InnovAntennas XR4C-MKII Instructions manual

XR4C 8 Element 4 Band Yagi

20/15/10/6M

Model: XR4C-MKII - Z08564-0134

Weight: 26,0 Kg.
Max Power: 10 kW+

Rev. V1.6 - 25/10/2019

Copyright 2019 InnovAntennas Limited

Contents

Antenna Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

Boom construction & boom join configuration. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

Element plate mount . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Boom to mast plates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

Boom to mast plate photos . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Illustration showing individual element joining methods . . . . . . . . . . . . . . . . . . . . . 8

Element sizes and taper layout with taper schedules. . . . . . . . . . . . . . . . . . . . . . . .9

Element layout on boom - illustration showing the built antenna . . . . . . . . . . . . . . 10

Installation photos - built antenna photos with close-up of feed system . . . . . . . . .11

Construction photos. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12

Parts list . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

Antenna Overview

The XR4C is a unique multi-band HF & 6m directional beam Yagi antenna. Some of the features
which make this antenna unique include the following:

Full-sized 4 band HF Yagi + 6m

The XR4C is the only 3 band HF and 6m Yagi available with full-sized elements in each band,
although this makes the XR4C some 11m (28') wide, the optimisation for extended bandwidth
means the elements are closed spaced meaning the boom is only 3.5m (12') long.

Interlaced elements for each band with no more than 3 bands

The more bands that are interlaced on a given boom, the more compromised the performance
becomes. With this in mind, the XR4C was optimised with no more than 3 bands interlaced at any
one position on the boom. The antenna has at least two active elements per band. On the 20/15
meter bands a more traditional reflector and driven element arrangement is used. 10/6 use a driven
element and director arrangement and are placed at the front of the boom in order the larger
elements of 20/15 (at the back of the boom) provide some directive properties to them too.

On the 6m band there are 2 elements although both are parasitically coupled (no physical electrical
connection to the coax or other elements).

SDR-friendly Yagi

Unlike ‘active’ dynamic antennas, the XR4C can be used on ALL BANDS AT ONCE. This means if
using a radio such as a Flex 6500/6700 which can have up to 8 operation receivers, 4 receiver slots
on 4 bands can be used at the same time on the XR4C.

Wet Weather Stable

Being optimised with close-spacing and wide bandwidth the XR4C provides stable operation within
wet weather.

Computer optimised Electromagnetic and mechanical design

In addition to using computer optimisation for the electromagnetic design, the XR4C has been
mechanically optimised by computer too, to ensure long-term survival. Elements all taper quickly
with the center sections of the 20m elements being 35mm in diameter in the middle and 13mm at
the tips.

Check your Parts and Read the Manual!

Before doing anything else, check the parts list in the back of this manual against what you have
received and read the construction information fully before attempting to build this antenna. This will
ensure your construction will be trouble-free and you will spend less time building the antenna too.

Boom Construction

The boom is constructed of 50mm diameter square tube (2mm wall thickness) in several
sections. A round joining tube is supplied and should be fitted as per the picture below.

Insert the M6 bolts into the holes and all the way through the boom secure on the opposite side
with an M6 nut and washer. It is advised that you insert the joining tube into one section of outer
boom, fully secure with the M6 bolts and then add the next piece of boom (also marked ‘A’ in
order the boom join now shows ‘A-A’ as in the below picture) and duplicate the finalisation
process with M6 bolts.

DO NOT over-tigthen the bolts and always oil or grease all hardware before joining to prevent
galling. Over-tigthening could weaken the join and lead to a shorter life length of your antenna
boom.

Below is one section of the XR 3 boom with the round joining tube inserted. The second square
section of boom should be slid onto the joiner and both sides bolted as shown in the photo below.

Boom Joining TubeBoom

Shown without nuts and washers

Boom to Element Plate Mounting

Element plates are bolted to the boom with the supplied M6 bolts.
fed dipole elements will use 4 insulator/plate arrangements while
all parasitic elements will use 2 insulator (shorter) plates.

Boom

Element insulators (white in shipped product)

M6 nuts

M6 bolts hold insulators
in place

M6 nuts

Plate is counter-sunk for screw heads

DIN 7991 M6 x 70mm bolt

DIN 127 M6 nut

EA010085

Bottom plate

Centre hole has a bolt which screws into a RivNut

which is inserted into the boom.

4 holes in a square around this one, have bolts which

go through them and sit either side of the boom, bolting

to a plate beneath the boom.

EA010320

Main boom to mast plate

Boom to Mast Plate Mounting

150mm

Rear boom to mast plate

EA010321

150mm

Boom

DIN 912 M6 x 80mm

Square Tube Boom

Nut and Bolts

DIN 985 M6
DIN 127 M6

Boom

70mm

150mm

U-bolt and Saddle

A-0163

50mm
U-bolt

MAST
50mm

23035.50

Saddle Clamp

Boom to Mast Plate Photos

All Element held in place with hose clamps to ensure a constant contact patch around each join.

Hose Clamp 20-32mm Ø Hose Clamp 25-40mm Ø

35mm Ø 30mm Ø

Hose Clamp 16-27mm Ø

25mm Ø

20mm Ø

30mm Ø

Hose Clamp 12-22mm Ø

20mm Ø

Hose Clamp 8-16mm Ø

16mm Ø

Smaller tube over-laps into next tube by 150mm

25mm Ø

16mm Ø

13mm Ø

Parallel Feed line fitment

The XR4C is feed at the 20m dipole centre. However, a pair of parallel square tubes
sit on top of the 3 sets of feed point terminals and are bolted to them. This ensures
that the one, single feed line connected to the antenna will feed all 3 bands. 6m
elements are not physically connected, these are parasitically coupled.

The photo across the page shows this arrangement on an XR 6 and therefore, there
are 5 dipoles connected in this example. On the XR4C, only three of these dipoles will
be joined by a much shorter pair of feed lines.

Capacity spokes for 20m elements

The 20m elements have capacity spoke elements fitted as per the above photo, 4 on
the tip of each 20m element. tighten until firm and do no over-tighten as this could
damage the capacity spoke or reduce its life length.

Final element tip adjustment

On most bands the XR4C will cover the majority if not all of the 4 bands it covers. However, as with most HF Yagis, proximity to ground, ground
type and nearby objects and antennas, may vary the point at which the antenna dips (lowest SWR). Therefore, the tips of each element on each
band can be adjusted in order that you can fine-tune your antenna for your working requirements.

Adjust the driven element of a given band for lowest SWR wherever that may fall, not where you want it to be. If the point of lowest SWR is
not in the band section you desire, adjust BOTH band elements by the same amount to move the dip to the desired point and then re-adjust
the driven element for lowest SWR dip.

For example, if after adjusting the 20m driven element for lowest SWR, the lowest point of SWR is 14.300MHz, then BOTH the 20m reflector
and driven element need to be made larger by the same amount. If you wanted your antenna at 14.100, add 10mm to each tip end on the
reflector and director 20mm to the total length of each element) and check SWR again. adjust the driven element in and out a few mm to
establish the final lowest dip and make adjustments accordingly. If the antenna dips on 13.9MHz rather than 14.1MHz then the reverse would
need to be applied, removing 10mm from each tip (20mm total from each element overall length).

The above examples are extremes and it is unlikely you will see the variants suggested above. Also note that 20m and 15m have a
reflector and driven element. 10m and 6m use a driven element and director.

Note also that any fine-tune adjustments to each band should be done in this order - 20m, 15m, 10m then 6m last of all.

Element Layout on the boom

(Not to scale)

20m Reflector

15m Reflector

Twin feedline connecting
all driven elements (not 6m)

4 spokes in total at the end of each element,

north, south, east and west facing

0mm

1224mm

Drop coax/balun 90 degress away

from feed point

10m Driven

15m Driven

20m Driven

17m Driven

6m Driven

6m Director

2186mm

Feed point at 20m element

2299mm

2714mm

2900mm

3190mm

3450mm

These parallel feed lines are made from square
aluminium tubing and are drilled to sit on top of
each feed point. Due to the variation in size of
each of the driven elements, the feed lines will
not sit flat on the boom and will need to be
fastened as per the photo (left).

Antenna Build Notes:

This drawing is NOT TO SCALE and the majority of elements in the drawing are far more widely spaced than on the
built antenna. This is in order to make the drawing clear for the constructor.

This antenna is better hung ‘upside down’ with all insulators and feedline facing towards ground. This will allow for
easy coaxial connection to the feed point and routing away form the antenna, towards and down the supporting
mast.

Element plates on antenna are NOT the same size as indicated in the drawing above, again this is presented this
way for clarity. the correct sized element plates for each band (and their respective size) can be found in the parts list
at the rear of this manual.

See photos on page 10 of a mounted antenna for the ‘ideal’ boom to mast plate mounting position and choke/1:1
balun/coax feedline routing.

Typically element placed on driven elements have four insulators, parasitic element plate holders have two while the
6M elements are held in place on the boom with one insulator and no plate.

For help and assistance: [e-mail]

Element Sizes & Taper

20m

8780mm 8020mm Reflector - Driven @16mm diameter

7084mm @20mm

Capacity loaded tips

20m elements

First spoke 20mm from end of element and 20mm spacing between remaining 3 spokes

5388mm @25mm
3692mm @30mm

1996mm @35mm

Centre element to

spoke tip 560mm

End view of 4-spoke capacity hats for 20m elements

15m

10m

6m

7450mm 7100mm Reflector - Driven @13mm diameter

5388mm @16mm

3692mm @20mm

1996mm @25mm

5420mm Driven - Director @13mm diameter 5010mm

3692mm @16mm

1996mm @20mm

2930mm Driven - Director @13mm diameter 2810mm

1996mm @16mm

Capacity Spokes

From the centre

of the 20m element

to the tip of each

spoke is 560mm

ROD / SPOKES
6mm diameter

At the ends of the 14MHz element sections
(16mm diameter) there are holes to allow for 4
spokes (capacity hat elements) to be installed.
These are bolted into place as shown.

Nuts and washers on

to a threaded shaft

(capacity spoke)

20m Band

Capacity hat spokes installed at

the element tips of the 20m

elements

Installation Photos

The twin feed lines of the XR4C (XR6 pictured) can be

clearly seen above with the coax cable directly

connected and running down the mast away from the

antenna.

Panned view of the feed arrangement on the XR4C

(XR6 pictured) with all elements in place on the boom

PART #

PART IMAGE

DESCRIPTION

SIZES

QUANTITY

PACKING LIST

PART #

PART IMAGE

DESCRIPTION

SIZES

QUANTITY

A-0163

U-BOLT

M8 x 50mm

BAG #1

2

23035.50

S127-98

S934-98

S7991-9630

P0100026

P0100025

P0100023

P0100024

SADDLE CLAMP

DIN 127 WASHER

DIN 934 NUT

Flat Head DIN 7991 Screw

Hose Clamp

Hose Clamp

Hose Clamp

Hose Clamp

50mm

M8

M8

M6x30mm

25-40mm

20-32mm

16-27mm

12-22mm

2

4

4

6

4

4

8

12

P0100033

S912-9660

S912-9650

S912-9640

S985-906

S7991-9470

S125-94

Hose Clamp

Allen DIN 912 Screw

Allen DIN 912 Screw

Allen DIN 912 Screw

DIN 985 NUT

Flat Head DIN 7991 Screw

Washer DIN 125

10-16mm

M6x60mm

M6x50mm

M6x40mm

M6

M4x70mm

M4

12

BAG #2

12

24

4

36

6

6

S9021-94

S934-94

Washer DIN 9021

DIN 934 NUT

M4

M4

12

18

PART #

PART IMAGE

DESCRIPTION

SIZES

QUANTITY

PART #

PART IMAGE

DESCRIPTION

SIZES

QUANTITY

S7380-9660

Allen DIN 7380 Screw

M6x60mm

BAG #3

8

S9021-96

S985-906

EAHYP035

EAHYP025

EAHYP020

EAHYP016

DIN 9021

DIN 985 NUT

Plastic Blocks

Plastic Blocks

Plastic Blocks

Plastic Blocks

M6

M6

35mm Ø

25mm Ø

20mm Ø

16mm Ø

8

8

BAG #4

6

6

6

2

BAG #5

PART #

PART IMAGE

DESCRIPTION

SIZES

QUANTITY

PART #

PART IMAGE

DESCRIPTION

SIZES

QUANTITY

PART #

PART IMAGE

DESCRIPTION

SIZES

QUANTITY

EA010085

S7991-9670

S127-96

S985-906

S912-9680

S127-96

BOOM plate 50mm

Flat Head DIN 7991 Screw

Lock washer DIN 127

DIN 985 NUT

Allen DIN 912 Screw

Lock washer DIN 127

70 x 50 x 6mm

70x6mm

M6

M6

80x6mm

M6

6

24

24

24

BAG #6

8

8

S985-906

EA010261

EA010267

EA010252

EA010255

EA010320

DIN 985 NUT

14 MHz. Elements plates DRIVEN

14 MHz. Elements plates REFLECTOR

21/24/28 MHz. Elements plates DRIVEN

21/28 MHz. Elements plates REFLECTOR/D1

Boom to Mast Plate

M6

SPARE PARTS

250 x 70 x 5mm

200 x 70 x 5mm

250 x 60 x 5mm

200 x 60 x 5mm

150 x 150 x 10mm

8

1

1

2

2

1

EA010321

EA010322

EA010313

Secondary Boom to Mast Plate

POLYCARBONATE ELEMENTS PLATE

+ PLASTIC TIES KIT

FEED SQUARE TUBE SET

150 x 70 x 8mm

375 x 50 x 3mm

410 x 15 x 15mm

1

2

1

PART #

PART IMAGE

DESCRIPTION

SIZES

QUANTITY

SPARE PARTS

XR4C

A-A

XR4C

A-B

EA0120502

XR4C 20#1

XR4C 20#1A

XR4C 20#2

XR4C 20#3

XR4C 20#4

XR4C 20#5R

...

.

.

.

BOOM A

BOOM B

BOOM JOINT

20m Centrall part

DE 20m Central part

20m 2nd PART

20m 3rd PART

20m 4th PART

20m 5th PART

REFLECTOR

1495mm x 50mm

1495mm x 50mm

200mm x 45mm

1996,0mm x 35mm Ø

1996,0mm x 35mm Ø

998,0mm x 30mm Ø

998,0mm x 25mm Ø

998,0mm x 20mm Ø

1048,0mm x 16mm Ø

1

1

1

1

1

4

4

4

2

XR4C 20#5D

XR4C 20#6L

XR4C 15#1

XR4C 15#1A

XR4C 15#2

XR4C 15#3

XR4C 10#1

XR4C 10#1A

XR4C 10#2

20m 5th PART

DRIVEN

CAPACITIVE HAT

15m Centrall part

.

.

.

.

DE 15m Central part

15m 2nd PART

15m 3rd PART

10m Centrall part

DE 10m Central part

10m 3rd PART

668,0mm x 16mm Ø

571,0mm x 6mm Ø

1996,0mm x 25mm Ø

1996,0mm x 25mm Ø

998,0mm x 20mm Ø

998,0mm x 16mm Ø

1996,0mm x 20mm Ø

1996,0mm x 20mm Ø

998,0mm x 16mm Ø

2

16

1

1

4

4

1

1

4

XR4C 15#4R

XR4C 15#4D

XR4C 10#3R

XR4C 10#3D

15m REFLECTOR Final part

15m DRIVEN Final part

10m REFLECTOR Final part

10m DRIVEN Final part

1196,0mm x 13mm Ø

1021,0mm x 13mm Ø

1089,0mm x 13mm Ø

854,0mm x 13mm Ø

2

2

2

2

PART #

PART IMAGE

DESCRIPTION

SIZES

QUANTITY

SPARE PARTS

XR4C 6#1

XR4C 6#D1

XR4C 6#D2

6m Centrall part

6m DIRECTOR 1 Final part

6m DIRECTOR 2 Final part

1996,0mm x 16mm Ø

617,0mm x 13mm Ø

557,0mm x 13mm Ø

2

2

2