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RF Choke for Amplifier class F on 15MHz?

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Astrid

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I have 150W RF amplifier in class F with broken RFC, current 3A, frequency about 15MHz.
Any as
RFC.png
RFC inductance is 9uH (11turn, measured on different piece) diameter 24mm
It follows Al=80nH/N2
What toroid use (core material)?
 

It seems that nobody knows. Actually, I do not either, but purely by AL
Ferrite TN23/14/7-4C65
maybe
Ironpowder (I'm not sure whether it is applicable to 15MHz)
T72 or T80 materiál **broken link removed**
 
Last edited:

Astrid said:
I have 150W RF amplifier in class F with broken RFC, current 3A, frequency about 15MHz.
Any as
View attachment 111663
RFC inductance is 9uH (11turn, measured on different piece) diameter 24mm
It follows Al=80nH/N2
What toroid use (core material)?
Click to expand...

For a rough guess, measure the resistance of the broken ferrrite if it is conductive, then it is low permeability VHF type. If not then high permeabilty HF type.

They metal oxide fillers to reduce mu and increase conductance to raise current capability and lower magnetic current lossy characteristics.

it may be a precision gapped core also.
 

Unfortunately, I have not broken piece available.
In functional piece is a toroidal core covered with white polyamide,
Yes core is similar TN23
I do not know whether it is relevant
Toroids in output networks are ironpowder, more precisely, amidon material 2, 6 and 10
 

This is close to what you need but wrong size. https://www.ferroxcube.com/FerroxcubeCorporateReception/datasheet/tn332011.pdf

Speaking of size, you gave OD but not ID and W.

In TN series the p/n is TN OD/ID/W -mat'l type
e.g. mat'l 2P90 has µe=90 ( very low ) to get in AL = 80
You may end up with higher µe for smaller size.

Use at least 1mm wire.

Their website search tool is not very good, distributor stock is slim, considering there are thousands of types of varieties of inductors. The free software they have does not seem to include torroids. good luck.

BTW they dont supply nylon coating anymore, mainly white epoxy.
 

I spoke to my amplifier manufacturer.
Large companies operating worldwide.
Over several marketing annoying I got to the attentive technicians.
Had a service manual, memory, knowing what kind of coil is speech.
Unfortunately, even he does not know what material is the core :-D.
modern classic, the renowned company of USA, bestows brand and price, the product proposals and produces some Chinese
 

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