On 4/8/2014 8:43 PM, Tom Osborne wrote:
On 4/8/2014 4:25 AM, john@kk9a.com wrote:
I just read the Joel Hallas, W1ZR article - "The 43 foot vertical
monopole
- What's the magic?". It was very interesting! The coax losses are
worse
than I imagined, up to 8dB though 100 feet of RG-213, and as my model
showed the radiation is very high above 20m. Certainly a relay to
electrically shorten the antenna would help 15m and 10m.
John KK9A
I always wondered why someone would pay $400- $500 for a '43 foot
vertical' when you can hang about $1.50 worth of wire in a tree and do
the same thing.
Or buy the material and build your own. They are a fairly simple antenna
plus matching network.
I do not like trap verticals. I had very good results with the AV640 on
40 meters through six. On 40, one day it'd beat the half wave, center
fed sloper and on other days the sloper would win.
The trap verticals never won.
We had one of those for FD and it was not a very good antenna.
With radials, I'd have expected it would do well on 40 and 75 although
the range on FD is a bit short for the vertical.
Here, both the slopers and AV640 worked better for DX, although the
slopers worked fairly well beyond 600 - 800 miles.
I didn't spend a lot of time on 75, but worked the world at the last
cycle low. The sloper on 75 worked well into Europe.
73
Roger (K8RI)
73
Tom W7WHY
_______________________________________________
_______________________________________________
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
|