eHam

eHam Forums => Station Building => Topic started by: BV2OZ on October 18, 2001, 01:19:44 AM



Title: new amateur station on 7th floor...
Post by: BV2OZ on October 18, 2001, 01:19:44 AM
Dear Friends,
   I need some advice.  I am setting up a radio
with a 4-band resonant antenna.  I live on the
top floor of a block building and plan to mount
the antenna just outside on the roof, either
in a pail of cement or on a pipe-wood base
bolted to the inside lip of the top wall...  I only
need to run maybe 5 metres of feeder line to
reach the antenna.  The radio is a new IC-718.
   
My question is this: are there any issues
regarding the proper grounding of my radio or
antenna that I need take care of?  I haven't
read Maxwell's book or anything.  So somebody
make suggestions.  (I'm still waiting to receive
everything through the mail...)

Regards,
BV2OZ


Title: new amateur station on 7th floor...
Post by: KL7IPV on October 19, 2001, 02:13:39 AM
My suggestion would be to mount the antenna mounting mast in a bucket of concrete. The mast needs to extend about 2 feet out of the concrete and the antenna will use the top 18 inches of the mast to mount on. Mount the antenna above the bucket and run some radials out around the antenna. It the upper most frequency of the antenna is 20 meters, the radials need to be no longer than about 16 feet. Run a couple for the 20 meter band, a couple for the 15 meter band , etc. If you use a ten gallon bucket and fill it with concrete, it is going to weigh about 100 pounds. Mix the concrete on the roof and fill the bucket there or have some BIG guys around to help you get it to the roof after you fill it. I used a 5BTV in a bucket here and it was plenty heavy enough to support that antenna. Good luck
73
Frank
KL7IPV


Title: new amateur station on 7th floor...
Post by: N6AJR on October 28, 2001, 10:52:16 PM
Also consider using either a mfj adjustable ground matcher or make your self a decent counterpoise. Look here for info on them, to give your rig some  kind of ground to work against.  Some folks say its a bunch of hoq wash, but I think they  work  and they are easy enough to build out of rotator wire, basically a series of 1/4 wave radials for each band worked, hooked to the ground of your tuner or radio.  Have fun, and check here and qrz.com as there is a wealth of info in the different fourms an questions and answers.. good luck and have fun  tom N6AJR


Title: new amateur station on 7th floor...
Post by: W9GB on November 06, 2001, 08:52:41 PM
Nice QTH location ! ... and short feedline !

w9gb


Title: new amateur station on 7th floor...
Post by: KC5CQW on May 18, 2002, 08:30:04 PM
go to www.tentec.com and look in the t-kits for the rf ground counterpoise model 1251. I use one in my apt. and BOY DOES IT WORK!!!!!!!!


Title: new amateur station on 7th floor...
Post by: KC5CQW on July 11, 2002, 06:58:40 PM
I now use an LDG AT-11MP with the TT-kit 1251 and it works the same as if you use a manual tuner.