Topics

UBITX Current Production (spur fix ?) #ubitx

NU8Z
 


Question?

Does the current uBITX production version include the spur  and harmonic improvement mods that have been discussed on this group? (ie new relays, etc)
If not,  when can one expect changes to be made to be made on present production. 

I'm Going to buy a ubitx, but wanted to wait unit purity issues are solved. 

Thanks in advance for info
Mark NU8Z



Jerry Gaffke
 

From this post, I assume the uBitx boards being shipped are still v4,
with no fixes for harmonics or spurs.
    https://groups.io/g/BITX20/message/62307 
Doesn't really spell out the current situation on spurs, so that's probably a "no".

However, the good news is there's a v5 board in the works, will have fixes.

Jerry


On Thu, Dec 6, 2018 at 09:12 AM, Mark Hinkleman wrote:
Does the current uBITX production version include the spur  and harmonic improvement mods that have been discussed on this group? (ie new relays, etc)
If not,  when can one expect changes to be made to be made on present production. 

RICHARD
 

Can I return my V4 and get a replacement V5 ?  NOT

 

Sent from Mail for Windows 10

 


From: BITX20@groups.io <BITX20@groups.io> on behalf of Jerry Gaffke via Groups.Io <jgaffke@...>
Sent: Thursday, December 6, 2018 9:48:43 AM
To: BITX20@groups.io
Subject: Re: [BITX20] UBITX Current Production (spur fix ?) #ubitx
 
From this post, I assume the uBitx boards being shipped are still v4,
with no fixes for harmonics or spurs.
    https://groups.io/g/BITX20/message/62307 
Doesn't really spell out the current situation on spurs, so that's probably a "no".

However, the good news is there's a v5 board in the works, will have fixes.

Jerry

On Thu, Dec 6, 2018 at 09:12 AM, Mark Hinkleman wrote:
Does the current uBITX production version include the spur  and harmonic improvement mods that have been discussed on this group? (ie new relays, etc)
If not,  when can one expect changes to be made to be made on present production. 

NU8Z
 

OK thanks for info.
Standing by for Version 5 !

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

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

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

Ripley
 

Evan,

 

You might want to check out my uBITX build on QRZ.

 

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

 

Many of the modifications discussed on this site have been implemented during the build including those to improve harmonic and spurious signal suppression. There are lots of pictures and SA screen shots before and after the modifications were done.

 

Ripley

 

Sent from Mail for Windows 10

 

From: Curt via Groups.Io
Sent: Friday, December 7, 2018 12:56 PM
To: BITX20@groups.io
Subject: Re: [BITX20] UBITX Current Production (spur fix ?) #ubitx

 

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

 

AndyH
 

Another member just received a new µBITX board and it has new relays.  Farhan reported that to be the case but we hadn't yet seen a board with the new relays 'in the wild'.  There's been no assessment yet on other mods that might mitigate spurs, and since there doesn't yet seem to be an assessment on the 'best' way to solve that problem, there likely aren't any spur fixes on production boards yet.

https://groups.io/g/BITX20/message/62415

73, Andy, KG5RKP


On Thu, Dec 6, 2018 at 11:12 AM, Mark Hinkleman wrote:


Question?

Does the current uBITX production version include the spur  and harmonic improvement mods that have been discussed on this group? (ie new relays, etc)
If not,  when can one expect changes to be made to be made on present production. 

I'm Going to buy a ubitx, but wanted to wait unit purity issues are solved. 

Thanks in advance for info
Mark NU8Z



Jerry Gaffke
 

I looked at the relay datasheet for the parts seen in post  https://groups.io/g/BITX20/message/62415
They don't appear to be anything special with regard to RF isolation, definitely not Axicom relays.
My guess is these are still about the same as what has always shipped with the uBitx.

And Farhan's message that you cite (62415) states:
"The boards continued to ship with the same relays as some have also reported no difference with the new relay."
I take that to mean that new uBitx boards continue to ship with no harmonic fix of any sort.
Or any spur fix.

Jerry



On Mon, Dec 10, 2018 at 10:34 AM, AndyH wrote:
Another member just received a new µBITX board and it has new relays.  Farhan reported that to be the case but we hadn't yet seen a board with the new relays 'in the wild'.  There's been no assessment yet on other mods that might mitigate spurs, and since there doesn't yet seem to be an assessment on the 'best' way to solve that problem, there likely aren't any spur fixes on production boards yet.

https://groups.io/g/BITX20/message/62415

AndyH
 

I understand that you're accurately reporting the latest comment from Farhan.  My V3 board was equipped with Virtual  VRS2H-S-DC12V-C relays.  It looks like the HFD27 relays in the current board were an upgrade and/or replacement but aren't a result of improving crosstalk.  Mea culpa.



On Mon, Dec 10, 2018 at 08:58 PM, Jerry Gaffke wrote:
I looked at the relay datasheet for the parts seen in post  https://groups.io/g/BITX20/message/62415
They don't appear to be anything special with regard to RF isolation, definitely not Axicom relays.
My guess is these are still about the same as what has always shipped with the uBitx.

And Farhan's message that you cite (62415) states:
"The boards continued to ship with the same relays as some have also reported no difference with the new relay."
I take that to mean that new uBitx boards continue to ship with no harmonic fix of any sort.
Or any spur fix.

Jerry



On Mon, Dec 10, 2018 at 10:34 AM, AndyH wrote:
Another member just received a new µBITX board and it has new relays.  Farhan reported that to be the case but we hadn't yet seen a board with the new relays 'in the wild'.  There's been no assessment yet on other mods that might mitigate spurs, and since there doesn't yet seem to be an assessment on the 'best' way to solve that problem, there likely aren't any spur fixes on production boards yet.

https://groups.io/g/BITX20/message/62415

Sascha Bohnet | DL5SMB
 

My V3 board was equipped with the HFD27 relays.

I already took them out to switch to Axicom-
might have been smarter to check first how bad the problems is.
Good to know at least that the  HFD27 are probably an improvement. 

Jerry Gaffke
 

I see no evidence in the HFD27 datasheet that these relays are better suited
with regard to RF isolation.

This post   https://groups.io/g/BITX20/message/62307 
suggests that HFSignals is not shipping the uBitx with improved relays.

There are a number of different manufacturers of similar low end relays.
HFSignals has likely qualified several of them as a source of relays.

Jerry, KE7ER


On Tue, Dec 11, 2018 at 04:13 AM, Sascha Bohnet | DL5SMB wrote:
My V3 board was equipped with the HFD27 relays.

I already took them out to switch to Axicom-
might have been smarter to check first how bad the problems is.
Good to know at least that the  HFD27 are probably an improvement. 

 

 

Evan Hand
 

It was my understanding that the significant difference was how the relays were constructed internally: the relays specified as the replacement had the contacts and wiring closer to the circuit board.  It was the physical layout that made the difference.  That would not show up in a normal relay specification.  It could even be changed if there was a "process improvement" at the relay manufacturer to change the configuration of the relay.

Unless you break open one of the relays, or find a diagram that shows the internal construction, there is not a way other than try them to verify that it helps in the RF feedback problem.

Above is my understanding; it could be wrong, so use your own judgement/research to verify.

Evan
AC9TU

Jerry Gaffke
 

Yes, the relays now shipped could be better.
Or could be worse, it's pretty much all conjecture.

The Axicom datasheets do talk about RF isolation.
The datasheet for the new relays does not.
Most of these low end relays assume you are switching at DC or audio frequencies,
and don't bother with the extra expense of addressing RF isolation.

Jerry


On Tue, Dec 11, 2018 at 08:21 AM, Evan Hand wrote:
It was my understanding that the significant difference was how the relays were constructed internally: the relays specified as the replacement had the contacts and wiring closer to the circuit board.  It was the physical layout that made the difference.  That would not show up in a normal relay specification.  It could even be changed if there was a "process improvement" at the relay manufacturer to change the configuration of the relay.
 
Unless you break open one of the relays, or find a diagram that shows the internal construction, there is not a way other than try them to verify that it helps in the RF feedback problem.
 
Above is my understanding; it could be wrong, so use your own judgement/research to verify.
 
Evan
AC9TU