On v6, it's a series diode included on the PC board, which should be quite safe. Downside is that you lose a diode drop worth from your power supply. Older versions of the uBitx recommended placing a reverse diode in parallel with the DC power jack, so if the external power supply was reversed the diode would conduct and hopefully blow a fuse somewhere. For this scheme, your criticism is valid, given that no mention was made in the uBitx instructions of needing a fuse. Reverse protection has been discussed long and hard over the years: ? ?? /g/BITX20/search?q=reverse+protectionRelatively simple to understand, but lots of different ways to do it. Everybody has an opinion, most of them are right enough. Lots of posts to the forum over the years from folks who blew up their rig with a backwards supply. The Raduino is usually toast, as the LM7805 offers no protection (but some other regulators do). Much of the rest of the rig should probably survive, though never did hear back from anybody who succeeded in bringing a ubitx back up, detailing what they had to fix. Jerry, KE7ER
On Mon, Dec 30, 2019 at 09:51 AM, Ian Reeve wrote:
A diode is not ideal as reverse polarity is going to destroy the diode to open circuit so unless there is a suitable quick bow fuse inline,it may not do the job.Always check and double check. I got caught out with a American cb rig with white and white with a black stripe.Assumed the latter was the negative...but no! The rig survived!
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A diode is not ideal as reverse polarity is going to destroy the diode to open circuit so unless there is a suitable quick bow fuse inline,it may not do the job.Always check and double check. I got caught out with a American cb rig with white and white with
a black stripe.Assumed the latter was the negative...but no! The rig survived!
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Hi Evan,
Mine is a different P/N.
Before plugging in, I checked the polarity with a DVM, even though the polarity is shown on the case (see photo).
On Dec 30, 2019, at 11:51 AM, Evan Hand <elhandjr@...> wrote:
?Jim,
As stated, not sure where it came from.? Part number is HP 1044A ac/dc converter.? I looked up the part on Google and found it was for an old HP printer.? I did say a computer device.
I guess the one point not made so far in the thread is to tame your excitement and take your time double checking all before applying the power.?
73
Evan
AC9TU
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On Monday, December 30, 2019, 3:23:12 PM UTC, poikaa3 <poikaarod@...> wrote:
?? Looks like what is used in FRS transceivers......??
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Not the way I see it ...note the contra wound "control winding"? The original note I found had a variable resistor and 2 coupled toroids ...per attached
Jim
On Monday, December 30, 2019, 10:59:41 AM UTC, Gordon Gibby <docvacuumtubes@...> wrote:
Does that work by saturating the toroid?
On Dec 30, 2019, at 01:22, jim via Groups.Io <ab7vf@...> wrote:
?So ..ran across this circuit the other day ..thot maybe those who might be looking at alternative agc circuits as well as transmitter alc? might be interested xmitter alc I would place the circuit at RV1 between Q90>>>Q911/912 and sample the rf at the output trans before the lpf/relay trees .. Jim <Antenna Attenuator.jpeg>
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Hi Evan,
Mine is a different P/N.
Before plugging in, I checked the polarity with a DVM, even though the polarity is shown on the case (see photo).
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On Dec 30, 2019, at 11:51 AM, Evan Hand <elhandjr@...> wrote:
?Jim,
As stated, not sure where it came from.? Part number is HP 1044A ac/dc converter.? I looked up the part on Google and found it was for an old HP printer.? I did say a computer device.
I guess the one point not made so far in the thread is to tame your excitement and take your time double checking all before applying the power.?
73
Evan
AC9TU
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Jim,
As stated, not sure where it came from.? Part number is HP 1044A ac/dc converter.? I looked up the part on Google and found it was for an old HP printer.? I did say a computer device.
I guess the one point not made so far in the thread is to tame your excitement and take your time double checking all before applying the power.?
73
Evan
AC9TU
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I use Linux and avrdude, sharing but may be easier to use the Arduino
GUI if using Windows
I think this may be useful, I wrote it to use it to update firmware
using Linux command line.
Save as program_ubitx.sh or whatever name you want.
--------------------- Snip -----------
#!/bin/bash
# Script to use avrdude on Linux to program HEX file into Ubitx
#Laurence Oberman
# KB1HKO
if [ -z "$1" ]
then
echo "USAGE: ./program_ubitx.sh <fw_name.hex>"
return
exit
fi
fw=$1
### Set your path to avrdude here
### Also ensure you are using the correct ttyUSBx port and that its
access is correct
avrdude="/home/loberman/.arduino15/packages/arduino/tools/avrdude/6.3.0-arduino14/bin/avrdude"
echo "Programming Ubitx with $fw"
$avrdude -C/home/loberman/.arduino15/packages/arduino/tools/avrdude/6.3.0-arduino14/etc/avrdude.conf
-v -patmega328p -carduino -P/dev/ttyUSB0 -b57600 -D -Uflash:w:$fw:i
---------------Snip --------------
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On Mon, Dec 30, 2019 at 11:47 AM Ken Hansen <ken@...> wrote:
With my new V6 uBitx competed (Latest design, bought with case) I've seen/heard there were some small software issues, discovered as the units are tested. I'm not an arduino or github guru, and I suspect many here are like me - willing to tinker, but this github/arduino ecosystem is totally new to me.
Does anyone have a link to a document/webpage that outlines the needed steps to:
1) set up a computer to load software onto uBitx,
2) download corrected software (once available),
3) load corrected software onto uBitx,
And 4) perform any needed calibration/alignment once loaded?
I understand updated software is not available yet, But I want to be ready when it is.
Thanks in advance,
Ken, N2VIP
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With my new V6 uBitx competed (Latest design, bought with case) I've seen/heard there were some small software issues, discovered as the units are tested. I'm not an arduino or github guru, and I suspect many here are like me - willing to tinker, but this github/arduino ecosystem is totally new to me.
Does anyone have a link to a document/webpage that outlines the needed steps to:
1) set up a computer to load software onto uBitx,
2) download corrected software (once available),
3) load corrected software onto uBitx,
And 4) perform any needed calibration/alignment once loaded?
I understand updated software is not available yet, But I want to be ready when it is.
Thanks in advance,
Ken, N2VIP
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Re: Need uBITX Memory Manager help?
I dumped the EEPROM when I first got my V3.? As you know, each requires it's own calibration. This may just get you started: MASTER_CAL 171500 // 0x00029DEC SB_CAL 11995250? // 0x00B70872 Rgds, Gary
/*
EEPROM_HEX_DUMP:
? ? |? ?0? 1? 2? 3? 4? 5? 6? 7? 8? 9? A? B? C? D? E? F
----------------------------------------------------------
0? ?|? EC 9D 02 00 FF FF FF FF 72 08 B7 00 FF FF FF FF
10? |? FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF
*/
?
?
/**
?* These are the indices where these user changeable settings are stored? in the EEPROM
?*/
#ifndef NO_EEPROM // use address
? ?#define MASTER_CAL 0
? ?#define LSB_CAL 4
? ?#define USB_CAL 8
? ?#define SIDE_TONE 12
? ?//these are ids of the vfos as well as their offset into the eeprom storage, don't change these 'magic' values
? ?#define VFO_A 16
? ?#define VFO_B 20
? ?#define CW_SIDETONE 24
? ?#define CW_SPEED 28
#else // use values
? ?#define MASTER_CAL 171500 // 0x00029DEC
? ?#define LSB_CAL 0? ? ? ? ?// ?not used?
? ?#define USB_CAL 11995250? // 0x00B70872 (would be set by code if out of range to 11997000)
? ?#define SIDE_TONE 0? ? ? ?// ?not used?
? ?#define VFO_A 7150000? ? ?// default value from orig code
? ?#define VFO_B 14200000? ? // default value from orig code
? ?#define CW_SIDETONE 800? ?// default value from orig code
? ?#define CW_SPEED 100? ? ? // default value from orig code
#endif
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Re: Need uBITX Memory Manager help?
Here is my recent backup.
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Re: Need uBITX Memory Manager help?
A starting point for me was:
Master Calibration - 157500
USB and LSB - 1105550
73
Evan
AC9TU
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Evan, ? Interesting. I use an HP brick from an old laptop. The center pin is +12! ? 73, ? KX4TD Jim ?
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From: [email protected] <[email protected]> On Behalf Of Evan Hand
Sent: Monday, December 30, 2019 11:25 AM
To: [email protected]
Subject: Re: [BITX20] DC Connector #v6 ? The protection is required.? I had it installed and it worked when I connected an HP brick for an older computer device (I no longer remember which one) and popped the diode.? I subsequently put a fuse ahead of the diode so that it would blow before the replacement diode. I am very glad that the protection was there.? Diodes are cheaper than the main board.
Other point is that there are other than old communication devices that for some reason have reversed polarity for the barrel plug.? Always check.
73
Evan
AC9TU
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Need uBITX Memory Manager help?
I just hooked up a new version 5, using a Nextion 3.2 display.? Through my exuberance to get it working, I accidentally blew away all the Memory manager settings.? Does someone have the settings, so I can get back to a starting point?
Thanks,
Jim W0CHL
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The protection is required.? I had it installed and it worked when I connected an HP brick for an older computer device (I no longer remember which one) and popped the diode.? I subsequently put a fuse ahead of the diode so that it would blow before the replacement diode. I am very glad that the protection was there.? Diodes are cheaper than the main board.
Other point is that there are other than old communication devices that for some reason have reversed polarity for the barrel plug.? Always check.
73
Evan
AC9TU
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Farhan,
Good to see the reverse protection diode at D6.
Are D6, D9, and D10 schottky diodes or standard silicon rectifiers??
D9, D10, and R1 implement a fairly simple scheme for having a battery inside the rig
that is charged at a rate of a few hundred ma or so whenever an external supply is plugged in.
Have you gotten this to work well when using a particular kind of battery?
The voltage of the bench supply should be carefully set to avoid burning out the battery
if left to charge for more than a few hours.? The battery may not have enough voltage to?
power the rig when approaching a discharged state.
I can imagine better schemes, but they quickly become much more complicated.
Jerry, KE7ER?
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On Sun, Dec 29, 2019 at 07:13 PM, Ashhar Farhan wrote:
There is finally a reverse voltage protection on v6.
?
- f
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^ I will second the above.? One main type bench connector helps;? in a pinch, it's easy to use alligator wires on them if one *really* has to; try that with a barrel connector jack....
Another (potentially important) aspect of using Andersen PowerPoles is that you can swap your various radios and batteries/power supplies around at home and in the field. Make up a few 1-to-2 Y adaptors. Should you find occasion to go to a field day or to help in a public service event, club meeting, county fair demo - or even a local emergency - you can bet that others who are halfway serious about accomplishing the mission have already outfitted their gear with these hermaphroditic connectors.? Need to swap out a mossion-critical asset with your own, or vice-versa?? Power adaptors and antenna fittings tend to be the determining element as to interchangability between different operators' stuff.
73,
Ted
K3RTA
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First, verify the obvious: That the 12vdc supply can provide the greater than 2 but less than 3 amps needed to power the transmitter. Use a current meter in series with the supply to verify the current draw.
If the supply is capable (more than 3 amps when transmitting),? I would start by separating the Power Amp (PA-brown wire) supply from the main board supply (red wire).? If the supply still dips, then the finals are not likely part of the problem.? I would then check wiring of the PTT and key to make sure you are not shorting the supply there.
If the supply does not dip, then the PA circuit is the problem.? You will then need to go through checks using the schematic.
In all cases, make the transmissions as short as possible to try to keep from damaging components.
Verify the above and get back to the group with any findings.? We will need more information to provide more help.
73
Evan
AC9TU
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?? Looks like what is used in FRS transceivers......??
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There are links on this page for the original software for the uBitx:
?
You should note that reloading the software will not reset the calibration.? You will need to do the calibration steps.? One note on calibrating v5 with original software is that a dummy load is required to be connected as a 10 MHz signal is transmitted as part of the calibration process.
For the BFO adjustment, the HFSignals BFO calibration page can be used by any version of uBitx:
?
The calibration of the stock v5 requires a frequency counter or another reciever that has been calibrated to measure the output frequency of the uBitx.? This is with the uBitx connected to a dummy load and the signal to the measurement device attenuated to a level that will not overload the receiving device.
This group is willing to help if you can explain the specific issues that you are having.
Best of luck whichever way you decide to go forward.? This is a hobby, and I would agree that adding frustrations without sight of a solution is not rewarding. However, when the problem is eventually overcome, the satisfaction of finding the solution, and the knowledge gained in the process, to me is worth the frustrations.
73
Evan
AC9TU
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I have a version 5 ubitx. When I key the Mike I don't get any rd out but it pulls down my power supply to around 6.5 volts. I don't know where to start looking. The transmit relay makes then it pulls down the PS.
Thanks Bruce
"A positive attitude may not solve all your problems, but it will annoy enough people to make it worth the effort."
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Jim Willis
Ted
poikaa3