Date   
Re: 50W amplifier kit documentation findings

Hans Summers
 

Hi Gregg

Congrats, it's nice to hear of some people starting to report successful builds of the 50W Amp kit. Hopefully some will be in time for some QSOs on the 2nd January in the new "QRP Labs QRO Party" :-)    An event whose title should be marginally concerning to political correctness hi hi. 

When you are referring to typos in the manual - which typos do you mean? I have fixed all the typos I know about. If there are any others please let me know. 

73 Hans G0UPL
http://qrp-labs.com

On Fri, Jan 3, 2020 at 9:00 AM Gregg Myers <gregg.w7grm@...> wrote:
Glad you fixed it, Vern. I just finished my 50w amp myself. All seem to check out ok on mine, and I measured 51watts out on 20m with 20V linear power supply and the QCX at 13.9v power. The current draw is under 4A on the Amp. Yippee! 

I noted the same typos you saw, but it wasn’t anything that one couldn’t figure out.

Tomorrow, I give it a real test on the air.

Gregg W7GRM

On Thu, Jan 2, 2020 at 12:32 PM harleyleenuke <vfrank59@...> wrote:
Update.  I got my amplifiers working. 
 I had to replace the IFR510's both of them and the R5 pot.   i lucked out, as those were the only broken parts.
 I used a 20 volt power supply and on 40m I am getting 45 watts.  on 20 meters I am able to get40 watts out.

I am pleased with the quality of the kit and the enclosure.  The heats sinks are doing a good job. They do get warm. 

Now to hit the airwaves!
Vern

Re: 50W amplifier kit documentation findings

Gregg Myers
 

Glad you fixed it, Vern. I just finished my 50w amp myself. All seem to check out ok on mine, and I measured 51watts out on 20m with 20V linear power supply and the QCX at 13.9v power. The current draw is under 4A on the Amp. Yippee! 

I noted the same typos you saw, but it wasn’t anything that one couldn’t figure out.

Tomorrow, I give it a real test on the air.

Gregg W7GRM

On Thu, Jan 2, 2020 at 12:32 PM harleyleenuke <vfrank59@...> wrote:
Update.  I got my amplifiers working. 
 I had to replace the IFR510's both of them and the R5 pot.   i lucked out, as those were the only broken parts.
 I used a 20 volt power supply and on 40m I am getting 45 watts.  on 20 meters I am able to get40 watts out.

I am pleased with the quality of the kit and the enclosure.  The heats sinks are doing a good job. They do get warm. 

Now to hit the airwaves!
Vern

Re: 50W amp T2 continuity check

Hans Summers
 

Hi all

I reviewed section 3.6 of the manual again and I think it is correct. 

In the end, all the 4 wires of T2 will end up having continuity between them. This is seen on the schematic. At the point of the text where it says you should see NO continuity, you have not yet soldered in the 4th wire and therefore at this point there IS no continuity. 

The procedure is designed to make sure that you get all the wires in the correct holes. If you follow it carefully step by step, then it will all work out fine. If you ignore this and don't do DVM checks until right at the end of T2 installation, then yes, all the wires will have continuity to each other and you will no longer have any capability to check whether or not they are installed in the correct place. 

All of the descriptions ("right-hand pad") are referenced to the layout diagram in the manual; so it means, you should hold the PCB looking at it from the top side (component side), and orientated the same way as the layout diagram in the manual. This is also the most intuitive way to check it. 

So I think it is correct and I am not convinced that it is unclear... but maybe I can't see the lack of clarity in my own ramblings!

73 Hans G0UPL


On Fri, Jan 3, 2020 at 8:28 AM Hans Summers via Groups.Io <hans.summers=gmail.com@groups.io> wrote:
Hello Dennis

Please can you clarify what you mean by:

"GAAA! You're right! The locations of T1 and T3 on the schematic are opposite from the layout diagram. I failed to make that distinction earlier, and so came up with the wrong result. Rats!"

I just checked - the layout diagram in the manual is the same as the silkscreen on the PCB itself, and the nomenclature T1, T2 and T3 also matches the schematic. (T1 = input transformer, T2 = drain choke DC feed transformer, T3 = output transformer). If you are referring to the fact that the physical layout isn't an exact mapping of the electrical schematic, this is normal generally anyway for any PCB. 

73 Hans G0UPL


On Fri, Jan 3, 2020 at 8:01 AM Hans Summers via Groups.Io <hans.summers=gmail.com@groups.io> wrote:
Hi Dennis

I will check the manual again and let you know what I find... in the light of all the comments here. I did build three amps myself (one for each band 40/30/20) and they all worked first time; but when you already know the location of the treasure, it's hard to be sure you're following the map. 

73 Hans G0UPL

On Fri, Jan 3, 2020 at 6:43 AM Dennis Shelton <nadie1943@...> wrote:

GAAA! You're right! The locations of T1 and T3 on the schematic are opposite from the layout diagram. I failed to make that distinction earlier, and so came up with the wrong result. Rats!

Hans, if you're reading this, HELP!


On 1/2/2020 6:38 PM, Jon Reck W8REA wrote:
Dennis,

Please correct me if I am wrong but it seems to me that since T3 HAS been installed  (according to the manual, it is the first thing to install) with one end of the non black winding yet to be soldered in, there is a path thru the two winding tube of T3 back thru the black winding of T2 to C7, therefor contrary to what the manual says, there SHOULD BE continuity between the middle pin of Q1 to the right (non ground) side of C7 before the final non black end is soldered in.

Whew-  I could really be off base here- I am new to this stuff. But I printed out the schematic today and studied it and it seems clear to me. (famous last words)

Jon W8REA

Re: 50W amp T2 continuity check

Hans Summers
 

Hello Dennis

Please can you clarify what you mean by:

"GAAA! You're right! The locations of T1 and T3 on the schematic are opposite from the layout diagram. I failed to make that distinction earlier, and so came up with the wrong result. Rats!"

I just checked - the layout diagram in the manual is the same as the silkscreen on the PCB itself, and the nomenclature T1, T2 and T3 also matches the schematic. (T1 = input transformer, T2 = drain choke DC feed transformer, T3 = output transformer). If you are referring to the fact that the physical layout isn't an exact mapping of the electrical schematic, this is normal generally anyway for any PCB. 

73 Hans G0UPL


On Fri, Jan 3, 2020 at 8:01 AM Hans Summers via Groups.Io <hans.summers=gmail.com@groups.io> wrote:
Hi Dennis

I will check the manual again and let you know what I find... in the light of all the comments here. I did build three amps myself (one for each band 40/30/20) and they all worked first time; but when you already know the location of the treasure, it's hard to be sure you're following the map. 

73 Hans G0UPL

On Fri, Jan 3, 2020 at 6:43 AM Dennis Shelton <nadie1943@...> wrote:

GAAA! You're right! The locations of T1 and T3 on the schematic are opposite from the layout diagram. I failed to make that distinction earlier, and so came up with the wrong result. Rats!

Hans, if you're reading this, HELP!


On 1/2/2020 6:38 PM, Jon Reck W8REA wrote:
Dennis,

Please correct me if I am wrong but it seems to me that since T3 HAS been installed  (according to the manual, it is the first thing to install) with one end of the non black winding yet to be soldered in, there is a path thru the two winding tube of T3 back thru the black winding of T2 to C7, therefor contrary to what the manual says, there SHOULD BE continuity between the middle pin of Q1 to the right (non ground) side of C7 before the final non black end is soldered in.

Whew-  I could really be off base here- I am new to this stuff. But I printed out the schematic today and studied it and it seems clear to me. (famous last words)

Jon W8REA

Re: 50W amp T2 continuity check

Hans Summers
 

Hi Dennis

I will check the manual again and let you know what I find... in the light of all the comments here. I did build three amps myself (one for each band 40/30/20) and they all worked first time; but when you already know the location of the treasure, it's hard to be sure you're following the map. 

73 Hans G0UPL

On Fri, Jan 3, 2020 at 6:43 AM Dennis Shelton <nadie1943@...> wrote:

GAAA! You're right! The locations of T1 and T3 on the schematic are opposite from the layout diagram. I failed to make that distinction earlier, and so came up with the wrong result. Rats!

Hans, if you're reading this, HELP!


On 1/2/2020 6:38 PM, Jon Reck W8REA wrote:
Dennis,

Please correct me if I am wrong but it seems to me that since T3 HAS been installed  (according to the manual, it is the first thing to install) with one end of the non black winding yet to be soldered in, there is a path thru the two winding tube of T3 back thru the black winding of T2 to C7, therefor contrary to what the manual says, there SHOULD BE continuity between the middle pin of Q1 to the right (non ground) side of C7 before the final non black end is soldered in.

Whew-  I could really be off base here- I am new to this stuff. But I printed out the schematic today and studied it and it seems clear to me. (famous last words)

Jon W8REA

Re: 50W amp T2 continuity check

Paul AI4EE
 

GAAA! You're right! The locations of T1 and T3 on the schematic are opposite from the layout diagram. I failed to make that distinction earlier, and so came up with the wrong result. Rats!

Hans, if you're reading this, HELP!


On 1/2/2020 6:38 PM, Jon Reck W8REA wrote:
Dennis,

Please correct me if I am wrong but it seems to me that since T3 HAS been installed  (according to the manual, it is the first thing to install) with one end of the non black winding yet to be soldered in, there is a path thru the two winding tube of T3 back thru the black winding of T2 to C7, therefor contrary to what the manual says, there SHOULD BE continuity between the middle pin of Q1 to the right (non ground) side of C7 before the final non black end is soldered in.

Whew-  I could really be off base here- I am new to this stuff. But I printed out the schematic today and studied it and it seems clear to me. (famous last words)

Jon W8REA

Re: testing tx

hbco2@...
 

Matt,

It sounds normal.  If the QCX is not shielded you may be picking up the signals directly from the board.  The giveaway is the signals you see with a dummy load connected.  The dummy load shouldn’t allow any signals to radiate from the QCX antenna circuit.  Things to check:

  1. Do you have a good RF earth ground?  If not, all the cabling to your long wire could be part of an “antenna”.
  2. Did you tune an antenna tuner to the antenna at the frequency you are operating?  If not, all the cabling could be part of an “antenna”.
  3. Is the QCX physically near the SDR receiver?  If so, coupling could exist between the circuits of the two devices, irrespective of any antenna connections.
  4. Power supply leads (or any other wires) can act as RF radiators, particularly if the equipment is not properly grounded.

73 de Bill, AB6MT

 


From: QRPLabs@groups.io [mailto:QRPLabs@groups.io] On Behalf Of Matthew Halsey via Groups.Io
Sent: Thursday, January 02, 2020 6:45 PM
To: QRPLabs@groups.io
Subject: Re: [QRPLabs] testing tx

 

The QCX was straight into dummy load.  The SDR was connected to outside long wire.  I also unplugged the antenna from the SDR, so no antenna at all, and I couldn’t see any carrier from the dummy load.

 

Matt



On Jan 2, 2020, at 7:49 PM, N3MNT <bob@...> wrote:

Did you use the dummy load with the SWR meter or an antenna?

Re: testing tx

Matthew Halsey <rftb_cowboy@...>
 

I was running off 12v lead acid battery.


On Jan 2, 2020, at 7:48 PM, Ronald Taylor <wa7gil@...> wrote:


Hi Matt. That isn’t normal. But it could be one if several things. Are you using a switching power supply on the QCX?  If so can you switch to a battery and rerun the test? If you still see all those spurs it’s possible you are simply overloading the front end of the SDR. Maybe take the antenna off the receiver and try again? 

Good luck. ... Ron

On Thu, Jan 2, 2020 at 16:52 Matthew Halsey via Groups.Io <rftb_cowboy=yahoo.com@groups.io> wrote:
I bought a ready made QCX 40 and have had issues getting it to show any forward power in an SWR meter.
I fired it up into the QRP-Labs dummy load and observed the spectrum on an SDR connected to a 50 foot long wire.  I saw the carrier come up on 7.040 but also saw carriers (about 20dB down) at 10 kHz increments above and below the intended carrier.  Is this normal?

Matt


Re: testing tx

Matthew Halsey <rftb_cowboy@...>
 

The QCX was straight into dummy load.  The SDR was connected to outside long wire.  I also unplugged the antenna from the SDR, so no antenna at all, and I couldn’t see any carrier from the dummy load.

Matt


On Jan 2, 2020, at 7:49 PM, N3MNT <bob@...> wrote:

Did you use the dummy load with the SWR meter or an antenna?

Re: testing tx

N3MNT
 

Did you use the dummy load with the SWR meter or an antenna?

Re: testing tx

Ronald Taylor
 

Hi Matt. That isn’t normal. But it could be one if several things. Are you using a switching power supply on the QCX?  If so can you switch to a battery and rerun the test? If you still see all those spurs it’s possible you are simply overloading the front end of the SDR. Maybe take the antenna off the receiver and try again? 

Good luck. ... Ron

On Thu, Jan 2, 2020 at 16:52 Matthew Halsey via Groups.Io <rftb_cowboy=yahoo.com@groups.io> wrote:
I bought a ready made QCX 40 and have had issues getting it to show any forward power in an SWR meter.
I fired it up into the QRP-Labs dummy load and observed the spectrum on an SDR connected to a 50 foot long wire.  I saw the carrier come up on 7.040 but also saw carriers (about 20dB down) at 10 kHz increments above and below the intended carrier.  Is this normal?

Matt


Re: Cat Control APP for QCX

George Korper
 

You will do this I think. Impressive work! Thank you. 
Show us how so we can QSO. 

On Thu, Jan 2, 2020 at 5:51 PM Guido PE1NNZ <threeme3@...> wrote:
Can the QCX do FT8 just because of the CAT control????
No, CAT control is not used by FT8 for the actual FSK modulation and do not think QCX currently supports a CAT command that can transmit frequencies on command.

FT8/JS8 can be done with a QCX, but you would need to modify it to bypass the CW filter, and find a way to convert the FSK TX audio into frequency changes that the si5351 PLL can follow. I got it working by writing this https://github.com/threeme3/QCX-SSB but you can also write your own piece of software that tracks the input tone and translates it to frequency changes.

I am curious to see who gets FT8/JS8 encoding and decoding working native on the QCX itself, lots of fun :-)

73, Guido
PE1NNZ

testing tx

Matthew Halsey <rftb_cowboy@...>
 

I bought a ready made QCX 40 and have had issues getting it to show any forward power in an SWR meter.
I fired it up into the QRP-Labs dummy load and observed the spectrum on an SDR connected to a 50 foot long wire. I saw the carrier come up on 7.040 but also saw carriers (about 20dB down) at 10 kHz increments above and below the intended carrier. Is this normal?

Matt

Re: 50W amp T2 continuity check

Jon Reck W8REA
 

Dennis,

Please correct me if I am wrong but it seems to me that since T3 HAS been installed  (according to the manual, it is the first thing to install) with one end of the non black winding yet to be soldered in, there is a path thru the two winding tube of T3 back thru the black winding of T2 to C7, therefor contrary to what the manual says, there SHOULD BE continuity between the middle pin of Q1 to the right (non ground) side of C7 before the final non black end is soldered in.

Whew-  I could really be off base here- I am new to this stuff. But I printed out the schematic today and studied it and it seems clear to me. (famous last words)

Jon W8REA

Re: Cat Control APP for QCX

Guido PE1NNZ
 

Can the QCX do FT8 just because of the CAT control????
No, CAT control is not used by FT8 for the actual FSK modulation and do not think QCX currently supports a CAT command that can transmit frequencies on command.

FT8/JS8 can be done with a QCX, but you would need to modify it to bypass the CW filter, and find a way to convert the FSK TX audio into frequency changes that the si5351 PLL can follow. I got it working by writing this https://github.com/threeme3/QCX-SSB but you can also write your own piece of software that tracks the input tone and translates it to frequency changes.

I am curious to see who gets FT8/JS8 encoding and decoding working native on the QCX itself, lots of fun :-)

73, Guido
PE1NNZ

Re: 50W PA for QCX Arriving in the US

Chris Smith <me@...>
 

Probably not for this list, but I'm not sure why the 60m option is discontinued. All the parts are available. If you ignore the transverter bit, all it consists of is two relays, a few discrete parts and a PIC. I'm sure someone enterprising enough could fire up the wrath of Elecraft and knock up something equivalent. All the PIC does is talk on AUXBUS (proprietary but from my pokings with a scope pretty simple to work out) in the radio and pop relays.

Best regards,

Chris M0XTE

On Thu, 2 Jan 2020, at 21:27, Don Richards wrote:
Thanks to all who responded re my questions about the K2. It is on my wish list, I am concerned that the 60 meter option is no longer available due to obsolete parts. 
Thanks and Happy New Year
73 Don ve3ids

On Tue., Dec. 31, 2019, 7:33 p.m. Brien Pepperdine, <brianpepperdine@...> wrote:

Don. As a born and bred citizen of your fine city....for what that matters....

I would strongly recommend you build a K2. I've done it and lived! Seriously though, it is an excellent radio despite its vintage.. and the ability to have it as a QRP rig or build it right up to QRO with its amp and tuner is phenomenal rig.

I think you have enough foundation with the Weber rig under your belt, bench time,  as well as the mcHF, IMHO. The Elecraft mail list is Capital E Excellent in its membership for helping you if in doubt about anything. Just take time to do the build.. I spent about twice as much time as I think the 'average' time doing it methodically and double-checking components going in for value, placement and the solder joints and continuity. And truly it worked out of the gate on power up after all the testing and setup  procedures etc. in the manual.

An opportunity and rig not to be missed. Still got my 100 watt version ready and willing.

73

Brian VE3VAW Toronto

---------- Original Message ----------
From: Don Richards <ve3ids.don@...>
Date: December 31, 2019 at 7:13 PM


Mark

Thanks for the reply and info. All reports I have seen point to the K2 being a great rig inspite of its age. I have some kit building experience, a few One Watters, a Weber tri bander and a mcHF full SMD build and I used to be a two way tech with bench experience. I would like to be able to do a build of what is likely the last full kit before it's gone and the only option we have is to buy a box and operate. I have heard from a couple others off list already, thanks!! I would welcome any other comments on the K2.
Congrats on the build Mark and Happy New Year!

73 Don ve3ids


On Tue., Dec. 31, 2019, 6:55 p.m. Mark, < mark.yergin@...> wrote:
Don-

It’s an outstanding kit but not for the first time builder. Having completed a QCX would be a good prerequisite. I had both a K1 (years ago) and a couple of QRP Labs kits under my belt before I decided to tackle the K2. I was motivated by the challenge and also my worry (shared by you it seems) that eventually this kit would disappear. I’m in the final stages of the build, having started back at the start of the year. Took the summer and fall off to do some operating. Great technical support via the elecraft email reflector. I’ve used it a couple times. There is also a nice set of YouTube videos of a K2 build that I watched. Search for K2BEW.

Mark W8EWH

 

 



 





Re: 50W PA for QCX Arriving in the US

Don VE3IDS
 

Thanks to all who responded re my questions about the K2. It is on my wish list, I am concerned that the 60 meter option is no longer available due to obsolete parts. 
Thanks and Happy New Year
73 Don ve3ids

On Tue., Dec. 31, 2019, 7:33 p.m. Brien Pepperdine, <brianpepperdine@...> wrote:

Don. As a born and bred citizen of your fine city....for what that matters....

I would strongly recommend you build a K2. I've done it and lived! Seriously though, it is an excellent radio despite its vintage.. and the ability to have it as a QRP rig or build it right up to QRO with its amp and tuner is phenomenal rig.

I think you have enough foundation with the Weber rig under your belt, bench time,  as well as the mcHF, IMHO. The Elecraft mail list is Capital E Excellent in its membership for helping you if in doubt about anything. Just take time to do the build.. I spent about twice as much time as I think the 'average' time doing it methodically and double-checking components going in for value, placement and the solder joints and continuity. And truly it worked out of the gate on power up after all the testing and setup  procedures etc. in the manual.

An opportunity and rig not to be missed. Still got my 100 watt version ready and willing.

73

Brian VE3VAW Toronto

---------- Original Message ----------
From: Don Richards <ve3ids.don@...>
Date: December 31, 2019 at 7:13 PM

Mark

Thanks for the reply and info. All reports I have seen point to the K2 being a great rig inspite of its age. I have some kit building experience, a few One Watters, a Weber tri bander and a mcHF full SMD build and I used to be a two way tech with bench experience. I would like to be able to do a build of what is likely the last full kit before it's gone and the only option we have is to buy a box and operate. I have heard from a couple others off list already, thanks!! I would welcome any other comments on the K2.
Congrats on the build Mark and Happy New Year!

73 Don ve3ids


On Tue., Dec. 31, 2019, 6:55 p.m. Mark, < mark.yergin@...> wrote:
Don-

It’s an outstanding kit but not for the first time builder. Having completed a QCX would be a good prerequisite. I had both a K1 (years ago) and a couple of QRP Labs kits under my belt before I decided to tackle the K2. I was motivated by the challenge and also my worry (shared by you it seems) that eventually this kit would disappear. I’m in the final stages of the build, having started back at the start of the year. Took the summer and fall off to do some operating. Great technical support via the elecraft email reflector. I’ve used it a couple times. There is also a nice set of YouTube videos of a K2 build that I watched. Search for K2BEW.

Mark W8EWH

 

 


 

Re: Cat Control APP for QCX

jmh6@...
 

Hi George,

I tried with JS8CALL. Qcx emulation was not close enough to 'just work'. Probably because there are some hamlib commands that need a response that are not getting one?

That said, audio hookup is easy. Just gotta get the levels so the QCX transmitter is not overloaded and the receiver gain so that it uses most of the computer's ADC bits.

The only part left is transmit control. Hamlib has LOTS of options so you just need to find one that works.

If you have a computer old enough to have a real serial and parallel port, that will be easy.

Lots of fun :).

On Thu, 2 Jan 2020, George Korper wrote:

After i kept reading your email it started to look like a  YES. -.--. /. / ...
On Thu, Jan 2, 2020 at 9:55 AM Alan G4ZFQ <alan4alan@...> wrote:
> I believe the QCX was modified for WSPR receive

George,

It is easy to bypass the CW filter for SSB receive. The audio can be
sent to any digimode program.
TX is another matter..

73 Alan G4ZFQ

Re: 50W amplifier kit documentation findings

harleyleenuke
 

Update.  I got my amplifiers working. 
 I had to replace the IFR510's both of them and the R5 pot.   i lucked out, as those were the only broken parts.
 I used a 20 volt power supply and on 40m I am getting 45 watts.  on 20 meters I am able to get40 watts out.

I am pleased with the quality of the kit and the enclosure.  The heats sinks are doing a good job. They do get warm. 

Now to hit the airwaves!
Vern

Re: Beware Buck converters

George Korper
 

There is a good YouTube with a cure for that that uses a voltage and current 
feedback circuit. Not too complicated. 

On Sun, Dec 8, 2019 at 6:10 AM Phil Crockford <pcc@...> wrote:
I have just blown both my SigGen and prorock by using a buck converter to provide the 5volt Supply. it would seem that on power up the converter givers a short burst of the I/p voltage before regulating to the required 5volts. Stupid!!!!!!!!