[UK-CONTEST] Butternut HF9V

[Clive Whelan]

Hi John


> On 14MHz the best match is about 1.6 to 1
> 
> On 18MHz the best match is only 2.2 to 1
>



14Mhz is very much a compromise, as you would guess from the 
matching section of 75 ohm coax, and the lowest SWR is never as 
good as the other bands. The upside is that it is very broad. If 
you are measuring at the antenna, then 1.6:1 will be of no 
consequence at all, and depending on the length of your 50 ohm 
line, amy present substantially less than that at the tx. Of 
course modern rigs do balk at greater than 1.5:1, but invariably 
the internal tuner addresses this problem.

18Mhz. Having erected three of the beasts, I can say with 
confidence that the supplied coil set up is *not* correct! Don't 
be afraid to deviate very substantially from the book, and see 
what you get. There is some interaction between the 18 and 24 
Mhz settings, so some experimentation will be required.


If you get stuck, email me privately, and I'll give you the 
range of coil dimensions that I have installed on my three, for 
both 18 and 24 Mhz.

The Butternut is a masterpiece of design; shame about the build 
quality! However it will survive 80mph + winds, to that I can 
attest, so what do we want?


73



Clive
GW3NJW