Date   
Re: UBITX Current Production (spur fix ?) #ubitx

Curt
 

Evan

wait seems like a good approach.  the mods we are doing do not require any holes or cuts into the board, but I imagine you meant it figuratively.  I have the parts and daughter board for the added relays, but have not started the repair.  the board we are using was designed by someone else who provided artwork, and we ordered enough of them for our group build (so possibly someone here knows it - a clue is that we replace the input side of the switched filter function).  then someone bought the needed parts from a single supplier.  when we have enough successful verification I will encourage our team to post the info.  to me it seems a nice approach for the world-wide community to use as it is arranged for ease of installation with simple tools and skills.  we have a spectrum analyzer available - but I get it, a desirable fix will be reproducible with confidence as few amateurs around the world have such equipment.  I did not see your email on qrz yet -- you are welcome to email me to gather further data when I have it.  Meanwhile enjoy your ubitx in the lower spectrum, not through a power amp. 

Curt

Re: Added characters while using the keyer function #ubitx

Dave Dixon
 

Hi,
         I placed a 5k1 resistor in each cw wiring line to the cw socket and do not get any extra charactors and get what i send,,,.It works for me and has done for 12 months.I use a bencher paddle key and 20 wpm and use my bitx most days on various bands plus i have 2 other ubitx transceivers which run KD8 CEC firmware,I am impressed with all 3..Regards  Dave G0AYD..


On Thu, 6 Dec 2018 at 19:45, john mathieson <john.ac8jw@...> wrote:
I have a V3 ubitx given to me and I have added a jack for an imabic keyer.  Seems to work but I am finding that it will sometimes send dah dit dit dit dah when I send the letter C.  Just a bit disconcerting. The contacts on the key have been cleaned but I  am still getting an occassional missed character when I send.  I am running KD8CEC firmware on the nano with Iambic B setting in Ian's program.  This of course does not happen when using a straight key but then there are other issues there as well.  

Thanks in advance
John AC8JW

Re: UBITX Current Production (spur fix ?) #ubitx

Evan Hand
 

Curt,

Good to hear about your plans.  Would you be so kind as to list the mods/updates you are making in your group build?  I am still waiting for feedback on the mods that are needed before I cut into my board.

73
Evan
AC9TU

Re: UBITX Current Production (spur fix ?) #ubitx

Curt
 

Mark

as you wish.  we have a world-wide community to work out the shortcomings.  in my area we are doing a group build of 23 rigs - at least one prototype has been fully cured and each builder is in the process of build and making the small changes.  flaws are less on the lower bands - we are confident that we will be compliant.  I anticipate sufficient direction and merchants to emerge, hopefully, to kit the parts.  its a nice rig to experience, not a bad thing that we need to make some updates. 

73 Curt

Re: I buy ubitx

Curt
 

dear OM - I am understanding you have a ubitx - welcome to the worldwide community.  be careful and patient, and enjoy assembly. 

73 curt wb8yyy

Re: Is push pull hf amp has higher spectral purity

Jerry Gaffke
 

Brian,

They were all busy looking at the harmonics, didn't think to check for that close in spur.
Would be interesting to see how strong it is on other rigs.

I believe the strength of the spur comes down to how strong that 4'th harmonic of the VFO is.
During transmit, the VFO mixes in after the signal passes through the crystal filter,
so a lousy crystal filter is not contributing to the spur.

Lesson learned:  Use high side local oscillators wherever possible.

Jerry


On Thu, Dec 6, 2018 at 02:56 PM, Brian wrote:
From memory, I measured the spur to be 35dB down on the 7.15MHz signal. Nobody else reported measuring it which surprised me since quite a bit was written about modding the LPF to meet fcc on harmonics.
The 12MHz xtal filter in my rig was very bad on the LF side, perhaps one xtal is slightly off frequency. I did consider building a new 12MHz filter but never got around to it. I have several home built filters at 8.86MHz but they are just a bit too big to fit in.
I decided to leave it as is and only use USB with digital.

Re: Is push pull hf amp has higher spectral purity

Brian
 

From memory, I measured the spur to be 35dB down on the 7.15MHz signal. Nobody else reported measuring it which surprised me since quite a bit was written about modding the LPF to meet fcc on harmonics.
The 12MHz xtal filter in my rig was very bad on the LF side, perhaps one xtal is slightly off frequency. I did consider building a new 12MHz filter but never got around to it. I have several home built filters at 8.86MHz but they are just a bit too big to fit in.
I decided to leave it as is and only use USB with digital.
Brian.

Re: [Joe] Bare Board Image

Ripley
 

Glad to be of service.

 

Ripley

 

Sent from Mail for Windows 10

 

From: Woody
Sent: Thursday, December 6, 2018 5:45 PM
To: BITX20@groups.io
Subject: Re: [BITX20] [Joe] Bare Board Image

 

Hi Ripley,

 

Thanks!  Exactly what / where I thought.  Appreciate the confirmation.

 

Woody

 

 

On 12/6/2018 22:31, Ripley wrote:

> Hello Woody,

> Maybe you will find this link to my uBITX build on QRZ helpful. There

> are a lot of pictures showing the implementation of a RF gain control

> and AGC circuit.

> https://forums.qrz.com/index.php?threads/ubitx-transceiver-semi-kit-build.624098/page-3

> There are also details pertaining to the harmonics mod with the relay

> replacement, 45MHz crystal filter ETC…  with before and after

> snapshots from my spectrum analyzer.

> Have fun

> Ripley

> Sent from Mail <https://go.microsoft.com/fwlink/?LinkId=550986> for

> Windows 10

> *From: *Woody <mailto:mailme@...>

> *Sent: *Thursday, December 6, 2018 4:52 PM

> *To: *BITX20@groups.io <mailto:BITX20@groups.io>

> *Subject: *Re: [BITX20] [Joe] Bare Board Image

> OK on all...

> What I really need is confirmation of a trace location to install an

> Attenuator / Amplifier I am working on.  Can't see under the relay ;)

> This is the trace I think I am looking for...  TNX, Woody

> _

 

 

--

 

 

 

 

Re: [Joe] Bare Board Image

Woody
 

Hi Ripley,

Thanks!  Exactly what / where I thought.  Appreciate the confirmation.

Woody


On 12/6/2018 22:31, Ripley wrote:

Hello Woody,

Maybe you will find this link to my uBITX build on QRZ helpful. There are a lot of pictures showing the implementation of a RF gain control and AGC circuit.

https://forums.qrz.com/index.php?threads/ubitx-transceiver-semi-kit-build.624098/page-3

There are also details pertaining to the harmonics mod with the relay replacement, 45MHz crystal filter ETC…  with before and after snapshots from my spectrum analyzer.

Have fun

Ripley

Sent from Mail <https://go.microsoft.com/fwlink/?LinkId=550986> for Windows 10

*From: *Woody <mailto:mailme@...>
*Sent: *Thursday, December 6, 2018 4:52 PM
*To: *BITX20@groups.io <mailto:BITX20@groups.io>
*Subject: *Re: [BITX20] [Joe] Bare Board Image

OK on all...
What I really need is confirmation of a trace location to install an Attenuator / Amplifier I am working on.  Can't see under the relay ;)
This is the trace I think I am looking for...  TNX, Woody


_

--

Re: [Joe] Bare Board Image

Ripley
 

Hello Woody,

 

Maybe you will find this link to my uBITX build on QRZ helpful. There are a lot of pictures showing the implementation of a RF gain control and AGC circuit.

 

https://forums.qrz.com/index.php?threads/ubitx-transceiver-semi-kit-build.624098/page-3

 

There are also details pertaining to the harmonics mod with the relay replacement, 45MHz crystal filter ETC…  with before and after snapshots from my spectrum analyzer.

 

Have fun

 

Ripley

 

Sent from Mail for Windows 10

 

From: Woody
Sent: Thursday, December 6, 2018 4:52 PM
To: BITX20@groups.io
Subject: Re: [BITX20] [Joe] Bare Board Image

 

OK on all...
What I really need is confirmation of a trace location to install an Attenuator / Amplifier I am working on.  Can't see under the relay ;)
This is the trace I think I am looking for...  TNX, Woody


 

 

Re: [Joe] Bare Board Image

Woody
 

OK on all...
What I really need is confirmation of a trace location to install an Attenuator / Amplifier I am working on.  Can't see under the relay ;)
This is the trace I think I am looking for...  TNX, Woody




Re: UBITX Current Production (spur fix ?) #ubitx

NU8Z
 

OK thanks for info.
Standing by for Version 5 !

Re: [Joe] Bare Board Image

Evan Hand
 

I do not believe that a bare board was ever shipped outside of units to India for assembly.  You might need to PM Ashhar Farhan to get a photo without components.

I may be wrong on the above, but I would try that route anyway, as he is the manufacturer of the kit.

73
Evan
AC9TU 

Re: [Joe] Bare Board Image

Jim Sheldon
 

I may be wrong, but I don't think anyone has a bare board from HF Signals that they could scan/post images from. I've never seen one on the site and I've been watching it for just such a set of images.

I know Ashhar Farhan doesn't communicate regularly with them these days as he stated, but possibly Ashhar could get the production house to scan both sides of one before they put components on. That would, as you say, be a huge help in troubleshooting.

Jim - W0EB

------ Original Message ------
From: "Woody" <mailme@...>
To: BITX20@groups.io
Sent: 12/6/2018 2:53:11 PM
Subject: Re: [BITX20] [Joe] Bare Board Image

Thanks Joe, These will help. Still would be nice if someone posts scanned images of bare boards. Wanted to overlay and the components are in the way...

Woody

On 12/6/2018 20:41, joel taylor wrote:
Hello Woody,

Here are a couple shots, if you have a section you need detail on, let me know and I will provide it.





On Thursday, December 6, 2018, 12:05:14 PM PST, Woody <mailme@...> wrote:



If anyone has an unassembled uBITX KIT, I sure would like to have scans
of the top and bottom. Would like pretty decent resolution, => 100 dpi
jpg files. Would make it easier to trace runs. Posting here would give
everyone access....

Thanks!
Woody - KZ4AK




Re: [Joe] Bare Board Image

Woody
 

Thanks Joe,  These will help.  Still would be nice if someone posts scanned images of bare boards. Wanted to overlay and the components are in the way...

Woody

On 12/6/2018 20:41, joel taylor wrote:
Hello Woody,

Here are a couple shots,  if you have a section you need detail on, let me know and I will provide it.





On Thursday, December 6, 2018, 12:05:14 PM PST, Woody <mailme@...> wrote:



If anyone has an unassembled uBITX KIT, I sure would like to have scans
of the top and bottom.  Would like pretty decent resolution, => 100 dpi
jpg files.  Would make it easier to trace runs. Posting here would give
everyone access....

Thanks!
Woody  -  KZ4AK



Re: spur & harmonics fix, v2

Evan Hand
 

I have a two tone audio oscillator project in the queue.  Before the info on the bitx20 threads I was planning on building it to establish the maximum level for audio into the rig.  Looks like I will need to resurrect that and start some more testing.

Thank-you for the information.

Evan
AC9TU

Re: Bare Board Image

joel taylor
 

Let me try that again...   Didn't mean to put photo inline.

On Thursday, December 6, 2018, 12:05:14 PM PST, Woody <mailme@...> wrote:



If anyone has an unassembled uBITX KIT, I sure would like to have scans
of the top and bottom.  Would like pretty decent resolution, => 100 dpi 
jpg files.  Would make it easier to trace runs. Posting here would give
everyone access....

Thanks!
Woody  -  KZ4AK




Re: Bare Board Image

joel taylor
 

Hello Woody,

Here are a couple shots,  if you have a section you need detail on, let me know and I will provide it.

Inline image
Inline image


On Thursday, December 6, 2018, 12:05:14 PM PST, Woody <mailme@...> wrote:



If anyone has an unassembled uBITX KIT, I sure would like to have scans
of the top and bottom.  Would like pretty decent resolution, => 100 dpi 
jpg files.  Would make it easier to trace runs. Posting here would give
everyone access....

Thanks!
Woody  -  KZ4AK




Re: Added characters while using the keyer function #ubitx

Evan Hand
 

Did you set the speed?

Re: spur & harmonics fix, v2

Jerry Gaffke
 

When transmitting in CW mode, clk0 and clk1 get shut down.
All we have active is clk2 set to the operating frequency.   
Nothing for clk2 to beat against and create a spur,
so the only bad stuff in CW mode is the harmonics.
Perhaps that is why you did not see any spurs?

The spurs only occur in SSB mode, not in CW mode.
I'd feed something like a 1khz tone into the mike jack,
and adjust the signal level for the maximum peak power out 
that you expect in SSB mode.  So around 5 or 10 watts out.
Probably around 50mv. pk-pk?
The spurs get much worse as you approach the maximum possible power out,
hence the cautions here to avoid overdriving the mike.

Don't transmit continuously or you will overheat the IRF510's,
Maybe have a helper pressing the PTT button for you periodically.
Or hack the firmware on the Nano to do this.
The Nano could also create the 1khz tone.

Jerry, KE7ER


On Thu, Dec 6, 2018 at 10:20 AM, Evan Hand wrote:
If I did try it out, it would only confirm that the board still works (assuming I don't destroy it in making the mods).  With the simple equipment that I have (the RFExplorer SA, Siglent SDS 1102CML+ and multiple VOMS) I can not seem to detect the spurs from my board.  I suspect it is operator error, not totally the fault of the equipment.