Date   
Re: Tracing receive signal for low signal

Dave Space
 

Does anyone have a link to an arrow part for the L5 and L7 replacement that works?

Re: Tracing receive signal for low signal

Jerry Gaffke
 

Bob,

No, that's not old fashioned thinking.
And nails the primary cause of spurs in the uBitx.
The gain of the 45mhz IF amp is too high for what the 2n3904's can give us,
so we get a 90mhz harmonic of the 45mhz signal going into the mixer at D1,D2.

As Allison has explained, the solution is to reduce the gains in those IF amps,
then add an extra stage to the power amp to bring the transmit signal back up to where it was.

On the other hand, the uBitx is drop dead simple compared to anything else like it.
That's why I have one, it's about the simplest possible analog transceiver, and easy to play with.
But along with simple, there come tradeoffs.

Jerry



On Tue, Jan 15, 2019 at 05:48 PM, Bob Lunsford wrote:
The gain was low on each tube and the idea
was with some techs was that if one tube got low gain due
to age, etc., it was only one of eight and the others would
compensate. It was more than that, though. The tubes
were run far below their saturation point where harmonics
would result.

Re: Tracing receive signal for low signal

Evan Hand
 

I used the link in this web page:
https://ubitx.net/spectral-purity/

Lead me to this ebay link:
https://www.ebay.com/itm/480pcs-kit-assorted-chip-inductor-coil-1210-1008-24x20pcs-EPCOS-TDK-MURATA-/143001305190?oid=142968653807

Raj did have the following caution:

Raj vu2zap rajendrakumargg@... via groups.io 

Tue, Dec 25, 2018, 5:44 AM
 
 
to BITX20
 
 
 
 
 
I hope you ordered the right ones like in the pic!

They are shielded and have a resistance of 2 ohms. TDK-EPCOS type is what I used
and also some marked S+M !

Raj

Evan
AC9TU

Re: Tracing receive signal for low signal

Dave Space
 

Thanks I missed that.

I do see arrow looks like they have something with that part number
https://www.arrow.com/en/products/b82422a3681k100/epcos-tdk



On Tue, Jan 15, 2019 at 06:47 PM, Evan Hand wrote:
I used the link in this web page:
https://ubitx.net/spectral-purity/

Lead me to this ebay link:
https://www.ebay.com/itm/480pcs-kit-assorted-chip-inductor-coil-1210-1008-24x20pcs-EPCOS-TDK-MURATA-/143001305190?oid=142968653807

Raj did have the following caution:

Raj vu2zap rajendrakumargg@... via groups.io 

Tue, Dec 25, 2018, 5:44 AM
 
 
to BITX20
 
 
 
 
 
I hope you ordered the right ones like in the pic!

They are shielded and have a resistance of 2 ohms. TDK-EPCOS type is what I used
and also some marked S+M !

Raj

Evan
AC9TU

Re: Tracing receive signal for low signal

Bob Lunsford <nocrud222@...>
 

Clicked on the eBay link and got this:

"The listing you're looking for has ended."

If you know the part number, this would be much more
useful since it is more important that the part is obtained
than that a few dollars are saved. For me, anyway.

Even that part may be reintroduced on eBay but the
part number is needed for a search.

Bob — KK5R
--------------------------------------------

On Tue, 1/15/19, Evan Hand <elhandjr@...> wrote:

Subject: Re: [BITX20] Tracing receive signal for low signal
To: BITX20@groups.io
Date: Tuesday, January 15, 2019, 9:47 PM

I used the link in this
web page:
https://ubitx.net/spectral-purity/

Lead me to this ebay link:
https://www.ebay.com/itm/480pcs-kit-assorted-chip-inductor-coil-1210-1008-24x20pcs-EPCOS-TDK-MURATA-/143001305190?oid=142968653807

Raj did have the following
caution:




Raj
vu2zap @Raj via groups.io 


Tue,
Dec 25, 2018, 5:44 AM
 

 




to BITX20





 
 
 


 
 

I hope you ordered the right ones
like in the pic!

They are
shielded and have a resistance of 2 ohms. TDK-EPCOS type is
what I used
and also some marked S+M !

Raj

Evan
AC9TU

Re: Tracing receive signal for low signal

Bob Lunsford <nocrud222@...>
 

Thanks, this is the part number I needed:

B82422A3681K100

Bob — KK5R

--------------------------------------------

On Tue, 1/15/19, Dave Space <davesspacebar@...> wrote:

Subject: Re: [BITX20] Tracing receive signal for low signal
To: BITX20@groups.io
Date: Tuesday, January 15, 2019, 10:19 PM

Thanks I missed that.

I do see arrow looks like they
have something with that part number
https://www.arrow.com/en/products/b82422a3681k100/epcos-tdk



On Tue, Jan 15, 2019 at 06:47 PM, Evan Hand
wrote:

I used the link in this web page:
https://ubitx.net/spectral-purity/

Lead me to this ebay link:
https://www.ebay.com/itm/480pcs-kit-assorted-chip-inductor-coil-1210-1008-24x20pcs-EPCOS-TDK-MURATA-/143001305190?oid=142968653807

Raj did have the following
caution:




Raj
vu2zap @Raj via groups.io 


Tue,
Dec 25, 2018, 5:44 AM
 

 




to BITX20





 
 
 


 
 

I hope you ordered the right ones
like in the pic!

They are
shielded and have a resistance of 2 ohms. TDK-EPCOS type is
what I used
and also some marked S+M !

Raj

Evan
AC9TU

Re: Tracing receive signal for low signal

Dave Space
 

Actually that part doesn't quite look the same from arrow or digikey.  The part in the ebay listing ends in K not K100 like I found on arrow so not sure that is right.   

I think that arrow part is unshielded.

Re: VK4PP uBitx add-on Boards. (VK4PLN)

vk6qa
 

Hi Nick
Are you going to make any more boards?

regards
Keith

V5 board

Doug Faunt N6TQS +1-510-717-1197
 

I'm new here, and I'm seeing references to a V5 board with fixes for previous problems.
Is this a real thing, or just wishful?
Should I wait?
73, Doug. N6TQS


_._,

Re: V5 board

MVS Sarma
 

The message reg v5 came from Lion's (designer)mouth.
I t has to be real.
If you have some rig to go about, perhaps you could wait for a shortwhile and by then the noards sould appear in 3td dim.....
 All the best regards 

On Wed, 16 Jan 2019, 1:07 pm Doug Faunt N6TQS +1-510-717-1197 <dougfaunt@... wrote:
I'm new here, and I'm seeing references to a V5 board with fixes for previous problems.
Is this a real thing, or just wishful?
Should I wait?
73, Doug. N6TQS


_._,

Re: V5 board

ronmhauser@...
 

Hi Doug, I am the same as you, new here fairly recently and reading along, deciding whether to buy v4 and apply fixes or wait for v5.  The latest was from January 10, Ashar seems to be testing a v5 design.

https://groups.io/g/BITX20/message/63636

Hope this helps!
73
--Ron
K0EIA

Re: Need a replacement Raduino.

_Dave_ K0MBT
 

I bought Jim's partially assembled kit Ordered it Friday evening and had it Monday. Soldering the smd components was a learning experience that I much appreciated. He responds to all emails. A good guy.

Good luck Billy
Thanks Jim.
73
Dave
k0mbt

Re: uBitx V4 test point measurement chart #ubitx #ubitx-help

Ted
 

Hello,

I did some measurements and it looks as if half of my driver transistors are toast, and a few resistors that feed them (actually, the 22-ohm resistors to earth).  As I planned to change them out for metal-can type 2N2222's anyway and drop those resistors accordingly, that will be part of the fix.  We'll see what happens after that.

Thanks so much for the assistance.


-Ted
K3RTA

Re: uBitx V4 test point measurement chart #ubitx #ubitx-help

MVS Sarma
 

Perhaps,  TO18  2n222 has its collector connected to can. we need to be careful while handling times .
 all the best  Ted

 


On Wed, Jan 16, 2019 at 6:56 PM Ted via Groups.Io <k3rta=yahoo.com@groups.io> wrote:
Hello,

I did some measurements and it looks as if half of my driver transistors are toast, and a few resistors that feed them (actually, the 22-ohm resistors to earth).  As I planned to change them out for metal-can type 2N2222's anyway and drop those resistors accordingly, that will be part of the fix.  We'll see what happens after that.

Thanks so much for the assistance.


-Ted
K3RTA

Astatic 636l Mic

Jericho Bates
 

I have a astatic 636l mic that has never been used. I was planning on using it on my ubitx build. After reading all the mods that have been tried on using dynamic mics, Im have second thoughts on using it. Could I remove the dynamic mic element from the astatic mic and replace it with the element that came with the ubitx kit? Or is there a better solution? Thanks

Re: V5 board

Robert Evans
 

Here's hoping that the 1st IF is moved up to like 69+ MHz for the V5 design.
BCNU DE N2LO~>


On Wed, Jan 16, 2019, 07:05 ronmhauser via Groups.Io <ronmhauser=yahoo.com@groups.io> wrote:
Hi Doug, I am the same as you, new here fairly recently and reading along, deciding whether to buy v4 and apply fixes or wait for v5.  The latest was from January 10, Ashar seems to be testing a v5 design.

https://groups.io/g/BITX20/message/63636

Hope this helps!
73
--Ron
K0EIA

Re: Astatic 636l Mic

iz oos
 

I wouldn't modify the mike. I would modify the mic input of the ubitx if necessary. Astatic are known to be good stuff. Don't ruin it.


Il 16/gen/2019 15:25, "Jericho Bates" <jericho.bates@...> ha scritto:
I have a astatic 636l mic that has never been used. I was planning on using it on my ubitx build. After reading all the mods that have been tried on using dynamic mics, Im have second thoughts on using it. Could I remove the dynamic mic element from the astatic mic and replace it with the element that came with the ubitx kit? Or is there a better solution? Thanks

Re: V5 board

Robert Evans
 

Btw i have a bit40 and 2 ubitxs which i tweeked to reduce the spurs. I just bought the 2 ubitxs in 2018NOV knowing about the spurs concerns. I operated them on the air and in the ft8v2 beta testing & contests last month and this. 

I have set them up as a ft8 & other modes monitors for wspr/pskreporting & revbeacon cause i did not want to leave a multiKiloBuck radio connected to antenna unattended.

They are such fun to mod and jury rig and operate.

V5's evolution will benefit from V1 to V4.

Thanks again.
BCNU DE N2LO~>



On Wed, Jan 16, 2019, 09:31 Robert Evans via Groups.Io <robertevansn2lo=gmail.com@groups.io> wrote:
Here's hoping that the 1st IF is moved up to like 69+ MHz for the V5 design.
BCNU DE N2LO~>


On Wed, Jan 16, 2019, 07:05 ronmhauser via Groups.Io <ronmhauser=yahoo.com@groups.io> wrote:
Hi Doug, I am the same as you, new here fairly recently and reading along, deciding whether to buy v4 and apply fixes or wait for v5.  The latest was from January 10, Ashar seems to be testing a v5 design.

https://groups.io/g/BITX20/message/63636

Hope this helps!
73
--Ron
K0EIA

Re: V5 board

Curt
 

There is hope for V3 and V4 boards - but I can see someone who is not a technical hacker having some challenge.  There is also the challenge of getting the parts and likely a daughter board to host relays (our approach in a local club). 

I have the 45 MHz xtal filter addition installed.  I have a board built with 3 relays (Gordon's design) ready to install.  All way going well until I mysteriously lost the analog chain - I hope it is something simple at the pot - I touched wire, it came back, soldered it again -- and no receive.  These things happen -- I stopped work until I can freshly look at it. 

I have a 2000-series K2.  The changes needed to remedy the uBITX are much less than what I had to do with the K2.  One can imagine that v4 boards need to be sold somewhere before the v5 rolls out -- so determine how fast you want to join us.  I would like to see HFSignals (or TBD suppliers around the world) offer the needed parts kits to update the rig for folk with supply chain challenges (yes buying a board and parts in small quantity is not affordable for many). 

73 Curt

Re: V5 board

Jack, W8TEE
 

There is much gnashing of teeth over the µBITX being "out of spec", and we all know that happens. However, we've looked that the units we have and all are in spec on 80M and 40M and right at the limit (or slightly better) on 20M. Since I don't use 15M and 10M right now anyway, I can use my µBITX's on my desired bands of operation and know I'm still within specs. Alas, not everyone has a spectrum analyzer and that's the only way to be certain of your specific rig.

I'm sure we will soon see a new µBITX come to the market that does not have these issues and cures are already known. In the meantime, I wish I knew of a way for everyone out there to determine if and where their rig is "out of spec". First source: Check your club to see if some other member has a SA. If not, check your local high school, junior college, college, or university physics or EE lab to see if you can take your rig there and borrow their SA. There may be other companies in your town that might have one, too, but I don't know how you'd find out about it.

Finding out the specs on your rig, even if it means it's within spec on only one band, is better than letting it sit on a shelf unused.

Jack, W8TEE


On Wednesday, January 16, 2019, 10:38:52 AM EST, Curt via Groups.Io <wb8yyy@...> wrote:


There is hope for V3 and V4 boards - but I can see someone who is not a technical hacker having some challenge.  There is also the challenge of getting the parts and likely a daughter board to host relays (our approach in a local club). 

I have the 45 MHz xtal filter addition installed.  I have a board built with 3 relays (Gordon's design) ready to install.  All way going well until I mysteriously lost the analog chain - I hope it is something simple at the pot - I touched wire, it came back, soldered it again -- and no receive.  These things happen -- I stopped work until I can freshly look at it. 

I have a 2000-series K2.  The changes needed to remedy the uBITX are much less than what I had to do with the K2.  One can imagine that v4 boards need to be sold somewhere before the v5 rolls out -- so determine how fast you want to join us.  I would like to see HFSignals (or TBD suppliers around the world) offer the needed parts kits to update the rig for folk with supply chain challenges (yes buying a board and parts in small quantity is not affordable for many). 

73 Curt