CB and Ham Radio Techs Love Their Bird Wattmeters

[Wallace Gasiewicz]

I do not recall seeing this power and swr meter mentioned in this thread.
This is a QRP meter. Up to 10 Watts.
Here is a link, there is some conversation on another group.

https://github.com/WB2CBA/Barb-A-Watt-QRP-POWER-and-SWR-Monitor

[bd139]

Fairly standard design that. Suffers from the inevitable non-linearity of the sensor diode at low power.

I think the AD8307 etc based solutions we are looking at here tend to have a far higher dynamic range, say 80dB realistically down to very low powers which simple diode detectors can't match. This has a great advantage because you can stick a 40dB power tap in and measure 100W easily and down to -60dBm or so with one sensor head!

There is some more mileage with those diode sensors which can be linearised by sticking a matching diode (in the same package) in the feedback loop of an opamp to compensate for the IV relation of the diode. This only works to a certain extent.

Oh bought a broken Marconi 2022E here so will be using that for evaluating mine when I've fixed that and built this (so next year at this rate) 

[joeqsmith]

I do not recall seeing this power and swr meter mentioned in this thread.
This is a QRP meter. Up to 10 Watts.
Here is a link, there is some conversation on another group.

https://github.com/WB2CBA/Barb-A-Watt-QRP-POWER-and-SWR-Monitor

https://groups.io/g/QRPLabs/topic/88936360#80471

Mine works fine into 50 ohms, but into 25 or 100 ohms, it reads only ~1.4:1, so it significantly under-reports a VSWR of 2.0:1  Have not tried other simulated VSWRs, but I'm pretty unhappy with the VSWR portion of the meter.

Does seem like a fair bit of error. 

[bd139]

Well that's rubbish then. Much like software folks they probably only tested the happy path 

[joeqsmith]

Here I thought you would jump on WM4B (he uses his call sign of course) use of the term "VSWRs".   Those hams....

[mnementh]

...No luck in my search of SWRs but learned about "sad hams"   

https://youtu.be/ZQnW_MBVf2c?t=695

https://youtu.be/1_arJOVUKmU

mnem
*impairing productivity since nineteen-mumblety-mumble*

[bd139]

Here I thought you would jump on WM4B (he uses his call sign of course) use of the term "VSWRs".   Those hams....

Stuck on conference calls today so haven’t watched all the videos to get angry yet 

...No luck in my search of SWRs but learned about "sad hams"   

https://youtu.be/ZQnW_MBVf2c?t=695

https://youtu.be/1_arJOVUKmU

mnem
*impairing productivity since nineteen-mumblety-mumble*

I’m never going to be able to undo that relation in my head now 

[bd139]

Here I thought you would jump on WM4B (he uses his call sign of course) use of the term "VSWRs".   Those hams....

Ok just read the thing properly. That hurts. Surely he would say "I will measure the VSWR for different mismatches" 

If I was going to do it I'd step it through 10, 25, 50, 75, 100, 200 resistive loads and see what it reports at the very least. Then test against some reactive loads.

Prefer return loss myself though. But they don't understand that. "35dB return loss" seems to translate into "where's my signal been lost" in some retard heads.

[joeqsmith]

If I was going to do it I'd step it through 10, 25, 50, 75, 100, 200 resistive loads and see what it reports at the very least. Then test against some reactive loads.

I had sorted carbon parts for 10, 25, 75, 100, 150, and 200.  Obviously the temperature stability is poor, especially when you start dissipating >5W on a 2W part.  The 8310/8307 are both sensitive enough I could collect some VSWRS at much lower power levels.   

[bd139]

That reminds me of the crappy load I bought from ML&S here. Was rated at 100W pulsed 25W continuous. I was bored one afternoon so I blew 100W down it for a few seconds and smoke came out of the SO239  . Measured 32 ohms immediately after that. Was back at 53 when it cooled down 

So yep that’s yet another thing to consider.

[joeqsmith]

There was a set of Wiltron (?) mismatch loads on ebay.  The had the wooden case still.   Asking price was next to nothing as I doubt anyone knew what they were used for.   Hams would be looking at them, I need 50 ohms.     

You may be able to find some old surplus loads cheap enough to make a few standards.   
https://www.surplussales.com/rf/RFDummy-4.html

[joeqsmith]

The second AD8307 eval board arrived.  Installed Amphenol connectors on these and modified the new board to match the original. 

Mismatched loads were soldered to some edge mount connectors.   Even at 50MHz, the 150 and 200 ohm loads are not very good.   Actually, none of them are very good but I am guessing more stable than that ham with his hot water tank load...    

[A.Z.]

Another ham term we used to knock people about was "73s". In ham language "73" means "best regards".

But people would say "see you later seventy-threes".

73s? 

"73" means "best regards" so 73s would mean "best regardses" 

Not much different to people referring to "ATM machines"------"Automatic teller machine machines".

oh... I wonder if the ATMs in Vegas have a pull lever

at any rate, adding such a thing to a bird meter would add some thrill to measurement

[bd139]

RST slot would be good. Hey they pulled a 599 AGAIN 

Going to Vegas in November. Bad bad bad idea.

[xrunner]

How about a CB radio themed slot machine?

Three Bird meters pegged at 10 kW is the jackpot.

 

[vk6zgo]

How about a CB radio themed slot machine?

Three Bird meters pegged at 10 kW is the jackpot.

 

Might have been big in the 1970s!
Anyone who is stll a CBer these days has probably spent all their money on physical scam "high power" amplifiers, with nothing left for imaginary  ones!

[vk6zgo]

Here I thought you would jump on WM4B (he uses his call sign of course) use of the term "VSWRs".   Those hams....

If we accept "various impedances" instead of "various loads of differing impedances", it is but a short step to  referring to "various VSWRs" instead of "various loads offering differing VSWR readings".
Aaaiieee! The Abyss yawns!!

[joeqsmith]

Assorted battery holders arrived.   Went ahead and added heatshrink to the test loads and labeled them.   Most likely will start out without an amplifier and using some of the test boards I made for the NanoVNA.   Also the trash picked 18650s I plan to use with it.     

Swapped in the new sampling boards.  It appears the 8307 also exhibits the step but to a much lesser degree than the 8310.   Steps are now 0.005 dBm with the inputs set to roughly the same conditions when I tested the 8310s.   The step frequency is also much lower.  Guessing it's just something inherent with this family of parts.     

[joeqsmith]

I wonder what they charge for those high powered amps.  Do you think the scam is that they work at all? no amplification?  Perhaps just a large electronic load?   Or is the scam just that they are sold to the CBers and against regulations? 

I wonder how many hams introduce themselves, not just by their call sigh but with their license.   I am stating to notice that more time they spend leaning the regulations.   

Billy Jim Bob Jr, KQEXVT, Extraclass   I guess it carries weight within the inner circle but to me, I equate with someone with a high degree as a nutritionist referring to themselves as a Dr.   

[joeqsmith]

Just driving the two channels still with a splitter.  Level set to 0dBm and manually sweeping from 30MHz to 1MHz.   The two boards track well and overall stays within a dB.   

It's sensitive enough to see the old Marconi RF gen skip.  Appears to loose lock in a few places.  It is referenced to the GPS at 10MHz.  Setting the generator to 10.000 will cause it to drop.    Nothing more than a point slope correction so far.   

[vk6zgo]

RST slot would be good. Hey they pulled a 599 AGAIN 

Going to Vegas in November. Bad bad bad idea.

I lost all my youthful illusions about Casinos back in '71 at the Estoril Casino in Portugal.

Instead of "Mr Bond" & various elegant villains surrounded by gorgeous ladies in low cut evening gowns----just a bunch of sad gambling addicts in street clothes.
One woman was feverishly feeding coins into two machines, & pulling levers on both like it was a job on a production line.

I have been to several Casinos in Oz, since then ---obviously newer technology, & much larger venues, but still just a place to burn your money that should be spent on Test Equipment, &,  dare I say it?--- ham radio!

[xrunner]

That skip isn't a design problem then so looks good Joe.

I lost all my youthful illusions about Casinos back in '71 at the Estoril Casino in Portugal.

Instead of "Mr Bond" & various elegant villains surrounded by gorgeous ladies in low cut evening gowns----just a bunch of sad gambling addicts in street clothes.
One woman was feverishly feeding coins into two machines, & pulling levers on both like it was a job on a production line.

I have been to several Casinos in Oz, since then ---obviously newer technology, & much larger venues, but still just a place to burn your money that should be spent on Test Equipment, &,  dare I say it?--- ham radio!

You have to show up in black tie and sit down like you are a cool character - they would have come eventually. 

[vk6zgo]

I wonder what they charge for those high powered amps.  Do you think the scam is that they work at all? no amplification?  Perhaps just a large electronic load?   Or is the scam just that they are sold to the CBers and against regulations? 

Some years back, there were often Youtube videos of CB high power "shoot outs".
It seems they don't measure power at all at these events, but instead, measure the level of signal received by a receiver some distance away.
I suppose that is fair, as someone with a functional antenna would then be rewarded for that.
Another thing which probably makes for a "level playing field" is if they are all equally deluded about their alleged power levels!

I wonder how many hams introduce themselves, not just by their call sigh but with their license.   I am stating to notice that more time they spend leaning the regulations.   

Billy Jim Bob Jr, KQEXVT, Extraclass

That seems pretty much non-existent in Oz.
Back in the day, you could work out the licence class by the callsign, if you cared enough to bother, but now, they are all "chucked into a big bucket", & you might get anything!

   I guess it carries weight within the inner circle but to me, I equate with someone with a high degree as a nutritionist referring to themselves as a Dr.   

In fairness, if they have a Doctor's degree in their subject, they are entitled to use it.
After all, we have Doctors of Divinity, Political Science, & so on.

Many medicos in Oz are not MDs, but "Bachelors of Medicine"!

[vk6zgo]

That skip isn't a design problem then so looks good Joe.

I lost all my youthful illusions about Casinos back in '71 at the Estoril Casino in Portugal.

Instead of "Mr Bond" & various elegant villains surrounded by gorgeous ladies in low cut evening gowns----just a bunch of sad gambling addicts in street clothes.
One woman was feverishly feeding coins into two machines, & pulling levers on both like it was a job on a production line.

I have been to several Casinos in Oz, since then ---obviously newer technology, & much larger venues, but still just a place to burn your money that should be spent on Test Equipment, &,  dare I say it?--- ham radio!

You have to show up in black tie and sit down like you are a cool character - they would have come eventually. 

I would have "stuck out like a pimple on a pumpkin" amongst that crowd of "deros"!

[joeqsmith]

That skip isn't a design problem then so looks good Joe.

I suspect both disruptions caused by the old Marconi and IC are by design and there's not much we can do about them.   I'm hunting pretty far down in the noise.   Next step is to incorporate support for some of the other equipment so we can run a few tests on it.

Paints been drying for a few days.  Put some labels on it and stuck the box together.