In recent times I’ve been feeling the urge to start experimenting with telescopic vertical whip antennas.  Vertical whip antennas appear to be somewhat simpler to setup than elevated dipoles.  So, it seems like a worthwhile endeavor to experiment with.

Recently, I purchased two Chameleons telescoping verticals whips:  their 17’ version and the 25’ version, for experimental purposes.  I’m looking forward to trying various configurations, which will likely not be until next spring or summer as our weather here in the Okanagan Valley of BC is starting to show hints that winter is just around the corner.  So, for now I have one specific configuration idea in mind that I have been itching to try:  a 1/2 λ Coaxial Sleeve Telescopic Vertical Dipole.  However, this configuration is required to be elevated with a tall mast.

In a sense, I suppose one could call this a Hybrid Telescopic Vertical Antenna because the top-half of the antenna will be a standard 17’ telescopic vertical whip from Chameleon.  And, instead of typical radials, the bottom-half of the antenna will be using the same concept of a Coaxial Sleeve Vertical Dipole, tuned for the 20m band.

I won’t take up too much space in this report outlining the construction details.  I just wanted to see if this antenna concept has any viable potential for ongoing uses.  This is the antenna I will be using today atop my 30’ carbon fiber telescopic mast.

Here we go with the events of the day.

Today I will be attempting to activate Vance Creek Ecological Reserve, CA-4252.  The Vance Creek activation spot is located about 1.5 hours drive NE of Kelowna, BC, Canada.  The access road into Vance Creek is a gravel forestry service road (FSR), just north of Lumby, BC.  I will be the 2^nd person to ever activate this park, and the 1^st to do it with CW.

We left home early with plans to make this another full day of playing with POTA.

Having never been here before, we drove the length of the reserve in search of a good spot and settled for a location just inside of the far-end of the park boundary at around 16:00 UTC (09:00 PDT).  We chose this location because it is one of the few areas to easily park off the roadway.  Beyond the sign titled “Woodlot” is a forestry logging harvest area (outside the park boundary).

There are no park facilities here, i.e. no parking lots, no camping, no picnic tables, and no outhouses, etc.; much like most of the areas I have been activating in the past year.

Alexis, my wife (VE7LXE) takes a short walk up and down the road just to get familiar with the area (we’ve never been here before).  It’s September 19^th 2024 and the mornings are getting quite cool now, so we are bundled up.

Time to unpack.  The first order of business is to erect the antenna system.  Today, I’m using the Chameleon CHA Porta Mount, Wheel Mount to support my 30’ carbon fiber telescopic mast.

After installing the wheel mount with mast inserted, the next step is to mount the Chameleon 17′ 3/8” threaded telescopic vertical whip to the top of the mast.

Basically, I made a mast-top adapter that holds a Firestick 3/8 to UHF adapter for mounting the 17’ telescopic vertical.  This is the top section of my hybrid vertical sleeve dipole.  I took some photos of this yesterday at home as I was testing and tuning the system for 20m operation.

I made the bottom half of the coaxial sleeve dipole using RG-8X (any size of 50 Ω coax will likely work).

Basically, I used 23’ of left-over RG8X  that I had left-over from other projects for the bottom half was of the coaxial sleeve dipole.  I measured 17’ from one end of the coax and wound it 13 turns through a #43 Fair-Rite 2.5” toroidal core.  This sets the length of the bottom half of the ¼ λ dipole and acts as an RF choke to isolate the antenna from the rest of the transmission line.  Then I terminated the ends with Amphenol BNC connectors using my BNC crimp tools.

The BNC male connects to the input of the 17’ telescopic whip and becomes the bottom ¼ λ section of the coaxial sleeve vertical dipole.

Yesterday, I setup my 30’ carbon fiber mast and tripod in the back yard to check the hybrid telescopic coaxial sleeve dipole tuning for the 20m band.

Based on my previous experience with my experimental coaxial sleeve dipoles (made-up of all-coax) I know that I need to provide some separation between the carbon fiber mast and the coaxial radiators that run parallel to the mast.  Thus, the 3’ plastic tubing near the toroidal choke is used to hold the bottom radiator away from the mast.
If I remember correctly, my initial test showed that the antenna was resonant about ~500 kHz too high.

I painstakingly re-threaded the core down about 6” to lengthen the dipole and lower its resonant frequency.

This did the trick.  It’s now tuned to the lower end of the 20m band. The lowest SWR is only about 1.75:1.  As well, it seems to be somewhat broadband and is thus usable across the whole 20m band as is.  The KX3 ATU will help with any remaining SWR issues.  I will be operating multiband; so, the length tuning is only primarily relevant to 20m band.
(I’m not sure yet but the broad-banding may be due to the remaining influence of the carbon fiber mast.

With that explained, time to get back to the Vance Creek activation.

The coaxial sleeve vertical dipole antenna is now erected.

One might ask the question, why go through the trouble to use an antenna like this?

My answer might be:

1. Why did the chicken cross the road?  Well, I don’t know about chickens, but I’m just plain curious to see how it works.
2. I’ve already tried an all-wire coaxial sleeve vertical dipole whose height it limited by the top of my mast which is about 30’ or so (or a throw bag height into a tree).  With the telescopic whip attached to the top of the mast, I gain an additional 17’ of maximum height.  That extra height could be useful.
3. Is it worth the trouble? Does it work?  I won’t know until I do a few outings and compare the results over time.

There are so many factors and variables that change from day-to-day, and location to location, when it comes to radio propagation.

Ok, everything is all set to start calling CQ POTA.

Once again, I’ll be operating CW at 10W with the KX3 and 4.5 Ah Bioenno battery.

This is where I’ll be sitting for the greater part of the next 7 hours, except for a short walk to stretch my legs and eat some lunch and snacks.

If I’m going to go through all the trouble to drive out here in the boonies, I might as well make it a whole day’s outing.  I often find that once I start operating, I find it hard to quit. You know how it goes…. Just one more contact, or just one more band… maybe the other band has opened back up…. It’s just one excuse after another. 😊

So, how did I do (and the experimental antenna)?
Here’s the play-by-play.

I start calling CQ on the 20m bread & butter band and make my first contact at 16:46 UTC (09:46 PDT) with NE1D in Massachusetts.  Both signals are quite weak, but still not bad for a coast-to-coast QSO.

Typically, my goal is to make my first 10 QSO’s on 20m before I move on up the bands.
I make my 10^th contact at 17:39 UTC with K9IS n Wisconsin.  During this past hour, I logged contacts from MA, ON, MN, NV, CO, CA and WI.

After getting stomped on again on 20m, it’s time to move on to 17m band.

My first contact on 17m is with NZ7Q in New Mexico at 18:13 UTC. Over the next 35 minutes, I log a total of 10 contacts on 17m with NM, WV, NJ, IL, VA, CA, and OH.  Once things slow down for a while, it’s time to move up the bands again.

So, let’s see who is hanging out on 15m.
I get the feeling NZ7Q in NM is following me and gives me a good 579 report.  Over a 10 minute period, I log 5 contacts on 15m with NM, LA, IN, OH, and IL.  The upper bands have a tendency to go hot and cold.

Time to move on to 12m.
Beginning at 20:54 I land KR4I in North Carolina.  Shortly after that, I get stomped-on by CO8LY in Chile, so I QSY up 1.  Shortly after, I land 3 more in TX over the next 35 minutes with descent signal reports.  But then the band goes quiet.

Anything happening on 10m today?  Dead. Nothing happing today on 10.

Once I give up on 10m, I work my way back down the bands to see if propagation has changed at all.

On 12m, I land two more contacts with Texas via WD5EEI and WB8QZM with strong signal reports.  But after that either the band goes cold, or nobody is chasing.  Propagation seems to be good to TX today.

Back on 15m band.
Wow; 15m seems to have waken-up this afternoon.  Beginning with KG8CO in MI at 21:33, he gives me a 599 report.  Over the next 35 minutes, I land 12 contacts via MI, TX, NY, IL, MA, ON, CA, and OK.

It’s just after 22:10 and the UTC day is nearing its end – I’m starting to run out of time.

So back down to 17m, I log 3 more contacts with CO, GA, and MI with good signal reports.

Another quick shot at 20m.
Between 22:35 and 22:50 UTC I snag 8 more 20m contacts via CA, NV, ND, UT, and WI.  Propagation is a bit on the short side, but I’m not complaining.

I get easily bored on 20m, so something tells me to give 15m another shot.
NO WAY!  Only one contact to be had here at 21:31 UTC……… and it’s LU4HK in Cordoba, ARGENTINA!  A weak signal report, but who’s complaining.  My first POTA Argentina.  Strangely enough, that was it for 15m band at this time – what a fluke!

Only 20 minutes left in the POTA UTC day.  One last shot at 17m to see if there is any magic there.
Between 23:42 and 23:56 I snag 6 more contacts on 17m with SC, TX, FL, LA, and MI.

The bell rings and I’m finished for the day.

The grand tally is in.
59 contacts in total for the day across 4-bands.  And a bonus contact with Argentina on 15m!

The 59 contacts didn’t come easy.  It took almost 7 hours of pounding brass and band hopping.  No magic here, just persistence. (Well, maybe there was some magic involved in snagging Argentina – the bands work in mysterious ways) 😊

(Tip:  Click on the image to enlarge the view.)

Time to head back home in Kelowna.

Thanks for reading.
(Hope I didn’t bore you too much with the play-by-plays.)

Jeff (VE7EFF) and Alexis (VE7LXE)

Equipment List:

Elecraft KX3 with internal antenna tuner
Elecraft KXPD2 paddle
Chameleon CHA Porta Mount – Wheel Mount
Gigaparts Telescopic Mast, 34ft, Carbon Fiber
17m ½λ Coaxial Sleeve Slanted Vertical Dipole, home brew
N9SAB 20m ½λ Rugged Nano Dipole
1:1 Low Power Balun/Choke for CMC/Noise Reduction Gen II
Bioenno 4.5 Ah LiFePo4 battery
PowerFilm F15-600 10W 600ma 15.4V Foldable Solar panel
Powerwerx PWRbox Portable Powe Box (no battery installed)
Dakota LiFePo4 Batteries (18Ah version replaced by 20Ah version)
Helinox Table One Hard Top
Helinox Speed Stool
Helinox Sunset Chair