DAIWA CN-901HP Forward Power Displayed Decreases

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BriansBrain
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DAIWA CN-901HP Forward Power Displayed Decreases

Post by BriansBrain » Sat Jul 13, 2019 1:21 pm

Hello guys :whistle

I purchased this new DAIWA CN-901HP a couple of months.
So I could keep an eye on power out and SWR and I am very pleased with it.
I use it on my little 150W FM ''Radio Brian'' at 96.8 MHz.

However...

It measures forward power of 150W for the first 4 > 5 minutes but then the display decreases to show +/- 130W.
It's as though there is something warming up inside the unit reducing the meters current.

I have tested the setup with my Bird 4304A which shows 150W output which proves the DAIWA display is at fault.
I have contacted DAIWA but not had a reply yet.

Anyone else had a problem with DAIWA meters ?
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Albert H
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Re: DAIWA CN-901HP Forward Power Displayed Decreases

Post by Albert H » Sat Jul 13, 2019 5:52 pm

It's NOT designed for continuous use!!! It's designed to be used just to check the antenna match and check the forward power (approximately) on a Ham transmitter - which is (usually) just transmitting with a very low duty cycle!

You can be sure that the diodes in the Breune Bridge inside the instrument are warming up and so it will then begin to display anomalous values.
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Re: DAIWA CN-901HP Forward Power Displayed Decreases

Post by sinus trouble » Sat Jul 13, 2019 10:53 pm

Greetings Mr Brain
Albert is correct, I have the CN-801 and it does exactly the same thing depending on duration, power and temperature!

If you removed it from the setup your losses will be reduced slightly, However as is... it provides a basic assurance that all is ok!

PS I have been to Lanza (Puerto Del Carmen) many times and can usually pick up radio from all the islands, I will check out 'Radio Brian' on my next visit :)
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Re: DAIWA CN-901HP Forward Power Displayed Decreases

Post by teckniqs » Sun Jul 14, 2019 11:57 am

Maybe you could try using one of these to measure your power output instead of the Daiwa...

https://www.ebay.co.uk/itm/SWR-Power-me ... 2192748887

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Re: DAIWA CN-901HP Forward Power Displayed Decreases

Post by BriansBrain » Sun Jul 14, 2019 12:29 pm

Albert H wrote:
Sat Jul 13, 2019 5:52 pm
It's NOT designed for continuous use!!! It's designed to be used just to check the antenna match and check the forward power (approximately) on a Ham transmitter - which is (usually) just transmitting with a very low duty cycle!

You can be sure that the diodes in the Breune Bridge inside the instrument are warming up and so it will then begin to display anomalous values.
Thanks for the info Mr. H

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BriansBrain
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Re: DAIWA CN-901HP Forward Power Displayed Decreases

Post by BriansBrain » Sun Jul 14, 2019 12:32 pm

sinus trouble wrote:
Sat Jul 13, 2019 10:53 pm
Greetings Mr Brain
Albert is correct, I have the CN-801 and it does exactly the same thing depending on duration, power and temperature!

If you removed it from the setup your losses will be reduced slightly, However as is... it provides a basic assurance that all is ok!
Yeah... I like the idea of seeing all is OK :smoke
sinus trouble wrote:
Sat Jul 13, 2019 10:53 pm
PS I have been to Lanza (Puerto Del Carmen) many times and can usually pick up radio from all the islands, I will check out 'Radio Brian' on my next visit :)
Look forward to your results :P
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BriansBrain
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Re: DAIWA CN-901HP Forward Power Displayed Decreases

Post by BriansBrain » Sun Jul 14, 2019 12:43 pm

teckniqs wrote:
Sun Jul 14, 2019 11:57 am
Maybe you could try using one of these to measure your power output instead of the Daiwa...

https://www.ebay.co.uk/itm/SWR-Power-me ... 2192748887
Thanks for the info...
But...
I'm not only old but... old fashioned.... I like Analog Meters :lol:

And...
Like I mentioned in my first post...
I have a Bird 4304A but if that's left ''ON AIR'' all day I don't have it for the work bench :roll:
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