Date   

Re: Shipping FAQ

RACHAEL SANDERS
 

Chiiiiill Mike!


On 9 Jun 2020, at 18:43, Mike Besemer - WM4B <mwbesemer@...> wrote:


Looks like one of mine broke loose. The oldest one is still lost in space.

Mike
WM4B
On Jun 9, 2020 9:55 AM, "KI7MWA via groups.io" <entilleser@...> wrote:
Well, perhaps it is my karma... TNT Tracking now says: "Scheduled delivery pending"...whatever that means...


Re: External amplifier control for U3

Phil Frost <indigo@...>
 

The U3S brings PB5 out to a header just for this. Check out the operating manual for the latest firmware and search the document for "amplifier": https://www.qrp-labs.com/ultimate3/u3firmware.html

I don't know if the U3 has the header connection, so maybe you just need to scab on a wire some other way.

On Sat, Jun 6, 2020 at 2:36 PM Manuel Verde Salmerón <ea7tb@...> wrote:
Hi.
I have ultimate U3, plate "Rev 2".
I want to put an external applicator to increase the output power
First I'm going to do the transformation to go from U3 to U3S. (Https://www.qrp-labs.com/ultimate3/u3mods/u3tou3s.html)
When making this modification, the microprocessor's PB5 signal is not used.
Can this signal be used to activate an external amplifier?
How else could it be done?
Regards.
Manuel EA7TB



Re: 5W HF PA - setting bias current

Arv Evans
 

Setting the bias current with no load may be risky.  If there is any 
oscillation in the finals they could be destroyed.

Arv
_._


On Tue, Jun 9, 2020 at 11:49 AM Martin <marting7mrv@...> wrote:
As I understand it, by adding a temporary link to load the DA shift register with 255, I can set the bias point by monitoring the supply current drawn, with no need for any RF drive.

Is this all there is to it? As theres no drive, do I take it that there is no requirement to terminate the output? Or, does the output require at least to 'see' a 50 ohm load?

I will be adding this amp into my 6-band U3S case,

Regards
Martin G7MRV


Si5351: P1, P2, P3, what's it really all about?

Phil Frost <indigo@...>
 

Reading AN6918 <https://www.silabs.com/documents/public/application-notes/AN619.pdf>, in configuring the PLL it talks of a fractional multiplier a+b/c. It then has some calculations to arrive at P1, P2, and P3 which are written to the configuration registers. I've been trying to come to some understanding about why this transformation takes place and the consequences.

The equations are:

P1 = 128 x a + floor(128 * b/c) - 512
P2 = 128 * b - c * floor(128 * b / c)
P3 = c

My first observation is P2 can be written more clearly (I think) as:

P2 = (128 * b) mod c

Secondly, only P1 depends on a, and if b/c is allowed to be an improper fraction than it can be simplified to:

P1 = floor(128 * b/c) - 512

Finally, b is always multiplied by 128. If we just say:

f_PLL = f_xtal * b / c / 128

then the equations can be further simplified:

P1 = floor(b / c) - 512
P2 = b mod c

I had assumed "b" must be an integer, and thus the smallest increment that could be represented is 1/1048575. But I don't see that directly stated in the documentation.

If c == 1048575 (as it always is, in the example code) and b is an integer, then as b increases by 1, P2 increases by 128 until it is no longer less than c. Then P1 increments by one and P2 "wraps around".

To illustrate here is a sequence of values, each one incrementing b by 1:

a b c -> P1 P2 P3

30 8190 1048575 -> 3328 1048320 1048575
30 8191 1048575 -> 3328 1048448 1048575
30 8192 1048575 -> 3329 1 1048575
30 8193 1048575 -> 3329 129 1048575
30 8194 1048575 -> 3329 257 1048575

What happens if P1 is set to values between those increments of 128? Equivalently, what if we allow b to be something other than an integer, like 8191.9921875?

30 8191.9921875 1048575 -> 3329 0.0 1048575

This is mathematically valid, does it work? Is there anything in the datasheet or application notes which says we can't do this? Is there any effect on the jitter or other performance?


Re: Modify REV 5 Already Built?

scot forshaw
 

Thanks Guido/Alison. 
Of course I forgot the QCX + can take it too. Good tip.

And guido thanks for the clarification, I assume the instructions you posted in the first rely are all that is needed to carry out ?

Best regards Scot 


On 9 Jun 2020, at 18:57, ajparent1/KB1GMX <kb1gmx@...> wrote:

The QCX+ can also be modded as its the same save for physical changes.

Allison
-------------------------------
Please reply on list so we can share.
No private email, it goes to a bit bucket due address harvesting


Re: 5W HF PA - setting bias current

ajparent1/KB1GMX
 

Any time you power an amplifier there should be a load.
Its a good practices thing and prevents any, oops.

Allison
-------------------------------
Please reply on list so we can share.
No private email, it goes to a bit bucket due address harvesting


Re: Modify REV 5 Already Built?

ajparent1/KB1GMX
 

The QCX+ can also be modded as its the same save for physical changes.

Allison
-------------------------------
Please reply on list so we can share.
No private email, it goes to a bit bucket due address harvesting


5W HF PA - setting bias current

Martin
 

As I understand it, by adding a temporary link to load the DA shift register with 255, I can set the bias point by monitoring the supply current drawn, with no need for any RF drive.

Is this all there is to it? As theres no drive, do I take it that there is no requirement to terminate the output? Or, does the output require at least to 'see' a 50 ohm load?

I will be adding this amp into my 6-band U3S case,

Regards
Martin G7MRV


Re: Shipping FAQ

Mike Besemer - WM4B
 

Looks like one of mine broke loose. The oldest one is still lost in space.

Mike
WM4B

On Jun 9, 2020 9:55 AM, "KI7MWA via groups.io" <entilleser@...> wrote:
Well, perhaps it is my karma... TNT Tracking now says: "Scheduled delivery pending"...whatever that means...


Re: Beep in TX

Daniel Conklin
 

Fabio,
Can you post a short audio recording? 


On Mon, Jun 8, 2020 at 01:11 PM, Eng. Fabio Barroso wrote:
Hi builders,
 
My QCX for 40m have a unpleasant beep, like switching, during the transmission, my board is Rev 5, and firmware is 1.04. Any suggestions?
 
Tks, 73
--
Fábio Barroso Brito
Engenheiro de Telecomunicações
CREA 061787033-0 

 
--
73, Dan - W2DLC


U3S kit, WSPR multiband schedule? #wspr #firmware #u3s

Cathal Ferris
 

Hi everyone.
I have what I hope is a quick question, hopefully that can be an interesting question.

When it comes to using WSPR mode on the U3S kit, with added GPS and the 6-band relay kit, is it possible to have a schedule of WSPR transmissions?
Even something like this as a yes/no menu selection option "Cycle WSPR?':
'band 0' , 'band 0' -> 'band 1' , 'band 1' -> 'band 2', 'band 2' -> 'band 3' , 'band 3' -> 'band 4' , 'band 4' -> 'band 5' , 'band 5' -> synchronisation and silence for 3 WSPR cycles -> and back to 'band 0' ; repeating each half hour like that ad infinitum?
One config item that when enabled would go through all of the bands, allows the extended WSPR double transmission to go out, allows the synchronisation against GPS, and keeps to the WSPR etiquette of 20% or under transmission time.

I haven't seen anything in the manual about it, so I assume the current state of things is that WSPR transmissions will only occur on one band unless manually changed as needed. Am I incorrect in the assumption that the U3S can't auto cycle across the bands in WSPR mode?
Would it be a useful feature request to add this, or is it even possible with amount of flash memory left available?

I've got this kit inbound in preparation for transmissions after I pass the licensing exams later in the summer, hopefully to be running from a large auto battery and solar cells. I'd like it to ideally need as little interaction as possible, and I'll have a small ATU built for it as well just for curiosity and interest, transmitting into whatever antenna I'll have up at the time. My antennas will be an all-band fan 1/4 wave vertical, a 42m Windom, a QRP-built trapped dipole, or an Aerial-51 404UL. Plenty of choice and interesting things to learn from the whole exercise. It won't be unattended, but will hopefully be automated as much as possible.

Thanks,
-Cathal


Re: Shipping FAQ

RACHAEL SANDERS
 

Mine did exactly that then shortly after was at the local depot then was pronounced ‘Out for delivery’
Have patience guys! As my then 3 year old used to say ‘Patience is a virtue, Mummy’
73
Rachael 

On Tue, 9 Jun 2020 at 15:56, N3MNT <bob@...> wrote:
Same here.  Originally showed the 3rd, which changed to the 8th and then to Scheduled Delivery Pending. .  Just confirming the same thing out of Hans' control.


Re: Shipping FAQ

N3MNT
 

Same here.  Originally showed the 3rd, which changed to the 8th and then to Scheduled Delivery Pending. .  Just confirming the same thing out of Hans' control.


Re: Shipping FAQ

KI7MWA
 

Well, perhaps it is my karma...  TNT Tracking now says: "Scheduled delivery pending"...whatever that means...


Re: Modify REV 5 Already Built?

Guido PE1NNZ
 

Hi Scot,

Which leaves me still a bit in the grey area, of if it is possible to modify the Rev 5 QCX to the full spec of your latest SDR firmware/capability without having to physically remove major numbers of components?...
I understand that is likely not switchable, but is it possible without taking out all the un required parts?
So, yes it's possible to modify Rev 5 QCX to the latest QCX-SSB firmware, even if you decide to keep the existing analog phase filters etc. It will automatically detect on startup and recognize there is the analog section; in this case it will keep the signal processing features disabled on the receiver.




Re: Modify REV 5 Already Built?

scot forshaw
 

Hi Guido,

Thank you for the reply, 

So to clarify....

Q1 Can the Rev 5 be modified without ripping out half the components?   [yes you can do the original SSB mod - thanks for the instructions in your last post]
Q2 If so, does it have the same features (sdr rx etc) as one built from scratch? [you seem to imply "no" only the generation 1 SSB mod with analog RX is possible?]
Q3 Finally, can it still be implemented with the ability to switch it in / out as in the first incarnation of QCX-SSB? [related to Q1 which you answered already ... the generation 1 mod was reversible but the SDR version of course not?)

Which leaves me still a bit in the grey area, of if it is possible to modify the Rev 5 QCX to the full spec of your latest SDR firmware/capability without having to physically remove major numbers of components?...
I understand that is likely not switchable, but is it possible without taking out all the un required parts?

I am perhaps contemplating modifying my very pristine Rev 5 and can live without the reversibility. I just don't fancy desoldering half the board but would like the full complement of your multiband with SDR features. 

Thanks again and yes if this expands much further I will take across your group.

Cheers
Scot



On Tue, Jun 9, 2020 at 7:45 AM Guido PE1NNZ <threeme3@...> wrote:
Hi Scot,

Yes, if you have a QCX already built you can still run the original SSB mod (without removing half of the components). It also works on as Rev 5 board. To do so make the following changes:
  • SSB receiver: Insert a SPDT switch between C21(+ side) and IC9(pin1) for CW and R27(pin2) for SSB (as was done in original QCX-SSB modification). This will implement an analog SSB backed. If you want to experiment with DSP, you can disconnect the SIDETONE pin, and hook up a loudspeaker with 10uF capacitor in series. It is not an SDR hence you still need to do the analog alignment procedure.
  • SSB transmitter: change D4,R56 (10k); R58 (.22uF); C32 (10uF), remove C31; wire IC2(pin21) to pin R57(side DVM-pin3); wire IC2(pin20) to DVM(pin2); wire IC2(pin18) to junction D4-C42-R58; install a microphone to tip (+ of electret) and sleeve GND of paddle-jack; PTT-switch to ring and sleeve (X1M-mic).


On Tuesday, June 9, 2020, scot forshaw <scot.forshaw@...> wrote:
Hi all,

With the demise of the original QCX before getting a chance to get another to modify, I was combing GitHub to work out if a fully built QCX R5 can be modified without butchering it?

By that I mean, the original QCX-SSB mod seemed to imply just 4 component changes and a few wires...
All the instructions there are for Rev4 boards to do the simple changes required, but then 5 comes along and separate instructions that all seem to consider a new unbuilt kit?
Seems also the project moved on and I can fully work out if the newer revisions of Guido's code and all the improvements will work with Rev 5 "unless everything is ripped out" making it no longer possible to switch the mods in/out.

So my questions are:-

Can the Rev 5 be modified without ripping out half the components?
If so, does it have the same features (sdr rx etc) as one built from scratch?
Finally, can it still be implemented with the ability to switch it in / out as in the first incarnation of QCX-SSB?


I am not particularly worried about backward compatibility I guess, but as it is already built it would be nice if possible.

Cheers
Scot




Re: Modify REV 5 Already Built?

Dean Smith
 

or if i get my act together HI :)
click here!
get there in the end...
Dean (G7EOB)


Re: Modify REV 5 Already Built?

Dean Smith
 

Hi Scott..
And just in case you and others may not be aware!
There is a forum dedicated to this project here..  https://groups.io/g/ucx/topics


Re: Modify REV 5 Already Built?

Guido PE1NNZ
 

Hi Scot,

Yes, if you have a QCX already built you can still run the original SSB mod (without removing half of the components). It also works on as Rev 5 board. To do so make the following changes:
  • SSB receiver: Insert a SPDT switch between C21(+ side) and IC9(pin1) for CW and R27(pin2) for SSB (as was done in original QCX-SSB modification). This will implement an analog SSB backed. If you want to experiment with DSP, you can disconnect the SIDETONE pin, and hook up a loudspeaker with 10uF capacitor in series. It is not an SDR hence you still need to do the analog alignment procedure.
  • SSB transmitter: change D4,R56 (10k); R58 (.22uF); C32 (10uF), remove C31; wire IC2(pin21) to pin R57(side DVM-pin3); wire IC2(pin20) to DVM(pin2); wire IC2(pin18) to junction D4-C42-R58; install a microphone to tip (+ of electret) and sleeve GND of paddle-jack; PTT-switch to ring and sleeve (X1M-mic).


On Tuesday, June 9, 2020, scot forshaw <scot.forshaw@...> wrote:
Hi all,

With the demise of the original QCX before getting a chance to get another to modify, I was combing GitHub to work out if a fully built QCX R5 can be modified without butchering it?

By that I mean, the original QCX-SSB mod seemed to imply just 4 component changes and a few wires...
All the instructions there are for Rev4 boards to do the simple changes required, but then 5 comes along and separate instructions that all seem to consider a new unbuilt kit?
Seems also the project moved on and I can fully work out if the newer revisions of Guido's code and all the improvements will work with Rev 5 "unless everything is ripped out" making it no longer possible to switch the mods in/out.

So my questions are:-

Can the Rev 5 be modified without ripping out half the components?
If so, does it have the same features (sdr rx etc) as one built from scratch?
Finally, can it still be implemented with the ability to switch it in / out as in the first incarnation of QCX-SSB?


I am not particularly worried about backward compatibility I guess, but as it is already built it would be nice if possible.

Cheers
Scot




Modify REV 5 Already Built?

scot forshaw
 

Hi all,

With the demise of the original QCX before getting a chance to get another to modify, I was combing GitHub to work out if a fully built QCX R5 can be modified without butchering it?

By that I mean, the original QCX-SSB mod seemed to imply just 4 component changes and a few wires...
All the instructions there are for Rev4 boards to do the simple changes required, but then 5 comes along and separate instructions that all seem to consider a new unbuilt kit?
Seems also the project moved on and I can fully work out if the newer revisions of Guido's code and all the improvements will work with Rev 5 "unless everything is ripped out" making it no longer possible to switch the mods in/out.

So my questions are:-

Can the Rev 5 be modified without ripping out half the components?
If so, does it have the same features (sdr rx etc) as one built from scratch?
Finally, can it still be implemented with the ability to switch it in / out as in the first incarnation of QCX-SSB?


I am not particularly worried about backward compatibility I guess, but as it is already built it would be nice if possible.

Cheers
Scot