CB and Ham Radio Techs Love Their Bird Wattmeters

[joeqsmith]

   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.

As the ham can call themselves what ever they like and as the owner of this forum has stated you are free to call yourself an engineer.   All three cases demand the same respect.  Just very little. 

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!

As long at the rules are clear, I don't see a problem and hardly consider it a scam.   Thing to do would be buy a smaller one and measure it.     

[vk6zgo]

   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.

As the ham can call themselves what ever they like and as the owner of this forum has stated you are free to call yourself an engineer.   All three cases demand the same respect.  Just very little. 

I would never call myself an Engineer----I have some standards!

As I pointed out, however, many of those we call "Doctors" as a courtesy title, are "Bachelors of Medicine".
I'm not saying they are not expert in their field---they don't really have the official title.

If people in other fields of study have completed a Doctorate, they surely have the right to use it.

Many do have them, but would only use them in official papers.

Buzz Aldrin is officially "Dr Aldrin", but I never knew that till the "Chief Scientist of Western Australia" used
his title in a lecture about Space science.

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!

As long at the rules are clear, I don't see a problem and hardly consider it a scam.   Thing to do would be buy a smaller one and measure it.   

I think the "scam" is not in the contest, but in the power output claims of those who produce such amplifiers.

[joeqsmith]

When

... I think the "scam" is not in the contest, but in the power output claims of those who produce such amplifiers. ...

Rather than stating it's a scam, you should post some data backing it up.  .... Oh right ....

[mnementh]

...Actually, none of them are very good but I am guessing more stable than that ham with his hot water tank load...

"...anything less than jigga-hurtz is essentially DC." ~overheard on eevBlog somewhere...

mnem

[bd139]

Oh that still gives me cancer seeing that load 

I bet it'd look "interesting" on a VNA. Smith chart looks like 2 year old got hold of a sharpie.

[mnementh]

"Empirical Engineering" at its finest, right there.

Bet it gets really interesting depending on where you decide to tap for your tests...

mnem
And whether it's wet or dry... and the curvature of the earth... and sunspots... Don't forget sunspots! CBers love to blame sunspots! 

[bd139]

Well to be fair there is some merit in sunspots affective propagation 

I was just mulling that it'd be interesting to try and build a matching network for that load. You might have to put a float attached to a big ass variable cap in the circuit somewhere to compensate for fluid evaporation 

[Mark19960]

When

... I think the "scam" is not in the contest, but in the power output claims of those who produce such amplifiers. ...

Rather than stating it's a scam, you should post some data backing it up.  .... Oh right ....

I think that's fair. Extraordinary claims require extraordinary evidence.... but I am not sure that this is really an extraordinary claim.
As to power, I saw a video of one of these amp builders in the states probably within the last year putting like 20 watts into one of those amplifiers and getting 1200 watts "BIRD" out.
Running on 14 volts and drawing 50 amps.

 

I would say that is a "happy" bird meter.

[joeqsmith]

A pretty decent video on power measurement.   The trusty Bird is even shown.

When

... I think the "scam" is not in the contest, but in the power output claims of those who produce such amplifiers. ...

Rather than stating it's a scam, you should post some data backing it up.  .... Oh right ....

I think that's fair. Extraordinary claims require extraordinary evidence.... but I am not sure that this is really an extraordinary claim.
As to power, I saw a video of one of these amp builders in the states probably within the last year putting like 20 watts into one of those amplifiers and getting 1200 watts "BIRD" out.
Running on 14 volts and drawing 50 amps.

 

I would say that is a "happy" bird meter.

Or, thinking at it from a continuous operation rather than looking at the duty cycle.   It would be fun to play with one.  I could do an unboxing video and blab about how good it is for a half hour as I personally don't have any way to test one.   

The manufacture's specs for the Bird meters is clear.   When the ham and CBers start calling them the gold standard and making claims about numbers without considering the errors, I laugh.   There's no getting around that.   

[joeqsmith]

Attempting to measure the VSWR with a few loads attached.  10ohms reads around 4.5.  500, about 12.   I then increased and decreased the drive.  There's no amplifier and about 25dB of loss.   As the signal gets lower, we see the error go up.   

[vk6zgo]

When

... I think the "scam" is not in the contest, but in the power output claims of those who produce such amplifiers. ...

Rather than stating it's a scam, you should post some data backing it up.  .... Oh right ....

I think that's fair. Extraordinary claims require extraordinary evidence.... but I am not sure that this is really an extraordinary claim.
As to power, I saw a video of one of these amp builders in the states probably within the last year putting like 20 watts into one of those amplifiers and getting 1200 watts "BIRD" out.
Running on 14 volts and drawing 50 amps.

 

I would say that is a "happy" bird meter.

Yeah, 171% efficiency is a fairly ambitious claim!

That said, RF amplifiers of around that sort of CW power level are quite readily realisable at UHF in a size you could fit into a car.
HF ham "linears" are made with similar ratings, so it is possible at 27MHz (& even below), although the linears usually need 100W drive.

Powering either such device is another question, as they are not designed for mobile use & normally have dedicated mains operated power supplies.
At a realistic 80% efficiency, the 14v source would have to supply 107 amps.

The claims I was referring to are of much higher power levels----the CB "shootout" guys often claim 10kW to 20 kW!

These things are crammed into long suffering vehicles, with hotted up V8 engines which seem to have, as their sole purpose, driving multiple heavy duty alternators.----I'm not sure if the vehicles are even driveable!
Even with all that effort, I am still dubious about their claims.

I have never seen any data backing up those claimed figures, so to me, they are in the same realm as the audiophile nonsense.

[vk6zgo]

A pretty decent video on power measurement.   The trusty Bird is even shown.

The water cooled load is how we measured power at several transmitter sites.
It is very repeatable, unless the Laws of Physics somehow change!

I think why they aren't used so much these days isn't because of any great breakthroughs in other methods, but because they are expensive & need maintenance, which starts to cost extra when sites are no longer staffed, & contractors must be used.
"Good enough" is ever the enemy of "perfect", & other methods are "good enough".

The "digital" meter is impressive, but it relies upon accurate positioning of the probe on the coax or waveguide line, just as its analog counterparts do.
Once that probe is correctly fitted, any peculiarities can be corrected for.

Practically, unless there is a disastrous failure of the sampling section, the probe can sit there for decades, so "good enough" becomes "very good, indeed"!

On the  subject of "the trusty Bird".

At 3:46 in, the big "Bird" meter has a pointer made of an offcut of red Dymo tape pointing to a particular point on the scale.
In practice, a Tech or EE would, in passing, check that the needle was at that mark showing the  correct power level, as previously determined by a more sophisticated instrument.
In other instances,a list of scale corrections, usually with "normal" figures highlighted may be attached.

As I have previously pointed out, many Birds were used in situations where they offered a good "quick check" that  all was well.
From the point of view of Broadcasting & Comms companies they were "dirt cheap".

I would say that is a "happy" bird meter.

Or, thinking at it from a continuous operation rather than looking at the duty cycle.   It would be fun to play with one.  I could do an unboxing video and blab about how good it is for a half hour as I personally don't have any way to test one.   

The manufacture's specs for the Bird meters is clear.   When the ham and CBers start calling them the gold standard and making claims about numbers without considering the errors, I laugh.   There's no getting around that.

[Mark19960]

When

... I think the "scam" is not in the contest, but in the power output claims of those who produce such amplifiers. ...

Rather than stating it's a scam, you should post some data backing it up.  .... Oh right ....

I think that's fair. Extraordinary claims require extraordinary evidence.... but I am not sure that this is really an extraordinary claim.
As to power, I saw a video of one of these amp builders in the states probably within the last year putting like 20 watts into one of those amplifiers and getting 1200 watts "BIRD" out.
Running on 14 volts and drawing 50 amps.

 

I would say that is a "happy" bird meter.

Yeah, 171% efficiency is a fairly ambitious claim!

That said, RF amplifiers of around that sort of CW power level are quite readily realisable at UHF in a size you could fit into a car.
HF ham "linears" are made with similar ratings, so it is possible at 27MHz (& even below), although the linears usually need 100W drive.

Powering either such device is another question, as they are not designed for mobile use & normally have dedicated mains operated power supplies.
At a realistic 80% efficiency, the 14v source would have to supply 107 amps.

The claims I was referring to are of much higher power levels----the CB "shootout" guys often claim 10kW to 20 kW!

These things are crammed into long suffering vehicles, with hotted up V8 engines which seem to have, as their sole purpose, driving multiple heavy duty alternators.----I'm not sure if the vehicles are even driveable!
Even with all that effort, I am still dubious about their claims.

I have never seen any data backing up those claimed figures, so to me, they are in the same realm as the audiophile nonsense.

I have personally seen the "CB shootout" or "keydown" performed many years ago.
It involved a tape recorder placed between the vehicles - usually suburbans.
The "competitors" then get on their radios and scream into them...

They have the bird meters at the front where the radio is often built into a console.
Some of them are done quite nicely. The goal being to see those bird meters moving!

As to the power.... I saw corona coming off the antennas. I am betting they are up there in terms of power.
The vehicles are driveable but mileage was already bad on a suburban, and even worse with that setup.

If you want to subject yourself to high levels of RF, go to a keydown...

[Wallace Gasiewicz]

Years ago we had a "shootout" champion show up at the radio shop. He turned on his radio to demonstrate.
Upon seeing the corona and sparks from his antenna, apparently all the observers ran inside. Pretty funny.
He had a special mounting on the front of his engine that supported several high amp alternators (six,I think), extra batteries also.
Yea, these vehicles are drive able. Maybe you could charge your Tesla from one of them???

Never been to one but I believe from all reports that Shootouts are usually staged in a spot where there is a clear line of sight to a receiving device  A radio, with attenuators. Results are the S meter reading. Accuracy is not important, relative signal strength is what is measured.

There are lots of amps that run on 14 volts that are used by CBers. A lot of them have huge gain that is not allowed in HAM equipment.
New solid state amps use 50 V supplies. A lot of CB amps used in base stations use commercial transmit tubes. With the required high volt power supplies. Scary Stuff.
Often a low power radio is fed into a linear and then that linear into still another bigger linear.
I know one guy who uses commercial hard line to his antenna. Some even have three phase power to their shacks.
Some use a big Henry as a "Driver" for their final amp. Go Think!

[vk6zgo]

When

... I think the "scam" is not in the contest, but in the power output claims of those who produce such amplifiers. ...

Rather than stating it's a scam, you should post some data backing it up.  .... Oh right ....

I think that's fair. Extraordinary claims require extraordinary evidence.... but I am not sure that this is really an extraordinary claim.
As to power, I saw a video of one of these amp builders in the states probably within the last year putting like 20 watts into one of those amplifiers and getting 1200 watts "BIRD" out.
Running on 14 volts and drawing 50 amps.

 

I would say that is a "happy" bird meter.

Yeah, 171% efficiency is a fairly ambitious claim!

That said, RF amplifiers of around that sort of CW power level are quite readily realisable at UHF in a size you could fit into a car.
HF ham "linears" are made with similar ratings, so it is possible at 27MHz (& even below), although the linears usually need 100W drive.

Powering either such device is another question, as they are not designed for mobile use & normally have dedicated mains operated power supplies.
At a realistic 80% efficiency, the 14v source would have to supply 107 amps.

The claims I was referring to are of much higher power levels----the CB "shootout" guys often claim 10kW to 20 kW!

These things are crammed into long suffering vehicles, with hotted up V8 engines which seem to have, as their sole purpose, driving multiple heavy duty alternators.----I'm not sure if the vehicles are even driveable!
Even with all that effort, I am still dubious about their claims.

I have never seen any data backing up those claimed figures, so to me, they are in the same realm as the audiophile nonsense.

I have personally seen the "CB shootout" or "keydown" performed many years ago.
It involved a tape recorder placed between the vehicles - usually suburbans.
The "competitors" then get on their radios and scream into them...

They have the bird meters at the front where the radio is often built into a console.
Some of them are done quite nicely. The goal being to see those bird meters moving!

As to the power.... I saw corona coming off the antennas. I am betting they are up there in terms of power.
The vehicles are driveable but mileage was already bad on a suburban, and even worse with that setup.

If you want to subject yourself to high levels of RF, go to a keydown...

Meh! I worked for years at a site which had a "dual tuned vertical radiator" fed by a 55kW & a 10kW MF broadcast Tx, whilst there were 50kW & 10kW HF b/cast Tx feeding nice big curtain arrays.

A pleasant stroll in the early afternoon  was to walk down alongside the "six conductor feeder" (erzatz coax , with two conductors connected in parallel for the centre conductor, with a "cage" of 4 conductors for the outer), down to the mast hut to do the routine meter readings.
(We later found out there was a big spike in RF exposure at each mounting post.)

The hut was interesting---you could see a lttle spark when you inserted the door key, & the inside smalled of ozone.
There was a constant "muttering" in the background from minor arcs between the sheets of copper coating the walls.

A "harmless" little trick was using a bit of heavy steel wire on the end of a long porcelain insulator to create an arc between the downpipe off the roof, & one of the posts of the mesh fence surrounding the mast base.
The arc, between these two nominally earthed points would demodulate the radio program from, counter-intuitively, the 10kW MF.

The Boss got a bit upset when he saw how much we had burnt off the end of the downpipe, & stopped our fun.

The Mast had "horn gaps" to discharge any pickup of charge from Thunderstorms in the region, or, of course, full on lightning strikes.
One day, there was a storm "brewing about 80km away, with "not much likelihood of seeing anything where we were for a few hours".
I had done my visit, & was on my way back, when one of the horn gaps "went over", & a Stentorian voice roared forth, as a mega version of our fun "singing arc"!

It sounded like The Almighty had taken an interest in the football scores!

[vk6zgo]

Years ago we had a "shootout" champion show up at the radio shop. He turned on his radio to demonstrate.
Upon seeing the corona and sparks from his antenna, apparently all the observers ran inside. Pretty funny.

Pretty much a demonstration of a highly inefficient antenna---acting more like a Tesla coil!

He had a special mounting on the front of his engine that supported several high amp alternators (six,I think), extra batteries also.
Yea, these vehicles are drive able. Maybe you could charge your Tesla from one of them???

I was thinking the other way round---using the higher voltage traction batteries of the Tesla to operate the amplifier.
At least you might get enough P=VI to make relatively high power useable.
I suppose that would be outside the "shoot out" rules, like fronting up with a trailer mounted 100kVa 3ph diesel gen set! 

Never been to one but I believe from all reports that Shootouts are usually staged in a spot where there is a clear line of sight to a receiving device  A radio, with attenuators. Results are the S meter reading. Accuracy is not important, relative signal strength is what is measured.

There are lots of amps that run on 14 volts that are used by CBers. A lot of them have huge gain that is not allowed in HAM equipment.

The big trouble with 14 volts is that for, say, 20kW, & a realistic 80% efficiency, you need 1,786 amps!

New solid state amps use 50 V supplies.

You can use inverters to get to 50v, but the problem remains, that for a mobile installation, 1,786 amps (plus more for inverter losses) is still sourced from your 14v batteries.

 A lot of CB amps used in base stations use commercial transmit tubes. With the required high volt power supplies. Scary Stuff.
Often a low power radio is fed into a linear and then that linear into still another bigger linear.

 Tubes, of course, introduce new overheads in the shape of filament current, which amounts to quite a massive figure in its own right!

I know one guy who uses commercial hard line to his antenna.

There is "hardline" & "hardline".

The "six wire line" I referred to in reply #589 has now been replaced by buried coax at that radio site----not sure of the size,  but it looks larger in diameter than the 31/8" stuff we used at the TV sites.

 Some even have three phase power to their shacks.

Funny, that! I have 3ph fed to my house-- I only use 2 phases for my kitchen oven--there was a hulking great 3ph outlet in the carport, but that's gone, now.

Some use a big Henry as a "Driver" for their final amp. Go Think!

I have no doubt that CBers are getting power outputs in the 1-2kW range with enormous effort, but, as I pointed out, 20kW sounds very fanciful!

[joeqsmith]

Some of them are done quite nicely. The goal being to see those bird meters moving!

That does seem to be the draw for the ham and CBers.   

When

... I think the "scam" is not in the contest, but in the power output claims of those who produce such amplifiers. ...

Rather than stating it's a scam, you should post some data backing it up.  .... Oh right ....

I think that's fair. Extraordinary claims require extraordinary evidence.... but I am not sure that this is really an extraordinary claim.
As to power, I saw a video of one of these amp builders in the states probably within the last year putting like 20 watts into one of those amplifiers and getting 1200 watts "BIRD" out.
Running on 14 volts and drawing 50 amps.

Yeah, 171% efficiency is a fairly ambitious claim!

...
Powering either such device is another question, as they are not designed for mobile use & normally have dedicated mains operated power supplies.
At a realistic 80% efficiency, the 14v source would have to supply 107 amps.

I would imagine for the shootouts they would run much higher voltages.    I doubt they have to run for very long but having never attended such an event, I don't know.  Say it's key down for 30 seconds but 20 minutes between rounds.  That's a lot of time to recharge your storage bank.  Without considering the duty cycle, the voltage/current means little.  Similar to the ham who doesn't consider the error of their Bird.   

... extra batteries also.
..

Never been to one but I believe from all reports that Shootouts are usually staged in a spot where there is a clear line of sight to a receiving device  A radio, with attenuators. Results are the S meter reading. Accuracy is not important, relative signal strength is what is measured.

Extra storage makes sense.  Depending how long it needs to run and how much time they have to recharge between rounds would be the key.   Like any competition, winners will  understand the rules and use them to their advantage.  The losers will go home sucking their thumbs and cry about the winners cheating.    

[joeqsmith]

Trying the second coupler.   Previously I used 10dB attenuators with the 19dB coupler.   This test the 30dB coupler was attached directly to the cheap AD8307 eval boards.   Like before, no amplifier was used and the output level was set to 13dBm @ 15MHz.   In both cases, point slope was used for each individual eval board using the 50ohm standards to calibrate the two directions.

[xrunner]

VSWR  results look pretty good. 

[joeqsmith]

Where I had previously adjusted the output level with the 500 ohm load attached, with the 30dB coupler I used the 50 ohm standard.   Starting at 10dBm and working down to -40 (-70dBm at the eval board) where the VSWR doubles.   

For the hams,  17dBm at our eval board (50mWish max).  30dB coupler gets us to 50W.   Put your 50W slug in your golden Bird and try these same tests.    

[joeqsmith]

Comparing the Signal Hound sweeping the input power at 3MHz.   

Increasing the power to 8Watts and frequency to 30MHz then letting it settle.    The two seem to track alright. 

***
Included the 30MHz power sweep.   

[joeqsmith]

Without any attenuators between the 30dB coupler and detectors, again, it's limited to about 50W.  Showing the stability with 38Watts applied at 30MHz.   The two sets of downward noise is me touching the amplifier's heatsink to monitor the temperature. 

[Wallace Gasiewicz]

To : VK6GO

ALL the CB antennas on mobiles are inefficient., You are correct. They all need a big loading coil, as do Ham HF antennas. To run what shootouts are running is just nuts.
 (I think that is the point however). They have multiple antennas on their trucks, how they match these to the amps, I have no idea.

50 volt linears I was referring to are for home base stations, as of course are the tube amps.

About amps: six 200 amp alternators would make 15,000 Watts. Maybe the amplifiers themselves are 50% efficient. Maybe 70%, so maybe 10.000 watts into the antenna. What portion of that goes into corona, I have no idea, but it must be quite significant.

I really like your Tesla battery suggestion, maybe I'll buy one and win the next shootout!

By the way, all of this stuff they do is illegal, both mobile and base station, but the regulatory agencies are concentrating on other issues.
Since digital TV arrived, there is no severe interference with the second harmonic of a 27 MHz transmission.

Here is an example of a CB Linear amp:  https://jokermanelectronics.com/base-amp-2-pic-unit-32-pill-2sc2879-with-power-supply/

I think this linear uses higher voltages than 14, but you get the idea.....

Edit: here are some more of their amps, some of these ore 14 Volt Supply
https://www.angelfire.com/crazy/bonacheeta/amps_and_pricing.html

[xrunner]

Edit: here are some more of their amps, some of these ore 14 Volt Supply
https://www.angelfire.com/crazy/bonacheeta/amps_and_pricing.html

Wait! It states -

Not intended to be used on the 11 meter band,
Doing so is a violation of FCC rules and regulations!!!

Where do you use them!

[vk6zgo]

I just love this spec from their 32 "pill" amplifier:

(3) BIRD W 800 RMS . 5000-8000 PECK

Well, Birds "peck", don't they?