Date   
Re: ubitx schematic cleanup #ubitx

Jerry Gaffke
 

You can spend a week looking at thousands of posts debating how to get the uBitx PA to behave.
And wind up being more confused than when you started.
Most of the trouble in getting RF power out is due to issues other than the use of that IRF510 FET. 
(Looked down on by some, I guess because it was designed for use in automotive turn signals.)

Namely:  
    Gain stages from IF on through the power amp are all trying for about 16dB, and failing miserably on the upper bands
    Transformers are not optimal
    The 10W PA is on the same PC board as some very low level IF amps, feedback is inevitable
    Not enough drive into the IRF510 gates to overcome the capacitive load there on the upper bands
    
Going to RD15**/RD16** devices can help that last issue, but that won't help much.

A better bet might be to buy the excellent PA kit from QRP labs:  https://qrp-labs.com/linear.html
Can give a flat 26dB gain from 3 to 30 mhz, 10W out, roughly 200 ohms in and 50 ohms out.
    https://groups.io/g/QRPLabs/message/30760
Note that it uses the $0.50 IRF510's.

At any rate, I agree with Evan.
If whoever's maintaining documentation up on hfsignals could find the time to correct errors
and show some history and add some needed information as pointed out here in the forum,
it would make success for thousands of *Bitx* owners considerably more likely.

Jerry, KE7ER



On Sat, Feb 23, 2019 at 08:52 PM, MadRadioModder wrote:

Well I didn’t want to be so obvious to say you may consider reading through the history of the development of the alternate PA transistors in the forum.  This is a support group but it only works if you read what has happened previously so you are “up to speed”.  That will probably clear up 99%+ of your confusion.

 

Re: Newbee needs some BITX40 assembly info

Dennis Beverage
 

Hi Paul,  Check our the link Jack sent me.  The resistors are really Raduino mods.  The Bitx 40 should be wired up and tested prior to trying to make these mods and system code changes.  My Bitx 40 board is a 4c version.

Re: Any Gerber Experts Round Here? #kicad #ubitx

AndyH
 

Hi Ben,

   Thank you for the file upload!  I played a bit with the drill files to see if OSHPark can use the files.  The good news is that their tool list editing tips show us how to combine the two drill files into one.  The other news is that OSHPark's import tool is stopped because the file set doesn't include a board outline file.  Oh well, wanted to give it a shot.

   73, Andy, KG5RKP

    https://docs.oshpark.com/troubleshooting/manually-adding-tool-list/


On Sat, Feb 23, 2019 at 03:38 PM, Ben Holmes wrote:
Wack me upside the head, should have thought of that ... I've uploaded the files I got... I cannot vouch that it makes a functioning uBitx, I can only vouch that a Chinese vendor used the files and sent me PCB boards.

Re: ubitx schematic cleanup #ubitx

Jerry Gaffke
 

The QRPlabs 10W PA kit is not a bolt-on solution for the uBitx.
I don't think anybody has posted how to use this with a uBitx.
But doing so would be considerably easier than addressing all the issues
with the uBitx PA if you are going after a flat response from 3 to 30 mhz.

Swapping to the RD15HV FET's on the uBitx might improve power out
on the upper bands some, but hardly seems worth the trouble.
 
Jerry


On Sun, Feb 24, 2019 at 08:26 AM, Jerry Gaffke wrote:
A better bet might be to buy the excellent PA kit from QRP labs:  https://qrp-labs.com/linear.html
Can give a flat 26dB gain from 3 to 30 mhz, 10W out, roughly 200 ohms in and 50 ohms out.
    https://groups.io/g/QRPLabs/message/30760
Note that it uses the $0.50 IRF510's.

Re: Bitx-40 - Where I Am Today

Donald <donwestpwl@...>
 

Pat,

I have heard that end-fed antennas are becoming popular with RVers. Palomar is just one company selling them:

https://palomar-engineers.com/antenna-products/End-Fed-Antennas-c25706168

Their site also has some information on that type of antenna.

Donald, KB5PWL

Re: The new uBITX boards are here

Curt
 

Ted

nice message - I don't even what to think what I paid for my first PC, and 8 bit Kaypro with not much RAM at all  I somehow am an EE too, I need to function as one for just a few more years.  

this uBITX is the cat's meow.  no it does not replace my K2 (or my homebrew rig in progress) - but I am thrilled that thousands around the world can easily enjoy a uBITX or BITX.  we need to remember those of us not on the same continent as the designer, and makers of the boards are guests enjoying this project.  my own confusion of the documentation merely gets me to dig deeper.  Let's not discuss my gaffe in integrating Gordon's relay board - its working nicely and I trust it will meet spurious now on the lower bands.  

not many hits on your qrz.com listing so perhaps you are newly active.  CUL

Curt

Re: ubitx schematic cleanup #ubitx

Evan Hand
 

Jerry,

Good page to find ubitx schematics. I am sure there will be those who apriciate you effort.  As I had stated earlier, this topic was not for my benefit, rather the new to ubitx journey. 

Thank-you!

73
Evan
AC9TU

Re: Bitx-40 - Where I Am Today

Truffies
 

-----Original Message-----
From: Donald <donwestpwl@...>
Sent: Feb 24, 2019 2:37 PM
To: BITX20@groups.io
Subject: Re: [BITX20] Bitx-40 - Where I Am Today

Pat,

I have heard that end-fed antennas are becoming popular with RVers.
Palomar is just one company selling them:

https://palomar-engineers.com/antenna-products/End-Fed-Antennas-c25706168

Their site also has some information on that type of antenna.

Donald, KB5PWL



Initial spectrum test on the V5 with my new spectrum analyzer #ubitx

Jim Sheldon
 

My wife was very nice to me and bought me a brand new Siglent SSA 3021X spectrum analyzer for my upcoming 77th birthday.

I have 1 Version 5 uBITX and another on the way.  The one I have I built up on my old, ugly open frame aluminum chassis for ease of getting at test points, etc.  I did not do a power output check, but during my spectral purity tests into a 20 watt dummy load, it was warming up the load pretty good even on 10 meters with the power control right where the factory set it.

Attached pictures are screen saves from the spectrum analyzer in .jpg format as they were being measured.  No editing has been done on any of them.  As I was uploading the pictures, I realized I did not save pictures for 30 and 12 meters so I'll re-do them and post the results at a later date.  These are posted "as-is" for people to see and make their own conclusions from them. 

Though I got a calibration certificate with it from the Siglent factory, I don't know how far I can trust that.  I do have a GPS Disciplined oscillator feeding the 10 MHz external reference.  As I get more experience with the SA, I may be able to get closer indications that this first run, right out of the box.

Jim Sheldon, W0EB
TSW Project Coordinator

Re: ubitx schematic cleanup #ubitx

Jerry Gaffke
 

You need to thank Tom for assembling those schematics:
    https://groups.io/g/BITX20/message/65671

Tom describes the Minima as the first uBitx,
but it was different enough that I'd just call it the Minima.
Here's the description of the Minima, and the mailing list where it was discussed
    http://www.phonestack.com/farhan/minima.html
    https://www.freelists.org/archive/minima
The Minima had it's issues, few managed to get it to work very well.

The first version of the uBitx was presented here:
    https://groups.io/g/BITX20/message/22888
    http://www.phonestack.com/farhan/ubitx/ubitx.html
and discussed extensively in this BITX20 forum.
It is recognizably similar to what is shipped now, primary change was going to
four transmit LPF's instead of just two, the push-pull IRF510's were not balanced enough
to sufficiently suppress the second harmonic.

The next time a schematic was presented, it was the v3 uBitx.
That is the first uBitx that got shipped out as a kit.


The Bitx40 is worth mentioning.
It came out as a kit in India, early 2016 I believe,
originally with an analog VFO and through hole parts.
Then moved to surface mount parts. 
You can read up on how this happened by looking at old posts in this forum.

In December of 2016, hfsignals added the Raduino to the Bitx40,
giving it a much more stable VFO through the magic of the si5351.
   https://groups.io/g/BITX20/message/19177

Neither the Bitx40 or the Raduino has changed since then.
The Raduino shipped with a new uBitx is the same as one on a Dec 2016 Bitx40
except for a different connector on the bottom and different firmware.

This forum was started back in 2004 to discuss the original Bitx20
    https://groups.io/g/BITX20/message/2
    http://www.phonestack.com/farhan/bitx.html
from which the Bitx40 design evolved.
There are many many variations on the Bitx20, including several successful commercial kits such as this:
    https://www.qrpkits.com/bitx20a.html

Throughout all of this, it's clear that Farhan is driving for a minimalist design that has just enough 
parts to get on the air properly.  There are many other designs that may have more features,
but wind up with far more parts.  The *Bitx* is ideal for experimenters, giving a starting point.
If you want all those features you can then add them once you have the basic rig working.

And of course, Farhan's projects go beyond HF transceivers:
    http://www.phonestack.com/farhan/

Jerry, KE7ER



On Sun, Feb 24, 2019 at 01:07 PM, Evan Hand wrote:
Jerry,

Good page to find ubitx schematics. I am sure there will be those who apriciate you effort.  As I had stated earlier, this topic was not for my benefit, rather the new to ubitx journey. 

Thank-you!

73
Evan
AC9TU

Re: ubitx schematic cleanup #ubitx

Laurence Oberman
 

Thank you to Tom and to all who make this Ubitx journey for us the
most satisfying way to participate in Ham Radio
73
Laurence Oberman
KB1HKO

On Sun, Feb 24, 2019 at 5:30 PM Jerry Gaffke via Groups.Io
<jgaffke=yahoo.com@groups.io> wrote:

You need to thank Tom for assembling those schematics:
https://groups.io/g/BITX20/message/65671

Tom describes the Minima as the first uBitx,
but it was different enough that I'd just call it the Minima.
Here's the description of the Minima, and the mailing list where it was discussed
http://www.phonestack.com/farhan/minima.html
https://www.freelists.org/archive/minima
The Minima had it's issues, few managed to get it to work very well.

The first version of the uBitx was presented here:
https://groups.io/g/BITX20/message/22888
http://www.phonestack.com/farhan/ubitx/ubitx.html
and discussed extensively in this BITX20 forum.
It is recognizably similar to what is shipped now, primary change was going to
four transmit LPF's instead of just two, the push-pull IRF510's were not balanced enough
to sufficiently suppress the second harmonic.

The next time a schematic was presented, it was the v3 uBitx.
That is the first uBitx that got shipped out as a kit.


The Bitx40 is worth mentioning.
It came out as a kit in India, early 2016 I believe,
originally with an analog VFO and through hole parts.
Then moved to surface mount parts.
You can read up on how this happened by looking at old posts in this forum.

In December of 2016, hfsignals added the Raduino to the Bitx40,
giving it a much more stable VFO through the magic of the si5351.
https://groups.io/g/BITX20/message/19177

Neither the Bitx40 or the Raduino has changed since then.
The Raduino shipped with a new uBitx is the same as one on a Dec 2016 Bitx40
except for a different connector on the bottom and different firmware.

This forum was started back in 2004 to discuss the original Bitx20
https://groups.io/g/BITX20/message/2
http://www.phonestack.com/farhan/bitx.html
from which the Bitx40 design evolved.
There are many many variations on the Bitx20, including several successful commercial kits such as this:
https://www.qrpkits.com/bitx20a.html

Throughout all of this, it's clear that Farhan is driving for a minimalist design that has just enough
parts to get on the air properly. There are many other designs that may have more features,
but wind up with far more parts. The *Bitx* is ideal for experimenters, giving a starting point.
If you want all those features you can then add them once you have the basic rig working.

And of course, Farhan's projects go beyond HF transceivers:
http://www.phonestack.com/farhan/

Jerry, KE7ER



On Sun, Feb 24, 2019 at 01:07 PM, Evan Hand wrote:

Jerry,

Good page to find ubitx schematics. I am sure there will be those who apriciate you effort. As I had stated earlier, this topic was not for my benefit, rather the new to ubitx journey.

Thank-you!

73
Evan
AC9TU

Re: Initial spectrum test on the V5 with my new spectrumanalyzer #ubitx

Albert Peter
 

Jim,

Very nice!  I have been using mine extensively on a project that involves crystal lattice filters.  It is invaluable in both characterizing the crystals for inclusion and for evaluating the final filters.

 

I have not checked the calibration as yet.  I have a Rubidium 10MHz source and will give it a try.  I’ll let you know.  The unit is very handy and is well done, as far as I am concerned.

 

Be sure to try out the Advanced Measuring options before they disappear after 48 hrs..

Al

 

Sent from Mail for Windows 10

 

From: Jim Sheldon
Sent: Sunday, February 24, 2019 5:24 PM
To: BITX20@groups.io
Subject: [BITX20] Initial spectrum test on the V5 with my new spectrumanalyzer #ubitx

 

My wife was very nice to me and bought me a brand new Siglent SSA 3021X spectrum analyzer for my upcoming 77th birthday.

I have 1 Version 5 uBITX and another on the way.  The one I have I built up on my old, ugly open frame aluminum chassis for ease of getting at test points, etc.  I did not do a power output check, but during my spectral purity tests into a 20 watt dummy load, it was warming up the load pretty good even on 10 meters with the power control right where the factory set it.

Attached pictures are screen saves from the spectrum analyzer in .jpg format as they were being measured.  No editing has been done on any of them.  As I was uploading the pictures, I realized I did not save pictures for 30 and 12 meters so I'll re-do them and post the results at a later date.  These are posted "as-is" for people to see and make their own conclusions from them. 

Though I got a calibration certificate with it from the Siglent factory, I don't know how far I can trust that.  I do have a GPS Disciplined oscillator feeding the 10 MHz external reference.  As I get more experience with the SA, I may be able to get closer indications that this first run, right out of the box.

Jim Sheldon, W0EB
TSW Project Coordinator

 

Re: Initial spectrum test on the V5 with my new spectrum analyzer #ubitx

 

Hi,

Can it do better than 1MHz RBW?

Do you have an external attenuator on it?  The display only shows 20dB which at 0dBm would be 0.1W input I think.

Power measurement would be better done on 'scope, diode probe, or wattmeter.

73,


Mark.

Re: Initial spectrum test on the V5 with my new spectrum analyzer #ubitx

Jim Sheldon
 

Yes it has an external 50 ohm RF sampler with a variable attenuator.  I'm measuring the harmonics relative to the RF carrier, not output power here.  Checking spectral purity. 

On Feb 24, 2019, at 6:21 PM, Mark McNabb <n7eku@...> wrote:

Hi,

Can it do better than 1MHz RBW?

Do you have an external attenuator on it?  The display only shows 20dB which at 0dBm would be 0.1W input I think.

Power measurement would be better done on 'scope, diode probe, or wattmeter.

73,


Mark.

Re: Initial spectrum test on the V5 with my new spectrum analyzer #ubitx

Tim Gorman
 

Nice job.

It looks like all the bands except 20m are pretty good. I assume this
was straight cw. I don't see any spurs.

It would be interesting to see the same sweeps with an audio tone
feeding the microphone for the same output levels. That would get all
the mixers into play as well.

I assume you are going to do two-tone and carrier suppression tests at
some point? I'm waiting on my v5 to come. I ordered back on 2/7 like
Ron did but I've not heard anything on it. When I get it going I'll
duplicate your measurements using my less expensive Rigol 815!

tim ab0wr

On Sun, 24 Feb 2019 14:24:04 -0800
"Jim Sheldon" <@W0EB> wrote:

My wife was very nice to me and bought me a brand new Siglent SSA
3021X spectrum analyzer for my upcoming 77th birthday.

I have 1 Version 5 uBITX and another on the way.  The one I have I
built up on my old, ugly open frame aluminum chassis for ease of
getting at test points, etc.  I did not do a power output check, but
during my spectral purity tests into a 20 watt dummy load, it was
warming up the load pretty good even on 10 meters with the power
control right where the factory set it.

Attached pictures are screen saves from the spectrum analyzer in .jpg
format as they were being measured.  No editing has been done on any
of them.  As I was uploading the pictures, I realized I did not save
pictures for 30 and 12 meters so I'll re-do them and post the results
at a later date.  These are posted "as-is" for people to see and make
their own conclusions from them. 

Though I got a calibration certificate with it from the Siglent
factory, I don't know how far I can trust that.  I do have a GPS
Disciplined oscillator feeding the 10 MHz external reference.  As I
get more experience with the SA, I may be able to get closer
indications that this first run, right out of the box.

Jim Sheldon, W0EB
TSW Project Coordinator


Re: Initial spectrum test on the V5 with my new spectrum analyzer #ubitx

Ashhar Farhan
 

Twenty looks terrible. You may have to increase the attenuation a bit and crank down the bandwidth to 10khz or 30khz to show up the crud hiding in the grass. Can you do a second pass on twenty? Keep the fundamental peak to -20 dbm.
- f
- f


On Mon 25 Feb, 2019, 7:02 AM Tim Gorman, <tgorman2@...> wrote:
Nice job.

It looks like all the bands except 20m are pretty good. I assume this
was straight cw. I don't see any spurs.

It would be interesting to see the same sweeps with an audio tone
feeding the microphone for the same output levels. That would get all
the mixers into play as well.

I assume you are going to do two-tone and carrier suppression tests at
some point? I'm waiting on my v5 to come. I ordered back on 2/7 like
Ron did but I've not heard anything on it. When I get it going I'll
duplicate your measurements using my less expensive Rigol 815!

tim ab0wr

On Sun, 24 Feb 2019 14:24:04 -0800
"Jim Sheldon" <w0eb@...> wrote:

> My wife was very nice to me and bought me a brand new Siglent SSA
> 3021X spectrum analyzer for my upcoming 77th birthday.
>
> I have 1 Version 5 uBITX and another on the way.  The one I have I
> built up on my old, ugly open frame aluminum chassis for ease of
> getting at test points, etc.  I did not do a power output check, but
> during my spectral purity tests into a 20 watt dummy load, it was
> warming up the load pretty good even on 10 meters with the power
> control right where the factory set it.
>
> Attached pictures are screen saves from the spectrum analyzer in .jpg
> format as they were being measured.  No editing has been done on any
> of them.  As I was uploading the pictures, I realized I did not save
> pictures for 30 and 12 meters so I'll re-do them and post the results
> at a later date.  These are posted "as-is" for people to see and make
> their own conclusions from them. 
>
> Though I got a calibration certificate with it from the Siglent
> factory, I don't know how far I can trust that.  I do have a GPS
> Disciplined oscillator feeding the 10 MHz external reference.  As I
> get more experience with the SA, I may be able to get closer
> indications that this first run, right out of the box.
>
> Jim Sheldon, W0EB
> TSW Project Coordinator
>
>
>




Re: Initial spectrum test on the V5 with my new spectrum analyzer #ubitx

Jim Sheldon
 

I'll let someone else do those. I only operate CW myself and don't even have a microphone made up for any of my uBITX rigs.

On Feb 24, 2019, at 7:31 PM, Tim Gorman <tgorman2@...> wrote:

Nice job.

It looks like all the bands except 20m are pretty good. I assume this
was straight cw. I don't see any spurs.

It would be interesting to see the same sweeps with an audio tone
feeding the microphone for the same output levels. That would get all
the mixers into play as well.

I assume you are going to do two-tone and carrier suppression tests at
some point? I'm waiting on my v5 to come. I ordered back on 2/7 like
Ron did but I've not heard anything on it. When I get it going I'll
duplicate your measurements using my less expensive Rigol 815!

tim ab0wr

On Sun, 24 Feb 2019 14:24:04 -0800
"Jim Sheldon" <@W0EB> wrote:

My wife was very nice to me and bought me a brand new Siglent SSA
3021X spectrum analyzer for my upcoming 77th birthday.

I have 1 Version 5 uBITX and another on the way. The one I have I
built up on my old, ugly open frame aluminum chassis for ease of
getting at test points, etc. I did not do a power output check, but
during my spectral purity tests into a 20 watt dummy load, it was
warming up the load pretty good even on 10 meters with the power
control right where the factory set it.

Attached pictures are screen saves from the spectrum analyzer in .jpg
format as they were being measured. No editing has been done on any
of them. As I was uploading the pictures, I realized I did not save
pictures for 30 and 12 meters so I'll re-do them and post the results
at a later date. These are posted "as-is" for people to see and make
their own conclusions from them.

Though I got a calibration certificate with it from the Siglent
factory, I don't know how far I can trust that. I do have a GPS
Disciplined oscillator feeding the 10 MHz external reference. As I
get more experience with the SA, I may be able to get closer
indications that this first run, right out of the box.

Jim Sheldon, W0EB
TSW Project Coordinator




Re: Initial spectrum test on the V5 with my new spectrum analyzer #ubitx

Jim Sheldon
 

Bench is shut down for the night.  I planned on re-running the tests tomorrow.

Jim 

On Feb 24, 2019, at 7:58 PM, Ashhar Farhan <farhanbox@...> wrote:

Twenty looks terrible. You may have to increase the attenuation a bit and crank down the bandwidth to 10khz or 30khz to show up the crud hiding in the grass. Can you do a second pass on twenty? Keep the fundamental peak to -20 dbm.
- f
- f

On Mon 25 Feb, 2019, 7:02 AM Tim Gorman, <tgorman2@...> wrote:
Nice job.

It looks like all the bands except 20m are pretty good. I assume this
was straight cw. I don't see any spurs.

It would be interesting to see the same sweeps with an audio tone
feeding the microphone for the same output levels. That would get all
the mixers into play as well.

I assume you are going to do two-tone and carrier suppression tests at
some point? I'm waiting on my v5 to come. I ordered back on 2/7 like
Ron did but I've not heard anything on it. When I get it going I'll
duplicate your measurements using my less expensive Rigol 815!

tim ab0wr

On Sun, 24 Feb 2019 14:24:04 -0800
"Jim Sheldon" <w0eb@...> wrote:

> My wife was very nice to me and bought me a brand new Siglent SSA
> 3021X spectrum analyzer for my upcoming 77th birthday.
>
> I have 1 Version 5 uBITX and another on the way.  The one I have I
> built up on my old, ugly open frame aluminum chassis for ease of
> getting at test points, etc.  I did not do a power output check, but
> during my spectral purity tests into a 20 watt dummy load, it was
> warming up the load pretty good even on 10 meters with the power
> control right where the factory set it.
>
> Attached pictures are screen saves from the spectrum analyzer in .jpg
> format as they were being measured.  No editing has been done on any
> of them.  As I was uploading the pictures, I realized I did not save
> pictures for 30 and 12 meters so I'll re-do them and post the results
> at a later date.  These are posted "as-is" for people to see and make
> their own conclusions from them. 
>
> Though I got a calibration certificate with it from the Siglent
> factory, I don't know how far I can trust that.  I do have a GPS
> Disciplined oscillator feeding the 10 MHz external reference.  As I
> get more experience with the SA, I may be able to get closer
> indications that this first run, right out of the box.
>
> Jim Sheldon, W0EB
> TSW Project Coordinator
>
>
>




Re: Initial spectrum test on the V5 with my new spectrum analyzer #ubitx

Evan Hand
 

I did not want to comment first, as I was not sure that i was interpreting the results correctly.  Based on Ashhar's comments, I was correct in that the what was a 40 meter problem is now a 20 meter problem.  I do not have a good SA, closest is an SDRPlat with beta software, so not sure that I will be able to verify the results.  I am to receive my v5 board this week.  Hopefully will get time to test it next weekend.

73
Evan
AC9TU

Re: Ammo case

AA9GG
 

I picked up 2 of them last time they were on sale for $2.95 each


On Fri, Feb 22, 2019 at 10:00 AM alans77 via Groups.Io <alans77=yahoo.com@groups.io> wrote:
Use this one: