Date   
Re: More paddles and keys ...

Eric KE6US
 

Clean, elegantly simple.

I love bugs most, but there's just nothing like a simple heavy straight key.

Eric KE6US

On 11/30/2019 7:19 AM, Bill Allen wrote:
>From 1979 when I still worked on the bench . . .

Re: Multiband QCX

Martin DK3UW
 

Hi Folks,

thanks for the many good hints.

So the final concept is not yet clear and I am not the technical brain behind it. As a start I ordered a QCX 40 and BPFand LPF for 5 bands.

As a first step I then will be busy competing the QCX without the obligation to wind toroids but there will be some waiting for the filters.

Change band via CAT ? I have a laptop but now idea on what has to happen between the QCX and the laptop. I use Swisslog and N1MM as softwares.

I thing easyest will be to use the 1 Mhz steps.

Axel, any doc in German would be fine

73s
Martin
DK3UW

Re: QCX 20 off frequency

Priyasloka Arya
 

N


On Sat, 30 Nov 2019, 02:16 George Korper, <georgekorper@...> wrote:
Hi All,
I just assembled a second QCX 20. The first unit is working well and made contacts,etc.
The second unit transmits 2 KHZ up the band  and likewise receives 2 KHZ
down the band. I have checked for solder joints, etc. and the receiver works but
the second stage of alignment is not working well. This unit has the 1.01 firmware.
Need help before I troubleshoot without narrowing this down.
Thanks,
George

Re: QCX-40 Power Out w/o Tuner and With

jim
 

Attached article from QEX

Jim

On Saturday, November 30, 2019, 4:22:36 PM UTC, Chuck Carpenter <w5usj@...> wrote:


Geoff,

Frank did a couple of other versions and settled on the one in QEX.  The uses the MFJ-259 as a signal source and either SWR or RL as the measurement value. I'm sorry, I can't find the copy I had from QEX

His Precision load box is a sequence of 1% resistors from 1.5 Ohms to 3.3 k Ohms.

The very short version:

The basic procedure is to select a load value say 100 Ohms.  Adjust the tuner for a match of 1.1 : 1 or better.  Switch to the next higher value resistor, 200 Ohms, and read RL.  Switch to previous lower resistor value, 50 Ohms, and read RL.  Then plug the two RL values into an equation.

Lest = ((RL1 + RL2) / 4) -4.77

I use this one as it's the easiest to work with.

You can also use values of SWR and Rho with other equations for the calculations.

Lest dB =  5log(S1+1)(S2+1) / 9(S1–1)(S2–1) (SWR

Lest dB = –5log(9|r1||r2|)

SWR = 1+|r| / 1 – |r|

|r| = SWR-1 / SWR + 1

RL = –20log(|r|)

rho = sqrt[(50-RL)2 + (XL)2 / ((50+RL)2 + (XL)2)]


I should have other info and  a schematic of the precision load box in archives someplace.  I can send a copy via eMail if that's OK.

If you have other instruments with greater accuracy and precision to make the measurements of SWR, RL and Rho, your calculations will be more precise.

Also, for my own amazement, I wrote a little utility in Small Basic to do the calculations.  Small Basic is intensely verbose but it fits nicely with my level of programming skill
I'll share if you'd like...8^)

Have Fun...!
--

Chuck, W5USJ (ex K2OFN)
EM22cv, Rains Co., Texas

Re: QCX 20 off frequency

N3MNT
 

The alignment section on page 100 says the 27MHz crystals can vary slightly and the menu item is provided to correct for the variances.

Re: #qcx CAT control #qcx

jjpurdum
 

No, I realize that. Programming is very much a personal endeavor and much of my predilection comes from teaching this stuff while I was at Purdue. You would not believe the variance you see in coding style even when the assignment is the same for all of the students. The best I could do was point out the options.

Jack, W8TEE

On Saturday, November 30, 2019, 11:52:51 AM EST, Roger Hill <rhill@...> wrote:


Cheers Jack. Not grumbling at all...to each his own.

Roger

On 30 Nov 2019, at 16:50, "jjpurdum via Groups.Io" <yahoo.com@groups.io target=_blank>jjpurdum=yahoo.com@groups.io> wrote:
I think it depends on what you're used to seeing. If I see a memset() call, I can figure out what it's doing much faster than I can if I have to read the 3 for loop expressions, and the statements controlled by that loop. To me, this is not "enhanced" or "elegant" code at all. It simply reflects familiarity with the System V Standard C library, of which the mem*() family of functions have been a part of for about 40 years. Indeed, a good part of becoming a C programmer is knowing what's available in the vast selection of libraries. As far as performance, some of those frequently-used library functions are written in hand-tweaked assembler and I know I cannot write it more efficiently. Given that, why waste time writing, testing, and debugging a section of code when you know it's already been done for you?

So, where you need to study what memset() does, I have to study what a multi-line for loop does. If you had been using memset() for 40 years, I think you, too, would find it takes more time to understand the for loop code than the lone memset() call, especially when you know the third parameter simply sets the byte limit for the initialization.

Jack, W8TEE

On Saturday, November 30, 2019, 11:12:09 AM EST, Roger Hill <rhill@...> wrote:


Yeah. After 50 years of coding in many languages, I still would prefer to have to maintain the 'less good' for loop.. it much more obvious what it is doing.

The fancy version might be more elegant or whatever but I would have to read it several times to decide what it was doing.

Roger

On 30 Nov 2019, at 16:07, Michael Welle < mwe012008@...> wrote:
Hello,

"jjpurdum via Groups.Io" <jjpurdum=yahoo.com@groups.io> writes:

Opps! Forgot to multiple the elements by the size:
    memset(myArray, 0, ELEMENTS(myArray) * sizeof(myArray[0]) );

with the macro expanded this results in

memset(myArray, 0, (sizeof(myArray) / sizeof(myArray[0]))*sizeof(myArray[0]));

Well, with optimisation enabled, the compiler can generate compact machine
code out of that. But as a human code reviewer I would question that and
would expect to find other interesting things in the code ;). I think
producing correct code is a complicated task and we should strive for
correct code first and then for beautiful or otherwise 'enhanced' code.

Regards
hmw



Re: #qcx CAT control #qcx

Roger Hill
 

Cheers Jack. Not grumbling at all...to each his own.

Roger

On 30 Nov 2019, at 16:50, "jjpurdum via Groups.Io" <yahoo.com@groups.io target=_blank>jjpurdum=yahoo.com@groups.io> wrote:
I think it depends on what you're used to seeing. If I see a memset() call, I can figure out what it's doing much faster than I can if I have to read the 3 for loop expressions, and the statements controlled by that loop. To me, this is not "enhanced" or "elegant" code at all. It simply reflects familiarity with the System V Standard C library, of which the mem*() family of functions have been a part of for about 40 years. Indeed, a good part of becoming a C programmer is knowing what's available in the vast selection of libraries. As far as performance, some of those frequently-used library functions are written in hand-tweaked assembler and I know I cannot write it more efficiently. Given that, why waste time writing, testing, and debugging a section of code when you know it's already been done for you?

So, where you need to study what memset() does, I have to study what a multi-line for loop does. If you had been using memset() for 40 years, I think you, too, would find it takes more time to understand the for loop code than the lone memset() call, especially when you know the third parameter simply sets the byte limit for the initialization.

Jack, W8TEE

On Saturday, November 30, 2019, 11:12:09 AM EST, Roger Hill <rhill@...> wrote:


Yeah. After 50 years of coding in many languages, I still would prefer to have to maintain the 'less good' for loop.. it much more obvious what it is doing.

The fancy version might be more elegant or whatever but I would have to read it several times to decide what it was doing.

Roger

On 30 Nov 2019, at 16:07, Michael Welle < mwe012008@...> wrote:
Hello,

"jjpurdum via Groups.Io" <jjpurdum=yahoo.com@groups.io> writes:

Opps! Forgot to multiple the elements by the size:
    memset(myArray, 0, ELEMENTS(myArray) * sizeof(myArray[0]) );

with the macro expanded this results in

memset(myArray, 0, (sizeof(myArray) / sizeof(myArray[0]))*sizeof(myArray[0]));

Well, with optimisation enabled, the compiler can generate compact machine
code out of that. But as a human code reviewer I would question that and
would expect to find other interesting things in the code ;). I think
producing correct code is a complicated task and we should strive for
correct code first and then for beautiful or otherwise 'enhanced' code.

Regards
hmw



Re: #qcx CAT control #qcx

jjpurdum
 

I think it depends on what you're used to seeing. If I see a memset() call, I can figure out what it's doing much faster than I can if I have to read the 3 for loop expressions, and the statements controlled by that loop. To me, this is not "enhanced" or "elegant" code at all. It simply reflects familiarity with the System V Standard C library, of which the mem*() family of functions have been a part of for about 40 years. Indeed, a good part of becoming a C programmer is knowing what's available in the vast selection of libraries. As far as performance, some of those frequently-used library functions are written in hand-tweaked assembler and I know I cannot write it more efficiently. Given that, why waste time writing, testing, and debugging a section of code when you know it's already been done for you?

So, where you need to study what memset() does, I have to study what a multi-line for loop does. If you had been using memset() for 40 years, I think you, too, would find it takes more time to understand the for loop code than the lone memset() call, especially when you know the third parameter simply sets the byte limit for the initialization.

Jack, W8TEE

On Saturday, November 30, 2019, 11:12:09 AM EST, Roger Hill <rhill@...> wrote:


Yeah. After 50 years of coding in many languages, I still would prefer to have to maintain the 'less good' for loop.. it much more obvious what it is doing.

The fancy version might be more elegant or whatever but I would have to read it several times to decide what it was doing.

Roger

On 30 Nov 2019, at 16:07, Michael Welle <mwe012008@...> wrote:
Hello,

"jjpurdum via Groups.Io" <jjpurdum=yahoo.com@groups.io> writes:

Opps! Forgot to multiple the elements by the size:
    memset(myArray, 0, ELEMENTS(myArray) * sizeof(myArray[0]) );

with the macro expanded this results in

memset(myArray, 0, (sizeof(myArray) / sizeof(myArray[0]))*sizeof(myArray[0]));

Well, with optimisation enabled, the compiler can generate compact machine
code out of that. But as a human code reviewer I would question that and
would expect to find other interesting things in the code ;). I think
producing correct code is a complicated task and we should strive for
correct code first and then for beautiful or otherwise 'enhanced' code.

Regards
hmw



Re: QCX-40 Power Out w/o Tuner and With

Chuck Carpenter
 

Geoff,

Frank did a couple of other versions and settled on the one in QEX.  The uses the MFJ-259 as a signal source and either SWR or RL as the measurement value. I'm sorry, I can't find the copy I had from QEX

His Precision load box is a sequence of 1% resistors from 1.5 Ohms to 3.3 k Ohms.

The very short version:

The basic procedure is to select a load value say 100 Ohms.  Adjust the tuner for a match of 1.1 : 1 or better.  Switch to the next higher value resistor, 200 Ohms, and read RL.  Switch to previous lower resistor value, 50 Ohms, and read RL.  Then plug the two RL values into an equation.

Lest = ((RL1 + RL2) / 4) -4.77

I use this one as it's the easiest to work with.

You can also use values of SWR and Rho with other equations for the calculations.

Lest dB =  5log(S1+1)(S2+1) / 9(S1–1)(S2–1) (SWR

Lest dB = –5log(9|r1||r2|)

SWR = 1+|r| / 1 – |r|

|r| = SWR-1 / SWR + 1

RL = –20log(|r|)

rho = sqrt[(50-RL)2 + (XL)2 / ((50+RL)2 + (XL)2)]


I should have other info and  a schematic of the precision load box in archives someplace.  I can send a copy via eMail if that's OK.

If you have other instruments with greater accuracy and precision to make the measurements of SWR, RL and Rho, your calculations will be more precise.

Also, for my own amazement, I wrote a little utility in Small Basic to do the calculations.  Small Basic is intensely verbose but it fits nicely with my level of programming skill
I'll share if you'd like...8^)

Have Fun...!
--

Chuck, W5USJ (ex K2OFN)
EM22cv, Rains Co., Texas

Re: More paddles and keys ...

Michael Welle
 

Hello,

"Bill Allen" <w0wcabill@...> writes:

From 1979 when I still worked on the bench . . .
and still a beauty today.

I saw a lot of ufb keys in this thread. The other day I saw small
portable keys at this internet auction platform. I think they are 8
bucks a piece and they look like they had been produced with a 3D
printer. I mean, you get what you can get for 8 bucks, but in this
thread you see keys in which people invest time, workmanship and pride
and I like that ;).

Regards
hmw

Re: Multiband QCX

Axel
 

Try again upload the schematics with better quality.

Re: #qcx CAT control #qcx

Roger Hill
 

Yeah. After 50 years of coding in many languages, I still would prefer to have to maintain the 'less good' for loop.. it much more obvious what it is doing.

The fancy version might be more elegant or whatever but I would have to read it several times to decide what it was doing.

Roger

On 30 Nov 2019, at 16:07, Michael Welle <mwe012008@...> wrote:
Hello,

"jjpurdum via Groups.Io" <jjpurdum=yahoo.com@groups.io> writes:

Opps! Forgot to multiple the elements by the size:
    memset(myArray, 0, ELEMENTS(myArray) * sizeof(myArray[0]) );

with the macro expanded this results in

memset(myArray, 0, (sizeof(myArray) / sizeof(myArray[0]))*sizeof(myArray[0]));

Well, with optimisation enabled, the compiler can generate compact machine
code out of that. But as a human code reviewer I would question that and
would expect to find other interesting things in the code ;). I think
producing correct code is a complicated task and we should strive for
correct code first and then for beautiful or otherwise 'enhanced' code.

Regards
hmw



Re: Multiband QCX

Axel
 

Hi,

the "Lima-SDR" of German OV Duisburg, L02, probably has a suitable multiband preselector (and optional preamp) for the RX. The Lima-SDR works quite similar to the QCX. Many documents of this RX are no longer available on the web, I'll post the schematic below. You can see the preselector here: https://www.dl1smf.de/de/node/2, first image, the lower section.

OV U02 and DJ0ABR have improved the preselector and made a very good one, but 1.) the original preselector is probably good enough and 2.) the description seems no longer available on the web.

There was also a TX, including a low pass filter, for Lima-SDR, but couldn't find the docs online anymore. (I have the complete RX-docs for I've built it, in German, but no TX-docs.)

U02/DJOABR have an improved Low-Pass for Lima-SDR-TX, doc is here: https://www.helitron.de/dj0abr/ > "Lima SDR und FA SDR ausgebaut" > "TX-Tiefpass"

Maybe, it is worth to take a look at the lowpass of KX2, saw it on the web recently.

Maybe, you could even get PCBs for preselector and TX-Lowpass from DJ0ABR.

As on how to handle the inductance at drain of the BSS170-Final stage, I don't know, could be difficult.

I'm quite interested in your work of building a multiband QCX, so would be glad to hear about your ongoing work.

Kind Regards,
Axel, DF1ET

Re: #qcx CAT control #qcx

Michael Welle
 

Hello,

"jjpurdum via Groups.Io" <jjpurdum=yahoo.com@groups.io> writes:

Opps! Forgot to multiple the elements by the size:
    memset(myArray, 0, ELEMENTS(myArray) * sizeof(myArray[0]) );
with the macro expanded this results in

memset(myArray, 0, (sizeof(myArray) / sizeof(myArray[0]))*sizeof(myArray[0]));

Well, with optimisation enabled, the compiler can generate compact machine
code out of that. But as a human code reviewer I would question that and
would expect to find other interesting things in the code ;). I think
producing correct code is a complicated task and we should strive for
correct code first and then for beautiful or otherwise 'enhanced' code.

Regards
hmw

Re: More paddles and keys ...

Mike Easterbrook
 

Hi All
Thanks for the various suggestions. Got to the DIY shop Friday and had a frustrating time sorting through their large collection of assorted springs (probably 95 percent wrong "sense") - just about to give up but found a small box at back of shelf with assorted brand new springs, correct sense & a few of exactly correct ID/OD. Took all day to remember how to reconstruct but my QCX now all OK for CW - if only retraining my stale brain to decode could be that quick!
73 Mike

On Fri, 29 Nov 2019, 14:06 Martin Rath, <martin.rath@...> wrote:
Hi,

Marina Square mall and i12 Katong mall both have music instrument shops. Should be pretty easy to find.

73’s 9V1RM 

On Fri, 29 Nov 2019 at 11:19, Mike Easterbrook <mike.easterbrook.2012@...> wrote:
Hi Eric
Thanks for the tips.  Never thought of taking the DIY to the next level - shame on me! 
Now I need to find a local source of piano wire (in 9V/9M) 
Thanks again Mike 

On Fri, 29 Nov 2019, 05:18 Eric KE6US, <eric.csuf@...> wrote:

They aren't difficult to wind. K&S Metals has small dia. piano wire. Use an ordinary screw as a form. I usually go with a screw the next size down from what I want as they tend to unwind a little. You can also wind them on dowels and bamboo skewers. I do this often when I need one right away for development, then replace it later when I have time as the commercial ones have much nicer finish winds on the ends.

Eric KE6US


On 11/27/2019 6:36 PM, Mike Easterbrook wrote:
Thanks for the suggestion Niels. That was one source of springs I hadn't thought of. Those that I've checked so far are either wrong ID for the 3mm screw or wound in wrong "sense" .

Continuing to look. Closest I've found is tensioning wire for net curtains but all I can get here are too small ID
Mike

On Mon, 25 Nov 2019, 19:34 Niels Jalling, <niels@...> wrote:
Take a look inside a ballpen from your pile of old pens.
73 de
OZ9NY Niels

Re: More paddles and keys ...

jjpurdum
 

Beautiful!

Jack, W8TEE

On Saturday, November 30, 2019, 10:20:01 AM EST, Bill Allen <w0wcabill@...> wrote:


From 1979 when I still worked on the bench . . .

Re: More paddles and keys ...

Bill Allen
 

From 1979 when I still worked on the bench . . .

Re: QCX-40 Power Out w/o Tuner and With

geoff M0ORE
 

Chuck, I am interested in your comment that the Z-Match ATU has a matched loss ~ 0.5dB based on the Frank Witt, AI1K, method.

I have searched web for both AI1K and Frank Witt with no results. I don't have copies of QEX for 2003 but can you point me to where I can find info on measuring loss through an ATU. A few of us in S England are in discussion on how to measure this in various ATU's. We have yet to establish a method that gives sensible results.

Geoff

On 30/11/2019 13:26, Chuck Carpenter wrote:
Input to the transmission looks like 70 -j18 Ohms --> MFJ-259C
Tuner --> Z-Match based on W6JJZ designs;  ~0.5 dB matched loss**
Power Meter --> WM-2 Work-A-Like
KC9ON -->  20W Dummy Load  50 j0 Ohms
FS meter -- Pickup Link Outside

Relative with this particular lash-up

Power Output (setup pictures attached)
Dummy Load -->  3.5 W
Antenna w/o Tuner --> 2.5 W,  FS meter 24 (0-100 scale)
Antenna with Tuner --> 5 W, FS meter 50



**Based on Frank Witt, AI1K, method, Sep/Oct 2003 QEX,


--

Chuck, W5USJ (ex K2OFN)
EM22cv, Rains Co., Texas

Re: QCX 20 off frequency

SkipF, NT1G <skip.flem@...>
 

Soldering iron temp is only 'loosely' related to the power.
Just as replacing a 50 hp engine with a 100hp doesn't
mean your car will 'overspeed'. It 'could' but it shouldn't.
And I've never seen 'quartz' as sensitive to soldering as some
earlier solid state bonding/interconnect technology.

Re: QCX 20 off frequency

George Korper
 

Thank you Jim and Allison, I have checked the RIT and it was O.00, and swapped out the firmware.
It was not the firmware. I did re-calibrate and set the crystal to 26,998. That worked.I have built three
kits and this one has been a little cranky. I switched solder and went up a little higher in wattage.
Big mistake, my old Weller was doing just fine.So I wonder have either of you seen crystals this low in freq. , because my two
previous kits were dead nuts at 27,004. Could the heat on my iron be too high and affected  the crystal?
I went from 25 to 45 watts.