Satish,
That is a good idea. At some point I'll look for a voltage booster to run the 510's at a higher voltage.
Thanks,
Mike
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Re: uBITX Power Output OK
Tim:
I didn't as I don't have the test gear. Next step is to get connected to my existing station antenna (carolina windom) and see how it sounds on another receiver on SSB. Certainly not a deep technical approach. I am trying to make a go of it with a single power supply. I have a second uBITX that will be assembled for portable emcomm use after I am satisfied with the first one.
Tim
WB7UVH? ? ?
toggle quoted message
Show quoted text
On 2018-03-24 18:53, Tim Gorman wrote:
Tim, Did you check your signal on a spectrum analyzer? When I cranked up RV1 for maximum power output my 3rd order IMD fell pretty drastically. I'm using 13v on the PA and 12.4v on the main board. Based on your data for using 13.8v with the factory setting it might be worth it for me to reset my power supply to 13.8v and use two dropping diodes to take it down to 12.6v on the main board. I've ordered a second ubitx and when it gets here I'm going to try changing out all the driver transistors to see what happens to the power output and the 3rd order IMD. tim ab0wr On Sat, 24 Mar 2018 13:58:25 -0700 "Tim Young" < tyoung@...> wrote:
The attached jpeg shows the results of testing (CW transmission) with
the out of the box RV1 setting and with RV1 set for maximum output.
Looks like the results are similar to what has been reported. My
primary interest is in 20M,40M and 80M emcomm QRP (bug out radio). I
was pleased with the power levels at 13.8VDC. I will be using a 12VDC
to 13.8VDC regulator to insure maximum voltage input at all times.
Tim
WB7UVH
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Ian,
I join the group in saying thank you for all the work you put into the software. I have really enjoyed using the uBitx since I loaded your software.
I run Macs at home. Is there any possibility you will write a uBitx utility version for the Mac? Also are you thinking of adding an S meter to the display? 73 Mike KF6KXG
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Re: uBITX Power Output OK
Tim, Did you check your signal on a spectrum analyzer? When I cranked up RV1 for maximum power output my 3rd order IMD fell pretty drastically. I'm using 13v on the PA and 12.4v on the main board. Based on your data for using 13.8v with the factory setting it might be worth it for me to reset my power supply to 13.8v and use two dropping diodes to take it down to 12.6v on the main board. I've ordered a second ubitx and when it gets here I'm going to try changing out all the driver transistors to see what happens to the power output and the 3rd order IMD. tim ab0wr On Sat, 24 Mar 2018 13:58:25 -0700 "Tim Young" <tyoung@...> wrote: The attached jpeg shows the results of testing (CW transmission) with
the out of the box RV1 setting and with RV1 set for maximum output.
Looks like the results are similar to what has been reported. My
primary interest is in 20M,40M and 80M emcomm QRP (bug out radio). I
was pleased with the power levels at 13.8VDC. I will be using a 12VDC
to 13.8VDC regulator to insure maximum voltage input at all times.
Tim
WB7UVH
|
Mike, I spent all afternoon with my spectrum analyzer, a two-tone generator, and my ubitx and came up with 10watts on 80m at 1.4amp total current draw being the cleanest signal I could get. I didn't chk 40m but on 20m I could only get 2 watts out. I tried every combination of PA bias and drive to mimimize 3rd order IMD products. I could crank the power output up further but 10watt out on 80m seemed to be the cleanest. I wonder if running higher voltage on the IRF510's would help with the 3rd order IMD so you could be more clean power out? Or will you wind up saturating the driver stages trying to drive the PA to get more power out and thus make the 3rd order IMD worse? tim ab0wr On Sat, 24 Mar 2018 13:53:09 -0700 "Mike R." <ubitx@...> wrote: Finally got around to working on the ubitx again.
I traced the logic for each of the three lines (TXA,TXB, and TXC) to
ensure the logic was operating as it should. They were. I then traced
through each of the relays and filters to see if and where the signal
might be getting attenuated. KT1 looked somewhat strange on the scope
when going into transmit - the signal started out strong but soon
went very low. Hmmm. I then went and re-heated the pins of each of
the three relays (KT1, 2, and3). I also re-heated some of the leads
on some of the components in the 4 filters that looked dull to me. I
then went back and had another look at the bias to the 510's. Both
were set to 100ma each. Here are the results: Band ?? Current
Wattage 80 ? ? ? ?? 1.84A ? ?? 9W 60 ? ? ? ?? 1.46A ? ?? 6W 40
?? 1.26A ? ?? 7.8W 30 ? ? ? ?? 1.26A ? ?? 4.2W 20 ? ? ? ?? 1.61A
5.5W 17 ? ? ? ?? 1.25A ? ?? 3W 15 ? ? ? ?? 1.07A ? ?? 2W 12
1.3A ? ? ?? 2W 10 ? ? ? ?? 1.0A ? ? ?? 1.5W Judging by others
results, it doesn't look like I can get much more out of the rig as
it stands without replacing finals, etc. It looks like my rig is now
"normal" for the ubitx. That seem like a fair conclusion? Thanks to
all for the help, now to start playing with larger displays, new
finals, new software, etc. It never ends! 73, Mike W1USN
|
"
Judging by others results, it doesn't look like I can get much more out of the rig as it stands without replacing finals, etc.
It looks like my rig is now "normal" for the ubitx."? I think there is still one thing remaining, replacing the heatsinks on both the
IRF 510's with larger one with proper insulation between them and the heatsink and increasing the PA voltage step by step to get more power. PA voltage 15V, 18V, 24V keeping the output impedance in consideration matching the output to antenna
On Sun, Mar 25, 2018 at 2:49 AM, Jerry Gaffke via Groups.Io <jgaffke@...> wrote: Very cool, good job!
If it was a bad solder joint in one of the lowpass filters, then only one of the 4 bands
would have failed to pass a signal.? So that probably was not the problem.
If all relays were permanently on we would only get the 80m lowpass filter and thus
none of the upper bands would get out.? But that would require 3 separate failures,
I don't see a single point of failure for this to happen.
If any relays are stuck off (perhaps the coil is burnt out) then that relay is stuck in the position it is drawn
in the uBitx schematic.? We would get a lowpass filter for one of the bands above the operating frequency.
That lowpass filter will? let our lower band through just fine and things will seem to operate normally.? ?
But not quite normally enough, as the rig will be transmitting?harmonics as well.?
Most of us would never notice till perhaps that letter from the FCC arrives.
Speaks for the need of a good cheap HF spectrum analyzer.
Jerry, KE7ER
On Sat, Mar 24, 2018 at 01:53 pm, Mike R. wrote:
Judging by others results, it doesn't look like I can get much more out of the rig as it stands without replacing finals, etc.
It looks like my rig is now "normal" for the ubitx.
|
Very cool, good job!
If it was a bad solder joint in one of the lowpass filters, then only one of the 4 bands
would have failed to pass a signal.? So that probably was not the problem.
If all relays were permanently on we would only get the 80m lowpass filter and thus
none of the upper bands would get out.? But that would require 3 separate failures,
I don't see a single point of failure for this to happen.
If any relays are stuck off (perhaps the coil is burnt out) then that relay is stuck in the position it is drawn
in the uBitx schematic.? We would get a lowpass filter for one of the bands above the operating frequency.
That lowpass filter will? let our lower band through just fine and things will seem to operate normally.? ?
But not quite normally enough, as the rig will be transmitting?harmonics as well.?
Most of us would never notice till perhaps that letter from the FCC arrives.
Speaks for the need of a good cheap HF spectrum analyzer.
Jerry, KE7ER
toggle quoted message
Show quoted text
On Sat, Mar 24, 2018 at 01:53 pm, Mike R. wrote:
Judging by others results, it doesn't look like I can get much more out of the rig as it stands without replacing finals, etc.
It looks like my rig is now "normal" for the ubitx.
|
The attached jpeg shows the results of testing (CW transmission) with the out of the box RV1 setting and with RV1 set for maximum output. Looks like the results are similar to what has been reported. My primary interest is in 20M,40M and 80M emcomm QRP (bug out radio). I was pleased with the power levels at 13.8VDC. I will be using a 12VDC to 13.8VDC regulator to insure maximum voltage input at all times.
Tim
WB7UVH??
|
Re: Custom Graphics help for S-Meter
Still not totally satisfied (are we ever?), but I did do most of the coding with the idea that others could easily adopt it. It is all addition to the v1.27.7 BitX40 sketch by Allard Munter, PE1NWL, and pretty much takes all available resources. My quick attempt to comment out some code related to the touch-key option was not successful and caused some odd behaviors, so I put it all back in. Also, I want to see if I can calibrate the S-meter better than just "eyeballing" it. maybe then I'll post it, but certainly will help anyone trying to implement the same thing.
=Vic=
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Finally got around to working on the ubitx again.
I traced the logic for each of the three lines (TXA,TXB, and TXC) to ensure the logic was operating as it should. They were. I then traced through each of the relays and filters to see if and where the signal might be getting attenuated. KT1 looked somewhat strange on the scope when going into transmit - the signal started out strong but soon went very low. Hmmm.
I then went and re-heated the pins of each of the three relays (KT1, 2, and3). I also re-heated some of the leads on some of the components in the 4 filters that looked dull to me. I then went back and had another look at the bias to the 510's. Both were set to 100ma each. Here are the results:
Band ?? Current ?? Wattage
80 ? ? ? ?? 1.84A ? ?? 9W
60 ? ? ? ?? 1.46A ? ?? 6W
40 ? ? ? ?? 1.26A ? ?? 7.8W
30 ? ? ? ?? 1.26A ? ?? 4.2W
20 ? ? ? ?? 1.61A ? ?? 5.5W
17 ? ? ? ?? 1.25A ? ?? 3W
15 ? ? ? ?? 1.07A ? ?? 2W
12 ? ? ? ?? 1.3A ? ? ?? 2W
10 ? ? ? ?? 1.0A ? ? ?? 1.5W
Judging by others results, it doesn't look like I can get much more out of the rig as it stands without replacing finals, etc.
It looks like my rig is now "normal" for the ubitx.
That seem like a fair conclusion?
Thanks to all for the help, now to start playing with larger displays, new finals, new software, etc. It never ends!
73, Mike W1USN
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Re: KD8CEC firmware and tuning speed
#ubitx
Here's Don Cantrell's description of Shuttle Tuning, using the tuning pot on the Bitx40: And a quote:
Not having an encoder, I decided to use the original tuning pot in a “shuttle” arrangement. (That was what we called the control on video editing boards back in the 1960's). Instead of?spinning?the knob, you?twist?it one way or the other. In the center position, it is idle: No tuning, the frequency is stable. Turn it clockwise slightly and the frequency starts to slowly increase. Counterclockwise, the frequency decreases. As you twist farther it tunes progressively faster. No buttons, no pressing. Tune any frequency in mere seconds and in single Hertz steps when you near your target.
The code in the uBitx as shipped has dynamic tuning, where spinning the encoder knob fast makes the step size bigger.
I prefer a quick button press to change the mode of the uBitx encoder between tuning and step size,
step size in factors of 10 from 1hz to 10mhz, tuning constrained to land at frequencies that are a multiple of the step size.
Lets me spin the knob as fast as I want?without sudden unexpected behavior.
Can set the step size to 1khz and only hit typical SSB operating frequencies.
Or 10khz and hit AM broadcast band frequencies.
Shortwave broadcast listeners might want to also have a 5khz step size in there somehow.?
Sudden unexpected behavior was also characteristic of the original Bitx40 code, in that I'd be turning the pot
toward the end of its linear tuning range and suddenly it would be galloping off in 10khz jumps.?
But a good solution if you insist on a linear tuning scheme at an extremely low price point.
Jerry, KE7ER
On Sat, Mar 24, 2018 at 12:56 pm, Arv Evans wrote:
I think the post was about a recent software upgrade, whether the new code retained
the dynamic tuning feature or if it had regressed to fixed-rate tuning.
Do you have a software example of your "shuttle tuning" system??
Arv? K7HKL
_._
. . .
?
On Sat, Mar 24, 2018 at 1:47 PM, Dexter N Muir <dexy@...> wrote:
I've mentioned this before: "shuttle tuning". There's a sketch way back in the dim dark past that dynamically changed the step size according to how fast the encoder was being spun. 1Hz/step slow to 100kHz? fast and pro rata ...? It may have been for the '40 and maybe only a demo for the encoder on Arduino (no real Bitx stuff).
Dex ZL2DEX
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Re: Micro bitx in the spectrum analyzer
#ubitx
Ashhar, I had 60db of external padding between the transmitter and the SA plus 30db padding in the SA itself. That should have been about 10 microwatts (10watt/1,000,000) of actual power feeding into the SA. Now I have to admit I haven't verified my pads for a long time but I don't think they are far enough off to make a huge difference since I was just looking for relative relationships. And I didn't see any harmonics that weren't at least 50db down from the fundamental. I have adjusted my drive level and bias to get as clean of a signal as possible. That's about 10 watts out on 3290kc. I haven't checked the other bands yet. I may diddle with the bias and drive some more to see if I can get more power while staying clean but I'm pretty happy with it as it stands. tim ab0wr On Sat, 24 Mar 2018 18:32:02 +0000 "Ashhar Farhan" <farhanbox@...> wrote: i hope you guys are using sufficient attenuation ahead of the spectrum
analyzer. typically, if you change the attenuation, the harmonica and
the fundamental should fall exactly the same dbs.
- f
On Sat, 24 Mar 2018, 23:55 Tim Gorman, <tgorman2@...> wrote:
Junior,
When doing a two-tone and single tone test I do not see these
harmonics.
Carrier suppression is not what I would like but no harmonics.
tim ab0wr
On Sat, 24 Mar 2018 09:50:30 -0700
Júnior PY2ADA via Groups.Io <aaj280174@...>
wrote:
Testing with the micro bitx in the spectrum analyzer, I found that
the harmonics reduction is very low. Has anyone else done this
measurement to compare? The photos are 3 per band (fundamental,
second harmonic and third harmonic). 73 de Júnior
PY2ADA
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Re: KD8CEC firmware and tuning speed
#ubitx
Mike
Because uBITX Encoder is very sensitive, I used the threshold method. It is not the same as the original firmware, although it gives a difference in the value when it is rotated slowly and when it is rotated rapidly.
Instead, as John and Vince said, I made the Tune Step changeable.
Press and hold the Function Key for more than 2 seconds to display the message. Then release the key.
You can select Tune Step by turning the dial.
If you are using uBITX Manager, you can also design your own Tune Step for yourself.
Thank you for using the uBITX Firmware CEC version.
Ian KD8CEC
I installed Ian's excellent uBitx firmware last night, version 1.04. I haven't played with the memory manager yet but I will today.
One feature that seems to be gone is what I call "ballistic" tuning. With the old firmware, when the encoder was turned rapidly, the frequency would move significantly. The new CEC firmware doesn't seem to do that anymore. Is it an option that can be turned on again or was that removed to add all the other excellent features currently in the firmware?
Best regards and 73
Mike M.
KU4QO
-- Best 73 KD8CEC / Ph.D ian lee kd8cec@...
(my blog)
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Re: KD8CEC firmware and tuning speed
#ubitx
Dex ZL2DEX
I think the post was about a recent software upgrade, whether the new code retained
the dynamic tuning feature or if it had regressed to fixed-rate tuning.
Do you have a software example of your "shuttle tuning" system??
Arv? K7HKL
_._
On Sat, Mar 24, 2018 at 1:47 PM, Dexter N Muir <dexy@...> wrote: I've mentioned this before: "shuttle tuning". There's a sketch way back in the dim dark past that dynamically changed the step size according to how fast the encoder was being spun. 1Hz/step slow to 100kHz? fast and pro rata ...? It may have been for the '40 and maybe only a demo for the encoder on Arduino (no real Bitx stuff).
Dex ZL2DEX
|
Re: KD8CEC firmware and tuning speed
#ubitx
I've mentioned this before: "shuttle tuning". There's a sketch way back in the dim dark past that dynamically changed the step size according to how fast the encoder was being spun. 1Hz/step slow to 100kHz? fast and pro rata ...? It may have been for the '40 and maybe only a demo for the encoder on Arduino (no real Bitx stuff).
Dex ZL2DEX
|
Mike
If an environment where have to continue using IF Shift,? I think it would be nice to adjust the BFO as you said.?Because IF-Shift is shift the BFO.
And I used Audio Spectrum for the first time on my cell phone and I was very satisfied.
I used Audio Spectrum for mobile phones when adjusting IF-Shift to remove background noise, which was very convenient.
Ian KD8CEC
You may just need to adjust the BFO. Out of the box mine was way off. Made everything sound tinny. If you use a program like spectrogram you can look at the audio output and see that it's shifted to? the right. Adjust the bfo and Center the passband between 300 and 2300 Hertz and you should be in the ballpark.
Mike M Ku4qo?
The other thing I've found is it makes listening a lot more pleasant. I shift mine about +700 hz and it really cuts the background hiss and improves the audio, on SSB. Is there a way to store that in Memory?? The CEC software upgrade is really nice.?
-- Best 73 KD8CEC / Ph.D ian lee kd8cec@...
(my blog)
|
Dennis
Thanks for your feed back. I just released uBITX Firmware CEC Version 1.061, It also includes uBITX Manager 1.01. Starting with uBITX Manager 1.0, there is an option for setting IF Shift.
If you select 'Auto Save IF Shift Value', uBITX will be restored when you turn it on again.
Ian KD8CEC
The other thing I've found is it makes listening a lot more pleasant. I shift mine about +700 hz and it really cuts the background hiss and improves the audio, on SSB. Is there a way to store that in Memory?? The CEC software upgrade is really nice.?
-- Best 73 KD8CEC / Ph.D ian lee kd8cec@...
(my blog)
|
You may just need to adjust the BFO. Out of the box mine was way off. Made everything sound tinny. If you use a program like spectrogram you can look at the audio output and see that it's shifted to? the right. Adjust the bfo and Center the passband between 300 and 2300 Hertz and you should be in the ballpark.
Mike M Ku4qo?
The other thing I've found is it makes listening a lot more pleasant. I shift mine about +700 hz and it really cuts the background hiss and improves the audio, on SSB. Is there a way to store that in Memory?? The CEC software upgrade is really nice.?
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Re: two-tone test on ubitx
Henning, I re-spaced the turns and reran the spectrum analyzer for both two-tone and single tone. No discernible difference from before. So you are correct. I still plan on building a similar mixer to see what I can get. It might be a while but I'll let you know what I find. Will just have to live with it for now I guess. tim ab0wr On Wed, 21 Mar 2018 11:32:53 +0100 "Henning Weddig via Groups.Io" <hweddig@...> wrote: I am not sure if the equal spacing of the trifilar winding alone
guarantees a perfect carrier suppresison.
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Re: uBITX Firmware CEC Version 1.06 Release (Added WSPR)
#ubitx
Philip
Thank you for important feed back when WSPR Menu, Fixed a bug where the LPF does not change with the WSPR band.? (Changed version to 1.061)
If you have spare time, please test WSPR function
Ian KD8CEC
Hi Ian.
I am afraid that the LPF selection problem is back with V1.06.
Need to select the correct band before doing a WSPR beacon. The same as V1.05, before V1.051.
Philip G7JUR
-- Best 73 KD8CEC / Ph.D ian lee kd8cec@...
(my blog)
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Satish Chandorkar
Vic WA4THR