It is also important to insure the dummy load is exactly 50 ohms. The
various hybrid couplers are designed to have exactly 50 ohms on the dump
port.
I check my dump power loads twice a year to make sure they are still 50
ohms. Sometimes they are not!
73,
Tim K3LR
-----Original Message-----
From: TowerTalk [mailto:towertalk-bounces@contesting.com] On Behalf Of David
Robbins
Sent: Friday, August 07, 2015 10:10 AM
To: john@kk9a.com; towertalk@contesting.com
Subject: Re: [TowerTalk] Phase Vertical Dummy Load
I use a vectronics DL-650m. Yes, it is overkill as it is rated at 1500w,
but it is small enough to fit in an upside down coffee can for protection
from the weather. A smaller one would probably be ok most of the time as
dump power normally should be 100w or less if you are well balanced... BUT
(yes, the BIG BUT) if something happens to one of the verticals and you
don't notice it right away a 100w or even 250w dummy load would fry pretty
quickly.
David Robbins K1TTT
e-mail: mailto:k1ttt@arrl.net
web: http://wiki.k1ttt.net
AR-Cluster node: 145.69MHz or telnet://k1ttt.net
-----Original Message-----
From: TowerTalk [mailto:towertalk-bounces@contesting.com] On Behalf Of
john@kk9a.com
Sent: Friday, August 07, 2015 13:44
To: towertalk@contesting.com
Subject: [TowerTalk] Phase Vertical Dummy Load
I am curious what people are using for the dummy load used on phased
vertical controllers and how they are mounted. I do NOT wish to have the
dummy load in the shack. My plan is to have something that will be outside
and work in a variety of temperatures. I can mount it in an enclosure
however heat is a concern. Is air cooled better than the oil type outdoors?
Who makes a quality dummy load that will work in this environment? What is
the typical percentage of dump power across 80m?
Any suggestions and pictures are welcome.
73,
John
_______________________________________________
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
_______________________________________________
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
_______________________________________________
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
|