[TowerTalk] 259 Grid dip meter adapter

Tom Rauch W8JI@contesting.com
Sun, 17 Sep 2000 19:55:31 -0400

> I also have found the 259 GD coil to be vy insensitive. I have used both
> the ac powered and battery powered Millen GDO's to cut 1/4 wave stubs.
> They work fairly well but there is a better way reccomended to me by K5GW
> of Tx Towers. It is used by VHFers.I understand he used it to make the
> stubs in his 2m moonbounce array. I believe it is 48 each 10 element
> yagis. 

The 259 GD adapter is an offshoot of a QST article (I think that 
article won some award).
Unfortunately, it does not work well. 

It can't work well because the coil in the adapter is not part of a hi-
Q resonant circuit. If the external system is high-Q, the adapter will 
work OK. If the external circuit is low Q, it will not. Stubs are 
generally low to moderate Q devices.

The 259 works better checking stubs by watching the "Impedance" 
meter. The 259B reads stubs directly.  

IMO, the GD adapter isn't very useful with the 259.

73, Tom W8JI

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