixer should be driven with a sine wave or square wave?

 

Re: Flutter fix (raduino v1.0.3)

Al Duncan VE3RRD
 

Is it possible to incorporate Jack W8TEE's idea in message https://groups.io/g/BITX20/topic/new_raduino_source_file/4422545 to reduce code size?

Spurious output.

Brian
 

I am using a BITX40 with Raduino. The only changes have been around the mic amp and getting rid of the tuning noises. This is related to the rx birdie just below 7.2MHz, which annoys me but I can live with that. However if I transmit on 7.15MHz I can measure an upper sideband signal at 7.4MHz which is only about 33dB down. This is the 4th harmonic of the vfo mixing with the 12MHz IF.

Can anyone with modern test gear confirm this? I would love to have a Rigol but have to make do with a receiver and switched attentuators. I am measuring the level across the R136 pot with no power applied to the IRF510. Twin-T af oscillator into the mic input.

Does the square wave from the Raduino make this worse than using a clean sine wave from the analogue vfo? Is there a conclusion as to whether a diode mixer should be driven with a sine wave or square wave?

73 Brian.