Date   

Re: QCX capacitors

James Daldry W4JED
 

Michael

33 pf plus 4700 pf equals 4733 pf. That's a long way from 39000 pf. Roughly as far as it is from 39 pf, which in turn is 1/1000 of 39 nf.

Jim W4JED

On 7/13/19 9:14 AM, Michael Babineau wrote:
Scotty : 

One option would be to install a 33 pF cap at C17 and then tack-solder a 4.7 nF across it on the bottom of the board.
That should be close enough. 

Michael VE3WMB

P.S. If you have the means to measure capacitance with some accuracy, you might even pick a 4.7 nF cap that  that read a little bit high
to get you closer to 39 pF.  


Re: QCX capacitors

James Daldry W4JED
 

Curt and the gang

This is not a critical circuit. A change of 10% in any component would not make an audible difference. The main thing is that the capacitor be reasonably stable and have low loss, low esr. Polyester or metal film capacitors are probably the best bet, with multilayer ceramic a close second.

Jim W4JED

On 7/13/19 7:34 AM, morseoneuk via Groups.Io wrote:
Thanks Curt,
I have disc ceramic to that value, but would prefer to keep it to Hans original choice of component..
I will keep digging... I do have 33nf and 47nf.. Multi layer ceramic caps,.    but the 39nf  eludes me at the moment .
Best regards to the group...  Scotty
On Saturday, 13 July 2019, 12:14:36 BST, wb8yyy via Groups.Io <wb8yyy@...> wrote:


Looks to me being in the audio filter its capacitance accuracy is paramount.

Curt


Re: TXing on 30/40 with a 20m QCX: will I destroy it? #qcx

Alan de G1FXB
 

Hi Reiner,

No reason to expect any increased risk of destruction,
There is a US ham who has jumpered across the inbuilt TX LPF and runs all external filters in the coax.

I think he has two physical QCX's and uses them 80-10 metres with great success.
search the forum for the reports from Bill,
N4QA for the techniques

Alan

On 14/07/2019 12:42, DL8LRZ wrote:
Hello
I have now succeeded in modifying my QCX-30 with a switch to Duoband 30 / 40m. The occasion was the temporarily difficult conditions at 30m. The biggest problem was the small space in my home-made housing.
I acted like this:
The switch is an Augat ASE62R (DIP, 6 changer)
The built-in low-pass filter is connected in parallel with 4 capacitors. The blocking effect for the 2nd harmonic (14 MHz, approx. 44dB) differs only slightly from the 30m filter according to RFSIM.
In addition, the resonant circuit in the built-in antenna tuner (simplified Z-match) selects Rx and Tx
The RX circuit is connected in parallel with a capacitor + trimmer for exact adjustment to 40m.
The keying was not changed.
Result: good sensitivity on both bands, unchanged output power, now on both bands.
The VFO frequency is recalled from memory as the band is changed.
A first test brought a 40m-QSO.
vy 73 Reiner DL8LRZ


Re: ProgRock not working #progrock

Alan de G1FXB
 

Hi Sid,

Created from a blank sheet of paper so all (?) will be my own, and no errant strings of ???????
Hopefully..........

Is this the same progrock build, you had the problem with in end of April where you report a consistent 1-3 Hz inaccuracy
What is different to now, where the current results reported are in the order of 2-3 KHz?


for the purposes of diagnosis.
Trial the progrock with it's minimum requirements

a/. In your additional details in section 2, you describe that the 5v supply is clean,
presumably this is reference to your "bench" top supply.
This suggests you are not using the 4.3.1. build choice, but it's built according to option given at step 4.3.2

b/. Therefore on the progrock PCB.
IC2 not fitted but in / out pads are jumpered across, and R1 & R2 are not fitted.

c/. On the Si5351 PCB.
IC2, R5, R6, C1 are not fitted.


d/. (the LM317 is not fitted on either progrock or the Si5351 PCB's. as you have taken over the task of providing the 5v supply)
(See all sections of 4.3.x of the build manual for verification)
As a final check, perhaps redo step 8 of page 10, and verify 5 and 3.3v (likely on the high side) voltages are present off board to the Si5351 module.

The progrock just requires just power in,
There are no other dependencies in order to output an signal to a "normal" Xtal controlled accuracy, the default is 10MHz.
Get that verified first before moving to PPS discipline

e/.
having removed the PPS signal make sure that pad of the progrock is grounded to the adjacent pad, to guarantee not inadvertently placing FW in PPS correction mode.

f/.
perform a factory reset, to give known straight out of the box settings

g/. Power cycle, to make sure latest configuration changes are applied

h/. what are the measurements results when made on the CLK0?
There "should" be a calibration error, and a smaller element of drift, likely caused by temperature variation

i/. if the CLK output is still "walkabout" in the order of KHz.? Taking care not to load it's oscillator, how stable is the 27MHz reference from which CLK0 is derived?


Alan



Re: TXing on 30/40 with a 20m QCX: will I destroy it? #qcx

DL8LRZ
 

Hello
I have now succeeded in modifying my QCX-30 with a switch to Duoband 30 / 40m. The occasion was the temporarily difficult conditions at 30m. The biggest problem was the small space in my home-made housing.
I acted like this:
The switch is an Augat ASE62R (DIP, 6 changer)
The built-in low-pass filter is connected in parallel with 4 capacitors. The blocking effect for the 2nd harmonic (14 MHz, approx. 44dB) differs only slightly from the 30m filter according to RFSIM.
In addition, the resonant circuit in the built-in antenna tuner (simplified Z-match) selects Rx and Tx
The RX circuit is connected in parallel with a capacitor + trimmer for exact adjustment to 40m.
The keying was not changed.
Result: good sensitivity on both bands, unchanged output power, now on both bands.
The VFO frequency is recalled from memory as the band is changed.
A first test brought a 40m-QSO.
vy 73 Reiner DL8LRZ


Re: A non GPS method of time keeping and calibration ? (U3's etc) ?

SkipF, NT1G <skip.flem@...>
 

You could always use a TXCO oscillator with a small arduino chip
to count 'microsteps', throw a high bit for a 'few more' then repeat the cycle.
A few people have taken this further by heating the xtal oscillator to an elevated
temp (~125F) with some small power resistors inside a 'thermos flask'.

On Sun, Jul 14, 2019, 4:28 AM Andy Brilleaux via Groups.Io <punkbiscuit=googlemail.com@groups.io> wrote:
I was just looking at real time clock modules for Raspberry Pi's and had a thought.

These tiny RTC modules often have outputs at 32Khz and 1Hz, are tiny and sell for about 1.25 £/$/euro !!

I wonder if the 1pps is good enough to a U3S disciplined for general purpose use.

Yeah I know a GPS system is the ultimate, but something this cheap for general use might be "good enough".

Thoughts anyone ?

73 de Andy


Re: A non GPS method of time keeping and calibration ? (U3's etc) ?

Alan G4ZFQ
 

I wonder if the 1pps is good enough to a U3S disciplined for general
purpose use.
Andy,

It will (if the PPS is even compatible) be as accurate as the crystal
used in the RTC. Which may/may not be as good as the 27MHz crystal in the U3.

73 Alan G4ZFQ


Re: Keyer Issue with QCX - missing or short dahs

Al Gritzmacher AE2T
 

I think you are misunderstanding what a dot/dash memory is.

It doesn't remember multiple key presses and stack them in a buffer of some sort. All that a dot/dash memory does is remember if the dot paddle is pressed some time during a dash, or vice versa. It only remembers one bit.

You cannot move your fingers as if you are sending 20wpm if the keyer is set at 15wpm. You have to keep pace with the keyer.

In the oscilloscope view, you close the dah and dah1 begins. While dah1 is underway, you hit dit1. It gets saved in the dot/dash memory and after the space after dah1 is finished, it generates dit1.

You pressed the dash paddle during the space after dah1. Dit1 is already in memory.

Then, during dit1's space, dit2 is keyed, which generates a second dit.

I don't know if a dit has priority over a dah, or whether only one element can be remembered at a time, but your dah2 request happens way too soon. If it didn't ignore it, you'd get two dahs in a row and lose a dit. Neither gives a 'C'

This is the way every Iambic B keyer I've ever used works. It just isn't a FIFO buffer that you can fill up with unlimited key closures ahead. The 'memory' is just for the next element and just enough to ease the timing of your fingers.


A non GPS method of time keeping and calibration ? (U3's etc) ?

Andy Brilleaux <punkbiscuit@...>
 

I was just looking at real time clock modules for Raspberry Pi's and had a thought.

These tiny RTC modules often have outputs at 32Khz and 1Hz, are tiny and sell for about 1.25 £/$/euro !!

I wonder if the 1pps is good enough to a U3S disciplined for general purpose use.

Yeah I know a GPS system is the ultimate, but something this cheap for general use might be "good enough".

Thoughts anyone ?

73 de Andy


Re: Half case for clock kit

dk5dc
 

Ihad a neighbour with a precision cutter :-). Thus I ended up with a case for the clock and another one for the vfo which is intended to provide the warc bands to my drakeline.

Schreibfehler macht mein iPad.
Peter Glasmacher, DK5DC


--
Peter Glasmacher, DK5DC/AA6HM


Re: Half case for clock kit

Bill Cromwell
 

Hi Mike,

A few things:

Use the finest pitch blade you can get for cutting the plastic.

Measure (twice) and put a set of layout lines on the case where it should be cut. Remember to account for the thickness of the blade. The path it takes through the plastic is the saw kerf and the two halves will be reduced in size by this amount. Cutting a four inch box will not yield a pair of two inch boxes. One or both will be reduced in size by the width of the kerf.

Clamp a pair of fences on opposite sides of the case to guide the saw in a straight cut. Use your layout marks to locate the fences.

Let the saw teeth do the work of cutting instead of *forcing* the saw through plastic box. Just lay the saw on the plastic and push it back and forth. Let the saw's weight (not much) carry it down through the cut.

If you are not accustomed to "one off" fabrication techniques like this you can practice on some scraps of wood or plastic first.

If you cannot afford to lose the one eighth inch or so of box volume where you make the cut you should buy the ready-made 'half-size' boxes (or make one yourself).

73,

Bill KU8H

On 7/13/19 7:37 PM, Michael Lloyd wrote:
Has anyone cut the standard QRPLabs beacon / clock case in half for the clock? I thought about using a hacksaw but the operative word is hack.I want to be able to use the front and back plates that Hans sells and the cut needs to be square.
Even better, rather than cut up one of my beacon cases, is there someplace I can buy a half sized case that will allow me to use the front and back plates? Like Box Enclosures for instance?
--
73
NE5U
Mike
--
bark less - wag more


Re: Half case for clock kit

Russ@va3rr
 

I've been thinking about buying a metal cutting wheel for my mitre saw, just for that purpose. I have an inexpensive AL case I'm going to try cutting in two...


Half case for clock kit

 

Has anyone cut the standard QRPLabs beacon / clock case in half for the clock? I thought about using a hacksaw but the operative word is hack.I want to be able to use the front and back plates that Hans sells and the cut needs to be square.

Even better, rather than cut up one of my beacon cases, is there someplace I can buy a half sized case that will allow me to use the front and back plates? Like Box Enclosures for instance?
--
73
NE5U

Mike


Re: ProgRock not working #progrock

Alan de G1FXB
 


Alan, Thanks for catching that.

Indeed my turn for a typo, a value of 5 equates to 5Hz threshold for the register 3 entries.
Not 5KHz my bad.....:-[

How many ???????? will get inserted on a UK character set this time(?)..........

Alan

On 13/07/2019 21:36, Alan G4ZFQ wrote:
>Register 3 (which has a default value of 5)
5 should equate to 5KHz threshold before correction, presumably values

Lets get the units correct, Sid has also used KHz. I hope this is a typo. No K, just Hz.

73 Alan G4ZFQ





Re: ProgRock not working #progrock

Alan G4ZFQ
 

Register 3 (which has a default value of 5)
5 should equate to 5KHz threshold before correction, presumably values
Lets get the units correct, Sid has also used KHz. I hope this is a typo. No K, just Hz.

73 Alan G4ZFQ


Re: ProgRock not working #progrock

Alan de G1FXB
 

Hi Sid,

No intention to make you look an idiot.

The "insertion" of ?????? is something related to use of a particular mail client, it has being present for a while since an "upgrade", and on two machines
especially prevalent when quoting in posts where the original poster does not share identical character sets?
(We may both "speak English" but different variations there of...........)
I do have a propensity to use a string of ....... to encourage stop & think, over topics. ?:-)?
To make it clear to all readers, I make a conscious effort to highlight through the use of bold type to draw attention to, or adding colour to the text where I cut and paste quotes.
Please do not feel singled out, check back on some of my past replies to others as far back as April(?), hopefully you should see similar findings.

Being open source and donation ware it perhaps owes me what I pay for it....... & off topic for this board.



To Progrock Business & recap.......

" But that is not the issue, the issue to me is that the controller is not making the necessary corrections. "
It's strange both you and Robin both have similar(?) setting problems currently.....

a/. searching the progrock threads is something encouraged for all for a global view to what the group knowledge is.
the progrock kit has being sold since, early 2016.
Hans hasn't indicated any recent changes, indeed he is otherwise occupied elsewhere.
If there were major flaws to it's operation it would be revealed by now.
It's a simple & cheap $18 kit it does what it advertises very well.
Indeed it has a unique PSU noise filter not found in any other kit?

b/. Enabling GPS correction resulting in 2 - 3KHz frequency swings in the 10MHz output over 15 minutes while a straight out of the box progrock is expected to have a 1KHz accuracy without any GPS correction
is a plain indication something is wrong.

two possibilities?

c/. A none intentional problem in the assembly or out of spec components.
There is little on the progrock PCB to go wrong without showing in areas other than the known 2-3KHz errors, you are communicating with the AVR fine through Hyperterminal.
The Si5351 pcb is harder to identify, but at the instance of manually updating the reg2 bin resulting a more stable condition, then increasing wild swings infers a clean bill of health to this as well,
as it can be be disciplined albeit manually.....
A next case check could be to make a observation of the 27MHz Osc, stability. It's what everything depends on.........

d/. I
ncorrect settings causing a race condition.
My initial post encouraged a reply to what you had modified beyond the defaults....
(especially the opportunity to reveal if you had opened "Pandora's box" and modified register 28 contents.)

e/. something I take aspects as a nothing more than perhaps a typo and inadvertently transferred the values, inconveniently it is also in a greater finding....
In your
" Some additional details...
4) I have tried different values for Reg 5 with no observable difference. It is otherwise set to 0. "
(Register 5 is reserved to set output frequency of Bank 0, Clk 1)

Without putting words in your mouth,
You meant to type something approximating
Register 3 (which has a default value of 5)
you have tried different settings beyond a value of 0, (0 being the instruction applying "continuous" GPS discipline.)
With no observable difference?

The no " observable difference " is perhaps a red flag as I'm sure you realise.
5 should equate to 5KHz threshold before correction, presumably values up to 9 are equally acceptable in the absence of a max value in the manual .
Which brings you back to your starting point, why have you residual 2-3KHz deviations.....

f/. Out of interest have you tried setting up another Bank & CLK 0/1 and does it exhibit the same fault symptoms, science suggests it will

g/. Hans has not revealed use of register 0.

h/. There is no chance you have anything generating EM / RF field around your measurement bench getting into either the progrock or test gear?

i/. A honest thought, having so many unknowns?
(Having easy serial access to editing some powerful registers and not pointing fingers.)
Nothing to loose in a factory reset, at this stage and taking stock of the symptoms again from a known, out of the box starting point..........

If Robin is reading this thread and makes similar checks he can perhaps provide the most useful second findings.


Alan


On 13/07/2019 17:21, w7qjq wrote:

for Alan de G1FXB
If you are going to quote my text, please don't edit it to make me sound like an idiot.?
What is the purpose?for all the "?????" that you added??

You said:
"I stand by a belief a OCXO reference is more preferable than applying correction to a less stable source.
?If a normal SI5351 module is used then best case construction applies, give the controller the easiest possible job.
?With thermal masses (others use the term heatsinks ;-)) & avoiding draughts....
?With GPS correction there needs to be a trade off between the choice of continuous discipline (reloading Reg2 every sec) or allowing an determinable amount of drift but maintaining a stable 50/50 duty cycle in the mean time. Ideally you don't want to have to recalculate Register 2, ever........"

I agree that stabilizing the xtal temp would allow for less frequent corrections.? But that is not the issue, the issue to me is that the controller is not making the necessary corrections.? Please look at my Photo 2.? I can? open the loop by removing the 1PPS and insert my self at the keyboard to close the loop by loading Reg 2 with whatever value is required to bring the CLK0 freq back to 10 MHz to within about 0.37 Hz.? (the Reg 2 resolution is 1 Hz at 27 MHz which is???? 10??/?27? =? 0.37 Hz? at 10 MHz).
But I don't have the patience to have to do this every few minutes, or hours, or days depending on how well I am controlling the xtal temp (or using an OCXO or whatever).? I want to let the controller use the 1PPS to do this for me...it's called disciplining an oscillator.
You continue:
"Maybe phase disturbance caused in the discipline process has more than an influence in the counter readings than it first appears / more so if clashing with the gate period?
?(It's something that often gets omitted in many discussions.... )"

Yes, thank you, I am aware that?when Reg 2 changes (either from the ATtiny84 or from the keyboard) that the current 10-sec count is to be disregarded.? Further, the visual info given by the technique of Photo 3 is as good or perhaps better than the counter value.

*******************************************************
for geoff M0ORE
you said:

"I think that it should be borne in mind that some builders are attempting to achieve stability from a unit costing a few dollars, in some cases the cost of a mug of coffee, that professionals spend thousands of dollars to achieve."

This builder was/is expecting to "...achieve stability from a unit costing a few dollars..." that was given on the web site.

and:

"The crystals supplied are standard computer grade units which are not intended to be used as a frequency standard, just to give timing signals for a micro-processor."

Nowhere?in the ProgRock description does is say, nor do I expect,??that the 27 MHz xtal is a "frequency standard".? The Si5351 does not measure the xtal freq.? It wants only two numbers (aside from some house-keeping stuff) from the controller...? the desired CLK0 freq and??the measured (by using the 1PPS) xtal freq.

The "...?just to give timing signals for a micro-processor." is a non sequitur, the only microprocessor involved uses its internal RC oscillator.

And finally:

"If you want to measure the stability of anything, you need to have the test equipment better than the unit you are testing to get any meaningful results. In the case of frequency, what standard are you going to use??"

I have twice given this information, but here comes number three...
"...my frequency standard is a Trimble ICM-SMT GPSDO and?my ultimate 'sanity check' is the 10 MHz xmtr at?WWV in Colorado."

Sid




?

?



Re: ProgRock not working #progrock

Alan G4ZFQ
 

Sid,

Going back to your first post

after a few minutes
the GPS receiver acquires enough sats to begin the 1PPS.  At that
point the (10 MHz) CLK0 freq error will be several KHz. The
ATtiny84 controller will begin pulling the freq towards 10 MHz. The Si5351 Reg 2 can be seen changing the 27,004,xxx MHz as
expected.  After another few minutes the Reg 2  value settles and
the CLK0 freq will be 10MHz +/-   2 or 3 Hz .  But the CLK0 freq
will not remain at any freq for very long...just a degree or two
temperature change will start it moving and the Reg 2 value will
not change as necessary to correct the error.
This is expected if register 3 is left at default. have you set it to 0 when it has got near to correct? (Manual section 4.4)
The PPS is obviously working but it will not adjust correctly if the 27MHz drifts too fast. Have you checked that?

You have detailed a lot of redundant information, perhaps that has confused people.

73 Alan G4ZFQ


Re: #QCX 3.3nF (332) C15/C53 needed #qcx

Dan Rahn
 

Thanks so much Chris!


Re: #QCX 3.3nF (332) C15/C53 needed #qcx

Chris - KC0TKS
 

Capacitor just went out via USPS, 73


On 7/13/19 8:49 AM, Dan Rahn wrote:
One of my kits seems to be missing (or I lost while unpacking the kit, my money is on the latter) the 3.3nF (332) capacitor. Does anyone happen to have any spares they would be willing to mail me in exchange for a couple bucks for the trouble? If not, does anyone know the specs (voltage & dielectric type) on these so I can try and source some? Thanks!


Re: ProgRock not working #progrock

w7qjq
 

for Alan de G1FXB
If you are going to quote my text, please don't edit it to make me sound like an idiot. 
What is the purpose for all the "?????" that you added? 

You said:
"I stand by a belief a OCXO reference is more preferable than applying correction to a less stable source.
 If a normal SI5351 module is used then best case construction applies, give the controller the easiest possible job.
 With thermal masses (others use the term heatsinks ;-)) & avoiding draughts....
 With GPS correction there needs to be a trade off between the choice of continuous discipline (reloading Reg2 every sec) or allowing an determinable amount of drift but maintaining a stable 50/50 duty cycle in the mean time. Ideally you don't want to have to recalculate Register 2, ever........"

I agree that stabilizing the xtal temp would allow for less frequent corrections.  But that is not the issue, the issue to me is that the controller is not making the necessary corrections.  Please look at my Photo 2.  I can  open the loop by removing the 1PPS and insert my self at the keyboard to close the loop by loading Reg 2 with whatever value is required to bring the CLK0 freq back to 10 MHz to within about 0.37 Hz.  (the Reg 2 resolution is 1 Hz at 27 MHz which is     10  / 27  =  0.37 Hz  at 10 MHz).
But I don't have the patience to have to do this every few minutes, or hours, or days depending on how well I am controlling the xtal temp (or using an OCXO or whatever).  I want to let the controller use the 1PPS to do this for me...it's called disciplining an oscillator.
You continue:
"Maybe phase disturbance caused in the discipline process has more than an influence in the counter readings than it first appears / more so if clashing with the gate period?
 (It's something that often gets omitted in many discussions.... )"

Yes, thank you, I am aware that when Reg 2 changes (either from the ATtiny84 or from the keyboard) that the current 10-sec count is to be disregarded.  Further, the visual info given by the technique of Photo 3 is as good or perhaps better than the counter value.

*******************************************************
for geoff M0ORE
you said:

"I think that it should be borne in mind that some builders are attempting to achieve stability from a unit costing a few dollars, in some cases the cost of a mug of coffee, that professionals spend thousands of dollars to achieve."

This builder was/is expecting to "...achieve stability from a unit costing a few dollars..." that was given on the web site.

and:

"The crystals supplied are standard computer grade units which are not intended to be used as a frequency standard, just to give timing signals for a micro-processor."

Nowhere in the ProgRock description does is say, nor do I expect,  that the 27 MHz xtal is a "frequency standard".  The Si5351 does not measure the xtal freq.  It wants only two numbers (aside from some house-keeping stuff) from the controller...  the desired CLK0 freq and  the measured (by using the 1PPS) xtal freq.

The "... just to give timing signals for a micro-processor." is a non sequitur, the only microprocessor involved uses its internal RC oscillator.

And finally:

"If you want to measure the stability of anything, you need to have the test equipment better than the unit you are testing to get any meaningful results. In the case of frequency, what standard are you going to use??"

I have twice given this information, but here comes number three...
"...my frequency standard is a Trimble ICM-SMT GPSDO and my ultimate 'sanity check' is the 10 MHz xmtr at WWV in Colorado."

Sid