Date   

Re: DC Connector #v6

Jerry Gaffke
 

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 


On Sun, Dec 29, 2019 at 07:13 PM, Ashhar Farhan wrote:
There is finally a reverse voltage protection on v6.
 
- f


Re: DC Connector #v6

Ted
 

^ 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


Re: direct short #ubitx40help

Evan Hand
 

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


Re: acg/alc

poikaa3
 

   Looks like what is used in FRS transceivers......  


Re: `FRESH START #bitx20help

Evan Hand
 

There are links on this page for the original software for the uBitx:
https://ubitx.net/2018/08/03/2924/ 

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:
https://www.hfsignals.com/index.php/bfo-tuning-aid/ 

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


direct short #ubitx40help

KG5YUO
 

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."


Re: DC Connector #v6

N1EDC
 

It looks like you already got the info you needed.

Typically the outer conductor is always ground, and the chassis of a device is ground as well.

Personally, I prefer Anderson Power pole connectors, and I would encourage you to look into them!  You can assemble them yourself, and when assembled properly they make it impossible to plug something in backwards.  Each contact is also color coded for polarity so you can easily see which end is positive/negative

The advantage they have over other power connectors though, is that there is no "male" or "female" connector - Every set of powerpoles can plug into every other set, which makes things a lot easier on the bench and eliminates the need for a lot of adapters.

Be aware though, there are two different ways of assembling them - You might call them "right-handed" and "left-handed.". If you plug a right-handed power pole onto a left-handed one, the polarity will be backwards, but you can clearly see that a red connector is plugged into a black one, so it's easy to fix if you assemble one backwards

If I made this sound complicated, it's really not.  You should look into them!


`FRESH START #bitx20help

dgclifford@...
 

hello men  i have had enough unless i can find a way to reset and reload  this ubitx v5  will be on ebay as a project for someone  is there a way to completely reset this radio  and a step by step guide to getting it working again  at the minute i am havig more fun using my pixie than this thing i juat want to put it all back to stock or bin it   will certainly never go down this road again
dave c   gw0nvf


Re: For Sale: v4 board plus Axicom relays AGC and filter boards etc. #parts #nextion #v4 #ubitx #filters

derek (G4VWI)
 

Thanks Dave for your interest. The Board and additional parts are on their way to you.

Thanks for everyone else's replies.

Best wishes Derek G4VWI. 


Re: Future Ubitx, SWR layout lines on PCB.

Nat Goldberg <nat@...>
 

Some people do not realize to reach the price point, the ubitx must be bare bones. All these features look good and most  likely attractive features and your cost goes up.
These brings you into a different market place. You might have to compete with the used Icoms, Keywood, etc.



On Dec 30, 2019, at 1:09 AM, Fred Finster via Groups.Io <wb7odyfred@...> wrote:

I Meant to suggest on some future revision X of Ubitx, a PCB layout to place a 3-5 mil wide  about 1.5" or 35-40 mm long trace from FET finals to round through hole for wire from PCB to RF connector.  Parallel to the RF trace are two narrow traces tight to the center trace.  These form the forward and reverse voltage detectors with diode's, cap and resistors.  Then use extra ADC inputs to measure the voltage.  If extra ADC inputs not available, use Tiny AT85 8 pin micro to generate I2C or other interface back to raduino for SWR display.  I liked the twin needles display on the MFJ 949 antenna tuner.


Just one of a thousand ideas to make the Ubitx better for a couple more discrete parts.  I have looked at SWR schematics and see some use parallel lines for measurements and others use a torroid,  with final current going straight through a wire or 1 or 2 turns around the torroid.  Several turns around the torroid for the output winding's.

Group members, Welcome your discussions, changes, modifications, corrections, or an outright NO, for a PCB layout that adds SWR capacity. IE You already have SWR Meter on an external antenna tuner.


Farhan, is there much interest in India for a dual band 10 meter 28- 29.7 MHz  and 6 meter 50-54 Mhz SSB transceiver?  I would think that smaller antenna size 8'6" for 1/4 wave 10 meter and a circular antenna for 6 meter omni-directional use, might be easier to setup in limited space.   Yes I know 80 meter ground wave on milliwatts will get a longer distance  to a fellow ham friend, than 10  meter wavelength band.  Yes the 2N3904 or 2N2222 transistors don't support the 50 MHz frequency very well.

Maybe instead of SSB mode make a FM only 10M & 6M Transceiver,. Use 700 hertz audio sine wave into FM for CW like keying an FM audio (not true CW mode).   Include Support for using through 10 meter & 6 meter FM repeater's for distance in India and other locations around the world.
.
Fred Finster
WB7ODY
Broken Windows😋



Re: acg/alc

Gordon Gibby
 

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>


Re: uBitx Digi-Interface Module (Add-on Board)

Gordon Gibby
 

Jim, more power to you!   

I hope you were able to benefit a lot of people.   Overtime, we changed a few of the resistor values to make the system work a little better.   You may see this in various iterations of the board and manual. 

The series resistor in the base lead of the input audio amp went from 47K to 4.7 K to make it more sensitive.  The collector resistor of that same audio amplifier went from 4.7K Down to about 2000 ohms to give it more oomph  driving the rectifier system.  

This system works really good with systems that use frequency shift keying, where the signal power is almost always the same, push to talk stays  in the whole time nicely. 

With systems that have a higher peak to average ratio, like phase shift keying it isn’t quite as perfect , and therefore we had to build in higher game to keep it working.   I think they call that crest factor. 

With packet it works perfectly because there is always a signal, same thing with RTTY.   


We have them all over town, and they have certainly saved me a pretty penny. 

For HF applications, I tended to (use 3 wires to ) take the transmitter gain  and wire it to a panel mounted 500 ohm potentiometer, because getting that gain as high as possible within the linear range was a lot more important with HF single side band than it was with VHF FM



Gordon



On Dec 30, 2019, at 01:56, kh6sky <kh6sky@...> wrote:

Gordon,

Just like you said - I sent the zipped gerber files you referenced to jlcpcb.com.  With my first order discount they are sending me 5 boards for only $10.  Delivery time 4 business days.  I have a dozen or so of those 600 ohm transformers, so now I can build the interface into any of my homebrew radios.  

Aloha,
Jim


Re: uBitx Digi-Interface Module (Add-on Board)

kh6sky
 

Gordon,

Just like you said - I sent the zipped gerber files you referenced to jlcpcb.com.  With my first order discount they are sending me 5 boards for only $10.  Delivery time 4 business days.  I have a dozen or so of those 600 ohm transformers, so now I can build the interface into any of my homebrew radios.  

Aloha,
Jim


acg/alc

jim
 

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


Future Ubitx, SWR layout lines on PCB.

Fred Finster
 

I Meant to suggest on some future revision X of Ubitx, a PCB layout to place a 3-5 mil wide  about 1.5" or 35-40 mm long trace from FET finals to round through hole for wire from PCB to RF connector.  Parallel to the RF trace are two narrow traces tight to the center trace.  These form the forward and reverse voltage detectors with diode's, cap and resistors.  Then use extra ADC inputs to measure the voltage.  If extra ADC inputs not available, use Tiny AT85 8 pin micro to generate I2C or other interface back to raduino for SWR display.  I liked the twin needles display on the MFJ 949 antenna tuner.


Just one of a thousand ideas to make the Ubitx better for a couple more discrete parts.  I have looked at SWR schematics and see some use parallel lines for measurements and others use a torroid,  with final current going straight through a wire or 1 or 2 turns around the torroid.  Several turns around the torroid for the output winding's.

Group members, Welcome your discussions, changes, modifications, corrections, or an outright NO, for a PCB layout that adds SWR capacity. IE You already have SWR Meter on an external antenna tuner.


Farhan, is there much interest in India for a dual band 10 meter 28- 29.7 MHz  and 6 meter 50-54 Mhz SSB transceiver?  I would think that smaller antenna size 8'6" for 1/4 wave 10 meter and a circular antenna for 6 meter omni-directional use, might be easier to setup in limited space.   Yes I know 80 meter ground wave on milliwatts will get a longer distance  to a fellow ham friend, than 10  meter wavelength band.  Yes the 2N3904 or 2N2222 transistors don't support the 50 MHz frequency very well.

Maybe instead of SSB mode make a FM only 10M & 6M Transceiver,. Use 700 hertz audio sine wave into FM for CW like keying an FM audio (not true CW mode).   Include Support for using through 10 meter & 6 meter FM repeater's for distance in India and other locations around the world.
.
Fred Finster
WB7ODY
WB7ODYFred@...
Broken Windows😋



Re: UBITX. FT8 heat sink requirements #ft8 #ubitx

Don - KM4UDX
 

Greggory -- I'm using 24v for the finals, and doing WSPR 24/7 untill something glitches. I had to add bigger heatsinks and a fan.  This was the result of melting the 510 internals due to carelessness on my part...hahah. 

Anyway...my bias is at 110ma per side.  Does that seem appropriate for 24v?  What got you to 36v? What happens to your output power as you increased from 12v to 36v?

Thanks for any insight!!

Don


Re: Software Change Recommendation

Bert N8NN
 

Yes, I used the mic button, but my antenna tuners will not tune when the mic button sends dots.  I must switch to Hand Key for a steady tone and then use the mic button (or key).

Bert N8NN


Re: DC Connector #v6

nolanturnerr@...
 

Thanks to all of you! I soldered the proper connections and powered up the transceiver with a dummy load. Everything seems to be working correctly, but not prepared with proper antenna yet to make contacts. I'm excited to put this to the test!

Glad to hear this protection against reverse voltage is now built in! Now that I have everything put together, hopefully this will no longer be an issue.

I have ordered a new voltmeter and ohmmeter as my son seems to have made the final use of my last one.

Thanks again! I hope to make your acquaintances through the airwaves soon!


Re: uBITX V6 heat sink temperature

Evan Hand
 

Joel,
I do not have a v6 uBitx, so do not have direct experience with that specific kit.  I do have both v4 and v5 boards, and all do run the regulator hot, especially if I use a 13.8 volt "big rig" power supply.  What I did to tame the temperature was to add a dropping resistor on the 12vdc (actually 13.8) in series with the regulator.  two 2 ohm 2 watt resistors in series.  This drops the voltage across the resistor so that the regulator does not have to disipate the heat.  This value can be up to about 47 Ohms depending on how much current you are planing to use for add on things.

Others have added a 7809 9vdc regulator in place of the resistor.  This spreads the load across the two devices and works well if the input voltage is always above 12vdc.  You would need to go to a buck/boost regulator if you are going to power from battery power if you want to rung the batteries to almost fully drained.

Most v3, v4 and v5 boards have been running with the stock circuit and no heatsink.  Adding the graphics display increased the current need, which is why I believe that HF Signals added the heatsink.

Bottom line of the above is that the heat dissipation at 12 votls is within the spec of the device, and I would not be worried.   If you are running over 12vdc in, then putting dropping diodes in series with the supply to the main board, NOT the power amp, would be my suggestion.  The finals can take the higher voltage and produce more power out, at the risk of overheating the finals.

Above should be verified before implementation
73
Evan
AC9TU


Re: Software Change Recommendation

Ashhar Farhan
 

Bert,
Thanks for the suggestions. Btw, you can key with the ptt as well. This is in case you need to tune up.
One evening, I found Nicaragua on 40m cw and I didn't have the key with me! I quickly patched the code to accept keying from the ptt and snagged the contact! 
- f

On Mon 30 Dec, 2019, 8:52 AM Bert N8NN, <bertgarcia73@...> wrote:
I know program space on the Nano is limited.  I recommend some changes to CW operation.

1.  Eliminate CW Keyer portion of the Setup menu and replace it with the function described below.  Eliminate Iambic A, leaving only Hand Key and Iambic B.

2.  Change CW WPM function by adding a value of 0 (zero).  When WPM is 0, make CW Keyer equal to Hand Key.  When WPM is not 0, make CW Keyer equal to Iambic B.

Switching to Hand Key is needed for adjusting antenna tuners and checking SWR.  Putting the choice of Hand Key or Iambic B on the main menu makes the switch much easier by avoiding the need to go to the Setup menu.  Hopefully, some program space will be saved.

Bert N8NN