Topics

ubitx.net up to date


Mike Woods
 

I have finally achieved the near impossible and cleared the back log of 2800 emails from the BITX20 list.  All posts of enduring interest between 15 December and today have been turned into news items on ubitx.net.

For those who haven't been on the uBITx information site lately, I had a break over the NZ summer - at first because of travel and summer vacation time - then because of ill health.  I had a fall and cracked open my forehead.  It has recovered well, just that slight "gang warfare" look!  You will find posts in December, January and February that were back-dated consistent with when topics were raised on the list.  Enjoy!

With the release of the JackAl and then the v5 Board there has actually been quite a bit of activity this year.

I made some judgement calls last year around the best mods for solving the harmonics/spurs issues on the v3 and v4 boards.  I think these are still valid and represent the easiest way of getting compliance (or near compliance) for your uBITx (see the menu "fix" and then "spectral purity").  I know that there are other mods and these are covered off in the news items.  I suspect most folk want fixes that require minimum effort - hence relay replacement and two replacement surface mount chokes is what ubitx.net recommends.  Other solutions are a bit more involved.

Hopefully all of you are still having as much fun as me at modifying your uBITx.  I have a feeling that there are more mods just around the corner.  Who knows where JackAl will take us, or what new features Ian KD8CEC will throw at us?

73 Mike ZL1AXG ubitx.net

--
Mike Woods
mhwoods@...


Joe Puma
 

Thanks Mike, hope your feeling better.

 

Joe

KD2NFC

 

 

Sent from Mail for Windows 10

 

From: Mike Woods
Sent: Monday, March 11, 2019 4:17 AM
To: BITX20@groups.io
Subject: [BITX20] ubitx.net up to date

 

I have finally achieved the near impossible and cleared the back log of

2800 emails from the BITX20 list.  All posts of enduring interest

between 15 December and today have been turned into news items on

ubitx.net.

 

For those who haven't been on the uBITx information site lately, I had a

break over the NZ summer - at first because of travel and summer

vacation time - then because of ill health.  I had a fall and cracked

open my forehead.  It has recovered well, just that slight "gang

warfare" look!  You will find posts in December, January and February

that were back-dated consistent with when topics were raised on the

list.  Enjoy!

 

With the release of the JackAl and then the v5 Board there has actually

been quite a bit of activity this year.

 

I made some judgement calls last year around the best mods for solving

the harmonics/spurs issues on the v3 and v4 boards.  I think these are

still valid and represent the easiest way of getting compliance (or near

compliance) for your uBITx (see the menu "fix" and then "spectral

purity").  I know that there are other mods and these are covered off in

the news items.  I suspect most folk want fixes that require minimum

effort - hence relay replacement and two replacement surface mount

chokes is what ubitx.net recommends.  Other solutions are a bit more

involved.

 

Hopefully all of you are still having as much fun as me at modifying

your uBITx.  I have a feeling that there are more mods just around the

corner.  Who knows where JackAl will take us, or what new features Ian

KD8CEC will throw at us?

 

73 Mike ZL1AXG ubitx.net

 

--

Mike Woods

mhwoods@...

 

 

 


Kevin Luxford
 

Tena koe Mike. Thanks for all your work.

This ex pat Kiwi dreams of the big rainbow trout in the Tongariro and the Waihatanui. Although cousin John tells me that the fishing at Taupo is not like it was 50 years ago. Anyway uBITX is not a bad substitute - at least my hands don't get frozen.
73 and thanks again.
Kevin VK3DAP / ZL2DAP
--
Kevin B. G. Luxford
kbgluxford@...


Laurence Oberman
 

Mike
Take care and thanks for your efforts.
Hopefully you are feeling better.
Sincerely
All of us here

On Mon, Mar 11, 2019, 4:17 AM Mike Woods <mhwoods@...> wrote:
I have finally achieved the near impossible and cleared the back log of
2800 emails from the BITX20 list.  All posts of enduring interest
between 15 December and today have been turned into news items on
ubitx.net.

For those who haven't been on the uBITx information site lately, I had a
break over the NZ summer - at first because of travel and summer
vacation time - then because of ill health.  I had a fall and cracked
open my forehead.  It has recovered well, just that slight "gang
warfare" look!  You will find posts in December, January and February
that were back-dated consistent with when topics were raised on the
list.  Enjoy!

With the release of the JackAl and then the v5 Board there has actually
been quite a bit of activity this year.

I made some judgement calls last year around the best mods for solving
the harmonics/spurs issues on the v3 and v4 boards.  I think these are
still valid and represent the easiest way of getting compliance (or near
compliance) for your uBITx (see the menu "fix" and then "spectral
purity").  I know that there are other mods and these are covered off in
the news items.  I suspect most folk want fixes that require minimum
effort - hence relay replacement and two replacement surface mount
chokes is what ubitx.net recommends.  Other solutions are a bit more
involved.

Hopefully all of you are still having as much fun as me at modifying
your uBITx.  I have a feeling that there are more mods just around the
corner.  Who knows where JackAl will take us, or what new features Ian
KD8CEC will throw at us?

73 Mike ZL1AXG ubitx.net

--
Mike Woods
mhwoods@...




Brutus Laurentius
 

Thank you for your work, Mike! Your website has been a great resource for me. I'm glad that you have recovered and I hope you continue to do well! Now I know who to call if I need an enforcer.


Curt
 

Mike

I suggest that more, clearer data is needed before recommending a particular spurious fix.  The Axicom relays may work if a board does not require a huge improvement - I think this may be why some are not seeing compliance with this solution.  The alternative solution using 3 relays on a daughter board is actually easier for many builders since it has no need to remove relays from the board - but problem is that no one is sourcing it as a kit.  On the 45 MHz fix, I am not sure that replacing two coils is adequate in itself.  We honestly need more data.  Our own local club has a large group build - we can contribute data when we have it on v4.  I don't want the community having a false hope on any particular cure - and also want the community to understand that a sufficient fix is possible. 

Curt


Brutus Laurentius
 

Hi Curt,
Can you elaborate on the "three relays on a daughter card" fix? I don't need a kit - I'll make my own!


Curt
 

A circuit board contains 3 added relays that connect to the input side of the 4 low pass filters.  Following assembly of this board, the user must cut a few traces and then install short pieces of thin coax to make the connection.  A pc board was designed by a list member, only the artwork is available.  Our club made a batch of these boards and kitted the needed parts - a few of us have them installed into our uBITX, but I only know of one unit being measured so far - it passed with margin.  My v4 needs over 10 dB improvement in the harmonics on some bands - I don't know if change to the alternate relay will achieve this or not. 


Now if this solution would be preferred - then 'all' that is needed is for someone(s) to kit and sell it maybe.  Clarifying, this fix only address one source of spurious. 

Curt



Brutus Laurentius
 

Thank you, Curt!   It's actually a very nice construction document.  Based on that, it wouldn't be too hard to make into a kit.


On Mon, Mar 11, 2019 at 09:03 AM, Curt wrote:
https://qsl.net/nf4rc/2018/OutboardRelaysDesignDocumentTry3.pdf


Mike Woods
 

Kia ora Kevin

C U back in ZL some time!

Mike

On 11/03/19 11:06 AM, Kevin Luxford wrote:
Tena koe Mike. Thanks for all your work.

This ex pat Kiwi dreams of the big rainbow trout in the Tongariro and the Waihatanui. Although cousin John tells me that the fishing at Taupo is not like it was 50 years ago. Anyway uBITX is not a bad substitute - at least my hands don't get frozen.
73 and thanks again.
Kevin VK3DAP / ZL2DAP
--
Mike Woods
mhwoods@...


Mike Woods
 

On 12/03/19 1:36 AM, Curt via Groups.Io wrote:

Thanks for all the "hope you are better" comments.  My head wound has healed and the other health problems are receding, so all good at this point.

Curt- I think that we may never get clearer data, unless your larger group build can provide this information!

Gordon's approach with the daughter board (single end relay replacement) may well be easier to effect, but it sounds like it may also be at a slightly greater cost and complexity.  I do accept that removing multi-legged through-hole parts is not always an easy task, especially if you have never done it before.  It would be good if somebody had a video of doing this with techniques for breaking up the existing part, solder flux/wick work and removal of the individual pins.  This may make the task more straightforward for the regular constructor. I have the relays on the bench, but not yet installed. When I get around to doing the replacement I plan to try and make a short video of the repair work.

Many constructors seem really concerned about their rig's compliance.  I think this is probably an unnecessary concern given the power output of the uBITx.  Doing the mods cannot guarantee compliance, but doing both mods is likely to significantly reduce spurs and harmonics bringing it well within the unwanted emissions from a 100w rig.

73 Mike

Mike

I suggest that more, clearer data is needed before recommending a particular spurious fix.  The Axicom relays may work if a board does not require a huge improvement - I think this may be why some are not seeing compliance with this solution.  The alternative solution using 3 relays on a daughter board is actually easier for many builders since it has no need to remove relays from the board - but problem is that no one is sourcing it as a kit.  On the 45 MHz fix, I am not sure that replacing two coils is adequate in itself.  We honestly need more data.  Our own local club has a large group build - we can contribute data when we have it on v4.  I don't want the community having a false hope on any particular cure - and also want the community to understand that a sufficient fix is possible. 

Curt


--
Mike Woods
mhwoods@...


Kobus ZS6CHK
 

Not so difficult for me to replace relays and other components. But I must admit that this is how I make my lively wood. Am a 2 way radio bench tech for more than 40 years. And that includes SMD as well. Also have a professional workshop at my disposal with test instruments that many can only dream of. And still working at the age of 67.

Virus-free. www.avast.com


On Tue, Mar 12, 2019 at 9:33 AM Mike Woods <mhwoods@...> wrote:
On 12/03/19 1:36 AM, Curt via Groups.Io wrote:

Thanks for all the "hope you are better" comments.  My head wound has healed and the other health problems are receding, so all good at this point.

Curt- I think that we may never get clearer data, unless your larger group build can provide this information!

Gordon's approach with the daughter board (single end relay replacement) may well be easier to effect, but it sounds like it may also be at a slightly greater cost and complexity.  I do accept that removing multi-legged through-hole parts is not always an easy task, especially if you have never done it before.  It would be good if somebody had a video of doing this with techniques for breaking up the existing part, solder flux/wick work and removal of the individual pins.  This may make the task more straightforward for the regular constructor. I have the relays on the bench, but not yet installed. When I get around to doing the replacement I plan to try and make a short video of the repair work.

Many constructors seem really concerned about their rig's compliance.  I think this is probably an unnecessary concern given the power output of the uBITx.  Doing the mods cannot guarantee compliance, but doing both mods is likely to significantly reduce spurs and harmonics bringing it well within the unwanted emissions from a 100w rig.

73 Mike

Mike

I suggest that more, clearer data is needed before recommending a particular spurious fix.  The Axicom relays may work if a board does not require a huge improvement - I think this may be why some are not seeing compliance with this solution.  The alternative solution using 3 relays on a daughter board is actually easier for many builders since it has no need to remove relays from the board - but problem is that no one is sourcing it as a kit.  On the 45 MHz fix, I am not sure that replacing two coils is adequate in itself.  We honestly need more data.  Our own local club has a large group build - we can contribute data when we have it on v4.  I don't want the community having a false hope on any particular cure - and also want the community to understand that a sufficient fix is possible. 

Curt


--
Mike Woods
mhwoods@...



--
Jakobus van der Merwe
zs6chk@...

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