Power Output


Dick <w1ksz@...>
 

I finished assembling my Nouveau 75 and find I only get
3.3 Watts out with a 13.6 VDC supply.

The measurement was made with a QRP Wattmeter that
I checked against my HP Wattmeter that I have periodically
sent to a local Cal Lab.

I checked the number of turns on the 4 toroids, so any other
thoughts ?

73, Dick, W1KSZ


ohwenzelph
 

Hi Dick,
So a bit low, it’s supposed to be 20 watts PEP, so 1/4 th of that (assuming 100% modulation) would be 5 watts carrier. If you are reporting the ‘carrier power’ then you are at 66% of the goal. From reports on the list, 4 watts carrier is not unusual. If there is a nearby webSDR, try transmitting into a good antenna and see if you can hear yourself over the web. It’s a low power rig so you won’t be real loud but if you can tell what it is you are saying then  you are capable of making contacts. If there is a local net, like the lonely guys net back here in New England on Saturday mornings, try signing into that. 
Bob Gass, post #123, reported “As an experiment, shorted one turn on L2, L3, L4 one at a time.  Found that with L2 and L3 with  one shorted turn narrowed the bandwidth and seemed to center it around 3.8 to 3.9 peaking around 5.5 watts there. Sensitivity improved to about 7 uv.“  I did not note any useful follow up, so who knows, but it’s something to consider.
Good luck and let us know.
thanks &
73 
jerry aa1of
franconia, nh


Dick <w1ksz@...>
 

I think I'll just live with it. I may do more damage getting the toroids out,
even using my Haako.

Tnx es 73, Dick, W1KSZ


From: main@4SQRP.groups.io <main@4SQRP.groups.io> on behalf of ohwenzelph via groups.io <Ohwenzelph@...>
Sent: Tuesday, March 8, 2022 8:34 AM
To: main@4SQRP.groups.io <main@4SQRP.groups.io>
Subject: Re: [4SQRP] Power Output
 
Hi Dick,
So a bit low, it’s supposed to be 20 watts PEP, so 1/4 th of that (assuming 100% modulation) would be 5 watts carrier. If you are reporting the ‘carrier power’ then you are at 66% of the goal. From reports on the list, 4 watts carrier is not unusual. If there is a nearby webSDR, try transmitting into a good antenna and see if you can hear yourself over the web. It’s a low power rig so you won’t be real loud but if you can tell what it is you are saying then  you are capable of making contacts. If there is a local net, like the lonely guys net back here in New England on Saturday mornings, try signing into that. 
Bob Gass, post #123, reported “As an experiment, shorted one turn on L2, L3, L4 one at a time.  Found that with L2 and L3 with  one shorted turn narrowed the bandwidth and seemed to center it around 3.8 to 3.9 peaking around 5.5 watts there. Sensitivity improved to about 7 uv.“  I did not note any useful follow up, so who knows, but it’s something to consider.
Good luck and let us know.
thanks &
73 
jerry aa1of
franconia, nh


Curt
 

Did you try spreading or squeezing the windings on the toroids? 

If you did adjust a toroid, you need to lift only one side. Kits should instruct up to tack solder one end down for these adjustments, as I confess in building several dozen rigs I still haven't learned that. 

Curt


Douglas L
 

About 2 turns need to be taken off several toroids in order to raise the frequency from around 3.6 MHz up to about 3.8 MHz where most AM activity is located.  
I’ve posted a bit about this on the Nouveau 75 user group’s site.

I wonder if toroid values are a problem in the other 4SQRP kits?

Doug/WA1TUT 


On Mar 8, 2022, at 5:32 PM, Curt via groups.io <wb8yyy@...> wrote:

Did you try spreading or squeezing the windings on the toroids? 

If you did adjust a toroid, you need to lift only one side. Kits should instruct up to tack solder one end down for these adjustments, as I confess in building several dozen rigs I still haven't learned that. 

Curt


Dick <w1ksz@...>
 

I measured the output power vs freq and got:

3.6 MHz    4.6W
3.7              3.5
3.8             2.7
3.9             2.1
4.0             1.8

I will pull one turn of each and see where we are.
I'll report back on my results.

73, Dick, W1KSZ


From: main@4SQRP.groups.io <main@4SQRP.groups.io> on behalf of Douglas L via groups.io <sparks06524@...>
Sent: Tuesday, March 8, 2022 6:36 PM
To: main@4sqrp.groups.io <main@4sqrp.groups.io>
Subject: Re: [4SQRP] Power Output
 
About 2 turns need to be taken off several toroids in order to raise the frequency from around 3.6 MHz up to about 3.8 MHz where most AM activity is located.  
I’ve posted a bit about this on the Nouveau 75 user group’s site.

I wonder if toroid values are a problem in the other 4SQRP kits?

Doug/WA1TUT 


On Mar 8, 2022, at 5:32 PM, Curt via groups.io <wb8yyy@...> wrote:

Did you try spreading or squeezing the windings on the toroids? 

If you did adjust a toroid, you need to lift only one side. Kits should instruct up to tack solder one end down for these adjustments, as I confess in building several dozen rigs I still haven't learned that. 

Curt


Dave Benson
 

Doug-

(This is general information, and not aimed at you)

The higher-than-expected inductance isn't just a 4SQRP thing. It's a common source of difficulty.  There's always stray capacitance between adjacent turns.  The calculations for inductance don't include that. They can't, since it's up to the care the builder takes when winding the toroids.  (Heavier-gauge wire also increases the effect due to its larger surface area. )

 It's important to make sure the turns are evenly spaced and spread out around the entire circumference of the toroid. This minimizes that unwanted effect. 

73- Dave, K1SWL


On Tue, Mar 8, 2022 at 8:36 PM Douglas L via groups.io <sparks06524=yahoo.com@groups.io> wrote:
About 2 turns need to be taken off several toroids in order to raise the frequency from around 3.6 MHz up to about 3.8 MHz where most AM activity is located.  
I’ve posted a bit about this on the Nouveau 75 user group’s site.

I wonder if toroid values are a problem in the other 4SQRP kits?

Doug/WA1TUT 


On Mar 8, 2022, at 5:32 PM, Curt via groups.io <wb8yyy=yahoo.com@groups.io> wrote:

Did you try spreading or squeezing the windings on the toroids? 

If you did adjust a toroid, you need to lift only one side. Kits should instruct up to tack solder one end down for these adjustments, as I confess in building several dozen rigs I still haven't learned that. 

Curt


w2sh@...
 

Instead of spreading a toroid inductor's winding fully around its circumference, it is better to reduce the winding portion from 360 degrees to 330 degrees.  The 30-degree gap thus created is then the form's surface that fits against the circuit board.  This reduces the capacitance between the outer surface of the windings and the ground plane effect of the circuit board.

 

A small piece of cork, 1/16" thick, cut from a wine bottle cork can be fixed with glue between the 30-degree gap on the form and the circuit board.  This will increase the separation between the two and also give a cushioning effect to the finished assembly.

 

Several years ago, a 1,500-word article I authored on how to wind and mount toroidal inductors was published in the QRP Quarterly.  If anyone would like to have this, please let me know.

 

Charles, W2SH



From: main@4SQRP.groups.io <main@4SQRP.groups.io> on behalf of Dave Benson <davek1swl@...>
Sent: Wednesday, March 9, 2022 7:17
To: main@4sqrp.groups.io <main@4sqrp.groups.io>
Subject: Re: [4SQRP] Power Output
 
Doug-

(This is general information, and not aimed at you)

The higher-than-expected inductance isn't just a 4SQRP thing. It's a common source of difficulty.  There's always stray capacitance between adjacent turns.  The calculations for inductance don't include that. They can't, since it's up to the care the builder takes when winding the toroids.  (Heavier-gauge wire also increases the effect due to its larger surface area. )

 It's important to make sure the turns are evenly spaced and spread out around the entire circumference of the toroid. This minimizes that unwanted effect. 

73- Dave, K1SWL

On Tue, Mar 8, 2022 at 8:36 PM Douglas L via groups.io <sparks06524=yahoo.com@groups.io> wrote:
About 2 turns need to be taken off several toroids in order to raise the frequency from around 3.6 MHz up to about 3.8 MHz where most AM activity is located.  
I’ve posted a bit about this on the Nouveau 75 user group’s site.

I wonder if toroid values are a problem in the other 4SQRP kits?

Doug/WA1TUT 


On Mar 8, 2022, at 5:32 PM, Curt via groups.io <wb8yyy=yahoo.com@groups.io> wrote:

Did you try spreading or squeezing the windings on the toroids? 

If you did adjust a toroid, you need to lift only one side. Kits should instruct up to tack solder one end down for these adjustments, as I confess in building several dozen rigs I still haven't learned that. 

Curt


--
Charles Moizeau, W2SH


keith ford
 

That would be great to rea! 


Sent from Yahoo Mail for iPad

On Wednesday, March 9, 2022, 11:48, w2sh@... wrote:

Instead of spreading a toroid inductor's winding fully around its circumference, it is better to reduce the winding portion from 360 degrees to 330 degrees.  The 30-degree gap thus created is then the form's surface that fits against the circuit board.  This reduces the capacitance between the outer surface of the windings and the ground plane effect of the circuit board.

 

A small piece of cork, 1/16" thick, cut from a wine bottle cork can be fixed with glue between the 30-degree gap on the form and the circuit board.  This will increase the separation between the two and also give a cushioning effect to the finished assembly.

 

Several years ago, a 1,500-word article I authored on how to wind and mount toroidal inductors was published in the QRP Quarterly.  If anyone would like to have this, please let me know.

 

Charles, W2SH



From: main@4SQRP.groups.io <main@4SQRP.groups.io> on behalf of Dave Benson <davek1swl@...>
Sent: Wednesday, March 9, 2022 7:17
To: main@4sqrp.groups.io <main@4sqrp.groups.io>
Subject: Re: [4SQRP] Power Output
 
Doug-

(This is general information, and not aimed at you)

The higher-than-expected inductance isn't just a 4SQRP thing. It's a common source of difficulty.  There's always stray capacitance between adjacent turns.  The calculations for inductance don't include that. They can't, since it's up to the care the builder takes when winding the toroids.  (Heavier-gauge wire also increases the effect due to its larger surface area. )

 It's important to make sure the turns are evenly spaced and spread out around the entire circumference of the toroid. This minimizes that unwanted effect. 

73- Dave, K1SWL

On Tue, Mar 8, 2022 at 8:36 PM Douglas L via groups.io <sparks06524=yahoo.com@groups.io> wrote:
About 2 turns need to be taken off several toroids in order to raise the frequency from around 3.6 MHz up to about 3.8 MHz where most AM activity is located.  
I’ve posted a bit about this on the Nouveau 75 user group’s site.

I wonder if toroid values are a problem in the other 4SQRP kits?

Doug/WA1TUT 


On Mar 8, 2022, at 5:32 PM, Curt via groups.io <wb8yyy=yahoo.com@groups.io> wrote:

Did you try spreading or squeezing the windings on the toroids? 

If you did adjust a toroid, you need to lift only one side. Kits should instruct up to tack solder one end down for these adjustments, as I confess in building several dozen rigs I still haven't learned that. 

Curt


--
Charles Moizeau, W2SH