Some calculations on the IF filter and USB filter
Hello,
When analyzing the programs KD8CEC or Ubitx V4,5,6 I have a little trouble to understand how the different values of First IF, Second USB, Second LSB and int USB are calculated.
In the KD8CEC program, there are different examples, but I¡¯m having a hard time figuring it out.
The best is an example, and it speaks louder:
Let¡¯s imagine (These are examples) that I have a 45 MHZ filter that has a center frequency of 45002200 htz with a bandwidth of 7.5 KHtz on each side of this frequency, and then an SSB filter of 12000800 htz in center frequency with a bandwidth of 2.5Khz on each side?
What are the calculations to make to find these 4 values.
This will allow the most accurate adjustment of the filter configuration.
So:
First IF= ? Calculation formula
Second USB=?? same
Second LSB=?? same
Init USB=?? same
?
Knowing that in all programs seen, VFOA and VFOB still have the same value (7150000 and 14200000)
?
Thank you
?
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Re: #sBitx Sbitx died mid transmission
#sBitx
Scott,?
Do you have a part number for your buck converter?? I think it's amazing that Ashar is sending replacements out.? However I am hoping to do a POTA activation next Thursday and I'd like to move as quickly as I can with the repair.? Tell me if I'm wrong, but the buck converter will replace the LM338, and I just swap 2 new IRFZ24 FET's onto the heat sink?
Thanks you for your explanation
Scott
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Hi,
send me a private message?and I will send you the .apk file. The link only contains the source code.
¸é²¹³¾¨®²Ô
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Re: #sBitx Sbitx died mid transmission
#sBitx
Begin by looking at the 5v regulator. It is the 388 or its replacement switching regulator just next to the 12 volt input to the unit.
Pete WK8S
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Re: #sBitx Sbitx died mid transmission
#sBitx
Scttmtclf,
What you describe is exactly my experience. ?The root cause is the LM338 failing and you probably lost one or both of the PA transistors as well. ?The overall problem is the heat sink clamp for the differing sizes of the devices. ?The cure, unfortunately, is to replace the PA transistors and the voltage regulator. ?The good news is Ashhar has just shipped replacement devices.
The replacement voltage regulator is a buck design that is extremely efficient and does not require a heat sink. ?The allows the PA transistors to be solidly clamped to the heat sink. ?I¡¯ve not had one problem since I replaced these devices.
I¡¯m not sure if there is a step-by-step instruction guide but it¡¯s a pretty easy replacement. ?The only tricky part is mounting the regulator.
Good luck, Scott
?
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Re: #sBitx Sbitx died mid transmission
#sBitx
Scttmtclf,
I would verify that the LM338T provides the 5volts to the Raspberry Pi (RPi).? You could verify that the RPi is still working by removing it from the radio, connecting an HDMI display, a USB Mouse, a USB keyboard,? and providing a USB-C voltage supply.? If the regulator has failed, I would wait for the upgrade kit from HFSignals that has the replacement regulator and finals.? If the RPi is the problem, you need to order a replacement.? The RPi 4 is hard to find at a reasonable price.
To reinstall the RPi, follow the assembly manual:
73
Evan
AC9TU
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Re: how can download file x sbitx
#sBitx
Use IDM Internet Download Manager or IDM Integration Module in your browser.
There is probably another download manager that can resume the interrupted download.
--
Gyula HA3HZ
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Re: #sBitx Sbitx died mid transmission
#sBitx
Yes it is getting power. I swapped power supplies, and it still did not turn on. I also used its power supply on another radio, and it worked correctly
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how can download file x sbitx
#sBitx
Hello everybody. I am trying to download the image for the Sbitx sd. i couldn't download it, despite trying with win10m win 7 and win xp. I can't finish the download. do you have any ideas? I should reload the soft sbitx, because due to my maneuver, I must have canceled some end and I can't get out of it. any help is appreciated. 73 de in3izq danilo
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Hi! APP software connection and download failed, Can the download link be re-provided? or email me xyjlxx@...
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Refer the Video of "uBITX_6_N8ME_3_VU3GAO_Mods" running on the transceiver.
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Re: #sBitx Sbitx died mid transmission
#sBitx
The first thing I would do is make sure the sBitx is getting power. If you're powering it through?a fused cable or a distribution box like a Rigrunner, you might have taken out a fuse. I did that in an early session, blowing a 5A fuse while attempting an SSB transmission at 10W. (The bias adjustments were not ideally set at the time; I tried adjusting them as explained in the original build instructions, not knowing that it had already been done at the factory. Fixed now. This is also with the original 5V linear regulator still in place.)
Tonight I had made15 contacts via ft8 with no issues on 40 meters through a vertical with 1.2-1 swr.? I switched to 20 meters, and adjusted my vertical till I had a 1.1-1 swr.? Mid-transmission, my sbitx shut down.? No smoke, just shut down.? I unplugged it and tried cycling the power again, but nothing.? There is no power to the pi, because the red led is not on.? Where should I begin my diagnosis?
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#sBitx Sbitx died mid transmission
#sBitx
Tonight I had made15 contacts via ft8 with no issues on 40 meters through a vertical with 1.2-1 swr.? I switched to 20 meters, and adjusted my vertical till I had a 1.1-1 swr.? Mid-transmission, my sbitx shut down.? No smoke, just shut down.? I unplugged it and tried cycling the power again, but nothing.? There is no power to the pi, because the red led is not on.? Where should I begin my diagnosis?
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Re: #sbitx Upgrades shipped
#sBitx
William, The kit has been despatched to everyone who has bought sbitx (either models) with LM338, across the countries. - f
On Fri, Sep 9, 2022, 5:56 AM William R Maxwell < wrmaxwell@...> wrote: I asked this question a few days ago but that post seems to have vanished from the earlier thread on this topic, without a response.
Has the upgrade kit been sent to purchasers outside the USA, Ashar?
If not, I don't know how many sBITX have been purchased in Australia but I am happy to act as a forwarding point for distributing the upgrade kit to Australian owners, if that is of assistance.
Bill, VK7MX
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Re: #sbitx Upgrades shipped
#sBitx
I asked this question a few days ago but that post seems to have vanished from the earlier thread on this topic, without a response.
Has the upgrade kit been sent to purchasers outside the USA, Ashar?
If not, I don't know how many sBITX have been purchased in Australia but I am happy to act as a forwarding point for distributing the upgrade kit to Australian owners, if that is of assistance.
Bill, VK7MX
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Re: File /uBITX_6_N8ME_2_VU3GAO_Mods.zip uploaded
#file-notice
not working for me Nitin.. cfg menu brings up some corrupt graphics. key mode not saved
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Re: #sbitx - an ugprade kit is on the way
#sBitx
I agree - The cost is not an issue as the parts are cheap and readily available.? I am just waiting because I don't want to end up buying a regulator that happens to be very noisy.
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Re: #sbitx Upgrades shipped
#sBitx
Is there any utility in adding an L-C noise filter, or would that be overkill?
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ok Nitin, noticed the new file. thanks
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Re: Loss of CW Side tone When load N8ME Firmware.uBITX V6
Chuck, koodos on what Dave,K8WPE said. This is a Hobby. And even if it wasnt, We all started from the ground up.
I remember when i first was licensed,my young brother and sister made fun of me by grabbing the ham out of the fridge everytime i set up my equipment to operate. They would say"ohhhhhhhhhhhhhh you want some mustard and cheese to go with that HAM?" Yea with their distractions,i fried some gear,but luckily it was tube type and was more forgiving.As for the solid state stuff,YEP fried loads of diodes in the power supply sections due to not ohming out the wires on the new plug i soldered on the power cord.IT HAPPENS more than anyone here wants to admit.I have even bricked a newer rig . got in there and reprogrammed a chip so i could have warc bands, and wala!! dead as a doornail. wound up having to order that particualr chip off the manufacturer . that chip cost more than the radio it seemed at the time. OOPS.
We all have had an "OOOPs" in our tenure ar Amateur Radio Operators. Thats what really binds us all. telling the stories of wiping the sleep or smoke out of your eyes while trying to finish a project at 2am or whatever,and watching the smoke roll out again of the project ohh so softly.HI HI. No question is stupid, and no solution is the solution to end all problems. if it was we would never get past Spark gap transmitters and crystal radio receivers.:)
Have fun, relax, and enjoy your? hobby.? There are probably about 95% of hams who build and experiment who have had OOPS times too. This is what separates the operators from the ones who actually USE their knowledge from their license . welcome
73 David ac9xh
On Thursday, September 8, 2022 at 08:40:46 AM EDT, david todd via groups.io <ac9xh@...> wrote:
Evan, I have N8ME software installed on my ubitxes,and i must say it makes the ubitx a new radio all over again.
It cuts out the latency ,or delay from key close to transmit. Also it seems to me on my radio,it reacts faster. Also it eliminates the frequency jumps when tuning. Mine,is smooth.
73 David ac9xh
On Thursday, September 8, 2022 at 05:12:46 AM EDT, David Wilcox K8WPE via groups.io <djwilcox01@...> wrote:
Chuck, quit apologizing for errors!!! This is a HOBBY! ?Most of my mistakes, errors of omission and commission are now called learning experiences. ?We learn best that way. I have great tales and one of them is reverse connecting a battery (with a big red price tag stuck near the negative pole of the battery¡. You can tell the rest of the story). ?An early Chinese YouKits radio went up in smoke because of no reverse voltage protection. ?I learned a lot that late night. Now I go to bed at 9:30 PM and paint all bought batteries with a big red patch near the + pole and remove all price tags and a few other things. ?The last radio item I reversed the power to was a completely different type of error but it did have a reverse protection diode in the circuit and I had a fuse in the line¡.. just had to replace the diode¡. My first effort at changing a SMD diode¡.. Was very lucky that time. We all make errors and I have many other tales since 1960 when I was first licensed.
On Sep 7, 2022, at 11:13 PM, Chuck Eglhaut <ceglhaut@...> wrote:
?
I feel stupid. Evan in your reply to me to make sure CW was selected , Then which it was but you said about checking the config. I did here I was suppose to be Iambic B and it was in Winkey . Set it to Iambic B and save it¡¯s working.? Thanks for your help it was all my stupidness.? uBITX seem be working proper I have side tone when I am sending CW. Thanks Evan 73 Chuck K3CWE?
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Gerard
HA3HZ
Shirley Dulcey KE1L