Friday 30 April 2010

St. Louis Vertical Part 1 - Prep

© VE3MPG_ST. Louis Vertical-3 The St. Louis Vertical portable antenna has been talked about and modified over the years. It’s a very portable antenna solution for Field Day or QRP enthusiasts. It’s easy to build and modify and covers 40 meters to 10 meters with the use of a tuner. Radials are a must with this type of antenna. I use a Shakespeare Wonderpole, a collapsible fishing pole. Fully extended it’s 20 feet long and collapses to 45 inches for storage and transport.

Years ago I purchased a good amount of Radio Shack twin lead for this project and like any good ham I’m finally getting around to building a St. Louis vertical for use at Field Day and with the Ottawa Valley QRP Society group outings.

© VE3MPG_ST. Louis Vertical-1 © VE3MPG_ST. Louis Vertical-2 The first preparation that must be done on the Wonderpole is the removal of the two clips midway up on the first section. These two brass clips are used to hold a fishing reel. The reason for removing these two clips is to assure that the twinlead once wound on the lower section is flat against the bottom section when you wind it on. It’s more esthetics and it makes it easier to wind without the bumps of the clips underneath the twinlead.

© VE3MPG_ST. Louis Vertical-4

I used a Dremel tool with a cutting disk attached to cut through the clips. I still have to smooth down the plastic adhesive used to attach the clips with a small grinding tool attachment on the Dremel.

For the last while I’ve been thinking quite hard to determine a good way to wind the twinlead onto the bottom section so it stays in place. In part 2 of this series I’ll show you a novel method that I devised to accomplish this – it’s weatherproof too.

A71EM in Quatar Have been listening to 17m psk this afternoon and just finished working A71EM in Qatar with 40 watts on the R6000 vertical. 17 is a fine band with some great DX and quiet band conditions – opportune for working DX. It seems to be open early morning till sundown here near Ottawa – always with some exotic stations waiting to be worked.

Here’s a link from the American QRP Club describing the St. Louis Vertical:

AMQRP.ORG St. Louis Vertical


Tom said...

Hi Bob -- I was cleaning out the garage and came across a SD-20 (I think) fishing pole and a bunch of parts, including a killer looking coil, in a box labeled St Louis vertical. Like you mentiioned in your blog I too had bought all this stuff a number of years ago and only now have re-discovered it.

I Googled 'St. Louis Vetical' and your blog post from last April came up. I was wondering how you are doing with it.

I'm a little antenna-phobic and thought it might be a good antenna to put up in the backyard and take down when the neighbors aren't looking...hi

At any rate, I don't know if you're still checking comments on your blog but thought I'd drop as line to see how it went with your SLV project.

I look forward to hearing from you.

Bob VE3MPG said...

Hi Tom,

Thanks for letting me know about that missing comment. Blogger does strange things sometimes and your comment just never showed up to be moderated - so far as I can see.

Your recent comment came through fine and it's posted along with the St. Louis vertical blog post.

My summers are quite busy as I have a large organic garden and 2 acres of grass along with 5 gardens. In the midst of all the commotion this year I have had to fly to Los Angeles on business several times and I'm headed back there during October.

The SLV will hopefully be tested sometime in mid-September so watch for a new chapter to that original post.

And thanks for reading my blog - hopefully with the changes Blogger is going through the comments sections should be fixed - they've just added a spam filter but it's still not catching some of the spam.

My SLV is intended for portable qrp work if I can ever find the time.


Bob Baillargeon VE3MPG
near Ottawa in FN25fe