Topband: Beverage Transformer?

[Tracey Gardner]

I would be grateful for some advice on the type of transformer to use on a 
Beverage antenna that I am in the process of erecting.

I have been reading the latest (5th edition) of ON4UN's Low Band DX'ing and, 
on Pages 7-67 and 7-68, he discusses the types of cores to be used and comes 
out strongly in favour of the binocular core type BN 73-202.
He states that test results for transformers using toroidal cores with type 
75 and 77 material turned out to be significantly inferior to what was 
obtained with the other two cores.

Now my problem lies in the fact that I want to use the Beverage on 1.8MHz 
and down to 150kHz.
I'm concerned that a transformer wound using the BN 73-202 core will not 
perform satisfactorily down to 150kHz.

The comments that ON4UN makes about the use of type 75 material have me 
puzzled as there is an excellent, lengthy article by Bill Bowers, the late 
John Bryant and Nick Hall-Patch, VE7DXR which comes out clearly in favour of 
75 type material for transformers for use between 100kHz and 7MHz.

http://www.dxing.info/equipment/impedance_matching_bryant.doc

I presume that I would have to significantly increase the number of turns on 
the binocular core in order to get it to perform down to 150kHz?
Is my presumption correct?

Many thanks

Tracey G5VU