Topics

Cricket 30 Output Power Statistics


WA0ITP
 

Tnx to all who responded to my request for the output power made by your Cricket 30s.

I received 8 responses, .6, 1, .7, .6, .8, 1, 1, and .9.  all on a 9V battery. The average is .8W.  Several made measurements on 12 volts and all were 1W or a bit more.

The data points show how manufacturing variation in the parts affects performance.  Wonder if receive sensitivity is affected as much xmitter performance, hmmm.

Being an old science teacher and manufacturing QC guy, this is interesting stuff.  I didn't expect to see such a large range in the data, min to max, in only 8 samples.  If this data spread came from a process I was monitoring, some quick studies would be warranted to find the root cause. OTOH there is just a little over 2 dB between 1 and .6, so if 1W can make haul, so can .6

Anyone else want to add their rig's info to the database? 

-- the rest 
72 WAØITP
I love this radio stuff.
Back to the bench, Winter is too valuable to waste.
www.wa0itp.com
www.4sqrp.com


AG1P Ron
 

Using 9V Duracell battery, my rig gets .7W out into dummy load as measured with my Diamond SWR/Power meter.

 

72 - Ron - AG1P

 

From: main@4SQRP.groups.io [mailto:main@4SQRP.groups.io] On Behalf Of WA0ITP
Sent: Sunday, April 29, 2018 9:45 AM
To: Cricket; 4sqrpio
Subject: [4SQRP] Cricket 30 Output Power Statistics

 

Tnx to all who responded to my request for the output power made by your Cricket 30s.

I received 8 responses, .6, 1, .7, .6, .8, 1, 1, and .9.  all on a 9V battery. The average is .8W.  Several made measurements on 12 volts and all were 1W or a bit more.

The data points show how manufacturing variation in the parts affects performance.  Wonder if receive sensitivity is affected as much xmitter performance, hmmm.

Being an old science teacher and manufacturing QC guy, this is interesting stuff.  I didn't expect to see such a large range in the data, min to max, in only 8 samples.  If this data spread came from a process I was monitoring, some quick studies would be warranted to find the root cause. OTOH there is just a little over 2 dB between 1 and .6, so if 1W can make haul, so can .6

Anyone else want to add their rig's info to the database? 


-- the rest 
72 WAØITP
I love this radio stuff.
Back to the bench, Winter is too valuable to waste.
www.wa0itp.com
www.4sqrp.com


John Lonigro
 

Terry:

You might ask how fresh the 9 volt batteries were, as well as the brand and the key-down terminal voltage when the power reading was taken.  Your analysis might be comparing batteries (or perhaps Wattmeters) more than crickets.

72,
John, AA0VE

On 04/29/2018 01:36 PM, Ron wrote:

Using 9V Duracell battery, my rig gets .7W out into dummy load as measured with my Diamond SWR/Power meter.

 

72 - Ron - AG1P

 

From: main@4SQRP.groups.io [mailto:main@4SQRP.groups.io] On Behalf Of WA0ITP
Sent: Sunday, April 29, 2018 9:45 AM
To: Cricket; 4sqrpio
Subject: [4SQRP] Cricket 30 Output Power Statistics

 

Tnx to all who responded to my request for the output power made by your Cricket 30s.

I received 8 responses, .6, 1, .7, .6, .8, 1, 1, and .9.  all on a 9V battery. The average is .8W.  Several made measurements on 12 volts and all were 1W or a bit more.

The data points show how manufacturing variation in the parts affects performance.  Wonder if receive sensitivity is affected as much xmitter performance, hmmm.

Being an old science teacher and manufacturing QC guy, this is interesting stuff.  I didn't expect to see such a large range in the data, min to max, in only 8 samples.  If this data spread came from a process I was monitoring, some quick studies would be warranted to find the root cause. OTOH there is just a little over 2 dB between 1 and .6, so if 1W can make haul, so can .6

Anyone else want to add their rig's info to the database? 


-- the rest 
72 WAØITP
I love this radio stuff.
Back to the bench, Winter is too valuable to waste.
www.wa0itp.com
www.4sqrp.com


gary Lyons
 

On 4/29/2018 12:45 PM, WA0ITP wrote:
Tnx to all who responded to my request for the output power made by your Cricket 30s.

I received 8 responses, .6, 1, .7, .6, .8, 1, 1, and .9.  all on a 9V battery. The average is .8W.  Several made measurements on 12 volts and all were 1W or a bit more.

The data points show how manufacturing variation in the parts affects performance.  Wonder if receive sensitivity is affected as much xmitter performance, hmmm.

Being an old science teacher and manufacturing QC guy, this is interesting stuff.  I didn't expect to see such a large range in the data, min to max, in only 8 samples.  If this data spread came from a process I was monitoring, some quick studies would be warranted to find the root cause. OTOH there is just a little over 2 dB between 1 and .6, so if 1W can make haul, so can .6

Anyone else want to add their rig's info to the database? 

-- the rest 
72 WAØITP
I love this radio stuff.
Back to the bench, Winter is too valuable to waste.
www.wa0itp.com
www.4sqrp.com

Terry, et al,

Finally cleared out all that "other stuff that happens in life" and getting back to clearing the email.

Every Cricket30 that tested in our room at the OzarkCon Builders' Session all reached .9 - 1.1w output as measured by a QRPOmeter.  This was all done with fresh 9V batteries that I distributed to each builder.  While there may be some variability in component tolerances I suspect the power supply may potentially (yep, pun intended!) have a more noticeable effect.  Mine here has always put out right at 1W on my very scientifically uncalibrated MFG meter.

--
73, Gary/w0gx


Gandalf The Gray <ronhogrider92@...>
 

Between .6 and 1 is really not much to write home about if I read your message correct.
The recipient won’t notice a difference.

Ron wb1hga

On Apr 29, 2018, at 12:45 PM, WA0ITP <wa0itp@...> wrote:

Tnx to all who responded to my request for the output power made by your Cricket 30s.

I received 8 responses, .6, 1, .7, .6, .8, 1, 1, and .9.  all on a 9V battery. The average is .8W.  Several made measurements on 12 volts and all were 1W or a bit more.

The data points show how manufacturing variation in the parts affects performance.  Wonder if receive sensitivity is affected as much xmitter performance, hmmm.

Being an old science teacher and manufacturing QC guy, this is interesting stuff.  I didn't expect to see such a large range in the data, min to max, in only 8 samples.  If this data spread came from a process I was monitoring, some quick studies would be warranted to find the root cause. OTOH there is just a little over 2 dB between 1 and .6, so if 1W can make haul, so can .6

Anyone else want to add their rig's info to the database? 

-- the rest 
72 WAØITP
I love this radio stuff.
Back to the bench, Winter is too valuable to waste.
www.wa0itp.com
www.4sqrp.com


wa2cky
 

Just as a FYI, another ham who built the Cricket found a strong dependence of power output with variations in the battery voltage (actually he substituted an external power supply and simply varied it). And obviously the various power meters we use throw another statistical uncertainty in there. It would be a nice little statistical analysis project for someone!

73
Bob Groh, WA2CKY 

On Sun, Apr 29, 2018 at 5:34 PM, Gandalf The Gray <ronhogrider92@...> wrote:
Between .6 and 1 is really not much to write home about if I read your message correct.
The recipient won’t notice a difference.

Ron wb1hga

On Apr 29, 2018, at 12:45 PM, WA0ITP <wa0itp@...> wrote:

Tnx to all who responded to my request for the output power made by your Cricket 30s.

I received 8 responses, .6, 1, .7, .6, .8, 1, 1, and .9.  all on a 9V battery. The average is .8W.  Several made measurements on 12 volts and all were 1W or a bit more.

The data points show how manufacturing variation in the parts affects performance.  Wonder if receive sensitivity is affected as much xmitter performance, hmmm.

Being an old science teacher and manufacturing QC guy, this is interesting stuff.  I didn't expect to see such a large range in the data, min to max, in only 8 samples.  If this data spread came from a process I was monitoring, some quick studies would be warranted to find the root cause. OTOH there is just a little over 2 dB between 1 and .6, so if 1W can make haul, so can .6

Anyone else want to add their rig's info to the database? 

-- the rest 
72 WAØITP
I love this radio stuff.
Back to the bench, Winter is too valuable to waste.
www.wa0itp.com
www.4sqrp.com



Chuck Carpenter
 

Even a fresh 9V battery has a high internal impedance.  And they droop quickly with a significant load.

Using a good power supply, well filtered and regulated would be requisite.  Also measure the key-down current and the power input to the final amp: determine efficiency. Then there is the also mentioned power meter. The QRPometer is a 2% accuracy meter, as I recall.
Otherwise, you might get good results with everyone using the same measuring method; a peak detector or an RF probe for instance and account for their associated tolerances.  A 10 meg, 1% DVM would help too. 

As Terry sez, from his QC experience and mine too, measurement can be a tricky business. Especially if you don't have traceability to a "gold standard"...
--
Chuck Carpenter, W5USJ
EM22cv Rains County, TX