CB and Ham Radio Techs Love Their Bird Wattmeters

[xrunner]

  From these few comments, you may reasonably conclude I am a dumb fuck and the only reason I continue to work is people feeling sorry for me.  I'm perfectly fine with that! 

Now that you've admitted that I'll say it - I feel really sorry for you. 

Oh bugger. In an unfortunate night of crazed temperature and maddening sweats I appear to have ordered some AD8307’s from China again.

Hold my beer. Joining the party.

(Eventually - moving house)

That's the spirit keep the thread going. Be interested on your take this time around. We might beat the NanoVNA thread views of 294k. I'm planning on making another different model more suited to my needs so I'll be here.

I think I finished (for now) the OLED display graphics. A warning appears at power-on for 1.5 s. I added a bar meter in the center the upper and lower limits of which will follow the atten. selection. That's about all I can cram onto one screen (and keep it readable).

Now let's see what the measurements tell us. The proof is in the pudding as they say

[vk6zgo]

The following comment was pulled from the attached video.

Bird didn't make their own meters, Before Bird moved production to china they used Simpson meters.. Ever since Bird, moved production to china their quality has gone down the crapper, The slugs are now brass plated plastic. Coaxial dynamics is really become a better product but they are still over priced.   

I'm curious as to why CB'rs have such a Bird fetish, I mean they aren't all that accurate.   Bird laughingly claims +- 5 percent of full scale but the calibration lab I use has told me in the 40 years they've been in business that the overwhelming majority of bird slugs they've tested barely met  +- 10 percent and they are a military contractor

I wonder what this brass plated plastic looks like. 



Also, an article on how to modify your Bird slugs:
https://www.hayseed.net/~jpk5lad/BIRD%20Slugs/birdslug4.htm

That bloke shits me!
Have you noticed how he pronounces "Bird" like Mr Snuffleupagas?

"Brass plated plastic" might be a thing.

Way back in the day, I owned a book about home electroplating.

It concentrated more on tin, copper, & chromium plating, but one thing which was interesting was electroplating wax.
This was achieved by coating the wax with graphite, then plating onto that.
If they plated enough material upon the wax pattern, they could melt the wax out & have an object made of the electroplated material.

I don't think they mentioned electroplating plastic, but I know it can be done, as when I was a little kid, I remember plastic toys with metal plating on them.
After a while, the plating would peel off.

Much more recently, my daughter's Hyundai Accent had chromed plastic internal door handles.
Unfortunately, in short order, they followed the example of my childhood toys!
The next model just used plain old plastic handles!

[joeqsmith]

I searched to see if I could find anything to backup that statement about plastic slugs.  I had no luck.   

  From these few comments, you may reasonably conclude I am a dumb fuck and the only reason I continue to work is people feeling sorry for me.  I'm perfectly fine with that! 

Now that you've admitted that I'll say it - I feel really sorry for you. 

You should feel sorry for those who employ and have to work with me.  Poor bastards.    

Oh bugger. In an unfortunate night of crazed temperature and maddening sweats I appear to have ordered some AD8307’s from China again.

Hold my beer. Joining the party.

(Eventually - moving house)

Bout time. 

I wasn't able to find a low cost supply for any of the more fancy parts I would like to try.  The vector detector is pretty slick but isn't a good fit.   I plan to use two of the easy to get parts and leave out the phase.  May add a third part to get the phase.   Xrunner is pretty much done and I haven't made it much further than making a decent coupler.   

Because I needed more than one channel,  I've been using that cheap LabJack DAS to collect the data rather than my old bench meter.  The long term plan is to use something dedicated.   

Now if this poor guy reads this post, they are going to suggest there is no way using a PC will ever be fast enough!! 

[xrunner]

Now if this poor guy reads this post, they are going to suggest there is no way using a PC will ever be fast enough!! 

LOL my meter updates faster that that thing and it's running on an Arduino platform and taking three samples per point.

 

Piping it to a PC shouldn't slow it down. I'd be interested in what internal system they put in the Coaxial Dynamics to take the samples. Just by looking at the video (but never using one), the presentation on the PC monitor seems a little clunky overall. I'd have put +/- 5% full scale error needles to follow the main needle, so these people would keep it in their head what they are looking at carries error with it. Naw, I guess that would ruin their feel-good outlook about the readings.

But uh, I guess he should've RTFM before he bought the thing if he wanted to observe SSB meter swings -
 

SPECIFICATIONS AND LEADING PARTICULARS

The Model 81041 Directional USB Wattmeter is an accurate and portable insertion RF
Wattmeter using plug-in power detectors and QUICK MATCH RF connectors, which measures
forward and reflected CW power. The Model 81041 features a large scale, easily read meter
movement in conjunction with a USB interface. Standard Ranges: 100 mW to 10 kW; 0.45-2300
MHz. Accuracy: +/- 5% of full scale
 
http://www.coaxial.com/manuals/81041.pdf

Since I'm making a post I will include a power meter cosmetic update. I received the button covers I wanted and they look a lot better. They are rubber too and feel nice. I want my power meter to have that feel of quality!

I'm taking data and making some graphs, should have something to show "soon".

[joeqsmith]

I like the black over the red.   

Some time when you have a chance,  post a picture of your label maker.   

I wondered on the last video, let's assume it was designed in the 80s for the IBM PC.  Say they send two double floats for both incident and reflection.  Maybe pad it out to 256 bits for a CRC error correcting start frame something or other.  Assume RS232 8,n,1 or 10 bits at 300BAUD or 33.3ms per byte.  With 32 Bytes, it we are at 1.06 second. 

I don't see a problem with a modern PC using Ethernet or USB.  Even 9600 BAUD would be fine.   

[xrunner]

Pic of label maker model. It's probably 3 years old and better ones are most likely available.

[vk6zgo]

I searched to see if I could find anything to backup that statement about plastic slugs.  I had no luck. 

It would hardly seem viable in any case, as the PRC makes plenty of water taps made of "pretend brass" that corrode out in a few years.
As Bird slugs, such crud would be perfectly servicable.
If Joseph Lucas made them, they would use "pot metal"

  From these few comments, you may reasonably conclude I am a dumb fuck and the only reason I continue to work is people feeling sorry for me.  I'm perfectly fine with that! 

On the contrary, Joe, you are a very clever guy,---- it is just your Jihad against hams & Bird meters that is annoying.

[vk6zgo]

Now if this poor guy reads this post, they are going to suggest there is no way using a PC will ever be fast enough!! 

LOL my meter updates faster that that thing and it's running on an Arduino platform and taking three samples per point.

 

Piping it to a PC shouldn't slow it down. I'd be interested in what internal system they put in the Coaxial Dynamics to take the samples. Just by looking at the video (but never using one), the presentation on the PC monitor seems a little clunky overall. I'd have put +/- 5% full scale error needles to follow the main needle, so these people would keep it in their head what they are looking at carries error with it. Naw, I guess that would ruin their feel-good outlook about the readings.

But uh, I guess he should've RTFM before he bought the thing if he wanted to observe SSB meter swings -
 

SPECIFICATIONS AND LEADING PARTICULARS

The Model 81041 Directional USB Wattmeter is an accurate and portable insertion RF
Wattmeter using plug-in power detectors and QUICK MATCH RF connectors, which measures
forward and reflected CW power. The Model 81041 features a large scale, easily read meter
movement in conjunction with a USB interface. Standard Ranges: 100 mW to 10 kW; 0.45-2300
MHz. Accuracy: +/- 5% of full scale
 
http://www.coaxial.com/manuals/81041.pdf

Since I'm making a post I will include a power meter cosmetic update. I received the button covers I wanted and they look a lot better. They are rubber too and feel nice. I want my power meter to have that feel of quality!

I'm taking data and making some graphs, should have something to show "soon".

I can't see the ham radio use case for continuous inline connection of such a meter as shown in the video.
Most ham transceivers have quite adequate meters built in that do follow modulation.

As I grumped on about in an earlier comment, the AM Broadcast Transmitters I worked with for years didn't change their average output power with the application of modulation.
Put the lineup tone on whilst watching the RF line current, & no change, or where they were fitted with wattmeters, no change in that reading.

The HF ISB Comms Tx did have power meters which varied with modulation, & SWR meters with computed the difference between forward & reflected power, using analog circuits they somewhat ambitiously styled as "computers".

[joeqsmith]

  From these few comments, you may reasonably conclude I am a dumb fuck and the only reason I continue to work is people feeling sorry for me.  I'm perfectly fine with that! 

On the contrary, Joe, you are a very clever guy,---- it is just your Jihad against hams & Bird meters that is annoying.

Unless you have come to the conclusion that there are similar religious and or cult behaviors when it comes to ham radio and Bird meters, it seems like a poor choice of words.  Even if that was your intent, I have little interest for anything related to organized religion. 

https://en.wikipedia.org/wiki/Jihad

It's interesting that you never call me out for picking on the CB group.  Rather, you tend to join.  It's funny how the two groups have similar behaviors on the air (when if comes to how they treat one another) but how hams have such a need to downtrodden the CB group.  It's very possible that CBers look upon the hams in much the same way but I just can't tell what it is they are saying.   

I can't see the ham radio use case for continuous inline connection of such a meter as shown in the video.

The idea is that you show this off to your fellow hams in order to advance your tech status within the group.    Perhaps seeing the needle bounce to the command of their voice appeals to their need to be in control of something??  Hard to say.       

...using analog circuits they somewhat ambitiously styled as "computers".

Early computers were humans and later analog.  It was the first application for operational amplifiers.  You like to talk about the old tube broadcast equipment you worked on.  I have a copy of book given to me by an old German friend which details making analog calculations with tubes.   I had the opportunity to meet a gentleman who worked on the early drum memory.  I have some of their papers on early analog computers as well. 

[bd139]

Quick poke. I hold more respect for the CBers than the 80m lot 

As for tech in the usual hams, I remember a comment I had at the local club:

“Aitch Pee? Don’t they make printers?”

 

[joeqsmith]

I had a friend who worked for them at the time they brought Carly Fiorina in.  If you ask employees who hired post CF, it seems to be a taboo subject internally.    

From what I saw posted, it sounds like the worse are active on 40 and 2. 

[vk6zgo]

Quick poke. I hold more respect for the CBers than the 80m lot 

As for tech in the usual hams, I remember a comment I had at the local club:

“Aitch Pee? Don’t they make printers?”

 

Some years back, when I bought my Tek 7613, at a Hamfest, as I was heading off on the long march to my car, with my arm seemingly stretching several inches with every step, I passed a group of the "New Generation" of hams lounging outside the entrance.

One of them asked "What's that?"

Another of the group answered before I could:-

"It's for looking at wiggly lines, like!"

[xrunner]

Here's a couple of pics of the testing. Transmitting on the 5W setting of the transceiver 146.520 MHz (FM of course). Using external 50 dB atten.

hp 437B vs. AD8310 project meter. How well do they agree?

hp 437B measures 3.97 W

Project meter measures 4.0 W

 

[vk6zgo]

Here's a couple of pics of the testing. Transmitting on the 5W setting of the transceiver 146.520 MHz (FM of course). Using external 50 dB atten.

hp 437B vs. AD8310 project meter. How well do they agree?

hp 437B measures 3.97 W

Project meter measures 4.0 W

 

So your meter is pretty good, but your radio's output power is 20% low at best?

[Bud]

Show us measurements of a signal with high crest-factor, i.e speech or music.

[xrunner]

Here's a couple of pics of the testing. Transmitting on the 5W setting of the transceiver 146.520 MHz (FM of course). Using external 50 dB atten.

hp 437B vs. AD8310 project meter. How well do they agree?

hp 437B measures 3.97 W

Project meter measures 4.0 W

 

So your meter is pretty good, but your radio's output power is 20% low at best?

Yep it is. I will be correcting that as much as possible using the service menu. I won't be surprised if I found that UHF highest power setting (50 W) will not be obtainable. If I remember I will post the power after adjustments.

I could do the CB thing and just max out the power in each menu. 

Show us measurements of a signal with high crest-factor, i.e speech or music.

You want me to turn on my spectrum analyzer I take it?

[Bud]

No, i am asking to compare the project meter against watever industrial RF power meter you have on hand, including the Bird one. Any idiot can use a spectrum analyzer.

[xrunner]

No, i am asking to compare the project meter against watever industrial RF power meter you have on hand, including the Bird one. Any idiot can use a spectrum analyzer.

I did in the picture I just posted, it's a CW power meter like the hp 437B.

Oh and a Bird - do not have ...

[Bud]

Well, CW measurement is a very limited use case, isn't it.

[xrunner]

Well, CW measurement is a very limited use case, isn't it.

That's what it's designed to do, just like the hp 437B. So it's as limited as that fine piece of engineering.

Is there something you are upset about? You seem very aggressive for no good reason.

(or both measure average power but I don't need to measure that)

[joeqsmith]

hp 437B measures 3.97 W

Project meter measures 4.0 W

 

Looking good.  Still waiting on the next round of parts. 

[vk6zgo]

Show us measurements of a signal with high crest-factor, i.e speech or music.

If he still uses an FM transceiver it won't be any different!

[joeqsmith]

...  i am asking to compare the project meter against watever industrial RF power meter you have on hand, including the Bird one.

Yeah Xrunner,  show us that Bird meter you covet!!!       

[xrunner]

 

No got Bird meter here amigo!

[joeqsmith]

Here is my early attempt at measuring power.   Simple 50ohm load, diode detector and filter.   Characterized with one of those fancy HP meters.