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Re: construction
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 |
Building a 12V Supply Board
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. |
Re: construction
Appears loose pins on the 3 wire power plug.? Especially if? Red wire is loose? and? some leakage current on the brown Tx wire somewhere could be an answer for 3.5mA Sarma vu3zmv On Thu, 9 Jul 2020, 5:16 pm Ray Lenthall VK3JH, <vk3jh@...> wrote:
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Re: construction
Not sure I understand bypassing the diode.? Per the wire up instructions, the supplied diode is to be used for reverse voltage protection, and if you wired it per the instructions then bypassing the diode would short out the supply.
I would verify that you are getting the 12volts to R18, R38, R52, and R71.? These are the active stages with power when the Raduino is disconnected.? The voltage drops that I got across them are: R18 = .4 volts? so that is drawing 40ma R38 = .4 volts so that is drawing 40 ma R52 = .52 volts so that is drawing 2.4 ma R71 = .46 volts so that is drawing 4.6 ma Total = 87 ma close to the 90 ma specified.? There could be other sections that make up the last 3 ma or it could be the meter or resistor value differences. Also, check that the power connector is plugged in correctly and not offset by a pin or in reversed.? I really do not know what could cause these symptoms, other than an open on the board or wiring.? I have not seen, nor read of this type of behavior.?? Happy hunting! 73 Evan AC9TU |
Re: construction
¿ªÔÆÌåÓýHi Evan ? Thanks for your reply.? I have checked the voltage form the power supply and it is 12.3 v.? I bypassed the diode in case there was a problem there but still came up with the same result of 3.5ma rather than the 90ma. ? 73 ? Ray ? From: [email protected] <[email protected]> On Behalf Of Evan Hand
Sent: Thursday, 9 July 2020 4:01 PM To: [email protected] Subject: Re: [BITX20] construction ? Ray, |
Re: construction
Ray,
There are 7 2n3904 transistors that should be on in a linear bias plus the LM386 audio amp when in receive.? If you have wired the power correctly (the RED wire is the +12volts to everything EXCEPT the PA)? it should read 90+ma.? I would check your power wiring as a start.? I would also check the power supply to verify that it is providing 12volts. The readings are without the Raduino connected, per the original wireup instructions.? The PA bias adjustments come later and will add another 200ma + the Raduino current requirements?to the readings.? My v5 is buried in a case with a 3.5" Nextion screen, AGC, and an outboard audio amp, so it is not easy for me to get to the readings from that board for comparison. As stated in the first paragraph above, you most likely have a power supply/wiring issue. 73 Evan AC9TU 73 Evan AC9TU |
Re: construction
¿ªÔÆÌåÓýHi Ted ? Thanks for the reply.? No the Raduino was not connected the picture in the documents doesn¡¯t have it connected ? Regards ? Ray ? From: [email protected] <[email protected]> On Behalf Of Ted via groups.io
Sent: Thursday, 9 July 2020 11:24 AM To: [email protected] Subject: Re: [BITX20] construction ? Hi, Ray. ? Is the Raduino connected? ? ? ? ? Ted |
Re: construction
That's what it should read when the finals have had their bias adjusted iirc On Thu, 9 Jul. 2020, 10:28 am , <vk3jh@...> wrote: Hi I purchased a V5 last year and am only now starting to put it together. I have wired up the DC power plug as per the instructions and the instructions tell me if I apply 12v it should draw between 90 and 110 ma.? Mine draws 3.5ma. Can anyone give me some clues.? Many thanks. |
construction
Hi I purchased a V5 last year and am only now starting to put it together. I have wired up the DC power plug as per the instructions and the instructions tell me if I apply 12v it should draw between 90 and 110 ma.? Mine draws 3.5ma. Can anyone give me some clues.? Many thanks.
Ray? VK3JH |
Re: Unpopulated board
Bob,
Mounting from the back side was only part of a complete mod.? Do only partial and you get poor result.? Basically for that iteration a half fast fix was not a fix at all. See the wiki for the fix and wiring plus the code patch to take advantage of it. Also if you burnt the tracks off that give you head start. If you still burning off tracks investigate a better tool and or soldering skills. The Mod I wrote up for V3.? By V4,? V5, and 6 it was incorporated into the board layout.? We have a Wiki here for history and knowledge. Allison --------------------------------- No direct email, it goes to bit bucket due address harvesting in groups.IO |
Tried to compile this on 1.8.13 and....
"C:\\Program Files (x86)\\Arduino\\hardware\\tools\\avr/bin/avr-size" -A "d:\\tmp\\arduino_build_194091/ubitxv6.ino.elf"
Sketch uses 30754 bytes (100%) of program storage space. Maximum is 30720 bytes.text section exceeds available space in board
?
Global variables use 819 bytes (39%) of dynamic memory, leaving 1229 bytes for local variables. Maximum is 2048 bytes.
.... so close and yet so far. Any ideas for shaving off a few bytes ? Thx! |
Re: Unpopulated board
I suggested mounting the relays on the opposite of the board's ground plane as you say back in the days of the V4 and I remember someone trying it. The results from him was it provided no great improvement as far as meeting FCC requirements, at that time. Please let us know if this does provide an improvement since the board for the V3 and the V4 may not be exactly the same. This would also mean making sure the four corners of the board are mounted to a metal box, for example, to make sure the ground plane is indeed at an effective ground for the RF signals and possibly ensure a better overall ground. Bob ¡ª KK5R
On Wednesday, July 8, 2020, 2:50:31 PM EDT, Mark - N7EKU <n7eku@...> wrote:
Hi Ken, I did Alison's changes for the relays on my v3.? It might work well for you, as with the relays mounted on the bottom side, their pins all end up on the top side where most of the traces are.? I can upload pictures of my board if you want.? The work will require changes to the raduino code afterwards. 73, Mark |
Re: D hole plate to fit SO-239 bulkhead hole - SO-239 to BNC conversion
Dale Parfitt
¿ªÔÆÌåÓýHi Allison, While that is still true of type N, ?75 Ohm BNC¡¯s changed over to the same ?diameter center pin as the? 50 Ohm version some time ago. In order to maintain 75 Ohms, the dielectric is configured differently. ? Dale W4OP ? From: [email protected] [mailto:[email protected]] On Behalf Of ajparent1/kb1gmx ? When I see a 50 ohm BNC receptacle that is unreliable its likely because |
Re: Unpopulated board
Mark - N7EKU
Hi Ken,
I did Alison's changes for the relays on my v3.? It might work well for you, as with the relays mounted on the bottom side, their pins all end up on the top side where most of the traces are.? I can upload pictures of my board if you want.? The work will require changes to the raduino code afterwards. 73, Mark |