CB and Ham Radio Techs Love Their Bird Wattmeters

[El Rubio]

How do the Bird wattmeter owners know those are accurate?

well...it's a Bird

[xrunner]

How do the Bird wattmeter owners know those are accurate?

well...it's a Bird

Ah OK, I didn't realize calibration was so simple. 

[joeqsmith]

It looks like he may have used the old Watt meter to mix up some epoxy.   Video talking about accuracy and showing how they modify that 1950's tech.   

How do the Bird wattmeter owners know those are accurate?

well...it's a Bird

Ah OK, I didn't realize calibration was so simple. 

While looking for a video showing the factory where the Bird meters are made and how they align them, I came across TEGAM's High Power RF Measurement and Calibration. 

[bd139]

I'm not sure I'd want to use the word accuracy too much around these. Even if they are calibrated. The specifications are quoted as 5% on CW signals between 100mW and 10kW on a mostly linear scale. Measuring VSWR with the same slug near edges of power limits on an analogue meter would be fairly pointless. Also if you have high harmonic content on the signal then your power measurement is going to be wrong.

I would consign them to history and use a spectrum analyser and suitable power taps, directional coupler and/or attenuator. Looking at the prices of a Bird wattmeter it doesn't make sense in 2022.

If you actually have to measure power up to 500MHz or so, the old W7ZOI AD8307 + 40dB power tap is a better solution as the thing has a dBm calibrated log converter in it.

[xrunner]

I've no doubt that the Bird watt meters are calibrated at the plant, and when they are purchased new they are within +/- 5%. However, years after that purchase my question was how does the CB or Ham user know the readings are within spec? The answer I got was "It's a Bird ...".

The abuse that I've seen hams give equipment and the stories related to me would give me no confidence that any Bird meter I bought used with the slugs wasn't hit with too high power, lightening strikes, slamming and banging against hard objects, or any other abusive use you can possibly imagine. I don't care what name is on the thing, it's no match for the abuse some Hams can dole out (or CBers too). They can turn a Bird into a Turd in seconds. Even if you were the only owner and very careful with it, how do you know 8 years later if the readings are within spec?

So, I would first have to test the meter and each slug and compare it to a trusted power reading such as I could get from any one of three hp power meters I have (2 437Bs and a 436A), a Rigol DSA 815, or a Boonton 4220). All these are verified accurate against multiple power references.

Do I expect every ham or CBer to have these instruments (or know how to properly use them)? No, I certainly do not. Hence my question again: How do (most) of them know the readings are within the rated specification?

Answer: They don't.

I added "most" because I'm a ham and I can do these tests, and there are other hams that can. However most hams cannot.

"It's a Bird!" Bird, Bird, Bird is the word (there's that damn song again ...)

[bd139]

I keep hearing Turd not Bird

https://youtu.be/clG4eggHIOM

[joeqsmith]

Bird's website shows they offer calibration.   

https://birdrf.com/Services/Service-Center/Calibration-Repair.aspx

[Wallace Gasiewicz]

In my experience the Bird Wattmeters are pretty good and retain calibration. Perhaps this is why they are popular.
Most of the "measurement" is in the sealed slugs.
I believe this is because there are no adjustments that can be accessed by golden screwdrivers.
Unless someone burned a slug.....
This does not include the uncommon Bird peak meters.

The Bird IS the word. By the way, the Bird was a dance, A pretty silly one.

[Mark19960]

The 5% spec is ignored by CB muppets. To them a Bird meter is absolute.
They are 100% accurate but only in their minds.
For that matter, their 50 year old CRO is 100% accurate too.

These people do not know ANYTHING about measurement. A bird meter is infallable to them.
If there is 100 watts showing on a Bird meter, to them it's 100 watts.

I also want to point out again that in CB land.. attenuators are evil devices that cause inaccurate measurements.
It doesn't matter that the CDMA base station test sets that they like have attenuators built into the unit.
If you point that out you are called a liar. There are no attenuators! It's a built-in dummy load!

I have seen these guys fight (as in a REAL brawl!) over two watts on a bird meter.
One guys meter read 98 watts, and the other read 100 watts.
The 98 watt guy accused the 100 watt guy of tampering with his meter.
The "customer" said the guy with the 98 watt bird meter's "s--t was broken"
Oh no, it was the "tune" of the radio.....

And These guys proceeded to throw fists over it.

Remember, the 11m band ..... the laws of physics, metrology, proper measurements... none of that matters there.
All that matters are those coax lengths and MO WATTS.

[joeqsmith]

 

Sadly I don't think it's unique to the CB crowd.  I will admit after watching so many hams and CB videos, I'm feeling a bit left out and I don't even have a CB or an amateur license.  So I spent a few minutes to make six virtual Bird meters.  I feel much better now.

[xrunner]

The 5% spec is ignored by CB muppets. To them a Bird meter is absolute.
They are 100% accurate but only in their minds.
For that matter, their 50 year old CRO is 100% accurate too.

These people do not know ANYTHING about measurement. A bird meter is infallable to them.
If there is 100 watts showing on a Bird meter, to them it's 100 watts.

I agree. Most hams I know don't really think about accuracy and tolerances. Whatever their low-cost SWR / PWR meter reads must be correct, even though it's lucky to be +/- 10% of full scale and they don't understand the error applies to all the readings on the scale.

Bird's website shows they offer calibration.   

https://birdrf.com/Services/Service-Center/Calibration-Repair.aspx

Joe,

They do offer such services, as do many other manufacturers, but that presumes two things:

1. That the person knows it needs calibration.

2. That the person is willing to pay for the shipping & service.

I've been a ham since I was a teenager (1974) - 48 years. I can honestly state here, I've never heard of a single ham sending any instrument in to any manufacturer to be calibrated. Nor have I ever heard them even talk about doing it and then not doing it. Never.

Also, most hams are notoriously tight with money. None of the hams I know would spend money on calibration services for any instruments they have (which mostly would be a cheap SWR / PWR meter or DMM). They would ask, perhaps, for me to check it out since they know I have the equipment and skills, but paying for shipping and the service from a manufacturer? No way.

What I'd really love to do, is get a Bird Wattmeter with elements for several ham bands, and I'd make sure it was within tolerances comparing the readings with my hp 437B power meter. Then I'd make up a story that I was collecting data for my own research. I want to know the power readings from HF, VHF, and UHF transceivers for a spreadsheet.

What I would do is send out the Bird meter and elements and have the guys hand it off to each other (I don't care how many 4, 6, 8 ...) after they collected the measurements. I want Low, Medium, and High power on as many bands as possible. So that makes them select the right element and power level. Take your time and get it back to me in 3 or 4 months. I want it to be passed to different people and used and whatever abuse it gets is what it gets. I'd give the minimum direction on how to use it if they didn't know already, but I wouldn't say a thing about any concerns about being "careful" just use it correctly please.

I wonder what I'd find when it finally got back to me? How many elements would still work? What damage would have occurred? How many times would the needle have been slammed into the max stop?

The above experiences/opinions are mine and not meant to represent all Hams - only the group I have been associated with.

[free_electron]

buy a real rf power meter from HP / agilent.

When i was working in the fab we had a Bird meter and a huge dummy load to check the 13.56MHz RF amplifiers for the plasma etchers. there was procedure to align those , check that the automatic matching network was doing its thing. Those things cranked out 1500 to 2000 watts. The control voltage was 0 to 10 volts and you needed to do a gain setting so the etcher could commandeer the right power. it also had an on-board power meter so you had to align that as well.
We had issues getting the etchers aligned to each other. Throw out the Bird crap and get a real power meter. You can't read that analog meter properly. is it 1.5 ? 1.6 ? 1.55 ? with a digital power meter you know what you are looking at.

[joeqsmith]

What I'd really love to do, is get a Bird Wattmeter with elements for several ham bands, and I'd make sure it was within tolerances comparing the readings with my hp 437B power meter. ...

I am guessing that you are suggesting their radios have some sort of built-in power meter that they are comparing with?  Without some known reference point, I don't get what you would be accomplishing.   Maybe they compare their in-line meters with yours as well.   Are you also sending a known load/s for these frequencies you plan to test?   Maybe that variable should be part of it.   A big source of error.   Then again, you send your load, it may return as an open... 

[xrunner]

What I'd really love to do, is get a Bird Wattmeter with elements for several ham bands, and I'd make sure it was within tolerances comparing the readings with my hp 437B power meter. ...

I am guessing that you are suggesting their radios have some sort of built-in power meter that they are comparing with?  Without some known reference point, I don't get what you would be accomplishing.   Maybe they compare their in-line meters with yours as well.   Are you also sending a known load/s for these frequencies you plan to test?   Maybe that variable should be part of it.   A big source of error.   Then again, you send your load, it may return as an open... 

No, no sorry if I wasn't clear. The data from the measurements would be for a comparison to the rated transceiver's power output specification in the respective manual. But that is just a ruse to get the meter passed around to see how much abuse it would get.

Yea I'd send a 100W 50 ohm dummy load. All hams should have those as well, but I think you can guess what the reality of that is ... 

[joeqsmith]

Ah, so just a mechanical stress test.  You do a before an after measurement of the meter.   I expect the average person would treat it with care, especially if they personally know you.   Wouldn't they just be using it on their desk.  Maybe make sure they do what ever is required for shipping the movement.       

That person with the 6 Bird meters showed their load.  I want to say that was a 10kW setup, for CB!      I think the little broadcast station in our town was 1kW.     Funny stuff.   

[joeqsmith]

Indeed, 10kW. 

[xrunner]

Ah, so just a mechanical stress test.  You do a before an after measurement of the meter.   I expect the average person would treat it with care, especially if they personally know you.   

Oh you're right! They can't know I have anything to do with this. I'd have to get a trusted associate to pretend they are in charge. 

Wouldn't they just be using it on their desk.  Maybe make sure they do what ever is required for shipping the movement.     

 

Whatever they do is what they do. The Bird is going into the field as they say, and however it's treated is a reflection of how real hams treat things. That's what I want to know and see.

That person with the 6 Bird meters showed their load.  I want to say that was a 10kW setup, for CB!      I think the little broadcast station in our town was 1kW.     Funny stuff.

[bd139]

Well that was a fascinating view into the world of CB radio. It's basically the electronic equivalent of rolling coal 

[xrunner]

He's got a 50 kW slug eh? So it's +/- 5% full scale, which is +/- 2,500 W for any reading on the scale. 

[joeqsmith]

He's got a 50 kW slug eh? So it's +/- 5% full scale, which is +/- 2,500 W for any reading on the scale. 

That's what he shows and assuming it's in cal, that's the way I would read it.   I like its a 27MHz, 50kW detector.  Made just for the CBers..

[joeqsmith]

While the CB guy buys an old Bird attenuator,  the hams attempt to make their own. 

Here's a 1.5kW load. 


Smaller one from WW resistors. 


23 minutes in, a dab of Loctite, proceeds to use a tea spoon of it....   

[bd139]

I know we bitch about the CBers but the hams are just as bad.

The dude at the local club destroyed a nice Kenwood rig using Jesus’ soldering iron 

[CJay]

If anything some of the hams can be worse, there's a non zero number of them who seem to think passing their licence imbues them with unassailable technical expertise and skill.

[rfclown]

Indeed, 10kW. 

Nice that he uses RG316. 35kW... hmmmm. Does he show the service panel of his home?

I picked up a pristine Bird APM-16 watt meter for free recently. I've also got a Bird 200W 30 dB attenuator that I bought on eBay years ago when I started doing some HF work. I had no idea how big and heavy it was till it arrived. I guess I should unload these things while certain individuals realize how incredibly valuable they are.

[bd139]

If anything some of the hams can be worse, there's a non zero number of them who seem to think passing their licence imbues them with unassailable technical expertise and skill.

The scary ones are the ones who couldn’t pass the foundation…