Date   
Re: wsprnet results, wsjt-x, and calibration success --> world domination V4 #calibration #firmware

Don - KM4UDX
 

There was so much trial, error, fumble, confusion and general stupidity in my process that it is a model of what not to do. 

I distill till the process:
1) express the 10mhz  freq error as a percent delta
2) apply that percent delta to the weird calibration number in memory manager, reboot
3) remeasure the error (a) if close enough to step 4, (b) if still to far off go to step 1
4) run WSJT-X freq calibration process and apply proposed adjustments
5) if your WSPRnet spots still work at all, consider yourself lucky, if you get lots more spots consider yourself very lucky.

This process took me hours and hours to develop and implement.  I recall reading about this exact process in one of my late night uBITX reading deep dives.  But I didn't just implement it. No, I had to invent it on my own at great expense.  

So as usual, I have discovered what others have known all along. 

Don
km4udx

Re: Antuino

Bruce Hall <bhall66@...>
 

Farhan,

I just saw your updated schematic on github.   Maybe the only issue is a faulty barrel connector.

- Bruce

On Fri, May 17, 2019 at 7:05 PM Bruce Hall via Groups.Io <bhall66=gmail.com@groups.io> wrote:
Farhan,

The unit I received at FDIM works fine with Vcc from the barrel jack, but not from the battery pack.   

Peeking at the PCB, the power circuit has changed from the schematic you posted on Dec 27th:  there are polarity protection diodes for each input now.  But it looks like batt(-) erroneously goes to the barrel jack instead of ground.  Would you mind checking it?   Should I cut this trace and add a wire to ground?  Or is there a better method?

- Bruce

On Fri, May 17, 2019 at 6:30 PM Ashhar Farhan <farhanbox@...> wrote:
I am building up the info on hfsignals.com. there is a place holdrr page for it already.
- f

On Fri 17 May, 2019, 3:33 PM Jack Purdum via Groups.Io, <jjpurdum=yahoo.com@groups.io> wrote:
It's his spectrum analyzer. I don't understand what Curt's PO'ed about? He's free to attend FDIM.

Jack, W8TEE


On Friday, May 17, 2019, 1:22:01 PM EDT, Roy Appleton <twelveoclockhigh@...> wrote:


And what "unit" pray tell are we talking about here?

Roy
WA0YMH

On Thu, May 16, 2019, 9:12 PM David Wilcox via Groups.Io <Djwilcox01=yahoo.com@groups.io> wrote:
Farhan,

I heard your lecture at FDIM and purchased one of the units but need instruction in how to use it.  Github only has the upgraded code files.  Please advise.

Re: Antuino

bhall66@...
 

Farhan,

The unit I received at FDIM works fine with Vcc from the barrel jack, but not from the battery pack.   

Peeking at the PCB, the power circuit has changed from the schematic you posted on Dec 27th:  there are polarity protection diodes for each input now.  But it looks like batt(-) erroneously goes to the barrel jack instead of ground.  Would you mind checking it?   Should I cut this trace and add a wire to ground?  Or is there a better method?

- Bruce

On Fri, May 17, 2019 at 6:30 PM Ashhar Farhan <farhanbox@...> wrote:
I am building up the info on hfsignals.com. there is a place holdrr page for it already.
- f

On Fri 17 May, 2019, 3:33 PM Jack Purdum via Groups.Io, <jjpurdum=yahoo.com@groups.io> wrote:
It's his spectrum analyzer. I don't understand what Curt's PO'ed about? He's free to attend FDIM.

Jack, W8TEE


On Friday, May 17, 2019, 1:22:01 PM EDT, Roy Appleton <twelveoclockhigh@...> wrote:


And what "unit" pray tell are we talking about here?

Roy
WA0YMH

On Thu, May 16, 2019, 9:12 PM David Wilcox via Groups.Io <Djwilcox01=yahoo.com@groups.io> wrote:
Farhan,

I heard your lecture at FDIM and purchased one of the units but need instruction in how to use it.  Github only has the upgraded code files.  Please advise.

Re: treble only SSB modulation

Vaughn
 

Hi, just to add my 2p worth. I had this problem and like above, used a dummy load and transmitted an LSB signal. This was received by another rig and showed the BFO was way off. 

I replace the SMD capacitor with a number of others in a number of values and parallels, but could not get the sound I was after. They were all too low or too high in pitch and often just unable to understand at all. Eventually I looked for another set of capacitors and found one from Rapid Electronics. variable 7pF to 50pF SMD. Fitted this and then adjusted it, a bit at a time. until I got the sound I wanted.

Thanks to all here for the help and discussions explaining the fix.

73s Vaughn

Re: Antuino

V Zecchinelli
 

HFSignals says available June 2

On 5/17/2019 12:02 PM, Karl Heinz Kremer, K5KHK wrote:
Farhan sold some last night at FDIM (and yes, I have one ;) ). The sign he had implied that there is a ‘normal’ price of $100, and he sold them at a discount, so I would assume that you will eventually be able to order them. 
--
Karl Heinz - K5KHK

Re: Antuino

Ashhar Farhan
 

I am building up the info on hfsignals.com. there is a place holdrr page for it already.
- f

On Fri 17 May, 2019, 3:33 PM Jack Purdum via Groups.Io, <jjpurdum=yahoo.com@groups.io> wrote:
It's his spectrum analyzer. I don't understand what Curt's PO'ed about? He's free to attend FDIM.

Jack, W8TEE


On Friday, May 17, 2019, 1:22:01 PM EDT, Roy Appleton <twelveoclockhigh@...> wrote:


And what "unit" pray tell are we talking about here?

Roy
WA0YMH

On Thu, May 16, 2019, 9:12 PM David Wilcox via Groups.Io <Djwilcox01=yahoo.com@groups.io> wrote:
Farhan,

I heard your lecture at FDIM and purchased one of the units but need instruction in how to use it.  Github only has the upgraded code files.  Please advise.

Re: treble only SSB modulation

laurent.bury@...
 

Hello Adrian,

a good avdice, I'll try this this week-end, as I need to bypass first my AGC board from kit-project (soldered on the slow agc position), who changes a littke the overall audio response...

I'll let you know here.

73s

--
Laurent F5FIE.

Re: setup for analysis of before/after measurements of v4 spectrum purity

Richard Spohn
 

Evan, thanks so much for the article from Phil Salas about the -50db
tap. Great advice -- and Mr. Salas is one of my gurus. 73 - Rich
WB2GXM

On 5/17/19, Evan Hand <elhandjr@...> wrote:
I have used the SDRPlay as a SA, and had some challenges.

1 - First of all, the frequency span was not big enough to measure the
harmonics on 40 meters in one test.  You need to change the center frequency
to do the test in two separate measurements.  I was not sure that the gain
stayed the same, so I my experience, the harmonics test was inconclusive.
2 - It was not clear how the gain controls operated in the SA software.  I
still am not sure, so maybe someone can be specific on how to defeat the AGC
and adjust the gain for a good capture.
3 - I built the following 50 ohm "tap":
http://www.ad5x.com/images/Articles/Tap50dbRevA.pdf
I still needed a step antenuator feeding the SDRPlay from the tap.

uBitx = TAP = Watt meter = Dummy Load
|
L= Step Antenuator = SDRPlay

It has been awhile, but I believe I had to adjust the step antenuator and
gain to insure that when I added or removed 10 db, the SA software reported
the same amount of change (this was how I overcame the AGC issues)

4 - The SDRPlay SA software will warn when you are getting close to
overload.  Even if you stay below the warning message, there is signal
compression even without the AGC engaged (reason for the set testing)

My experience was it was good for close in purity testing, not so good for
the harmonics

Above is my experience, things may have changed, or there may be better ways
to accomplish the task.  Yours may vary.

73
Evan
AC9TU



Re: Antuino

Jack, W8TEE
 

It's his spectrum analyzer. I don't understand what Curt's PO'ed about? He's free to attend FDIM.

Jack, W8TEE


On Friday, May 17, 2019, 1:22:01 PM EDT, Roy Appleton <twelveoclockhigh@...> wrote:


And what "unit" pray tell are we talking about here?

Roy
WA0YMH

On Thu, May 16, 2019, 9:12 PM David Wilcox via Groups.Io <Djwilcox01=yahoo.com@groups.io> wrote:
Farhan,

I heard your lecture at FDIM and purchased one of the units but need instruction in how to use it.  Github only has the upgraded code files.  Please advise.

Re: Antuino

Karl Heinz Kremer, K5KHK
 

Re: Antuino

JT Croteau
 

What is an Antuino?


On Fri, May 17, 2019, 12:22 Roy Appleton <twelveoclockhigh@...> wrote:
And what "unit" pray tell are we talking about here?

Roy
WA0YMH

On Thu, May 16, 2019, 9:12 PM David Wilcox via Groups.Io <Djwilcox01=yahoo.com@groups.io> wrote:
Farhan,

I heard your lecture at FDIM and purchased one of the units but need instruction in how to use it.  Github only has the upgraded code files.  Please advise.

Re: Antuino

Roy Appleton
 

And what "unit" pray tell are we talking about here?

Roy
WA0YMH

On Thu, May 16, 2019, 9:12 PM David Wilcox via Groups.Io <Djwilcox01=yahoo.com@groups.io> wrote:
Farhan,

I heard your lecture at FDIM and purchased one of the units but need instruction in how to use it.  Github only has the upgraded code files.  Please advise.

Re: Low power output on ubitx

sdr freak
 

I have check all again, and the rv1 at 2/3 was best modulation but the output doesn't get higher than 4-5W on 80m an 3W on 40M.. the other Bands still get 1-2 on 15M or 10M

THIS CAN NOT BE THE UBITX OUTPUT THAT SHOULD BE THE RIGHT ONE , WHAT CAN I CHECK IF Q90 IS NOT SHORTET I REALLY GONE CRAZY..

sorry this makes real bad vibrations everytime i get outdoor for testing on lagre antenna in the nature and everytime there is no way, or even when have luck it really strong to get qso with this.. and this issue should be able to find but i'm doesn't find till now 

Hope for any idea

Re: Antuino

Curt
 

Nice

Hmmm - could I buy enough stuff that the discounts could greatly supplement the travel cost?  LOL with that but nice of those merchants to make the gesture. 

selling kits at FDIM implies that the hardware design is complete!  adding a larger display and updating firmware code can be down-loadable.  one can imagine more will come for sale at HFSignals to help fund his long trip to Dayton!  (ditto with QSX for another VIP who was at FDIM).

It takes some time to supply and kit things - nice that some folk at FDIM have first fruit.  They owe use reports after building and using them! 

73 Curt

Re: Antuino

Karl Heinz Kremer, K5KHK
 

Farhan sold some last night at FDIM (and yes, I have one ;) ). The sign he had implied that there is a ‘normal’ price of $100, and he sold them at a discount, so I would assume that you will eventually be able to order them. 
--
Karl Heinz - K5KHK

Re: setup for analysis of before/after measurements of v4 spectrum purity

Mark Hatch
 

Robert and Evan,  thank you for sharing! I have some heavy duty hp variable attenuators that I can front to the fixed ones when they arrive. But the 50db tap looks easy to make and probably can put it together before the fixed set arrives from China. 

Did either of you use the two tone window sound generator?  How did you set the input volume?

73
Mark
AJ6CU

Re: setup for analysis of before/after measurements of v4 spectrum purity

Evan Hand
 

I have used the SDRPlay as a SA, and had some challenges.

1 - First of all, the frequency span was not big enough to measure the harmonics on 40 meters in one test.  You need to change the center frequency to do the test in two separate measurements.  I was not sure that the gain stayed the same, so I my experience, the harmonics test was inconclusive.
2 - It was not clear how the gain controls operated in the SA software.  I still am not sure, so maybe someone can be specific on how to defeat the AGC and adjust the gain for a good capture.
3 - I built the following 50 ohm "tap":
http://www.ad5x.com/images/Articles/Tap50dbRevA.pdf
I still needed a step antenuator feeding the SDRPlay from the tap.

uBitx = TAP = Watt meter = Dummy Load
               |
               L= Step Antenuator = SDRPlay

It has been awhile, but I believe I had to adjust the step antenuator and gain to insure that when I added or removed 10 db, the SA software reported the same amount of change (this was how I overcame the AGC issues)

4 - The SDRPlay SA software will warn when you are getting close to overload.  Even if you stay below the warning message, there is signal compression even without the AGC engaged (reason for the set testing) 

My experience was it was good for close in purity testing, not so good for the harmonics

Above is my experience, things may have changed, or there may be better ways to accomplish the task.  Yours may vary.

73
Evan
AC9TU

Re: setup for analysis of before/after measurements of v4 spectrum purity

Robert D. Bowers
 

I'd start with 60db at the least, and go up from there.  60db is 1000x voltage (loss or gain).  Those SDR dongles are quite sensitive (mine is down in the microvolts, maybe fractional microvolt range), and if the Bitx puts out 7 watts, that's roughly 53 v p-p in a 50 ohm setup.  

80 to 100 db would be better IMO.  That would help to not overload the dongle... and should get the signal level down to the point where you wouldn't be encountering any limiting in the signal.   Put a t fitting on your dummy load - one side goes to the radio, the other to your attenuator.

If you have access to a step attenuator, even better.  That's the way I'd do it (I've got one 120db to 0).  Start with 120 and reduce the attenuation until you have enough signal to measure - I think the specs call for better than 40 or 45db down for unwanted signals, so you'd want your carrier to be higher than that.

I've done the "coax into dummy load, and then used a dongle to measure near the coax" method.  That also worked well enough for what I was doing.  It's a quick way to do it... without all of the extra components.  You just start moving the dongle closer and closer until you get enough signal.

Bob

N4FBZ

On 5/17/19 10:15 AM, Mark Hatch wrote:
Hi,

Have all the "recommended" parts (inductors + relays) that is supposed to make a "typical" v4 either FCC compliant or very close. But before I did the surgery, wanted to do a before/after measurement.

I am going to try to use the sdrplay sa software. I have seen where several people have used it to at least get a ranging shot on the spectrum. Will also send in a two tone signal thru microphone port using a windows soundboard app that was suggested on these forums.

So I do know I need to send the ubitx into a dummy load.... duh

And that I want to put lots of attenuation in front of the sdrplay (people seem to be typically using 40db, but I will put more than that to start until I figure it out.)

But nobody seems to mention how the sdrplay will pick up the signal? I am guessing that I don't use *any* antenna and just let the attenuators sit open.  Can someone validate this? Also, any experience in using the sdrplay SA software will be appreciated. Would prefer not to blow it up if possible. :-)

73
Mark
AJ6CU

setup for analysis of before/after measurements of v4 spectrum purity

Mark Hatch
 

Hi,

Have all the "recommended" parts (inductors + relays) that is supposed to make a "typical" v4 either FCC compliant or very close. But before I did the surgery, wanted to do a before/after measurement.

I am going to try to use the sdrplay sa software. I have seen where several people have used it to at least get a ranging shot on the spectrum. Will also send in a two tone signal thru microphone port using a windows soundboard app that was suggested on these forums.

So I do know I need to send the ubitx into a dummy load.... duh

And that I want to put lots of attenuation in front of the sdrplay (people seem to be typically using 40db, but I will put more than that to start until I figure it out.)

But nobody seems to mention how the sdrplay will pick up the signal? I am guessing that I don't use *any* antenna and just let the attenuators sit open.  Can someone validate this? Also, any experience in using the sdrplay SA software will be appreciated. Would prefer not to blow it up if possible. :-)

73
Mark
AJ6CU

Re: Original Bitx20 design

 

Hi N7QL,

The original Bitx20 is a single band design, thus one would generally just be concerned with harmonics generated by the PA.  These should have been taken care of by the low pass filter in the design.  However, for higher output probably another pole on the filter would be advised.  Of course overdriving the mic amp circuit can cause IMD too if one decides to change that part of the circuit.

The original design was fine, although there were many improvement to the design done by builders over the years.  It's biggest issue was no AGC and a loud burst of audio noise on PTT engagement and disengagement.

73,


Mark.