Calculated Data

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Marvin Richardson Marvin Richardson
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Calculated Data

I am using Windows 7 Home Edition and my amplifier is the 8410. Under Calulated Data I am showing the following on 20 meter band as an example: Gain 19db Plate disipation 0 W Grid 1 Disipation 0.0 Wasred heat 1 W Can these readings possibly be right?
Dan AE9K Dan AE9K
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Re: Calculated Data

Marvin,

Welcome to the forum!

The calculated data in the monitor is updated as telemetry provides new data from which the calculations are made.  

Gain
Gain is reported via telemetry regardless of whether you're transmitting or not (or even powered up) thus the dB calculation is always present.  

Plate dissipation
Plate dissipation is calculated from efficiency, plate voltage and plate current.  Efficiency, like gain, is always reported via telemetry regardless of whether you're transmitting or not.  Normally the plate current returns to zero when not transmitting but when the amp is off, telemetry may report an insignificant plate voltage (mine shows 3 V) and a very large plate current so plate dissipation may be positive with the amp off.

Grid dissipation
Grid dissipation is calculated from grid voltage and grid current.  Grid voltage is always reported via telemetry and grid current normally returns to zero when not transmitting so the grid dissipation does too.

Waste heat
Waste heat is calculated from peak power output and efficiency.  Since efficiency is always positive and always reported, waste heat will only go to zero if peak power does.  Peak power is averaged in firmware that results in positive peak power values being reported via telemetry a significant fraction of a second beyond key-up.  This will result in waste heat being positive shortly after key-up as well.

When the amp is powered off telemetry reports some nonsensical values like 2+ amps of plate current.  I thought about ignoring all of these when the amp is off (state = 0) but elected so far not to.  The monitor was meant to show telemetry, good or bad, and not selectively hide some of it.  Whether it shows up is better controlled in firmware.

I'm assuming you're observing these values when the amp is idle or off.  If you're seeing these values when transmitting then there's a problem.

If you can reply and attach a screen shot or two of the monitor I can provide a more definitive answer as the raw telemetry string and all the parsed and calculated data are captured.

Thanks.

Dan
Marvin Richardson Marvin Richardson
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RE: Calculated Data

HI Dan;

 

Thank you for your response and also for creating this fantastic monitor!  I just wanted to verify that what I was seeing was what I should be expecting.  I have attached three snippets of my results.

 

Thanks again

Marv W0ZK


power on idle.JPG (104K) Download Attachment
power on keyed.JPG (108K) Download Attachment
powered off.JPG (106K) Download Attachment
Dan AE9K Dan AE9K
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RE: Calculated Data

Marvin,

Thanks for the images. Those help a lot.

I marked up the image that shows the 1 W of waste heat and pointed out the two values that contribute to the waste heat calculation.



From the formula:

you can see our waste heat is (1 - 0.60) / 0.60 * 1 = 0.67 W

Because waste heat is usually several hundred to a thousand watts, the monitor rounds this to 1.


Great question. Keep them coming as that's how bugs and quirks are uncovered.

Thanks,

Dan