QRP Club

QRP Station => Builder's Corner => Topic started by: G6URM on February 13, 2017, 12:02:13 UTC

Title: atu for 2 m
Post by: G6URM on February 13, 2017, 12:02:13 UTC
(http://www.reduceimages.com/download.php?image=284bc01029)  here a simple atu for 2 meters - 100 pf Vc - coils 5 turns on a 45 mm former ( drill bit )  nothing complex - ok up to about 25 w depending on plate spacing  - will work with long wires too - note the TOP of box mounted o/p so239 or n- type socket  ( to which you could screw a 1/4 wave or whatever for a simple expediant antenna )  - the  brass bolt is the earth point and you should use a counterpoise rod or wire at least 1/4 wl long here if using it as a stand alone antenna base
Title: Re: atu for 2 m
Post by: iw1au on February 17, 2017, 22:27:59 UTC
Hi!
Could you attach a diagram, also hand made, to be more sure? Do you have some pics also?
Thanks.
Title: Re: atu for 2 m
Post by: vu2nan on February 23, 2017, 04:31:38 UTC
Hi OM Brett,

Please try uploading the images again. However I am able to visualise it since I have seen commercial 2m and 70cm ATUs. I am sure the former diameter is 4.5mm (decimal point missing!).

Having the output connector on top along with a point to connect a radial is a good idea.

Have fun!

73,

Nandu.