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What's a Reason for less Power Output ONLY get 4W on 80m?.., 3-4W on 40/20m, 1W on 15/12/10m #ubitx #ubitx-help

sdr freak
 

I need your Help, reaaly no Idea for this low, very low Power Output..

...if there is an way, an idea or something i could do it was not described in any post till now or i read it not because i have read all post for this "low output power" issue what i can read in this forum, but i find difference things was write there and i look to make all i can test or put like these post was saying.. but nothing get right..

My problem is the output transmit power, get only 4W on 80m, 3-4W on 40m/20m and 1-2W on 15m/12m/10m and the messuare was take by Dummy Load and on Antenna the Value is the same so there not different and i have on 80m only 2 Qso and 40m only 1 Qso till now with many Antenna testet and other Band testet but not heared by other ham so same by test with websdr.com try to hear me, but there was nothing able to hear me..

so the test on RV2 and RV3 with fully clockwise: Rx only is 150mA, Tx PTT only without speaking is 380-400mA 
when set on RV2 and RV3 for each on 100mA, both together 200mA to the 380-400mA then i have 600mA PTT no speaking when the Bias setting up like it should sayed on hfsignals.com but now when Tx PTT now with a load Hallooo to the original Mic Cap, then the Current is 1Ampere but on Dummy Load only 10-11V and on Power Meter 3-4W and when set RV1 to max power at fully counter clockwise then 5W getting but overmodulation so i seg RV1 like half way like it was before.. now i have test the Q90 Transistor in no Battery,no Power up Ubitx for shortet Transistor but it does not give a short with dvm test or should i test it in other way?

The Q90 was my only idea to try a new on in TO-92 solder in but i don't know if i should do this or should test other things..

The R63 resistor i have read can be reduced to 22Ohm for more mic audio.. but that should not give the issue away because on CW my power output is the same low value at the bands and on 80m get 3-4W cw on 40m 2-3W and than it goes lower,too .. on higher bands like 20m,15m,10m it was 1-2W..

What can i do, WHAT SHOULD I DO? I want only the normaly power output like on hfsignals.com saying and the other user would have..i want it too..the normaly power..this is all i want, please..

The ubix, when it have at one day should have 10w on 80m and 7w on 40m and 20m, than i would be lucky as hell but in reality the ubitx should have this 10w on 80m and 7w on 40/20m or have i fucked something up in readi g this information all there was saying by the motly ubitx users they have this minimum 10w.. 

I have good Receive, very good sounding and the only thing whit trouble is the power output is too low and thats all i would be have missing would say, when this issue gone cleaned up and the power output is on the right value with 10w my ubitx would be very best Qrp Transeiver for me and i'am lucky when dreaming of this many days outdoor transmitting i would love so much with this lovley little machine.. i have so much love to give kn this ubitx and i thought for many upgrades would be present when the transmitting output issue was done in right setting, i would upgrade things like agc, s-meter, cw-filter, battery-case, speech-ic, integrated qrp tuner with swr meter, these are the things i have here for waiting to build up and put in the ubitx..

So my project only make trouble in one point where i have no idea..

Curt
 

OM

how is your output power on CW?  take power readings on CW even if you don't use this mode.  this will tell us how the PA etc are working. 

some experience weak audio drive that hampers SSB transmit power - a few in our club build.  I am fortunate that using a surplus speaker microphone I had works swell, but others are not so happy.  some are adding a preamp or even a speech processor IC to their audio chain.  I think you need some patient experimenting, after affirming CW power is okay.

if you have a different microphone to try - I would.  also consider building an audio oscillator as a test source. 

73 Curt

Vic WA4THR
 

You mentioned "on Dummy Load only 10-11V", is that your power supply voltage when transmitting? The power output is very dependent on the voltage to the PA line, and if your power supply sags to 10-11 volts when transmitting then you will only get maybe 60% of normal power. Similarly, if you increase the voltage on the PA line youcan get more than "spec" power. It is a good idea to keep the main board voltage at 12v or less to avoid overheating the voltage regulators, but that is why there is a separate line to the final amplifier.

=VIc=

sdr freak
 

Hello and thank you HAMs!!

This is the Ubitx of mine:


How exactly is this meant by the audio oscillator, a 2 tone generator? I don't have one yet.
Use only the original mic cap and a zetagi m99 as second mic for testing, both have the same output power. 
 
Measure the CW power? How can there be differences, how is that meant? 
The CW Key is an older model which I had on the Kennwood TS140s, so I always set the SWR for antennas. Tuner is the MFJ 948 Versa II with SWR and Watt Power Meter. 
 
The 10-11V which I read 80M in the dummy load I measure with the DVM in position DC, dummy load DL1 QRP replica of the Elecraft DL1... and my input in the Ubitx is the same at 12V on the red and brown cable. Even at 12.5V input power there is hardly any difference. The 10-11V at 80m and at 40m there are only 8-10V at the dummy load.
 
I just wanted to say I use the Ubitx 3 with FCI Sound IC and have connected a 20x4 display and installed the software from CEC 1.08. Use indoor a 12V 3A power supply(can handle up to 15V but i don't do more than 12V or maximum 12,5V for the Ubitx) and outdoor a 12V 3Ah battery from motorcycle.
 
Indoors I test with dummy load, replicated from the Elecraft DL1 QRP 20W dummy load schematic with the same components and outdoors with 80m dipole, 40m dipole, 20m delta loop, 15m dipole, 10m yagi, 40m groundplane with loaded coil and another 20m groundplan worth of 1/4 wave lenght.

With 40M Groundplane with loaded and 3 radials, i have an little qso from Germany to France last Week but with 3-4 watts.. but this was the only Qso able to make because many other try but with no copy, and i look for hear me at websdr.com in half europe i select stations and try to hear me in ssb and cw, but nothing was heared, not even a cw signal heared from my self..
 
What is meant by measuring CW? Measure the power of CW when Ubitx is on a frequency for it and with a normal Morse key. Then I read the power on the wattmeter and so I should be able to see what the right result is or how should I do it, is there an error in my method or is 4-5W on 80M and 2-3W on 40M and 20M on CW normal? 
 
I have the homebrew Mic with the standart delivered Mic Cap which was in the Ubitx Box und my second Mic is a Zetagi M99 with Hall function, but on both mic the output is same.. Even many other Mic Cap i have tested with same or lower Output..
 
The main question now is which part of the Ubitx should I check and are there data for the voltage or current values of the parts to be tested which correspond to the correct value? 
 
I have the idea to minimize the R63 to 22Ohm to not have to scream so close in mic to get any performance out of it, because it's really bad if I don't eat the mic very close to my mouth.
 
I had an idea to replace the Q90 transistor with a TO-92 type 2N3904 transistor and hope for an improvement of the higher watt output power. But should I do that even if the Q90 doesn't have a short circuit?
 
If I open the RV1 completely I don't have much more power than before with half to 2/3 counterclockwise. Only from 4W on, if at all, 5W are there to measure at 80M is the increase at full counterclockwise.
 
I was able to measure from 1.2A(4W) to 1.8A(5W) at this RV1 test with PTT with loud hello.
Then I tested if the other transistors in the amplifier stage have a short-circuit, but also here none was to be found, all tested in the switched off state as well as in Q90 test for short-circuit... 
 
Or should I test this for short circuits of the transistors in switched on state with device in Rx or in Tx mode?
 
What cause can it still have that instead of the normal power of the 10W like hfsignals.com also writes on their page, and also here the users except for a few who had there also problems but with other cause, only this few watts with my ubitx comes out although I have no other problems with the reception and use the 12V power supply with 3A as recommended?
 
What exactly could I do now, what exactly should I measure for you or could a video of something help, then I would do it, I just need to know what I should show then I do it immediately.
 
I want to make it somehow but I need your help, I am so thankful for every help!

Curt
 

OM

Very nice work on your enclosure,  and nice pictures.

The path used to do CW in the ubitx is different than CW. In summary, a signal comes from the PLL at 45 MHz to almost directly feed the transmit finals. If this can make 8 to 10 watts into a dummy load, then it says your transmit finals are fine, and the issue is in the ssb path or transmit audio.

Any short across the key connection will exercise the cw path.

An audio oscillator just needs a single tone, it can be simple. I imagine there is an example here somewhere,  otherwise email me. No unusual parts are required.

Unless one mosfet was damaged, my first guess its the transmit audio.

Curt

PS mine doesn't quite make 5w on 40m, but I enjoyed several ssb contacts. Some folk live with enough noise to cover over your signal, so keep trying others.

sdr freak
 

Good morning, Curt! Thank you for helping me.
 
I'm not so well trained in this area yet, I've recently upgraded my class E to class A license, but it's a real project for the first time and I'm not so experienced yet. This is really embarrassing for me and I would like to learn more, but right now I'm a little bit overwhelmed with all this.

Ok, when 8-10W output in CW was fine, i can only say the maximum ever seen was 4-5W in 80m CW on Wattmeter/Dummy Load..

The measurement of the CW power and the 45Mhz signal is such a thing, what am I supposed to do now?
Should I just do a test with a dummy load connected to the antenna socket and then measure on 80m or 40m CW and read the value with the DVM? If so, I did that.
 
But the one with the 45Mhz signal surely concerns another measurement that is printed, right?
 
And because of the audio oscillator I found a circuit diagram, but is a simple 2-tone generator with NE555 IC and I would build that, or should I do something else?
 
If it helps I could make a video of the previous measurements and then upload it with a link, but there would be good to know what exactly you would need to see to help me. I have few kinds of instruments here that are for a beginner, 100Mhz Digital Storage Oscilloscopes, Signal Generator, RCL Meter, AC Millivoltmeter, RC Generator, Lab Power Supply, and many components to build schematics for various projects.
 
Only the experience is missing.
 

Curt
 

OM (I don't want to call you Mr. Freak) --

I should have asked how are you measuring power?  If for example you are measuring on a 50 or 100 watt scale - I would not trust the accuracy on the extreme low part of the dial. 

We should wonder if your rig is really outputting more power than you think is being measured?  Its actually pretty hard to reduce its power by a couple dB with circuit issues! 

Do measure your Power Supply voltage while transmitting !  If it is pulled down below 13 or 12 volts, the output power will go down.  its related to the square of the bias voltage on the finals. 

I am fortunate to have a WM2 wattmeter - its not perfect, but reasonable.  Its designed for QRP.  A decent power measurement can be made with a diode detector.  W7ZOI describes this method, and I have a widget for doing it.  It works nicely.  You need a 50 ohm dummy load (I used a couple 100 ohm 2 watt resistors in parallel) followed by a silicon diode in series, and there is a shunt capacitor I can't recall the value.  Then measure the voltage here at the output with a DVM - and its as easy conversion to power.  If you email me, I could dig to find the info. 

Your lab is quite good !  Most hams use only simple test equipment, and some of it can be homebrewed. 

A ham license is a life-long learners permit.  Don't fret but enjoy the journey.  See I learned something as I did not ask you enough questions ! 

This is a cool rig, owned by thousands around the world. 

73 Curt

DJ2AG
 

Curt,

I understood Fabian is already measuring output power according to your description above with his homemade Elecraft DL1 dummy load clone. I googled the schematics:

Together with the Elecraft supplied Voltage vs Power chart this looks fine for me. 

My first thought  also was that it could  be  a power supply problem. Maybe a test with separated supplies for PA and the rest could be performed using the bench supply and the motorcycle battery. Or making use of  the oscilloscope,  monitoring power supply when keying in CW mode.

73 de Armin, DJ2AG

 

If power out on CW and SSB are both low then the PA gain is lower than expected or something with filters.

Raj

At 20/05/2019, you wrote:
Good morning, Curt! Thank you for helping me.

I'm not so well trained in this area yet, I've recently upgraded my class E to class A license, but it's a real project for the first time and I'm not so experienced yet. This is really embarrassing for me and I would like to learn more, but right now I'm a little bit overwhelmed with all this.

Ok, when 8-10W output in CW was fine, i can only say the maximum ever seen was 4-5W in 80m CW on Wattmeter/Dummy Load..

The measurement of the CW power and the 45Mhz signal is such a thing, what am I supposed to do now?
Should I just do a test with a dummy load connected to the antenna socket and then measure on 80m or 40m CW and read the value with the DVM? If so, I did that.

But the one with the 45Mhz signal surely concerns another measurement that is printed, right?

And because of the audio oscillator I found a circuit diagram, but is a simple 2-tone generator with NE555 IC and I would build that, or should I do something else?

If it helps I could make a video of the previous measurements and then upload it with a link, but there would be good to know what exactly you would need to see to help me. I have few kinds of instruments here that are for a beginner, 100Mhz Digital Storage Oscilloscopes, Signal Generator, RCL Meter, AC Millivoltmeter, RC Generator, Lab Power Supply, and many components to build schematics for various projects.

Only the experience is missing.

Curt
 

Armin & Raj

thanks for checking in !  yes credit W7ZOI and others for that nice tool from Elecraft - that is exactly Wes's circuit.  it should provide good power measurements, so like you I am asking him to check his voltage (I recommend key up and key down, but if our 'sdr freak' is not also a CW geek he may not resonate with this wording!).  yes less voltage 'key down' makes less RF power.  Given the high manufacturing quality of the boards, I always assume its my workmanship or use first before blaming the board !  too easy to send the board into surgery without its cause. 

I hope Fabian finds what is going on.  If voltage is okay, I suspect the audio drive could be low - hence my recommendation to measure CW output levels. 

73 CUL Curt

sdr freak
 

How to check the Filters for failure that lowering the power output ? In the software i use CEC 1.08 is an option in the programm ubitx manager with the filter value and now i think about the value if is not right then the low power output is produced by this way or is that an other way you mean with check the filter..

When the power output (ssb and cw) is max 5w at 80m and 4w max on 40m and 20m, but only 1w or 1.5w on 15m and 10m and the messuare with the Dummy Load and on many antenna tested with 2 different Tuner and every time the power is same and not higher, what should i check in the ubitx circuit for V oder A or mA value at few points to figure out the issue at which point it is, are there any value i should messuare on the board, to help me better? 

The oscilloscope, i thought could be useful for see the modulation to set the right value on RV1 i thought, when see how many grade of modulation, to keep not over modulation but use the maximum power for RV2 and RV3, but the messuare should figure the maximum modulation point in sine wave looks good. Is this right and which way you connect the ubitx transmitter to an oscilloscope for see the modulation grade in rv1 is ok? ubitx-》dummyload-》attenuator-》oscilloscope ? The rv1 is select to a sine wave before over modulation it, and then should be the power output in the original ubitx over 10w on 80m and 40m, but not only 5w? 

The RV2 and RV3 is set like hfsignals was say, and even when i set rv1 to max ccw then the power is not much more, perhaps 1w more than before on the band messuared

The R63 resistor 47ohm, to this i soldered and 47ohm resistor parallel in hope for more output but only the mic speaking would be better then before i eat the mic to have output and now it was able to speaking in normaly volume but the same 5w output power. 

(mic gain soldered a 47ohm parallel to the R63)


Ok i hope for any answer. Thanks.

iz oos
 

Once my Drake was delivering just 70 watts... I thought it was the age... Nope... There was a bad solder in my SWR PWR.... and the power was back to 140w! This is to say not to always trust in power meter.


Il 03/giu/2019 15:48, "sdr freak" <sdrfreak55@...> ha scritto:
How to check the Filters for failure that lowering the power output ? In the software i use CEC 1.08 is an option in the programm ubitx manager with the filter value and now i think about the value if is not right then the low power output is produced by this way or is that an other way you mean with check the filter..

When the power output (ssb and cw) is max 5w at 80m and 4w max on 40m and 20m, but only 1w or 1.5w on 15m and 10m and the messuare with the Dummy Load and on many antenna tested with 2 different Tuner and every time the power is same and not higher, what should i check in the ubitx circuit for V oder A or mA value at few points to figure out the issue at which point it is, are there any value i should messuare on the board, to help me better? 

The oscilloscope, i thought could be useful for see the modulation to set the right value on RV1 i thought, when see how many grade of modulation, to keep not over modulation but use the maximum power for RV2 and RV3, but the messuare should figure the maximum modulation point in sine wave looks good. Is this right and which way you connect the ubitx transmitter to an oscilloscope for see the modulation grade in rv1 is ok? ubitx-》dummyload-》attenuator-》oscilloscope ? The rv1 is select to a sine wave before over modulation it, and then should be the power output in the original ubitx over 10w on 80m and 40m, but not only 5w? 

The RV2 and RV3 is set like hfsignals was say, and even when i set rv1 to max ccw then the power is not much more, perhaps 1w more than before on the band messuared

The R63 resistor 47ohm, to this i soldered and 47ohm resistor parallel in hope for more output but only the mic speaking would be better then before i eat the mic to have output and now it was able to speaking in normaly volume but the same 5w output power. 

(mic gain soldered a 47ohm parallel to the R63)


Ok i hope for any answer. Thanks.

sdr freak
 

Then ok but in 2 different SWR POWER Meter the low power of only 5w and in the Dummy Load,  too? This means the Dummy Load is bad, too? Have you any other ideas to my postet infos please? Any idea i should do?

Arv Evans
 

A detector probe or oscilloscope should show where power differs from one band to another. 
Voltage measurements should show relative differences.
That could provide some clue as to where to start troubleshooting.

_._


On Mon, Jun 3, 2019 at 10:40 AM sdr freak <sdrfreak55@...> wrote:
Then ok but in 2 different SWR POWER Meter the low power of only 5w and in the Dummy Load,  too? This means the Dummy Load is bad, too? Have you any other ideas to my postet infos please? Any idea i should do?

iz oos
 

The fact that pwr out is around 50% is suspicious. Maybe one of the two sides of the pushpull PA has an issue.


Il 03/giu/2019 18:40, "sdr freak" <sdrfreak55@...> ha scritto:
Then ok but in 2 different SWR POWER Meter the low power of only 5w and in the Dummy Load,  too? This means the Dummy Load is bad, too? Have you any other ideas to my postet infos please? Any idea i should do?

ajparent1/KB1GMX
 

I would ask questions like:

What is the DC applied voltage during TX?   It sounds low for CW even.
For CW I'd expect near 10-12W however if you Power supply is below
12V what you are getting is then good.

What is the mic level or if your using a tone osc what audio (AC) votlage?

is the bias correctly set?

IS the calibration done correctly? is the sideband carrier or the second
conversion is off the band pass filters (crystal filters) will eat your RF.

NOTE CW is done differently than SSB so if SSB is more than half the CW
something is wrong. 

Look at the obvious before progressing.

Allison