[MRCA] how much power does this say?

[W2HX]

No, I never owned a bird. But I do have lots of analog meter'd radios and power meters including dual needle things like this:

http://w2hx.com/x/TMC/ATS-2-for-sale/0902181629.jpg (sorry all sold).


While I was pretty sure I knew how to read that bird, I had to be very sure. It was measuring the output on a very rare radio that I was considering acquiring and I didn't want to make a simple mistake like misreading the meter. So I got a lifeline!


As for "The Bird model 43 thru line is at least for me the standard that everything else is compared to..."


I think technically the HP 432A is considered the de facto  NIST transfer standard even to this day. Which I have with just recently out-of-calibration 478A sensor and HP 8498A 30dB attenuator.  I believe that is the standard to which everything else is compared hihi.


Eugene






________________________________
From: Ray Fantini <RAFANTINI at salisbury.edu>
Sent: Friday, February 15, 2019 9:15 AM
To: W2HX; mrca at mailman.qth.net
Subject: RE: [MRCA] how much power does this say?

Wow, that's mind blowing! You never learned how to read an analog meter? We old timers were borne with a thru line in our hands. I remember that on the old commercial license test that you had to read pictures of meters and write down the answers. The Bird model 43 thru line is at least for me the standard that everything else is compared to, although I do know that they have not been teaching analog meters for some years now.
The great advantage of that meter is you can read power in the direction that the arrow is pointing so you can read forward power in one direction and flip the element and read reflected in the other and get an indication of how efficient the match between source and load is. By knowing forward and reflected power you can calculate return loss and SWR. When used with a dummy load with no reflected power and with good elements you can read forward power to a degree that the FCC considers accurate. They use to use the same meter themselves.
The 43 dose fall down when you get into checking PEP on a SSB radio but the one in the picture has the peak reading option that's used for SSB measurements, also they are not considered accurate for use in digital systems but still now that you have been exposed think that you will soon discover that your life won't be complete without one. Most of us have several and at least a dozen or so slugs.
That's another issue is that for different power levels and different bands, HF, VHF and UHF different slugs are required but the 43 also has convenient holes in the case so you can mount a couple spare slugs for different power levels or frequency ranges.
In the past several years I have been forced to move to an Agilent forty four hundred series digital power meter for any stuff at work but still carry my Bird 43 as the go to meter.

Ray F/KA3EKH


From: mrca-bounces at mailman.qth.net [mailto:mrca-bounces at mailman.qth.net] On Behalf Of W2HX
Sent: Friday, February 15, 2019 8:03 AM
To: mrca at mailman.qth.net
Subject: Re: [MRCA] how much power does this say?

Thanks to everyone who replied. 70W it is! Thanks

Sent from Nine<http://www.9folders.com/>
________________________________
From: W2HX
Sent: Friday, February 15, 2019 7:22 AM
To: mrca at mailman.qth.net<mailto:mrca at mailman.qth.net>
Subject: [MRCA] how much power does this say?


Hi friends, I do not own a bird meter so I am not familiar with how to read the scales. This picture shows a meter with a 250W slug. The meter seems to show either 7W on the lowest scale, 15W on the center scale and 30W on the highest scale.

The lowest scale looks like it goes to a maximum of 25W. If the scale is intended to be 10X then it would show 70W. Maybe this is the answer? thanks










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