Re: Efficient Class E generation of SSB Using the EER Method
That's really interesting. I googled Guido and QCX and found the thread on the QRP Labs group and another interesting hit. I'll include the links here for anyone interested. /g/QRPLabs/message/30792This is a fun topic with some interesting experimentation going on.?I think FT8 could be generated just by updating the Si5351 over i2c?¨¤ la what CEC did for WSPR in his firmware. But that is a side issue not directly related to the SSB topic. Yes, the DSP code for a digital approach would be interesting. Tom, wb6b
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Thanks for that Sarma. I've placed an order for 300 and I expect them around 11 february. As I'll have a lot to spare, I'm quite willing to pass them on at cost (plus postage) to anyone in UK who needs them. I'll let you know when they arrive. Peter G8FWY On 02/02/2019 06:39, MVS Sarma wrote: I can't buy that large quantity? as it is not edible item. we cant use . But this is supposedly the part that RaAJ used.
On Sat, Feb 2, 2019 at 11:12 AM Raj vu2zap <rajendrakumargg@... <mailto:rajendrakumargg@...>> wrote:
0603 does not work.
At 01-02-19, you wrote:
>Can someone help me with the part number and supplier ( UK ) for
the 680nH smd inductors used to replace L5 and L7.
>
>Just found some on Digikey but they were very small (0603) and
they wanted ?12 for shipping!
>
>Peter G8FWY.
--- This email has been checked for viruses by AVG.
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I requested him to sell small lots but he was not willing. He suggested that I buy his lots and
sell in small amounts. Maybe someone can do this for good of mankind :-)..
One or two lots in US and EU will help everyone.
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At 02-02-19, you wrote: sorry for wrong typing Raj sir.
regards
sarma
vu3zmv
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sorry for wrong typing Raj sir.
regards
sarma
vu3zmv
?
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I can't buy that large quantity? as it is not edible item. we cant use . But this is supposedly the part that RaAJ used.
0603 does not work.
At 01-02-19, you wrote:
>Can someone help me with the part number and supplier ( UK ) for the 680nH smd inductors used to replace L5 and L7.
>
>Just found some on Digikey but they were very small (0603) and they wanted ?12 for shipping!
>
>Peter G8FWY.
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If the circuit board design includes a really solid ground layer(s) and lots of via connections to them should work better with plastic cases. In the case of the uBITX, with likely circulating ground loops from the finals, the power connector, some of the IF chain, and to other parts of the board, bolting the four corners of the board, the antenna connector and such to a good ground plane like a metal case may help. A metal case may make the radio get along with the other transmitters in your shack; especially if they are high power. [although the recent fixes show that ground loops are not a major contributor to the spurs].
Speaking of copper tape. I ordered a roll and generally like it. It is handy for creating big ground islands on prototype boards as well as shielding. However, the claim that the adhesive is conductive was bogus. I cut a hole in a piece of paper and stuck one layer of copper tape to another. The hole in the paper made sure the edges of the top layer of copper tape did not make contact with the bottom layer it was stuck to. I could not measure any conductivity between the layers.
If you stick one layer over another and let the edges touch the bottom layer, a connection may be made where the rough edge of the top layer presses against the bottom layer. So, I solder the edges at multiple points to assure a reliable connection where the tape joins together.?
Tom, wb6b
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Re: Spurs/Harmonics fixes for v4 based on v5 board design?
What inductors did you use, please share a pic.
There is always a carrier leak at 12Mhz and 12-7 = ~5 Mhz could be what you see.
Most spurs are created by the harmonics of the carrier feeding back to the first BiDi amp. Changing to Axicom relays
eliminates a lot of these dancing dervishes.
Raj
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At 02-02-19, you wrote: Thanks I'll try the two tone test next. Tonight I replaced L5 and L7 Raj's fix to see if I noticed any differences. Using LSB on 7.15 into 40db attenuator get-55db main signal and I see some sort of spur at around 5MHZ that is about -85db, doesn't fluctate with voice it's constant when I key the transmitter. Wonder what could be producing around 5 MHZ.
I wonder if the v5 board redesign changes next might help. Might see if I can figure out where on the board that could be introduced.
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Re: Spurs/Harmonics fixes for v4 based on v5 board design?
Thanks I'll try the two tone test next.? Tonight I replaced L5 and L7 Raj's fix to see if I noticed any differences.? Using LSB on 7.15 into 40db attenuator get-55db main signal and I see some sort of spur at around 5MHZ that is about -85db, doesn't fluctate with voice it's constant when I key the transmitter.? Wonder what could be producing around 5 MHZ.
?I wonder if the v5 board redesign changes next might help.? ?Might see if I can figure out where on the board that could be introduced.
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On Fri, Feb 1, 2019 at 03:02 PM, Evan Hand wrote:
I did not measure with no sound, as that should be almost 43 db down already (no audio).? At that low of a level you may see things relative to the carrier that leaks through.? I would not expect to see harmonics.? Wonder if the BFO is off so that the crystal filter is not removing the BFO that becomes the "carrier"??
Can you do the test with a dual tone input to the mic?? There is a simple PC 2 tone generator that you can use through the mic to run the test:?
I did a quick test that way before I completed the 2 tone audio circuit from Peter Rachow, DK7IH.
Ran it with a 9v battery.??
Not Pretty, but it works
I also used the "multi tone" setting on my Koolertron signal generator and got the same general results.
To be able to keep the transmitter on, I added a slide switch to the tone board and connected through the 3.5mm plug to the PTT and the tone out to the mic input on the ubitx.? I was careful and monitored the temps on the finals (they did get warm when I had the audio drive too high).
As I stated in the prior email, I used the CW power output reading on my Nissei SWR/Power meter to set the audio drive to get the same power out.? I had adjusted the two tones relative amplitude to each other using the audio spectrum analyzer program that I listed before.? Would like to know the design value for the audio input of the ubitx, would be easy to set that up with a scope.
Net result is that there is a spur issue, though not high enough, nor on a band that I use.? CW harmonics are out of compliance, however there were not above the -43db with the two tone input.? Became just as bad if audio drive was increased to an above CW power level (8.5 watts for me on 40 meters with 13.5 volts to PA only, 12v to rest of rig)
Still learning how to use the tools.? Not exactly as I expected, need to adapt to what is available.? Still think a Siglent or Rigol is in my future shack.
Waiting on the QSX to become available to do comparison testing.
Above are my interpretations of my experiences.? Yours may differ
73
Evan
AC9TU
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At 02-02-19, you wrote: Plastic cases and RF do NOT Go together. Have you ever seen a radio in a plastic case? Yes, many! FT747 is in a plastic case. All my "radios" are in plastic cases! :-))
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0603 does not work.
toggle quoted message
Show quoted text
At 01-02-19, you wrote: Can someone help me with the part number and supplier ( UK ) for the 680nH smd inductors used to replace L5 and L7.
Just found some on Digikey but they were very small (0603) and they wanted ??12 for shipping!
Peter G8FWY.
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Re: Efficient Class E generation of SSB Using the EER Method
Guido has a first pass at something that sort of works, running on a QCX.
In his case, he avoids analog entirely, PLL updates are carried out over the i2c bus into the Si5351.
If that proves not precise enough, perhaps use the $2 Si5351B, which has a "VCXO" pin, could be driven with a DAC.
The challenging (dreadful?) part will likely be in developing the DSP code that steer this thing,?
trying to create an acceptably clean signal.
No need for a debate here, this is just an invite to join the conversation if interested in technical puzzles.
And no need to be careful, these are all $1 and $2 parts.?
If you want an expert designing your gear, go buy an Elecraft.
But why should they have all the fun?
Jerry
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On Fri, Feb 1, 2019 at 06:29 PM, Curt wrote:
But modulating a PLL, that sounds like dreadful analog complexity.
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Re: Efficient Class E generation of SSB Using the EER Method
I think that would be a cool way to build a SSB transmitter. I've been doing some reading as I'm investigating the possible use of a FPGA for creating a SSB signal to drive my uBITX (in this case the signal will be feeding a linear TX chain). In the analog days it seems the results were somewhat marginal. One technique described splitting things up so the carrier was "FM" modulated (I imagine that is an over simplification) and the envelope was used to modulate the carrier with another class D audio range amplifier modulating the voltage to the class E final.
It would seem that in this age of DSP processors and such this should be a realizable design. In my limited searching I haven't found much on realized designs. I'm really interested if others with more experience in this, know of working designs.?
I'd been thinking about building a tiny, portable, low power battery operated digital mode HF transceiver. By limiting it to just digital modes with constant power modulation types, it could use a class E output and be easy on batteries.?
Tom, wb6b
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Re: Efficient Class E generation of SSB Using the EER Method
Jerry
Be careful what you spread. Of course feeding accurate info into a D to A converter can produce the voice, and with some predistortion correct for non linearity in the power stages. But modulating a PLL, that sounds like dreadful analog complexity. I suggest emailing an expert on PA designs, like Paul NA5N versus a debate. Anything that seems real can be tried, but this seems a bit unwieldy to me, but I don't have expertise in modulation.
Curt
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JackAl modI used a component leas through the gnd via to c210 to help with the ground.
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Efficient Class E generation of SSB Using the EER Method
We've got an interesting discussion going over in the qrplabs group regarding a possible way to transmit SSB signals much more efficiently (and cheaply) than through the use of a linear amp:? ?? /g/QRPLabs/topic/29572792EER is an acronym for Envelope Elimination and Restoration. Traditionally, this apparently meant to build an SSB exciter, then amplify and limit the? output such that all that remains is a square wave with the frequency information. Amplify that square wave efficiently with a class C or D or E amp, and restore the envelope information by modulating the power supply to that amp. The envelope information could be obtained with a diode detector that watches the output of the SSB exciter. A more interesting approach might be to do away with the SSB exciter entirely. Audio comes into a uC through an ADC from the mike, calculations are performed on that audio to compute the desired frequency and envelope information, then the uC steers the frequency of a PLL (such as the si5351) and also modulates that final amp with envelope information. Seemed only fair to mention it here. One possible piece of the puzzle might be to modulate an si5351 clock by jerking around the reference oscillator as Farhan first described in this forum: ? ? /g/BITX20/message/34020Jerry, KE7ER?
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Shipping times/responsiveness from amateurradiokits.in?
I ordered one of Sunil's uBITx cases with a Nextion front panel on the 23rd.? I sent an email on the 29th asking about my order status.? I haven't gotten a reply or a ship notification.? Is this normal?? Does it just show up one day, or should I have gotten a tracking number?
Thanks!
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Re: Spurs/Harmonics fixes for v4 based on v5 board design?
I did not measure with no sound, as that should be almost 43 db down already (no audio).? At that low of a level you may see things relative to the carrier that leaks through.? I would not expect to see harmonics.? Wonder if the BFO is off so that the crystal filter is not removing the BFO that becomes the "carrier"?? Can you do the test with a dual tone input to the mic?? There is a simple PC 2 tone generator that you can use through the mic to run the test:? I did a quick test that way before I completed the 2 tone audio circuit from Peter Rachow, DK7IH. Ran it with a 9v battery.??  Not Pretty, but it works I also used the "multi tone" setting on my Koolertron signal generator and got the same general results. To be able to keep the transmitter on, I added a slide switch to the tone board and connected through the 3.5mm plug to the PTT and the tone out to the mic input on the ubitx.? I was careful and monitored the temps on the finals (they did get warm when I had the audio drive too high). As I stated in the prior email, I used the CW power output reading on my Nissei SWR/Power meter to set the audio drive to get the same power out.? I had adjusted the two tones relative amplitude to each other using the audio spectrum analyzer program that I listed before.? Would like to know the design value for the audio input of the ubitx, would be easy to set that up with a scope. Net result is that there is a spur issue, though not high enough, nor on a band that I use.? CW harmonics are out of compliance, however there were not above the -43db with the two tone input.? Became just as bad if audio drive was increased to an above CW power level (8.5 watts for me on 40 meters with 13.5 volts to PA only, 12v to rest of rig) Still learning how to use the tools.? Not exactly as I expected, need to adapt to what is available.? Still think a Siglent or Rigol is in my future shack. Waiting on the QSX to become available to do comparison testing. Above are my interpretations of my experiences.? Yours may differ 73 Evan AC9TU
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Re: Spurs/Harmonics fixes for v4 based on v5 board design?
I was transmitting with no sound LSB, so I guess it lets some carrier through plus some other IMD/spurs +/- 5MHZ of the transmit frequency there were maybe 2? in the 5mhz above and and 2 on the 5mhz below side only -30? down (-85db)? from the -55db carrier.
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On Fri, Feb 1, 2019 at 10:24 AM, Evan Hand wrote:
Verify the input level for the audio.? I ran into those when I increased the audio input level (showed up as higher power out, though that was probably because of the extra garbage being amplified).? I adjusted the output of the audio generator to match the CW power level,? being read on an Nissei SWR/Power meter between the rig and the dummy load, when I noted that the spurs dropped down in relative level.? Another way to tell for me is when the audio from the rig speaker gets distorted.? There is a lot of leakage being detected by the muting Q74 MOSFET.
On my rig, using the RSP2, I did not get 2 peaks with the two tone audio, instead there were 3.? I did not figure out how to determine what the third spike was.? I am assuming that it is the carrier getting through the SSB filter.? Did not get the frequency measured, so will do that this weekend (working now).
73
Evan
AC9TU
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Re: Weird Issue looking for suggestions
The nano can be bought for under $5.00 when bought 3 at a time on Amazon, there are lower cost options from other suppliers (Banggood - $2.19 : ? do not know shipping costs).? Just be sure that you get it without headers soldered in, as they go on the "wrong" side of the nano.?
Nano's do have issues with loosing I/O, as we are running them at close to the max of the 5 volt input.? If the 12 v from the rest of the card gets to an input it would be toast.? Good to have a backup since they are so cheap.
Again, my opinion
73
Evan
AC9TU
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Just put up a short video on the keyers
-- David
?N8DAH
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Raj vu2zap
N8DAH