43 Foot Vertical Antenna

And

K9AY Receive Antenna

By: Rick, VE7TK

Why Choose a Vertical Antenna

Pro: Small footprint

Unlike wire antennas, no supports needed

Low-angle of radiation (better DX)

Much cheaper than a tower and yagi

Less visible than a tower and yagi

Good choice for an inexpensive multi-band station

A good option for lower frequency DX

Why Choose a Vertical Antenna Con:

Local communication (inside 300 km) can be poor

Much lower gain than a yagi antenna

Not directional

More susceptible to atmospheric noise than dipole or yagi

Requires a good ground radial system

My Antenna Farm

Current Antennas •43 foot Vertical Antenna

• 80, 40 and 30 m

• 3-element SteppIR yagi on a 48 foot tower

• 20 thru 6 metres

My Goals I am an avid DXer

I have worked and confirmed 100 or more countries separately on the 40, 20, 15 and 10 metre bands

On 80 metres I have worked only 50 countries and I would like to get DXCC on this band.

I chose the DX Engineering 43ft

Came with tilt plate and 4:1 Unun

I have installed 25 radials - 10 @66 ft, 12 @33ft and 3 less than 33ft.

43 foot vertical with:

• Tilting base mechanism

• 4:1 Unun • AD5X Matching

network for 80 and 160

• Home-brew radial plate

Interfacing the antenna The 43 foot vertical is NOT resonant on any of the HF

ham bands.

The AD5X matching network with switched coils and 4:1 unun brings the SWR into a range accessible by most transmatches (or tuners) without significant loss at the antenna to coax junction.

43ft Matching Network

Coils are switched in for 80 and 160 only

An antenna “tuner” is required

AD5X Matching Network

In an effort to reduce the inherent noise that comes with a vertical antenna, I built a receive only antenna .

I built my antenna from a kit available from Far Circuits

Commercially built units are available for approx. $300+

Schematics are available.

•The antenna consists of a pair of delta shaped loops at 90 degrees to each other.

•In the head unit are a series of relays.

•Relays select which loop is in use and (through a phasing circuit) the direction the loop is listening

•Originally the loop was designed for 160 and 80 metres

•My loop is about 2/3rds size – Optimized for 80m and it still functions on 160.

Head Unit

•2 larger relays select the loop and direction

•3 smaller relays change the load resistance and impact on front to back

•The small white device is a 9:1 balun

•Control lines and coax are buried in the grass and run back to the shack

RemoteController

•The kit does not include any switches, LEDs or the boxes themselves •All this came out of my junk box. •The circuit includes a bandpass filter and low noise pre-amp. •Switching of the Matching Network for 160, 80 and other bands is provided

K9AY Interfacing

•Connecting the K9AY antenna requires a dedicated receive antenna port on your rig.

•The Ten-Tec Orion has such separate receive antenna port

•To protect the front end of the rig from damaging currents when transmitting, front-end protection similar to that sold by Array Solutions is needed.

•Demo

Comments

The switchable receive antenna is a nice addition.

Generally signal strength is much lower on the K9AY than the vertical

However, the noise floor is substantially lower as well

The signal to noise is often MUCH better

The Pre-Amp is operable below 7 MHz only

In some situations the vertical antenna is better?

With this set-up I have the option of choosing the best receive antenna for the situation.

My K9AY

The yellow flagging tape shows the bottom of the loops and was there for the dog!

Results

Since Installing the vertical and the K9AY I have finally obtained DXCC on 80 metres.

I received 5BDXCC in 2014 with additional endorsements on 30, 17 and 12 metres.

To follow my progress go to ve7tk.com