Date   
Re: Known issues on uBITX r4 #ubitx

Bill Cromwell
 

Hi,

I'm using batteries..even with some of my vacuum tube gear. What noise?

73,

Bill KU8H

On 06/29/2018 04:46 PM, Daniel Conklin wrote:
If you don' want to deal with RFI problems from the power supply, then
get a good analog supply like the Pyramid PS12KX. I have a couple of
switching supplies that were made for use with communications devices,
but they both interfere somewhere on the spectrum. I've never had a
problem with analog power supplies.
Dan, W2DLC
--
bark less - wag more

Re: Known issues on uBITX r4 #ubitx

Bo Barry <bobarr@...>
 

I have a v3 & v4 and am "tickled to death" (American slang expression) with both of them.
NO mods (except KD8CEC mods to one) so far except for a tiny 5v fan.
As a retired engineer having done design, programming, & construction, I continually think about the excellent efforts that went into bringing this unique hardware and software to the market for "pennies'" or free.
I reserve any comments that may be considered criticism by the creators.
I'm sure they appreciate constructive comments about improvements to consider when they have time from their schedules.
So much more fun than the Heathkit days!
73, Bo W4GHV since '54   (at 78, just glad to be alive!)

Re: Known issues on uBITX r4 #ubitx

iz oos
 

I confirm my 2A was not enough and shut down. Use at least a real 3A, linear is better to avoid any issue you might not even a clue.


Il 29/giu/2018 22:48, "Daniel Conklin" <danconklin2@...> ha scritto:
The other thing you can do if you don't have a 5A or better supply is turn back the drive to your finals.
Dan, W2DLC

Re: Ubitx receive intermittent

Daniel Conklin <danconklin2@...>
 

Intermittent issues are hard to diagnose because they never show up when the technician is looking for them.  You have to force the issue.  As you check for continuity, you wiggle and flex the PCB and other suspect things until the problem rears its ugly head.
Dan, W2DLC

Re: Known issues on uBITX r4 #ubitx

Daniel Conklin <danconklin2@...>
 

The other thing you can do if you don't have a 5A or better supply is turn back the drive to your finals.
Dan, W2DLC

Re: Known issues on uBITX r4 #ubitx

Daniel Conklin <danconklin2@...>
 

If you don' want to deal with RFI problems from the power supply, then get a good analog  supply like the Pyramid PS12KX.  I have a couple of switching supplies that were made for use with communications devices, but they both interfere somewhere on the spectrum.  I've never had a problem with analog power supplies.
Dan, W2DLC

JackAl board pricing

Jack, W8TEE
 

Not yet. We are getting bids on the complete assembly of the PCB, so that all the SMD's are in place. We do know that the Teensy 3.6 is $30 and their audio board which piggybacks on the Teensy and we use for DSP is $14 and the 5" touch screen is a little under $35 (7" is about $45). Our best guess is that the board will be sold for $40-$50. So the bad news is that our addon is almost as much as the µBITX. However, when you're done, you'll have a pretty impressive xcvr. Also, we have some interesting plans for Rev 2.0 software, too, so it will be an ongoing project. BTW, the audio library is a treasure trove of functionality, including a worthwhile FFT library. Finally, we've added a small knot of extra I/O pins which coupled with 1MB of flash and 256K of SRAM should make it a hacker's dream. Despite all that we've done, we're still using less than 20% of the flash and only 12% of the SRAM. Al and I are expecting great things from you people down the road!!

Jack, W8TEE

On Friday, June 29, 2018, 2:38:15 PM EDT, Dennis Yancey <bigbluedry@...> wrote:


Have any pricing done on them yet?

Re: RF power chain mods and improvements..

Jer Tres
 

Re predriver (Q911, Q912):

”The 5109 was best even though I used only 1”

So, the question is:
If I use a 2N5109 for the predriver “Should I also change some resistors to adjust the bias? Or should it work without doing so?” and do I need to change any of the caps?

Re: Known issues on uBITX r4 #ubitx

Ralph Mowery
 


I don't know anything about those.  They do say for using with LED strips only.

Most likely they are not regulated and will put out over 12 volts with a light load. 

Another thing is they are probably not very well filtered if any and you may get a lot of hum on your signal.

If they would be regulated and filtered, the 12 volt and 3 amp supply would be the one, but I don't think I would use any of those.

73 de ku4pt


On Fri, Jun 29, 2018 at 1:33 PM, hirosmb JAZZ <hirosmb@...> wrote:
IC.


Is the one like above OK?

Thanks in advance, Ralph.

// hiro, JJ1FXF

Ubitx receive intermittent

M0CLS
 

Hi, 

The receive on my ubitx has gone very intermittent! One minute everything is coming in strong then all of a sudden it drops out and stronger stations are in the noise then back again. More often than not the receiver is deaf! I had problems with this last week after I soldered coax to R43 and C32 and it turned out R43 went bad. I replaced it and all has been fine since. Then this morning it  started again, although this time R43 is fine. But I have just noticed I have continuity over a lot of resistors in that area of the board including over both ends on r43?? If I have a short somewhere where do I start?? Would it even power up and work at all if this was the case? 

Help would be much appresciated! 

Carl.

Re: Known issues on uBITX r4 #ubitx

Bill Cromwell
 

Hello Hiro,

I understand about the excitement. I had a dreadful time resisting the urge to power mine up on a sheet of cardboard (for insulation) before I formed the case to fit. I did connect power just to confirm whigh way the display had to be mounted :) Murpy's Law you know.

At my shack 'temporary' measures have a habit of becoming more permanent:)

73,

Bill KU8H

On 06/29/2018 12:28 PM, hirosmb JAZZ wrote:
Yes, Bill.

As far as I know, the distortion issue comes up with only v4 ubitx, however it’s just a matter of degree.

I already placed my order with DHL, while taking a train back home today! :)

I also plan to use CEC firmware which I already modified a bit to limit the frequencies to TX in accordance with Japanese regulation.

I compiled the modified firmware which successfully runs on my Arduino UNO now.

Also I ordered a Nextion LCD at eBay which presents really lovely UI/UX.

I don’t think I can sleep properly tonite coz I’m so much excited. :)

Thank you, all of you here who share all the information of ubitx, such a wonderful rig!

// hiro, JJ1FXF



2018/06/30 0:21、Bill Cromwell <wrcromwell@...>のメール:

Hi,

I have V3 with a socketed audio chip labeled as Feb 2018. It worked right out of the box - as advertised. I have not had to make *any* mods at all. I do expect to install the CEC software but that is only to get some options I would like to have for CW. I am already using it for CW. I do not have distirtion, I can tune in SSB and AM stations and they are clear. Lucky me?

Wait until you have actually used your radio to decide if you 'need' mods. Most of the mods I see described are optional and only for the owners perefernces - like my plans to install the CEC software. There will be no hardware changes to mine.

73,

Bill KU8H
--
bark less - wag more

Re: RF in 12v Supply

Bill Cromwell
 

Hi Mark,

I laid out and folded a case of steel for my ubitx. Looking from the front, my antenna connector is at the far right rear corner and the internal connector wire is less than two inches long to reach from the board with just a little slack. The DC power connector is over at the far left back. The volume control is way over on the lower right corner of the front panel along with the on-off switch. I routed the power wires under the ubitx board to take advantage of the mostly ground plane board to help shield it from RF at the finals, output filters, and antenna connector. The power line runs much closer to the front of the radio until it gets to the left side and then back. It only comes out from under the circuit board *AT* the back corner. There is no problem with RF. I hope this is helpful to you and others when they layout and assemble theirs.

On 06/29/2018 01:17 PM, Mark M wrote:
The issue discussed in the 'RFI from uBitx TX after AGC and other mods
installed' thread appears to be caused by RF getting into the 12v supply
and from there into the 5v supply that feeds the AGC board (the
ND6T/K5BCQ kit). At least that appears to be the issue on mine. I
thought I'd start another thread to talk about that.

I have the ubitx in a case from amateurradiokits.in. The power comes in
thru a plug in the rear panel at the right of the panel (looking at it
from the front), thru a fuse and then thru three wires twisted together
along the rear panel to the connector on the board at the far left.
There's also a polarity protect diode across the supply. The power
connector is right next to the antenna connector and the supply wires
run past the final transistors and .

I'm running the ubitx on 13.8v from an Astron 20A power supply, The
testing was done feeding a Heathkit Cantenna dummy load.

So, any suggestions on how to fix this would be appreciated. Don
mentioned heavier supply wires and capacitor at the input. I thought I'd
try re-routing the supply wires inside case to get them away from the RF
section. Moving the power connector to the other end of the rear panel
would make the run much shorter. Other than that, I don't know. RF
hardware is not my forte (I'm mostly a software guy).

Thanks.... Mark AA7TA
--
bark less - wag more

Re: A Breadboard Technique for the uBITX

Dennis Yancey <bigbluedry@...>
 

Have any pricing done on them yet?

Re: Known issues on uBITX r4 #ubitx

Arvo W0VRA
 

On Fri, Jun 29, 2018 at 10:19 am, Ralph Mowery wrote:
You may just get by with a 2 amp supply...
My 2A supply will not work the µBITX on 80M.  The supply trips out on overcurrent.  It works well on 40M and above.

Re: RF in 12v Supply

Arv Evans
 

0.1 mfd across the power leads at the power supply and again at the uBITX power
connector.  It could be that RF is modulating the 12V power lead and that causing
RF in the power supply regulator.  Bypassing the DC power at the power supply
should stop that if it is the problem. 

Arv
_._


On Fri, Jun 29, 2018 at 11:20 AM Lawrence Galea <9h1avlaw@...> wrote:
Try RG58 for the supply.


On Fri, Jun 29, 2018 at 7:17 PM, Mark M <junquemaile@...> wrote:
The issue discussed in the 'RFI from uBitx TX after AGC and other mods installed' thread appears to be caused by RF getting into the 12v supply and from there into the 5v supply that feeds the AGC board (the ND6T/K5BCQ kit). At least that appears to be the issue on mine. I thought I'd start another thread to talk about that.

I have the ubitx in a case from amateurradiokits.in. The power comes in thru a plug in the rear panel at the right of the panel (looking at it from the front), thru a fuse and then thru three wires twisted together along the rear panel to the connector on the board at the far left. There's also a polarity protect diode across the supply. The power connector is right next to the antenna connector and the supply wires run past the final transistors and .

I'm running the ubitx on 13.8v from an Astron 20A power supply, The testing was done feeding a Heathkit Cantenna dummy load.

So, any suggestions on how to fix this would be appreciated. Don mentioned heavier supply wires and capacitor at the input. I thought I'd try re-routing the supply wires inside case to get them away from the RF section. Moving the power connector to the other end of the rear panel would make the run much shorter. Other than that, I don't know. RF hardware is not my forte (I'm mostly a software guy).

Thanks....    Mark    AA7TA





Re: RFI from uBitx TX after AGC and other mods installed

Don, ND6T
 

Seems like the problem is coming from the 5 volt lead. I am hesitant to try more than 10uF from it to ground due to the charging surge. It already has 2uF when the AGC is connected. What about some ferrite beads on that lead? Lawrence, others tried moving the boards without effect. Additionally, this seems to be audio!?! Interesting. Hey Rick, cool idea with the fan! An audible voltage indicator, too! -Don

Re: Running on a Jump Box

Gwen Patton
 

You misunderstand me, Ralph. I don't WANT it to act the same. If I wanted that, I'd just run it directly from the jump box. But I don't want it to run away in RF, as at that level it can damage my tuner. I want it to run at 5-10 watts, not 18-20! I can control it with the amperage, and since the fuse is a 2A inline, I don't want it to run more than that. So I'm certainly not going to set it to 3A unless I want to toast marshmallows on my tuner.

Re: Known issues on uBITX r4 #ubitx

hirosmb JAZZ <hirosmb@...>
 

Ah, ubitx.net says “5 Amps should suffice”.

// hiro, JJ1FXF



2018/06/30 2:33、hirosmb JAZZ <hirosmb@...>のメール:

IC.


Is the one like above OK?

Thanks in advance, Ralph.

// hiro, JJ1FXF



2018/06/30 2:19、Ralph Mowery <rmowery42@...>のメール:

You may just get by with a 2 amp supply, but I would go with at least one rated for 3 or 4 amps. It is always to have a few more amps than needed so the supply runs cool. 

On Fri, Jun 29, 2018 at 12:59 PM, hirosmb JAZZ <hirosmb@...> wrote:
Thanks, R.E.

Yes, I read about the power supply in different thread.

If I am correct, ubitx works properly with 12V 2A power supply, right?

Let me at first carefully find the one at AKIHABARA where is a famous place to buy those electric parts and devices in TOKYO.

Actually I am going to AKIHABARA tomorrow to buy some other necessary items coz I already ordered my ubitx. :)

Many thanks for your advice!

// hiro, JJ1FXF



2018/06/30 0:29、R. E. Klaus via Groups.Io <reklaus@...>のメール:

The new audio amp in the V4 uBITS is a very common design in inexpensive audio equipment for many years. It could be sensitive to power supply voltage levels and if you are using it at below its design supply voltage it may not have enough bias current resulting in crossover distortion. The 2 solutions would be to make sure you have the proper minimum voltage applied or re-bias the outputs...add a third diode, or use a potentiometer in place of the diodes so the bias can be adjusted. In higher power systems, the 2 diodes would be in physical contact with the output transistors and would self adjust the bias as the transistors heat up to reduce the chance of thermal runaway.  


Re: RFI from uBitx TX after AGC and other mods installed

Lawrence Galea
 

Those two daughter boards especially with those long wires are a sure way of inviting RF pickup especially being so near the LPFs relays.
It could be that the boards are picking RF directly by being so near the LPFs relays.
Have you tried shifting them to the front and using shielded cables for all connections?

On Thu, Jun 28, 2018 at 4:33 PM, alans77 via Groups.Io <alans77@...> wrote:
Hi Don: In an effort to eliminate the RF getting back into the audio amp I replaced the TX RF output twisted pair between the uBitx board and my PL259 with coax also switched to coax wrapped 5 turns around a 120-43 core between the volume control and the AGC board. I still hear my voice loud and clear from the speaker on 80 and 40M. I am going to look for an easy way to to mute the amp or speaker.


Re: Known issues on uBITX r4 #ubitx

hirosmb JAZZ <hirosmb@...>
 

IC.


Is the one like above OK?

Thanks in advance, Ralph.

// hiro, JJ1FXF



2018/06/30 2:19、Ralph Mowery <rmowery42@...>のメール:

You may just get by with a 2 amp supply, but I would go with at least one rated for 3 or 4 amps. It is always to have a few more amps than needed so the supply runs cool. 

On Fri, Jun 29, 2018 at 12:59 PM, hirosmb JAZZ <hirosmb@...> wrote:
Thanks, R.E.

Yes, I read about the power supply in different thread.

If I am correct, ubitx works properly with 12V 2A power supply, right?

Let me at first carefully find the one at AKIHABARA where is a famous place to buy those electric parts and devices in TOKYO.

Actually I am going to AKIHABARA tomorrow to buy some other necessary items coz I already ordered my ubitx. :)

Many thanks for your advice!

// hiro, JJ1FXF



2018/06/30 0:29、R. E. Klaus via Groups.Io <reklaus@...>のメール:

The new audio amp in the V4 uBITS is a very common design in inexpensive audio equipment for many years. It could be sensitive to power supply voltage levels and if you are using it at below its design supply voltage it may not have enough bias current resulting in crossover distortion. The 2 solutions would be to make sure you have the proper minimum voltage applied or re-bias the outputs...add a third diode, or use a potentiometer in place of the diodes so the bias can be adjusted. In higher power systems, the 2 diodes would be in physical contact with the output transistors and would self adjust the bias as the transistors heat up to reduce the chance of thermal runaway.