Re: Hello dear I am Dr. Aisha Gaddafi
This is SPAM that needs to be blocked...
On Saturday, July 11, 2020, 7:22:14 PM EDT, Dr aisha gaddafi <draishagaddafi92@...> wrote:
Hello dear I am Dr. Aisha Gaddafi
I am Dr. Aisha Gaddafi, the daughter of late Libyan president, am contacting you because I need a Partner or an investor that will help me in investing the sum of $27.500.000.00 USD in his or her country, the funds is deposited here in Burkina Faso where I am staying for the moment with my children as my husband is late, I would like to know your mind and interest towards the investment of the total sum mentioned Above, as my partner and beneficiary of the funds I want to inform you that you will receive 40% share of the total sum after the transfer of the said funds {$27.5 Million USD} is completed into your account, while the balance as my own share will be used for the investment in your country.
Please after reading this mail try and make sure you reply and contact me with this my private email address: { draishagaddafi92@...}
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Dr. Aisha Gaddafi.
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Re: Building a 12V Supply Board
FYI I used an LM2596 dc to dc converter to drop the 13.8 vdc from P1 to 5vdc It¡¯s rated to 3a. I use it to feed my TDA 2030a audio amp, my SSM 2167 mic preamp/compressor and theRaduino ?board.I bent the raduino1 pin 4 up so it doesn¡¯t set into the socket thus isolating the 13.8 supply from the raduino board.seems to work well. I did put a choke on the 5vdc output wire and I don¡¯t have a problem with RF noise.-- ?
73
Mick VA3EPM?
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Re: Building a 12V Supply Board
To get an efficient 12V to 5V regulator, you can look at the 7805 equivalent modules like the AMSRO1-7805 or the VXO7805, these are switching regulators so they are efficient but noisy so you might want to put them in a metal enclosure (a heat sink as part of the enclosure is a good idea) and put say a 10 uF and 0.1 uF capacitor right next to them, to reduce radiated noise. They are pretty much a drop-in replacement (double check that you have the pinout right though as otherwise you can let the magic silver-grey smoke out.)
You can search for such things on https://www.findchips.com/ - They cost me $2 or so each, not lots more than a regular 7805, and I tend to install those in anything battery-powered as you get ~90% efficiency, which beats the heck out of the ~42% efficiency you get out of a stock 7805 run on 12V! Reminds me to buy a few more. I'm putting some into a couple always-on AC powered devices just to reduce power costs on AC.
Mark
On Thursday, July 9, 2020, 06:36:15 PM PDT, Bob Lunsford via groups.io <nocrud222@...> wrote:
I remember reading in an old spec sheet for a three-terminal regular that the operating voltage of the regulator was three volts. This no doubt depends largely on the design of the regulator but 3-4 volts should be considered operational. Keep in mind that if you use the maximum applied voltage, that means about 30 volts at the operating current needs to be dissipated unnecessarily because of the heat. Applying 12V is not excessive to me, though. Still, however, some kind of heat sink or fins on the three-terminal regulator is to me cheap insurance.
Bob ¡ª KK5R
On Thursday, July 9, 2020, 12:28:59 PM EDT, Evan Hand <elhandjr@...> wrote:
Peter,
Before you go through the trouble of building in the "noise" filter, I would first verify that the noise is coming from the 12 supply.? The best way to do that is to test the noise level on battery power.? You do not need to transmit, so any 12v battery capable of supplying 250 to 300 ma for a short time should do.? I have used a car jumper battery that I have and found little to no difference in the noise level on battery power vs mains supplied through either of my TexPower 13.8volt switching supplies. The noise is coming from the antenna in my neighborhood caused by QRM and high QRN noise levels on the air in general.
With the above understanding, I will make some suggestions for R2 to reduce the power dissipation of the 7805 regulator.? ?That does depend on the total current that you will need from the regulator, and THAT depends on what you have planned to add onto the rig that will need 5 volts.? If you add up the power requirements of all of the devices on the stock rigs, the total current is much less than 200ma, more like 120 ma (approximate, as I have not done all of the spec sheet validations? I did look up the stock version 6 2.8" display and that has a max of 80ma).? Then you have the minimum voltage that the 7805 needs to regulate to 5 volts.? I use 3 volts to get some safety margin.? That means you need to supply 5 + 3 = 8volts minimum at maximum current.? If the input voltage is truly 12 volts, and you want 8 volts to the regulator minimum at 200ma, and you need a 4volt drop at 200 ma, then 4/.2=20ohms.? That resistor will need to dissipate 4*0.2 = 0.8 watts.? All of these calculations are DC values, so the simple E=IR and P=EI and the transforms work.
For my rigs, I am adding second Nanos, larger displays with built-in GUI processors, and signal processors, so I have upped the max current to <1 amp (the maximum that the 7805 provided by HFSignals can regulate) and added other safety margins to get 4 ohms at 4 watts.? Were I to do it again, I would have added a second 7805 to supply the auxiliary equipment and not modified the Raduino board.
In general, the stock setup works well, and no changes are needed.? Adding a heatsink to the regulator can help if you are going to operate in high ambient temperatures.??
The other comment that I would make is that if you find you have RF noise from the power supply, then you will need to add capacitors to filter the higher frequency.? Something like a 0.1 to 0.01 uF ceramic disc.? The 470uF will not filter higher frequency stuff.? There is too high of internal resistance at RF in electrolytic capacitors.? You may also be better off to add an RF choke instead of the resistor.? I will let someone more knowledgable on that subject to make a true recommendation.
The above are my thoughts and should be verified before you take action on them.? I do make mistakes at times.
73
Evan
AC9TU
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Building a 12V Supply Board
(Resending because when I reported that obvious SPAM about the 27 mil or whatever funds, I was auto-kicked from the group?! Weirdness. Very sorry if this is a repeat but guessing that my post was lost due to being booted. Weird.)
Mark ----- Forwarded Message -----
From: M W <rd232d@...> Sent: Saturday, July 11, 2020, 04:39:53 PM PDT Subject: Re: [BITX20] Building a 12V Supply Board
To get an efficient 12V to 5V regulator, you can look at the 7805 equivalent modules like the AMSRO1-7805 or the VXO7805, these are switching regulators so they are efficient but noisy so you might want to put them in a metal enclosure (a heat sink as part of the enclosure is a good idea) and put say a 10 uF and 0.1 uF capacitor right next to them, to reduce radiated noise. They are pretty much a drop-in replacement (double check that you have the pinout right though as otherwise you can let the magic silver-grey smoke out.)
You can search for such things on https://www.findchips.com/ - They cost me $2 or so each, not lots more than a regular 7805, and I tend to install those in anything battery-powered as you get ~90% efficiency, which beats the heck out of the ~42% efficiency you get out of a stock 7805 run on 12V! Reminds me to buy a few more. I'm putting some into a couple always-on AC powered devices just to reduce power costs on AC.
Mark
On Thursday, July 9, 2020, 06:36:15 PM PDT, Bob Lunsford via groups.io <nocrud222@...> wrote:
I remember reading in an old spec sheet for a three-terminal regular that the operating voltage of the regulator was three volts. This no doubt depends largely on the design of the regulator but 3-4 volts should be considered operational. Keep in mind that if you use the maximum applied voltage, that means about 30 volts at the operating current needs to be dissipated unnecessarily because of the heat. Applying 12V is not excessive to me, though. Still, however, some kind of heat sink or fins on the three-terminal regulator is to me cheap insurance.
Bob ¡ª KK5R
On Thursday, July 9, 2020, 12:28:59 PM EDT, Evan Hand <elhandjr@...> wrote:
Peter,
Before you go through the trouble of building in the "noise" filter, I would first verify that the noise is coming from the 12 supply.? The best way to do that is to test the noise level on battery power.? You do not need to transmit, so any 12v battery capable of supplying 250 to 300 ma for a short time should do.? I have used a car jumper battery that I have and found little to no difference in the noise level on battery power vs mains supplied through either of my TexPower 13.8volt switching supplies. The noise is coming from the antenna in my neighborhood caused by QRM and high QRN noise levels on the air in general.
With the above understanding, I will make some suggestions for R2 to reduce the power dissipation of the 7805 regulator.? ?That does depend on the total current that you will need from the regulator, and THAT depends on what you have planned to add onto the rig that will need 5 volts.? If you add up the power requirements of all of the devices on the stock rigs, the total current is much less than 200ma, more like 120 ma (approximate, as I have not done all of the spec sheet validations? I did look up the stock version 6 2.8" display and that has a max of 80ma).? Then you have the minimum voltage that the 7805 needs to regulate to 5 volts.? I use 3 volts to get some safety margin.? That means you need to supply 5 + 3 = 8volts minimum at maximum current.? If the input voltage is truly 12 volts, and you want 8 volts to the regulator minimum at 200ma, and you need a 4volt drop at 200 ma, then 4/.2=20ohms.? That resistor will need to dissipate 4*0.2 = 0.8 watts.? All of these calculations are DC values, so the simple E=IR and P=EI and the transforms work.
For my rigs, I am adding second Nanos, larger displays with built-in GUI processors, and signal processors, so I have upped the max current to <1 amp (the maximum that the 7805 provided by HFSignals can regulate) and added other safety margins to get 4 ohms at 4 watts.? Were I to do it again, I would have added a second 7805 to supply the auxiliary equipment and not modified the Raduino board.
In general, the stock setup works well, and no changes are needed.? Adding a heatsink to the regulator can help if you are going to operate in high ambient temperatures.??
The other comment that I would make is that if you find you have RF noise from the power supply, then you will need to add capacitors to filter the higher frequency.? Something like a 0.1 to 0.01 uF ceramic disc.? The 470uF will not filter higher frequency stuff.? There is too high of internal resistance at RF in electrolytic capacitors.? You may also be better off to add an RF choke instead of the resistor.? I will let someone more knowledgable on that subject to make a true recommendation.
The above are my thoughts and should be verified before you take action on them.? I do make mistakes at times.
73
Evan
AC9TU
|
Bora,
You have an incorrect file loaded for the v6 board.? The correct version is in the attached zip file on GitHub:
The uBITXV5 folder has the correct files for the v6 board as well.? You can use Xloader to load the hex file into the uBITX without going through the Arduino IDE.? I have not used the source code for the CEC software, so not sure which define statements you need to set in order to compile for a v6 board.? Just use Xloader and the?UBITXV5_CEC_V1.200_NX.hex file.? I am assuming that you have the Nextion display configured with the correct tft files.
73
Evan
AC9TU
|
Hi all,
I use UBITX_CEC_V1.1_NX. hex for V6. But I can't found open code. My BFO fabrication setting 11.996.850Mhz. But I need an 11.050.00Mhz fabrication setting because of my SSB ladder filter 11.059MHz.
Please help
--
TB3EN From Turkey. Electronic Communication Technician, Member YM3KM.
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Re: The 1926 ?bitx of my great father
I would bet it was a kit. ?And almost all of those radios used 01A tubes or the equivalent. ? ?
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From: [email protected] [mailto:[email protected]] On Behalf Of Peter LB0K
Sent: Saturday, July 11, 2020 7:08 AM
To: [email protected]
Subject: Re: [BITX20] The 1926 ?bitx of my great father ? Hi Gerard
I would like to echo Michael's comment about pulling apart an ANTIQUE receiver that looks to be relatively whole. Your Grandfather's old wireless receiver would go well in the collection at the Bergen Broadcasting station () There we have two transmitters (one delivered from Germany and one from England in 1936-7), and a fairly wide selection of receiver sets, mostly from after 1945.?
This receiver does have some intriguing details that I'd like to find out more of. ? Could you find it possible to take more pictures of the receiver, of the top and inside from several angles; of the two handles on the front,? from the back, if that has any details.?
Also interesting would be info about the valves or tubes if any are still fitted, a manufacturers label or mark, size etc. etc.? and if you could send these to me off the list I will be grateful. I beg understanding for using this list for a reply, it is after all very seldom one sees any untouched examples of these antique wireless receivers.
Having apologised I can now go back to modifying my uBITX,
LB0K -? Peter ?
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This email has been checked for viruses by AVG antivirus software.
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-- ¡_. _._
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Re: The 1926 ?bitx of my great father
Hi Gerard
I would like to echo Michael's comment about pulling apart an ANTIQUE receiver that looks to be relatively whole. Your Grandfather's old wireless receiver would go well in the collection at the Bergen Broadcasting station () There we have two transmitters (one delivered from Germany and one from England in 1936-7), and a fairly wide selection of receiver sets, mostly from after 1945.?
This receiver does have some intriguing details that I'd like to find out more of. ? Could you find it possible to take more pictures of the receiver, of the top and inside from several angles; of the two handles on the front,? from the back, if that has any details.?
Also interesting would be info about the valves or tubes if any are still fitted, a manufacturers label or mark, size etc. etc.? and if you could send these to me off the list I will be grateful.
I beg understanding for using this list for a reply, it is after all very seldom one sees any untouched examples of these antique wireless receivers.
Having apologised I can now go back to modifying my uBITX,
LB0K -? Peter ?
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Re: The 1926 ?bitx of my great father
Restore that fantastic piece of history. It would be a shame not to restore it and make it work. Just my 2 cents.
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Re: The 1926 ?bitx of my great father
Hate to see you destroy that piece of history for just the capacitors¡ ? ?
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Show quoted text
From: [email protected] [mailto:[email protected]] On Behalf Of ³Ò¨¦°ù²¹°ù»å
Sent: Friday, July 10, 2020 1:27 PM
To: [email protected]
Subject: [BITX20] The 1926 ?bitx of my great father ? Hello,
Seriously, I found this old TSF, and the variable capacitors will serve me for an antenna loop.
I¡¯m still working on my own construction of ?Bitx where I can go from A to Z. The power supply is made, the box is pierced. There I made the printed circuits, it remains to be drill.
For the components, it comes from China, I received 95%.... over 2 months! But I have time.
But since I can only put a piece attached, I will open another post. You may see it.
Cdt -- ¡_. _._
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I only have access to one of my calibrations for a v4.? It was 175000.
73
Evan
AC9TU
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Re: The 1926 ?bitx of my great father
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Show quoted text
On Fri, Jul 10, 2020 at 11:57 PM ³Ò¨¦°ù²¹°ù»å < kabupos@...> wrote: Hello,
Seriously, I found this old TSF, and the variable capacitors will serve me for an antenna loop.
I¡¯m still working on my own construction of ?Bitx where I can go from A to Z. The power supply is made, the box is pierced. There I made the printed circuits, it remains to be drill.
For the components, it comes from China, I received 95%.... over 2 months! But I have time.
But since I can only put a piece attached, I will open another post. You may see it.
Cdt
|
hello,
Here you can see a sides of my printed circuit board. I modified for the Ardino power supply (10 ohm resistance + capacitors. For the power supply of the Nextion, it can be done directly on the 5v or by another regulator. I added a coil and capacitors too. On my alim block, I put an automatic regulation of the fan. it triggers when too hot.?
It takes time, but it¡¯s very informative. I think I would also modify some transistors according to the wiki. (Ex 2n2222) etc...
cdt
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The 1926 ?bitx of my great father
Hello,
Seriously, I found this old TSF, and the variable capacitors will serve me for an antenna loop.
I¡¯m still working on my own construction of ?Bitx where I can go from A to Z. The power supply is made, the box is pierced. There I made the printed circuits, it remains to be drill.
For the components, it comes from China, I received 95%.... over 2 months! But I have time.
But since I can only put a piece attached, I will open another post. You may see it.
Cdt
|
Thank you Gentlemen!
I am now able to tune in strong local AM stations.? I went back to the BFO tuning tool and watched Ashhar YouTube.? I was not believing the tuning adjustment coming in around 150000, I just thought that was to far out of tolerance.? The video shows Ashhar adjusting to 130000 plus. So I think I am good.
Let me throw a broad question out there, what is the typical freg offset that others are coming up with???
Bruce Morrell KB8MW
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Re: Building a 12V Supply Board
I remember reading in an old spec sheet for a three-terminal regular that the operating voltage of the regulator was three volts. This no doubt depends largely on the design of the regulator but 3-4 volts should be considered operational. Keep in mind that if you use the maximum applied voltage, that means about 30 volts at the operating current needs to be dissipated unnecessarily because of the heat. Applying 12V is not excessive to me, though. Still, however, some kind of heat sink or fins on the three-terminal regulator is to me cheap insurance.
Bob ¡ª KK5R
On Thursday, July 9, 2020, 12:28:59 PM EDT, Evan Hand <elhandjr@...> wrote:
Peter,
Before you go through the trouble of building in the "noise" filter, I would first verify that the noise is coming from the 12 supply.? The best way to do that is to test the noise level on battery power.? You do not need to transmit, so any 12v battery capable of supplying 250 to 300 ma for a short time should do.? I have used a car jumper battery that I have and found little to no difference in the noise level on battery power vs mains supplied through either of my TexPower 13.8volt switching supplies. The noise is coming from the antenna in my neighborhood caused by QRM and high QRN noise levels on the air in general.
With the above understanding, I will make some suggestions for R2 to reduce the power dissipation of the 7805 regulator.? ?That does depend on the total current that you will need from the regulator, and THAT depends on what you have planned to add onto the rig that will need 5 volts.? If you add up the power requirements of all of the devices on the stock rigs, the total current is much less than 200ma, more like 120 ma (approximate, as I have not done all of the spec sheet validations? I did look up the stock version 6 2.8" display and that has a max of 80ma).? Then you have the minimum voltage that the 7805 needs to regulate to 5 volts.? I use 3 volts to get some safety margin.? That means you need to supply 5 + 3 = 8volts minimum at maximum current.? If the input voltage is truly 12 volts, and you want 8 volts to the regulator minimum at 200ma, and you need a 4volt drop at 200 ma, then 4/.2=20ohms.? That resistor will need to dissipate 4*0.2 = 0.8 watts.? All of these calculations are DC values, so the simple E=IR and P=EI and the transforms work.
For my rigs, I am adding second Nanos, larger displays with built-in GUI processors, and signal processors, so I have upped the max current to <1 amp (the maximum that the 7805 provided by HFSignals can regulate) and added other safety margins to get 4 ohms at 4 watts.? Were I to do it again, I would have added a second 7805 to supply the auxiliary equipment and not modified the Raduino board.
In general, the stock setup works well, and no changes are needed.? Adding a heatsink to the regulator can help if you are going to operate in high ambient temperatures.??
The other comment that I would make is that if you find you have RF noise from the power supply, then you will need to add capacitors to filter the higher frequency.? Something like a 0.1 to 0.01 uF ceramic disc.? The 470uF will not filter higher frequency stuff.? There is too high of internal resistance at RF in electrolytic capacitors.? You may also be better off to add an RF choke instead of the resistor.? I will let someone more knowledgable on that subject to make a true recommendation.
The above are my thoughts and should be verified before you take action on them.? I do make mistakes at times.
73
Evan
AC9TU
|
Back in the days of the Commodore 64, there was a recurring problem with the main power connection pin on the board having a hairline crack in the solder joint. All that needed to be done was reheat it. It was a simple repair that caused many techs to have some crazy moments on the repair bench.
Bob ¡ª KK5R
On Thursday, July 9, 2020, 11:37:23 AM EDT, Evan Hand <elhandjr@...> wrote:
I believe that Sarma has hit on the most probable cause.? I have had issues with the antenna pins coming loose, so the red power lead to the mainboard is a good candidate.? If you add the leakage current of the finals to the 87 ma that I measured you get the 90ma.? Could also be just a bad connection to the pin in the connector.? If you have a pin you could measure the red wire connection to see if there is 12 volts on it.
73
Evan
AC9TU
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Re: Building a 12V Supply Board
Keep all leads short or be prepared to add large and small caps at each end of the long leads because voltages can build up across stray inductance caused to long leads. Like a 10 MFD and a 0.1 disc ceramic (also with short leads) in parallel. A disc ceramic cap can be a problem at 20M and above if the leads are too long.
IBM axiom: "Anything can be done if it is logical. The only problem is implementation." An extension of this is a lot of small problems can jump out at the builder if too little thought is put into the process.
If something works satisfactorily, theory is no longer a factor.
Bob¡ª KK5R
On Thursday, July 9, 2020, 11:23:00 AM EDT, peter.mccracken@... <peter.mccracken@...> wrote:
Hi all, I want to build a dedicated power supply board mounted to the back of the case and remove the regulator that is currently on the raduino, I also want to try to "clean" as much noise as possible from the supply whilst doing this. I only have rudimentary knowledge of this stuff but the below is my attempt at designing something for this. The idea is to clean up the 12V supply before connecting it to the ubitx mainboard and also use a resistor to drop the voltage into the regulator somewhat before feeding that into the Raduino. I am not sure what value would be good for R2. I would be grateful for any suggestion as to how I could do this better.  Best regards, Peter.
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Bruce,
As Curt said in his response, the BFO has a HUGE impact on the sensitivity of the rig.? You need to have the audio response centered in the passband of the SSB filter.? The way that I have done that is to use either an audio spectrum analyzer or the BFO Tuinig aid web page here:
The full alignment process is outlined in this video from Ashhar Farhan:
Note that the first BFO adjustment is to provide the low audio frequency response for zero beating, then use it to calibrate, then set the BFO for the full audio spectrum.? It is important to adjust the BFO for the low range response so you can hear the zero beat signal better.? Then for best sensitivity and audio response to center the plateau properly. between 300 and 3,000 Hz.
Try the BFO adjustments to see if that helps get you on the frequency and with a good response.??
BTW, For me in Illinois WWV on 10MHz at night has been the best source for calibration.? There other frequencies at 2.5, 5, 15, and 20MHz as well.? Low frequencies during the night, and higher frequencies during the day.
73
Evan
AC9TU
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Bruce
have you performed an alignment of the BFO?? if it were decently off sensitivity would be reduced.? of course listen to the lower ham bands as their should be strong signals there.?
Curt wb8yyy
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Bob Lunsford
Mick
Bora G¨¹rb¨¹z
MadRadioModder
