Date   
QCX 20 Finished! Hum on SideTone

Daniel Conklin
 

I got my QCX basically finished and aligned, and it receives and transmits.  I listened to it on my base radio with the dummy load attached and it has a good note.  The only issue is there is a hum or buzz on the sidetone.  Has this happened to anyone else?

--
73, Dan - W2DLC

Re: T1 wire

Howie WA3MCK <Wa3mck@...>
 


QSL. My pleasure


On Sat, Jan 18, 2020 at 14:10 Don Blachura <w2xbwa2hpw@...> wrote:

TU Howie,

Sent for 28 ga from amazon. Thanks much for the thought.

 

Don..w2xb…….73

 

Sent from Mail for Windows 10

 

From: Howie WA3MCK
Sent: Saturday, January 18, 2020 2:00 PM
To: QRPLabs@groups.io
Subject: Re: [QRPLabs] T1 wire

 

What gauge wire and how much do you need Don. I might have some down in the shack.

 

Howie WA3MCK

 

 

On Fri, Jan 17, 2020 at 10:40 Don Blachura via Groups.Io <haircutter=verizon.net@groups.io> wrote:

Hello folks,
Need wire to wind my T1 torrid for 40 meters. Where can I buy It?
My old fingers broke the wire couple times..

Don...w2xb

--

"Quis custodiet ipsos custodes?"

 

--
"Quis custodiet ipsos custodes?"

Re: QRPLabs 10W HF Linear Amp Kit #pa #wspr

ajparent1/KB1GMX
 

The switched LPF on the output should be sufficient.


Allison
-------------------------------
Please reply on list so we can share.
No direct email, it goes to bit bucket due address harvesting in groups.IO

Re: T1 wire

Don Blachura <w2xbwa2hpw@...>
 

TU Howie,

Sent for 28 ga from amazon. Thanks much for the thought.

 

Don..w2xb…….73

 

Sent from Mail for Windows 10

 

From: Howie WA3MCK
Sent: Saturday, January 18, 2020 2:00 PM
To: QRPLabs@groups.io
Subject: Re: [QRPLabs] T1 wire

 

What gauge wire and how much do you need Don. I might have some down in the shack.

 

Howie WA3MCK

 

 

On Fri, Jan 17, 2020 at 10:40 Don Blachura via Groups.Io <haircutter=verizon.net@groups.io> wrote:

Hello folks,
Need wire to wind my T1 torrid for 40 meters. Where can I buy It?
My old fingers broke the wire couple times..

Don...w2xb

--

"Quis custodiet ipsos custodes?"

 

Re: T1 wire

Howie WA3MCK <Wa3mck@...>
 

What gauge wire and how much do you need Don. I might have some down in the shack.

Howie WA3MCK


On Fri, Jan 17, 2020 at 10:40 Don Blachura via Groups.Io <haircutter=verizon.net@groups.io> wrote:
Hello folks,
Need wire to wind my T1 torrid for 40 meters. Where can I buy It?
My old fingers broke the wire couple times..

Don...w2xb

--
"Quis custodiet ipsos custodes?"

Re: QRPLabs 10W HF Linear Amp Kit #pa #wspr

Brian George
 

Thanks Allison. I have learned a lot from your helpful responses to others on this list. Just a quick follow-up question if that's OK ....   will it be sufficient to use a QRPLabs relay-switched LPF on the P.A. output or should I also have low pass filtering between the SI5351A and the P.A. input?  

Brian
G3ZOH
 

Re: QRPLabs 10W HF Linear Amp Kit #pa #wspr

ajparent1/KB1GMX
 

A single stage 2n3904 will make up the difference.
Drive control as described before the 3904 amp will set power.

Don't forget the low pass network for clean output.

Allison
-------------------------------
Please reply on list so we can share.
No direct email, it goes to bit bucket due address harvesting in groups.IO

Re: QCX Modification Suggested In 50w Amp Assembly Instructions

Curt M.
 

Thanks guys!  Currently building a 20m and 40m amp at the same time. Hope to have them both done later today. Getting ready to mount T1 in both of them. Should be smooth sailing after that’s done.

Curt M.

Re: QRPLabs 10W HF Linear Amp Kit #pa #wspr

Brian George
 

Hi Shirley, Thank you very much. That's useful info.

73
Brian
G3ZOH

SVHFS 2020 Conference Announcement & Call For Papers/Presentations

Robin Midgett
 

The 2020 Southeastern VHF Society Conference will be held in Gainesville, Georgia on April 24-25, 2020. Gainesville, GA is approximately 60 miles north of Atlanta in EM84ch. It is about 1.5 miles from I-985. 

The Ramada Inn, of Gainesville, Georgia is the conference hotel for the 2020 SVHFS Conference. The hotel is now taking reservations directly. To book your room, please see the conference page or follow this information:

The conference rate is $80 per night. To secure this rate, call the hotel directly at 770-531-0907. Do not call Ramada central reservations or book through the Ramada Website.

 

Ramada Inn

400 E.E. Butler Parkway

Gainesville, GA 30501

770-531-0907

N34.297420 / W083.8222475 – Google Maps link

 

Call for papers:

Papers and presentations are solicited on both the technical and operational aspects of VHF, UHF and Microwave weak signal amateur radio. The deadline for the submission of papers and presentations for this year’s conference is March 7, 2020. Please indicate when you submit your paper or presentation if you plan to attend the conference and present your paper in person or if you are submitting solely for publication.  Papers and presentations are being handled by Charles Osborne, K4CSO, and they should be sent to Charles via K4CSO@.... Charles can be contacted at the same email address if you have any questions.

 

Please see http://svhfs.org/wp/conference/call-for-papers/ for complete details concerning papers and presentations.

Some suggested areas of interest are:

Transmitters

Receivers

Transverters

RF Power Amplifiers

RF Low Noise Pre Amplifiers

Antennas

Construction Projects

Test Equipment And Station Accessories

Station Design And Construction

Contesting

Roving

DXpeditions

EME

Propagation (Sporadic E, Meteor Scatter, Troposphere Ducting, etc.)

Digital Modes (WSJT, etc.)

Digital Signal Processing (DSP)

Software Defined Radio (SDR)

Amateur Satellites

Amateur Television

Unexpected project challenges, things that didn't go right at first; this information helps others avoid the issues.


Thanks,
Robin Midgett K4IDC

Re: QCX Modification Suggested In 50w Amp Assembly Instructions

Hans Summers
 

Hi the other Curt

No, that was a different mod. Tje pin 13-14 mod is a new one that prevents a brief keying of the transmitter on switch-on.

The mod is harmless on any QCX, whether used with a 50W amp or not. 

It probably isn't even important when you have a 50W amp. I used my QCX-40 with 50W amp for 6 months and over 500 QSOs before I had a problem with it... and then only because I switched on and off quickly. Some kind of power supply glitch. So it's a pretty non-critical kind of a mod, but useful to give you a little extra peace of mind if you believe in 3 belts and 3 sets of braces.

73 Hans G0UPL 

On Sat, Jan 18, 2020, 17:56 wb8yyy via Groups.Io <wb8yyy=yahoo.com@groups.io> wrote:
Many of us did this mod on our qcx early versions just to get it to power on properly. All should be well.

I guess I need to start building my 50w amp.

The other Curt M

Re: QCX Modification Suggested In 50w Amp Assembly Instructions

@CurtisM
 

Many of us did this mod on our qcx early versions just to get it to power on properly. All should be well.

I guess I need to start building my 50w amp.

The other Curt M

Re: QRPLabs 10W HF Linear Amp Kit #pa #wspr

Shirley Dulcey KE1L
 

The amp has 26dB gain, which means you need 25mW to drive it to full output. The Si5351A synthesizer board will not do that, and it likes a good match for best spectral purity. One stage of amplification between them will provide more than enough gain to get to 10W.

To get to WSPR power levels, reduce the drive that comes from your driver stage. The 10W amp is linear so nothing bad will happen.

On Sat, Jan 18, 2020, 8:13 AM Brian George via Groups.Io <george.familyuk=ntlworld.com@groups.io> wrote:

I'm going to build a QRPLabs 10W HF linear amp kit as a stand-alone unit for a variety of applications. Is there any chance someone could give advice on a couple of quick(?) questions :-

a) will the QRPLabs SI5351A generator (capacitor coupled but with no additional amplification) drive the P.A. to 10W output power up to 30 MHz?

b) what would be the best way of using this P.A. for WSPR power levels? Could a potentiometer be used across the SI5351A output with drive taken from the wiper or is there a better way? 

Thanks very much,

73
Brian
G3ZOH

Re: FOR SALE

steve_wg0at
 

Hi Jim, I have a unbuild kit SN 409 (a very early version) I just never found the time to build it ...I'll happily donate it your HSRC maybe your club will find it fun to assemble and launch some RF!

Cheers, Steve/wGOAT

QRPLabs 10W HF Linear Amp Kit #pa #wspr

Brian George
 

I'm going to build a QRPLabs 10W HF linear amp kit as a stand-alone unit for a variety of applications. Is there any chance someone could give advice on a couple of quick(?) questions :-

a) will the QRPLabs SI5351A generator (capacitor coupled but with no additional amplification) drive the P.A. to 10W output power up to 30 MHz?

b) what would be the best way of using this P.A. for WSPR power levels? Could a potentiometer be used across the SI5351A output with drive taken from the wiper or is there a better way? 

Thanks very much,

73
Brian
G3ZOH

Re: QCX Modification Suggested In 50w Amp Assembly Instructions

Gregg Myers
 

Hi Curt,
It won't affect the QCX during operation without the 50w amp. The modification is just a pull up resistor such that at initial QCX power up, the RX signal is held high (and therefore the TX line low) until the Microprocessor boots fully and takes over the job of controlling RX/TX. It works fine with or without the 50w amp attached.
73,
Gregg

On Sat, Jan 18, 2020 at 4:55 AM Curt M. <WU3URADIO@...> wrote:

Hi guys, if I do this modification will it affect the QCX under normal operation when not using the 50w amplifier?

It is strongly recommended to connect a 10K resistor in the QCX from IC3 pin 13 to IC3 pin 14. This modification is detailed further, here:

http://www.qrp-labs.com/qcx/qcxmods/ptt.html

Curt M.

QCX Modification Suggested In 50w Amp Assembly Instructions

Curt M.
 

Hi guys, if I do this modification will it affect the QCX under normal operation when not using the 50w amplifier?

It is strongly recommended to connect a 10K resistor in the QCX from IC3 pin 13 to IC3 pin 14. This modification is detailed further, here:

http://www.qrp-labs.com/qcx/qcxmods/ptt.html

Curt M.

Re: Dupont Leads get loose

Brian George
 

Hi Eric, Thanks for the useful tip about shortening URLs - I didn't know about that!

73
Brian
G3ZOH 

How to zero beat QCX? #qsx

Derek KJ4BQS
 

Is there a way to zero beat with the QCX? Does it work to put the keyer into practice mode so I can generate a tone and then tune to the beat? Is there a fast or more efficient way to do this?

Re: QCX post build testing #bias #dummy #problem

Gregg Myers
 

There you go! Good job finding the broken connection point. You can sleep well now!

Congrats,
Gregg

On Fri, Jan 17, 2020 at 9:00 PM Ryan Laurie <bigwowly@...> wrote:
Found it. I'm not sure if it's just solder or a bad component yet but I have the voltage off of IC10 pin 3 running up to the first half of c40. It doesn't get to the other side on the bottom of the board. So either I made a bad joint and it gets to the to the other pole of c40 but doesn't contact it's trace, it I have a bad capacitor which I find hard to believe but we'll see. My joints look ok but no signal in any of the resistors after c40 so it definitely stops there. 
--
Ryan