Open Roads Radio forum for Ham, Amateur Radio and RV camping


Reply
 
Thread Tools Display Modes
 
Old 12-11-2015, 06:27 PM   #1
KL7V
Junior Member
 
KL7V's Avatar
 
Join Date: Dec 2015
Location: Fairbanks, Alaska
Posts: 12
Default Starting Work on a Big Vertical for 40/75

I am working on a vertical that will be a full 1/4 wave on 40, which will also have a center load coil for use on 75. I am going to shunt the coil for use on 40, and add a capacity hat when used on 75.

The RV is a 36' 92 Nu-Wa Snowbird 5th wheel. This trailer is constructed of a fiberglass outer layer, with hard blueboard insulation and an inner plywood covering. SO... no metal in the body or on the roof.

My idea is to fabricate a custom antenna mount on the pinbox, where the HF antenna will mount. VHF and AM, etc. will go on the roof with an artificial groundplane.

I have lots of old scrap aluminum tubing of different lengths on hand to build with, thinking about using 2" tubing for the first 15 feet, with a 5" copper coil for loading, then a telescoping whip about 17' long from a salvaged CB 5/8 groundplane.

I am getting ready to assemble it and test away from the RV with radials to see how it plays! Of course, it will be huge and not meant for any kind of mobile ops. The coil is optimized for high Q, 5" in diameter and 5" long and about 33 uh, it should be close to correct...

Any other experimenters out there?
Attached Images
File Type: jpg 75coil.jpg (37.5 KB, 41 views)
KL7V is offline   Reply With Quote
Old 12-13-2015, 01:02 PM   #2
KL7V
Junior Member
 
KL7V's Avatar
 
Join Date: Dec 2015
Location: Fairbanks, Alaska
Posts: 12
Default

With the vertical mounted on the pin box, I will deploy temporary radials in several directions from the pinbox to improve the counterpoise. Since there is no metal in the body or roof, I think the pin box will be an excellent place to mount the antenna. The frame should make a good counterpoise. When I don't want to unhook the tow rig, a couple large heavy grounding straps will attach to the truck to use it as well.
__________________
Dale Powell KL7V
Fairbanks, Alaska
First licensed in 1985. 36' 92 Nu-Wa Snowbird 5'er, 2010 Dodge Ram 3500 Crewcab Dually Laramie, 6.7 Cummins, 6-speed manual. Retirement is coming soon, turning the RV into my new radio shack. We also show Shetland Sheepdogs.
KL7V is offline   Reply With Quote
Old 12-13-2015, 06:19 PM   #3
NN5I
Carl, nn5i
 
NN5I's Avatar
 
Join Date: Sep 2011
Location: Tallahassee, FL
Posts: 1,407
Default

Dale, are you joshin' us? Looks to me like you're actually building a moonshine still.
__________________
-- Carl
NN5I is offline   Reply With Quote
Old 12-14-2015, 12:23 AM   #4
KL7V
Junior Member
 
KL7V's Avatar
 
Join Date: Dec 2015
Location: Fairbanks, Alaska
Posts: 12
Default Might Build a 160 Version Also...

Now you're talking! How about a combination still/vertical antenna? Very low loss, very high Q, but very narrow bandwidth. I will be parked on nets mostly. Santa may be bringing me that antenna analyzer to fine tune with.
__________________
Dale Powell KL7V
Fairbanks, Alaska
First licensed in 1985. 36' 92 Nu-Wa Snowbird 5'er, 2010 Dodge Ram 3500 Crewcab Dually Laramie, 6.7 Cummins, 6-speed manual. Retirement is coming soon, turning the RV into my new radio shack. We also show Shetland Sheepdogs.
KL7V is offline   Reply With Quote
Old 12-14-2015, 06:14 PM   #5
Radio
Administrator
 
Radio's Avatar
 
Join Date: Nov 2007
Location: Fayetteville, GA, USA
Posts: 3,004
Default

So what did you use for a coil forming tool?
Radio is offline   Reply With Quote
Old 12-29-2015, 01:54 AM   #6
W7JZE
RV in 2016
 
W7JZE's Avatar
 
Join Date: Apr 2014
Location: Patterson, CA (CA central Valley east of SF)
Posts: 92
Thumbs up

Quote:
Originally Posted by Radio View Post
So what did you use for a coil forming tool?
Yah... that thar is one purdy coil :-)
__________________
73,

Bill - W7JZE
"Dar" - XYL
(And our little Bichon Frisť "Sparkle")
W7JZE is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

Powered by vBadvanced CMPS v3.2.3

All times are GMT -5. The time now is 10:49 AM.


Powered by vBulletin® Version 3.8.9
Copyright ©2000 - 2018, vBulletin Solutions, Inc.