Date   

Re: Transmit Output Power (CW) #v5

Andy_501 <andrew.webb.501.ve4per@...>
 

Here are a couple of tone clips that might be useful; 700-1900 is 2 tone  300 and 3000 are voice BW max & min. I use another SDR spectrum display to check spectral purity for things like harmonics. depending where you feed it into system you might have to fashion an atten pad

cheers


On 2020-03-11 10:05 p.m., Matthew Chambers NR0Q via Groups.Io wrote:
why? he already did the test with CW which will give the maximum power out vs a whistle which will vary and may have a complex signal component and reduce how much power you see on a non-peak reading meter. in radio shops we always test in either CW or FM for max power out, and then in AM to set the carrier level.

Matthew Chambers, CBT, NR0Q
Owner/Engineer
M Chambers Communications Engineering LLC
PO BOX 855, Moberly, MO 65270
Mobile (660)415-5620


On Wed, Mar 11, 2020 at 9:57 PM Joe Puma <kd2nfc@...> wrote:
Do the same test but in SSB. Give a steady whistle.  

Joe
KD2NFC 



On Mar 11, 2020, at 10:13 PM, Rob French (KC4UPR) <kc4upr@...> wrote:



I've collected all my parts to do Allison's transmit chain modifications (BFR106, 2N2222, 11 ohm resistors...).  I'm ready to go... but I wanted to QC my output power first.  Now, I have noticed on 40 meters (where I spend most of my time), that the output power is low, so now that I finally have a power meter, I went ahead and tuned RV1 while transmitting into a dummy load.  I tuned RV1 to get 12W output on 3.500 MHz, and then checked the output power across the rest of the bands.  This is what I got... is this representative of what other people have seen?  I know I'd seen reports of crazy low output power (<1 W) on 10 meters, which I did NOT observe here, obviously.  (Note, all of these were done with CW.)

Frequency

SWR

Power (W)

3500000

1.00

12

4000000

1.00

9.4

5332000

1.00

6.3

5405000

1.00

6.2

7001000

1.00

6.7

7300000

1.00

5.6

10100000

1.00

5.2

10150000

1.00

4.7

14000000

1.01

6.6

14350000

1.01

6.2

18068000

1.02

5.5

18168000

1.02

5.5

21000000

1.04

5.8

21450000

1.05

8

24890000

1.04

4.1

24990000

1.04

4

28000000

1.04

4.8

29700000

1.03

4

Any thoughts?  (a) Are these typical of what others have observed?  (b) What can I expect from the transmit modifications, relative to this?  Higher output on 30, 20, 17?

Thanks!

-Rob KC4UPR

PS - Random aside.  So I am using KD8CEC firmware version 1.2.  I noticed something weird on 40 meters... If I tune to exactly 7.000.000 MHz, or lower, in the 40 meter band, I hear the T/R relay switch and the display indicates in CW transmit, but there's 0 W output power.  But if I tune to 7.000.010 or higher, it's fine.  It's kind of like it's enforcing transmit restrictions, except that the ONLY place that it seems to do this is on the bottom end of 40 meters!  I've tried to trace code behavior for the band limiting, and could not identify anything that would make this happen.  Has anyone else observed this???


Re: Transmit Output Power (CW) #v5

jim <ab7vf@...>
 

Just a random thought ...do you have any way to check for harmonics/spurs at these settinjgs?

while tuning for "maximum smoke" is one way to do it, what you are measuring with the power meter is ..along with the fundamental frequency, ALL the spurs/harmonics/random trash being radiated...would be great to see some measurements of them before the modding as well as after

Jim

On Thursday, March 12, 2020, 2:13:41 AM UTC, Rob French (KC4UPR) <kc4upr@...> wrote:


I've collected all my parts to do Allison's transmit chain modifications (BFR106, 2N2222, 11 ohm resistors...).  I'm ready to go... but I wanted to QC my output power first.  Now, I have noticed on 40 meters (where I spend most of my time), that the output power is low, so now that I finally have a power meter, I went ahead and tuned RV1 while transmitting into a dummy load.  I tuned RV1 to get 12W output on 3.500 MHz, and then checked the output power across the rest of the bands.  This is what I got... is this representative of what other people have seen?  I know I'd seen reports of crazy low output power (<1 W) on 10 meters, which I did NOT observe here, obviously.  (Note, all of these were done with CW.)

Frequency

SWR

Power (W)

3500000

1.00

12

4000000

1.00

9.4

5332000

1.00

6.3

5405000

1.00

6.2

7001000

1.00

6.7

7300000

1.00

5.6

10100000

1.00

5.2

10150000

1.00

4.7

14000000

1.01

6.6

14350000

1.01

6.2

18068000

1.02

5.5

18168000

1.02

5.5

21000000

1.04

5.8

21450000

1.05

8

24890000

1.04

4.1

24990000

1.04

4

28000000

1.04

4.8

29700000

1.03

4

Any thoughts?  (a) Are these typical of what others have observed?  (b) What can I expect from the transmit modifications, relative to this?  Higher output on 30, 20, 17?

Thanks!

-Rob KC4UPR

PS - Random aside.  So I am using KD8CEC firmware version 1.2.  I noticed something weird on 40 meters... If I tune to exactly 7.000.000 MHz, or lower, in the 40 meter band, I hear the T/R relay switch and the display indicates in CW transmit, but there's 0 W output power.  But if I tune to 7.000.010 or higher, it's fine.  It's kind of like it's enforcing transmit restrictions, except that the ONLY place that it seems to do this is on the bottom end of 40 meters!  I've tried to trace code behavior for the band limiting, and could not identify anything that would make this happen.  Has anyone else observed this???


Re: uBitx v6 Microphone #v6

Evan Hand
 

There is other software, but none of them are going to solve your problems.  They change some of the operation, or add features that are not there now.  Nothing to solve the calibration, low audio,  and feedback issues you have listed so far.

My recommendation is to put the radio back together and then follow the instructions for calibration from Farhan in this YouTube video:
https://www.youtube.com/watch?v=t6LGXhS4_O8&feature=youtu.be

The BFO calibration page used in the video is here:
https://www.hfsignals.com/index.php/bfo-tuning-aid/

If you follow the steps in the video, you should be able to get the ubitx receive function working.

I did not follow all of the mic/audio issues you are having, however the most common is low audio followed by RF feedback through the coiled mic cord back into radio.

There is no easy solution for the low audio other than a new mic or addition of a preamp.

The RF feedback is solved with .01 mF across the lead from the mic to ground inside the ubitx chases and a snap on ferrite over the straight part of the mic cord just before the connector.  I do not have a v6 so can not send you a picture of how and where to add the capacitor.  Hopefully someone on the message board can help with that.

I feel sorry for you that you are having so much trouble with the kit.  I hope you can look at it as an opportunity to learn and a hunt to fix the problems.  For me that has been the most fun that I have gotten from the 3 that I own.

Good luck in the reassembly and calibration.
73
Evan
AC9TU


Re: Transmit Output Power (CW) #v5

_Dave_ AD0B
 

We have three power meters. None of them read the same. On one it reads 5 and the other 20 on some bands. Which is real?

Have 4 ubitx and the best comparison is to compare between the units. The reality is they sound the same to stations I work. I doubt if they are identical but are "nomal".

Don't take your working radio and make it not work. The forum is full of those. I have fixed a number of them and the first thing I do is to make the radio stock.  If you do decide to work on it change one stage of transistor and bias at a time and test. There are pitfalls. burn up a trace and find out.
--
73
Dave
ADOB
Raduino bracket and Ham_Made_Keys


Re: uBitx v6 Microphone #v6

Rene
 

Is there maybe a diffrent software i can put on the raduno?? or a total reset??


Re: uBitx v6 Microphone #v6

Rene
 

Now i have the radio dis manteled, and try to build it up again....but no hope for it, 250 euro in the trascan maybe???


Re: Transmit Output Power (CW) #v5

Rob French (KC4UPR)
 

Thanks, Curt.  I will be sure to look at my output in SSB before I go do any further surgery on my board... I also have some small fear of breaking something I can't fix when I go swapping out these transistors and soldering in new SMD resistors! (and that tiny little BFR106...)


Re: uBitx v6 Microphone #v6

Rene
 

I have the speaker from the baofeng microphone removed and put a new electred in the microphone, every move i make seems to be worse......maybe gonna drive with my car over it. Pffffff if i reed al those massages, it should be easy but man o man. I feel now sorry that i diddn't bought a Icom or something cause all those problems. Starting with wishkey now, maybe better ;-(((


Re: Antenna Question #antennas #v3

Christopher Miller
 

Thank you for all the information and advice. I have a few ideas now, especially the ham sticks and end fed / tuner ideas. 

I’ll post photos etc as I go. The rig is coming in today!

Chris KF4FTR


Re: CW Filter

Bob Benedict, KD8CGH
 

I also use the Sotabeams filter. As a bonus for us tone deaf operators it includes a CW tune aid that lights an led when well tuned to a signal.


Re: CW Filter

Reg
 

A better video for the VK3YE AGC is here and it's in two parts.


Reg       G4NFR


Re: Transmit Output Power (CW) #v5

Curt
 

Rob

your as-is numbers are not bad on CW.  (some of us would gladly trade board with you - actually mine is somewhat simpler - except I had an even larger dip on 40m, that I corrected with a capacitor change pointed out by Asshar).  remembering each S-unit on receive is approximately 6 dB - I would not myself want to change anything.  (if you really really want a flatter PA - you could possibly buy the 10 watt PA kit from QRP-Labs, and use it instead of this portion of the ubitx - but funny thing when we get good solar flux in 4-6 years from now - you might be using a uBitx v12 or a QSX v3 ....)

SSB needs to be evaluated separately, using an audio oscillator as an input.  the SSB path uses the 45 MHz mixer 'as a mixer.'  CW is different because it puts a bias onto the mixer, and then leaks through a signal at the intended RF (no mixing!). 

keep in mind the driver and PA are common to both CW and SSB - the overall behavior should track but you may experience different degrees of dip and peaking.  with the circuit board as is - you can only do so much with the overall behavior of the PA and tweaking of the driver frequency response.  you might work very hard to get a better measurement into your power meter on 40m that the operator on the other end will not even notice. 

73 Curt


Re: CW Filter

Reg
 

Hi Laurent,
The Sotabeams filter is very good and saves messing about making one. I would think that it should be O.K when used in line with an AGC control. But that's a guess as I haven't got any AGC control. I might look at the simple AGC setup designed by Peter Parker VK3YE

https://www.youtube.com/watch?v=GdpOkjETtw8

But that's a future  project.

Reg     G4NFR


Re: #v6 control settings for 12V fan #v6

_Dave_ AD0B
 

My experience with fans and uBITX.

Some fans are electrically noisy and can be heard through the audio. I used a squirrel cage fan that was the pits. So if your fan is noisy you might want it on when transmitting only.

Since the fan  is cooling off a heat sink it makes sense to me to just run it at a low speed rather than complicate with a sensor or something. I have one that uses an 80 mm fan with big heat sinks and it never gets warm. Found a cat sitting on a morse key for a long period. All was well. 

On the last one I put together I isolated the power transistors and bolted them to a 1x1x1/8 aluminum angle stock and riveted the angle stock to the back of the aluminum case. No heat no noise. Super reliable. 

Between my wife and I we have 5 BITX radios.

That said I would turn on the fan at maybe 45. Use your hand and see when you think it is too warm. You may have to turn it lower than you think it ideal to keep it from getting hot running a digital mode. They are neat modules we have one driving our chicken brooder pen.
--
73
Dave
ADOB
Raduino bracket and Ham_Made_Keys


Re: CW Filter

laurent.bury@...
 

Hi Reg,

sounds great, as the uBitx lacks a good CW filter (the provided one is set for SSB, that is much too wide when chasing for DX stations listening up...about 1Khz, right in the audio response :( ).

As you talked about the volume control, I wondered if the CW filter was compliant with any audio AGC one can have already add, that is connected  to the volume pot ?

73s
--
Laurent F5FIE.


For Sale: uBITX V6

Bob WB8CAC
 

V6 for sale.  Unmodified, stock firmware, assembled (with cabinet), and calibrated.  I've made about a dozen CW contacts with it. No SSB contacts only listened to the SSB signal on a web SDR receiver.  I'm never going to get around to messing with it to make CW operation  "convenient." $175 shipped US.  Paypal accepted.  Bob  WB8CAC, currently@...


Re: Transmit Output Power (CW) #v5

Joe Puma
 

...and NOT* use the CW carrier.


On Mar 12, 2020, at 9:16 AM, Joe Puma via Groups.Io <kd2nfc@...> wrote:

Thanks Evan. I have done the power mod on V3 and also used different sized bias resistors which worked better for my board.  My power out on CW is slightly higher then on SSB and it’s not because of the CW carrier. My emails are along the 331 emails as I was asking questions so I am familiar with Allison’s mod and comments about the differences between power out on CW And SSB. I know if you’re going to do the mod. It’s best to test your SSB out and use the CW carrier. 

Joe
KD2NFC 


On Mar 12, 2020, at 9:02 AM, Evan Hand <elhandjr@...> wrote:

Joe,

To the best of my knowledge, the v5 boards have the upgrades in the sections prior to the first mixer (upgrading the 2n3904 to BFR93W) related to SSB performance.  The upgrades that are not done are in the driver and predriver stages where the 2n3904s are suggested to be replaced with 2n2222a or better devices.  Those sections are the same for both CW and SSB and can be modified for more consistent performance per Allison/KB1GMX in messages over a year ago.  The original work was done on the v3 and v4 boards, which then brought up the harmonics and spurs issues.  This lead to the v5 fixes that solved them through both redesign of the output filter sections of the board and the addition of a 45 MHz low pass filter between the 45 MHz IF stage and the first mixer T2.  The 40 meter power "dip" has not been addressed.  I believe that the v5 boards are not as bad as some of the prior boards.  I conjecture that one of the issues was incorrect turns or spacing of the 40 meter lpf inductors that seems to have reduced the problem, but not eliminate it.

To get more information of what has been tried to balance power out across bands I would read through the 331 messages that start with this one from Allison:
Message #49729
https://groups.io/g/BITX20/message/49729

There has not been a significant change to the uBitx in the stages from Q90 through the output lpf, so there is some opportunity to improve, though the output that Rob listed is not as bad as some that have been posted on this message board.

All,
Above are just suggestions, conjecture, and beliefs on my part.  Please take that into account and please excuse any errors or misconceptions on my part.

73
Evan
AC9TU


Re: Transmit Output Power (CW) #v5

Joe Puma
 

Thanks Evan. I have done the power mod on V3 and also used different sized bias resistors which worked better for my board.  My power out on CW is slightly higher then on SSB and it’s not because of the CW carrier. My emails are along the 331 emails as I was asking questions so I am familiar with Allison’s mod and comments about the differences between power out on CW And SSB. I know if you’re going to do the mod. It’s best to test your SSB out and use the CW carrier. 

Joe
KD2NFC 


On Mar 12, 2020, at 9:02 AM, Evan Hand <elhandjr@...> wrote:

Joe,

To the best of my knowledge, the v5 boards have the upgrades in the sections prior to the first mixer (upgrading the 2n3904 to BFR93W) related to SSB performance.  The upgrades that are not done are in the driver and predriver stages where the 2n3904s are suggested to be replaced with 2n2222a or better devices.  Those sections are the same for both CW and SSB and can be modified for more consistent performance per Allison/KB1GMX in messages over a year ago.  The original work was done on the v3 and v4 boards, which then brought up the harmonics and spurs issues.  This lead to the v5 fixes that solved them through both redesign of the output filter sections of the board and the addition of a 45 MHz low pass filter between the 45 MHz IF stage and the first mixer T2.  The 40 meter power "dip" has not been addressed.  I believe that the v5 boards are not as bad as some of the prior boards.  I conjecture that one of the issues was incorrect turns or spacing of the 40 meter lpf inductors that seems to have reduced the problem, but not eliminate it.

To get more information of what has been tried to balance power out across bands I would read through the 331 messages that start with this one from Allison:
Message #49729
https://groups.io/g/BITX20/message/49729

There has not been a significant change to the uBitx in the stages from Q90 through the output lpf, so there is some opportunity to improve, though the output that Rob listed is not as bad as some that have been posted on this message board.

All,
Above are just suggestions, conjecture, and beliefs on my part.  Please take that into account and please excuse any errors or misconceptions on my part.

73
Evan
AC9TU


Re: Transmit Output Power (CW) #v5

Evan Hand
 

Joe,

To the best of my knowledge, the v5 boards have the upgrades in the sections prior to the first mixer (upgrading the 2n3904 to BFR93W) related to SSB performance.  The upgrades that are not done are in the driver and predriver stages where the 2n3904s are suggested to be replaced with 2n2222a or better devices.  Those sections are the same for both CW and SSB and can be modified for more consistent performance per Allison/KB1GMX in messages over a year ago.  The original work was done on the v3 and v4 boards, which then brought up the harmonics and spurs issues.  This lead to the v5 fixes that solved them through both redesign of the output filter sections of the board and the addition of a 45 MHz low pass filter between the 45 MHz IF stage and the first mixer T2.  The 40 meter power "dip" has not been addressed.  I believe that the v5 boards are not as bad as some of the prior boards.  I conjecture that one of the issues was incorrect turns or spacing of the 40 meter lpf inductors that seems to have reduced the problem, but not eliminate it.

To get more information of what has been tried to balance power out across bands I would read through the 331 messages that start with this one from Allison:
Message #49729
https://groups.io/g/BITX20/message/49729

There has not been a significant change to the uBitx in the stages from Q90 through the output lpf, so there is some opportunity to improve, though the output that Rob listed is not as bad as some that have been posted on this message board.

All,
Above are just suggestions, conjecture, and beliefs on my part.  Please take that into account and please excuse any errors or misconceptions on my part.

73
Evan
AC9TU


Re: Transmit Output Power (CW) #v5

Rob French (KC4UPR)
 

Looking at the schematic for the V5, I understand that the way it works is that the CW key line (DC) is fed into mixer 1 along with the Clock #2 signal.  The output signal path from this is then through the 45 MHz low pass filter (I think that's what it is on the schematic) and then into the normal transmit power output chain through Q90.  Isn't that the same as CW?

Regardless, for testing it in SSB, could I use the tune output from a digimode program such as Fldigi?