Date   
Re: Experiences with 50 watt Amp

Gregg Myers
 

My opinion? What a tremendous deal this $29 amp is. Do I need it all the time? No. I just made a QRP 5w contact yesterday from Idaho to Arizona on 20m with a 599 signal report. I didn't need 50w to do that. And a QRP QSO is still thrilling to me! But I also don't mind 50w when the occasion arrises. I have been participating in the K3Y straight key event this January, and on 20m I have been almost exclusively using a 20m QCX + 50w amp and a very mediocre dipole (for the 20m success you see below). How am I doing? Just great (compared to my past success). You see my 20m contacts here, and most all those 20m are with my very modest antenna and all are 50w.

Cheers,
Gregg W7GRM


On Sat, Jan 25, 2020 at 8:28 PM George Korper <georgekorper@...> wrote:
  Hi All,

I would like to hear from those who have used the new 50 watt amp,
or had the smoke rise from one ( it did smell like an old radio store
in my shack for a few days. My dad use to say I must like the smell of burning phenolic! ).

I also had a successful build and the documentation is amazing. I do think the board could use a revision
for part sizing and with 20 volts on my one misfortune I did notice that 20 volts and higher currents destroy the 
traces making a burnout blow up the board, burn traces and make it BER.  Hey $29, I don't mind, except it would
be better if there were an inventory in the States. 

I did notice that when I did get 30 watts on 20 I felt
crestfallen. Like it wasn't QRP anymore.  And one S Unit wasn't much.
All those hams who spent a thousands to go to 10 or 15 watts, thinking it was important.
Hans just saved me from that delusion. 

But being a realist I can see it has utility and would help the person at the other end.  I just don't see it as something i'll keep plugged in,but rather use when the occasion arises. 
Worth it for the build but not the outcome. And to carry an additional item and battery  around, that decreases thrill, is a risk of becoming a burden. 

The packaging in the enclosure is brilliant  Now mine has a distinctive aroma like in the tube days.
Friendly like my old baseball mitt. 

That is my story, but I would sure like to hear from the group, and your stories thus far. 
And BTW a short can actually make an inductor completely disappear. Just two wires and dust. Cool. 

Thanks,

George K3GK

Experiences with 50 watt Amp

George Korper
 

  Hi All,

I would like to hear from those who have used the new 50 watt amp,
or had the smoke rise from one ( it did smell like an old radio store
in my shack for a few days. My dad use to say I must like the smell of burning phenolic! ).

I also had a successful build and the documentation is amazing. I do think the board could use a revision
for part sizing and with 20 volts on my one misfortune I did notice that 20 volts and higher currents destroy the 
traces making a burnout blow up the board, burn traces and make it BER.  Hey $29, I don't mind, except it would
be better if there were an inventory in the States. 

I did notice that when I did get 30 watts on 20 I felt
crestfallen. Like it wasn't QRP anymore.  And one S Unit wasn't much.
All those hams who spent a thousands to go to 10 or 15 watts, thinking it was important.
Hans just saved me from that delusion. 

But being a realist I can see it has utility and would help the person at the other end.  I just don't see it as something i'll keep plugged in,but rather use when the occasion arises. 
Worth it for the build but not the outcome. And to carry an additional item and battery  around, that decreases thrill, is a risk of becoming a burden. 

The packaging in the enclosure is brilliant  Now mine has a distinctive aroma like in the tube days.
Friendly like my old baseball mitt. 

That is my story, but I would sure like to hear from the group, and your stories thus far. 
And BTW a short can actually make an inductor completely disappear. Just two wires and dust. Cool. 

Thanks,

George K3GK

Re: Keying hum

Gregg Myers
 

I see. Well, my ears aren't the best but I don't hear a hum on mine. I guess if you have access to an oscilloscope you could try and quantity it.

73,
Gregg


On Sat, Jan 25, 2020 at 5:40 PM Matthew Halsey via Groups.Io <rftb_cowboy=yahoo.com@groups.io> wrote:
I am using a battery.
It’s not too bad but is noticeable a little.

Matt


On Jan 25, 2020, at 7:09 PM, Gregg Myers <gregg.w7grm@...> wrote:


I don't notice a hum. Is it perhaps the power supply you are using? Maybe try comparing it to using battery power?

73,
Gregg

On Sat, Jan 25, 2020 at 5:07 PM Matthew Halsey via Groups.Io <rftb_cowboy=yahoo.com@groups.io> wrote:
Just getting my QCX on air.  When keying and wearing headphones I noticed a slight hum.  Do others get the same?

Matt



Re: Keying hum

Matthew Halsey <rftb_cowboy@...>
 

I am using a battery.
It’s not too bad but is noticeable a little.

Matt


On Jan 25, 2020, at 7:09 PM, Gregg Myers <gregg.w7grm@...> wrote:


I don't notice a hum. Is it perhaps the power supply you are using? Maybe try comparing it to using battery power?

73,
Gregg

On Sat, Jan 25, 2020 at 5:07 PM Matthew Halsey via Groups.Io <rftb_cowboy=yahoo.com@groups.io> wrote:
Just getting my QCX on air.  When keying and wearing headphones I noticed a slight hum.  Do others get the same?

Matt



Re: Keying hum

Gregg Myers
 

I don't notice a hum. Is it perhaps the power supply you are using? Maybe try comparing it to using battery power?

73,
Gregg

On Sat, Jan 25, 2020 at 5:07 PM Matthew Halsey via Groups.Io <rftb_cowboy=yahoo.com@groups.io> wrote:
Just getting my QCX on air.  When keying and wearing headphones I noticed a slight hum.  Do others get the same?

Matt



Keying hum

Matthew Halsey <rftb_cowboy@...>
 

Just getting my QCX on air. When keying and wearing headphones I noticed a slight hum. Do others get the same?

Matt

Re: Measuring output watts with an oscilloscope

Zdenek OK2BQN
 

It is quite possible to measure the output power using
automatic antenna tuner ATU-100 by N7DDC.
The photo shows the performance of a well tuned QCX 20m at
supply voltage 13,8V. Version 5Lx5C is small and fine tunes QCX.
Production lasted 1 weekend. Due to low power consumption is ATU
suitable for SOTA.

Re: T1 Installation problem

Leland L. Bahr
 

No doubt the T-1 transformer is a challenge.  Especially for 60 or 80 meters.  Lots of good ideas have been given.  To each his own what works best for him.  For me, I have found using smaller gauge wire for 80 meters helpful.  I also found using at least two different colored wires helpful too.  I also found using a very very small dab of clear 5 minute epoxy on each end of the BIG winding helpful too.  (Keeps it in place while doing the other three windings.)  Lastly, I always scrape the wires clean of insulation and then tin them before inserting into the PC board.  Learning how to not nick the wires with a knife is not hard to master.  I find that good insurance you will make a good electrical connection when soldering the wires on the board.  Lastly, I always check the connections with a VOM to insure it indeed was soldered properly.

Lee, w0vt

On 1/25/2020 12:26 PM, Jim W7EED wrote:
John, take a look at https://groups.io/g/QRPLabs/message/27864
--
73,
Jim W7EED

Re: Measuring output watts with an oscilloscope

GM4CID
 

The easiest way.

73 Bob GM4CID

Re: Measuring output watts with an oscilloscope

Zdenek OK2BQN
 

I think the correct formula for calculating power from peak-to-peak voltage from an oscilloscope is:

P = Upp^2/8R (R=50 Ohms)

73 Zdenek

Re: T1 Installation problem

Jim W7EED
 

John, take a look at https://groups.io/g/QRPLabs/message/27864
--
73,
Jim W7EED

Re: T1 Installation problem

Jim Mcilroy
 

Hi

Use a knife to take off a bit of enamel near the PCB hole. Can be tricky and depends on space.

Then put some solder on your iron and run it to and fro on the enamel wire to get it hot. If it starts to burn off you'll notice the smell (try not to breath it in)

Now solder the wire at the hole like you normally would.

73

Jim

G4EQX

On 25/01/2020 14:28, Alan G4ZFQ wrote:
So I did try to melt the enamel with the wire inserted in the PC board. That appears to be a bad approach.
John,

Not for thin wire according to Hans https://groups.io/g/QRPLabs/message/38391?p=,,,20,0,0,0::Created,,Hans+solder+enamel,20,2,0,34291462
It is important to have a hot enough iron. I attack the very end of the protruding wire first, the cut end helps heat the wire then add a little more solder.

This is one of the regular topics, I guess it depends on an individual to find what method works best for him.

73 Alan G4ZFQ

Re: T1 Installation problem

Alan G4ZFQ
 

So I did try to melt the enamel with the wire inserted in the PC board. That appears to be a bad approach.
John,

Not for thin wire according to Hans https://groups.io/g/QRPLabs/message/38391?p=,,,20,0,0,0::Created,,Hans+solder+enamel,20,2,0,34291462
It is important to have a hot enough iron. I attack the very end of the protruding wire first, the cut end helps heat the wire then add a little more solder.

This is one of the regular topics, I guess it depends on an individual to find what method works best for him.

73 Alan G4ZFQ

Re: T1 Installation problem

George Korper
 

Will this strip as small as #28 wire?


On Sat, Jan 25, 2020 at 5:52 AM David Wilcox via Groups.Io <Djwilcox01=yahoo.com@groups.io> wrote:
I endorse the Knipex if you are going to continue building kits throughout your life in this great hobby.  Get the “tweezers” as Knipex makes all kinds of wire strippers.  I bought extra blades too, different sizes.  I am 75 but plan on building for a lot of years.  My people live long and get crabby.  My wife says I am already there on number two.

Knipex 1511120 Coated-Wire Stripping Tweezers, 4.75 Inch https://www.amazon.com/dp/B003RWS8XE/ref=cm_sw_r_cp_tai_p1blEbJFTSC91

Dave K8WPE

David J. Wilcox K8WPE’s iPad

On Jan 25, 2020, at 5:16 AM, geoff M0ORE via Groups.Io <m0ore=tiscali.co.uk@groups.io> wrote:



Using steel wool in a radio workshop is bad news. The small pieces that detach themselves will invariably find their way onto the board and cause shorts. I have used fine grade steel wool myself in the past for cleaning a new board but do it in the garage and clean thoroughly in clean running water in the kitchen sink before going any near the radio workshop.

On 25/01/2020 03:35, Bruce K1FFX wrote:
Hi, John -

I've used the "solder blob" method exclusively, since stumbling across a "how to" video a number of years ago,
as I was just getting underway assembling an Elecraft K2 (lots of toroids to assemble!).  I have had 100%
success rate doing it this way.  The only think I'd add is that I've taken to rubbing some steel wool on the
now tinned toroid wire, resulting in a shiny and smooth surface, before proceeding to insert the toroid.

Cheers -

Bruce K1FFX

Re: T1 Installation problem

David Wilcox
 

I endorse the Knipex if you are going to continue building kits throughout your life in this great hobby.  Get the “tweezers” as Knipex makes all kinds of wire strippers.  I bought extra blades too, different sizes.  I am 75 but plan on building for a lot of years.  My people live long and get crabby.  My wife says I am already there on number two.

Knipex 1511120 Coated-Wire Stripping Tweezers, 4.75 Inch https://www.amazon.com/dp/B003RWS8XE/ref=cm_sw_r_cp_tai_p1blEbJFTSC91

Dave K8WPE

David J. Wilcox K8WPE’s iPad

On Jan 25, 2020, at 5:16 AM, geoff M0ORE via Groups.Io <m0ore@...> wrote:



Using steel wool in a radio workshop is bad news. The small pieces that detach themselves will invariably find their way onto the board and cause shorts. I have used fine grade steel wool myself in the past for cleaning a new board but do it in the garage and clean thoroughly in clean running water in the kitchen sink before going any near the radio workshop.

On 25/01/2020 03:35, Bruce K1FFX wrote:
Hi, John -

I've used the "solder blob" method exclusively, since stumbling across a "how to" video a number of years ago,
as I was just getting underway assembling an Elecraft K2 (lots of toroids to assemble!).  I have had 100%
success rate doing it this way.  The only think I'd add is that I've taken to rubbing some steel wool on the
now tinned toroid wire, resulting in a shiny and smooth surface, before proceeding to insert the toroid.

Cheers -

Bruce K1FFX

Re: T1 Installation problem

geoff M0ORE
 

Using steel wool in a radio workshop is bad news. The small pieces that detach themselves will invariably find their way onto the board and cause shorts. I have used fine grade steel wool myself in the past for cleaning a new board but do it in the garage and clean thoroughly in clean running water in the kitchen sink before going any near the radio workshop.

On 25/01/2020 03:35, Bruce K1FFX wrote:
Hi, John -

I've used the "solder blob" method exclusively, since stumbling across a "how to" video a number of years ago,
as I was just getting underway assembling an Elecraft K2 (lots of toroids to assemble!).  I have had 100%
success rate doing it this way.  The only think I'd add is that I've taken to rubbing some steel wool on the
now tinned toroid wire, resulting in a shiny and smooth surface, before proceeding to insert the toroid.

Cheers -

Bruce K1FFX

Re: Bilar and trifilar transformer winding direction

James Sweeden
 

Are we talking about T1 and T2 in the 50W PA?

Thanks,
James/KB7LJP

Re: Bilar and trifilar transformer winding direction

@tonyw8cdc
 

I can install both transformers, just not in the "over/under" way that is described in the instructions.  They will be sort of backward, but still neatly installed.  Will that matter.  (I am hoping Hans picks up on this, because my problem is caused by the photos in the instructions.)

Re: T1 Installation problem

Bruce K1FFX
 

Hi, John -

I've used the "solder blob" method exclusively, since stumbling across a "how to" video a number of years ago,
as I was just getting underway assembling an Elecraft K2 (lots of toroids to assemble!).  I have had 100%
success rate doing it this way.  The only think I'd add is that I've taken to rubbing some steel wool on the
now tinned toroid wire, resulting in a shiny and smooth surface, before proceeding to insert the toroid.

Cheers -

Bruce K1FFX

Re: More than Doubled the 1000 mile per watt goal with my QCX

@CurtisM
 

Wonderful contact nonetheless. Someone with too much time on their hands can consider the distance squared relationship to path loss, making result more amazing. Sure make some more contacts, amazing miles per watt per dollar is off the charts ham radio, with low solar flux even. Let's await a 10m qcx like rig at sunspot peak, or use a qsx.

73 curt