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Re: [Amps] Bird Element Calibration?

To: Mark Hill <g4fph@mjha.co.uk>
Subject: Re: [Amps] Bird Element Calibration?
From: Gary Schafer <garyschafer@comcast.net>
Reply-to: garyschafer@comcast.net
Date: Mon, 21 Mar 2005 11:41:24 -0500
List-post: <mailto:amps@contesting.com>
Guys, keep in mind that 5% accuracy spec is of FULL scale. That means 
that a 2500 watt slug has +- 125 watt accuracy at ANY part of the scale.
If you read 1000 watts on the meter with the 2500 watt slug the actual 
power could be from 875 to 1125 watts and still be in spec! That's 12%.

At 250 watts on that same slug the error is +- 50%.

The lower you get on the scale the worse the accuracy will become.

73
Gary  K4FMX

Mark Hill wrote:
> Phil,
> 
> Further to my post of yesterday.
> 
> Last night, I briefly checked the response of a Bird 2500H at 4, 3, 2, 1.8 
> and 1.6 MHz.  The readings I took were (for a nominal 1 kW CW RF) 1050, 
> 1100, 1030, 1000, 900 respectively.  I suspect the readings of 1100 and 900 
> reflect the lack of gain flatness of my TX rather than calibration bumps of 
> the insert, although I did not have time to confirm this.
> 
> Looks pretty good to me!
> 
> Regards.
> 
> Mark.
> 
> --------------------------------------------------------
> 
>>At 22:26 19/03/2005, Phil Clements wrote:
>>
>>>Just a note for my fellow 160 meter operators. The 2-30 mhz Bird slugs are
>>>VERY inacurate below 2 mhz. At 1.8 mhz they read so low that you think you
>>>have amp problems or terrible efficiency. I once worked for hours on an amp
>>>to try to get the power output up to the level it was on 80 meters. I even
>>>went so far as putting in a plate choke with more L. All this time, the
>>>actual 160 meter output was > 80 meters! I hope this might save someone some
>>>grief that has'nt run into this yet!
>>>
>>>(((73)))
>>>Phil, K5PC
>>
> 
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