Antenna Notes from the Field – QRP

Antenna Notes from the Field

 

Here are some observations from using the following antennas for QRP operations in the field

 

Hamsticks

 

Hamsticks are classified as helical wound 4 foot antennas that have a tuning tip on the end. They come with a 3/8-24 stud for easy mounting to magnetic mounts or other mounts adapted for fixed use.

 

Hamsticks are easy to use, quick to set up and can be found for $5 at most hamfests.

 

I have had good success with using them with magnet mounts for mobile or fixed mobile operations and the efficiency is greater on the higher bands. They do work on 40m and 80m but bandwidth and efficiency is reduced but its suitable for local traffic.

 

You will get better results on 40m and 80m by using the Hustler antenna as its longer and its coil offers better bandwidth and supports higher power. This is the antenna of choice for mobile county hunters.

 

If you wish to operate 5 bands you will need 5 hamsticks. Hamsticks with a dipole mount can also be used for portable operations eliminating a need for a ground.

 

hamstick

Buddistick – PAC 12 – Superantenna – Chameleon- Ozipole

 

 

These are shortened antenna systems that offer greater flexibility than a cheap hamstick. They can also be part of a system of parts that can be adapted for various configurations.

 

They make the use of tapped coils or broadband baluns to provide a wide swath of bands that can be deployed.  The advantage is that you can also add longer whips to increase efficiency or even adapt for use as a dipole.

 

They all need a counterpoise for best results.

 

The Chameleon doesn’t use any tapped coils but it does have a broadband transformer and will require an antenna tuner. I have found this to be a versatile antenna especially with the longer whip and can be also used as NVIS by angling the mount that I use.

 

My PAC-12 is an easy home brew as is the Ozi-pole and they work as well as a standard Buddistick. The SuperAntenna MP-1 seems to be the worst performer and the tripod is very flimsy.

 

The tapped coil whips all need some fiddling around with and the best suggestion is when you get close to the frequency you can adjust the SWR by tuning the counterpoise. This wire is also a radiator and is a MUST to get a signal out.

EFHW Antennas

 

The EFHW or End Fed Half Wave antenna is another great antenna for field use as it only needs a single elevated endpoint (Tree or Fishing Pole). I have various versions but I tend to grab the PackTenna version most often for 20m. For 17m I am using the SOTABeam version. Many hams are using the PAR Endfedz version as well. Throw it up and get on the air – no tuner required.

packtenna.png

Long Wire 9:1

 

This is another simple set up for multi-band use with a tuner. There are various 9:1 balun designs and I have made several EARCHI and UK designs. They all work well from a T-50 to a FT-200 toroid. I have several purchased baluns and the LDG and PackTenna versions are what I use the most for higher power. I have a pocket balun for QRP use that is on a key chain that I use a lot. This to me seems to be a better antenna for the lower bands as it does need a minimum 29 foot radiator.

 

For the end fed vertical offers advantages such as easy band change from 80m to 10m using an external auto tuner and ability to run higher power.

I usually run mine in a Marconi NVIS configuration for the lower bands.

 

packtenna marconi NVIS endfed

Norcal Doublet

 

The Norcal Doublet is a favourite antenna that can be made for $2. Its basically a 44-foot dipole made from speaker lead and does need a tuner. You will need to suspend it but it can also be used as a long wire with your tuner by shorting out the feed end if you only have a single tree to support the end. I have hung it over balconies as well or draped within a hotel room.

 

norcal doublet

 

Magnetic Loops

 

This is another antenna for field use that is becoming popular. My version uses the Chameleon DIY kit that replicated their F-Loop and P-Loops. The AlexLoop is another version that works well. I am hoping to do some shootout tests when the Toronto QRP Society gets together for a field operation in May.

 

So for portable use, the Magnetic loop antenna has a few advantages: Deployed in 3 minutes, Low receive noise, Some directionality, typically tripod mounted and external antenna tuners not required.

chameleon floop

Motorized Mobile Antennas

 

I have no experience with these antennas. They are basically tapped antennas for mobile use that have a motorized assembly to tune them for multiband.

 

tarheel

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One comment

  1. Mike Hohmann · July 17

    Useful info., now digitized in my library. Thanks.

    Like

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