K5TRA

Stealth Antenna Farm

1T.Apel

K5TRA

Preliminary Considerations

2T.Apel

• Why stealth ? Restrictive neighborhood covenants !

• Attic performance factors– Location /ground elevation

– Longley-Rice propagation plot for VHF/UHF/mWave

– Attic size and height

– Reflective clutter: furnace/AC/ducting

– Roof insulation (reflective or not)

– Feedline routing plan

• Improvements– Plywood flooring

– 120 V AC power

– Overhead lights

– CAT-5 ?

K5TRA

440 MHz Longley-Rice Plot

3T.Apel

• Analysis before I purchased my home

• Planned for repeaters and weak-signal operation

K5TRA

Keys to Performance

4T.Apel

• HF– Balanced antennas: large loops or dipoles – eliminates problems with

grounding/counterpoise– Lots of copper – I use copper tubing for my HF loop– A good balun with plenty of reserve power rating – I use a 10KW, 4:1

• VHF-UHF-mWave– Stacked beam antennas reduce boom length– Line loss management is key to performance at higher frequency bands

• Remote LNA establishes system NF at antenna –• LNA preselector filter is a MUST below 440 MHz• Remote PA provides ‘free’ boost to transmit power• CAT-5, IP control of remote power supplies for LNA/PA works well

– Omni antennas are useful for local QSO’s

• Filters are needed with co-located transmitters / repeaters– Receiver desense– Reverse IMD

• Crossband couplers reduce the number feedlines

K5TRA T.Apel 5

K5TRA Shack

HF, 50 and 222 MHz

144, 432, 902 and 1296 MHz

K5TRA

Home Repeater

6T.Apel

927.1125

K5TRA

Shack Configuration

7T.Apel

CROSSBAND

COUPLER

OMNI / YAGI

SELECT

CROSSBAND

COUPLER

CROSSBAND

COUPLER

440 MHz

HF

50 MHz222 MHz

144 MHz432 MHz

1296 MHz

902 MHz

927 MHz440 MHz

HF

6 M

222 MHz XVTR

1296 MHz XVTR

902 MHz XVTR

146 MHz

432 MHz

902 MHz

144 MHz

432 MHz

K5TRA

HF and Weak Signal Antennas

8T.Apel

CROSSBAND

COUPLER

CWS

10KW

4:1 BALUN

LOOP

REMOTE

TUNING

CROSSBAND

COUPLERCROSSBAND

COUPLER

OMNI / YAGI

SELECT

CROSSBAND

COUPLER

HF

50 MHz222 MHz

144 MHz432 MHz

1296 MHz

902 MHz

927 MHz440 MHz

HF COPPER TUBING LOOP

50 MHzOMNI

22

2 M

Hz

OM

NI

14

4, 4

32

, 90

2 &

1

29

6 M

Hz

STA

CK

90

2 M

Hz

OM

NI

12

96

MH

z O

MN

I

Dia

mo

nd

X-5

0

SCA

LA O

GB

6-9

00

222 MHz

144 MHz

432 MHz

50 MHz

1296 MHz

902 MHz

440 MHz

927 MHz

K5TRA

Beam Antennas

9T.Apel

• 3 STACKED 144/432 5EL LP• 17 ELEMENT M2 902 YAGI• 2 x 22 ELEMENT M2 1296 YAGI

K5TRA

CROSSBAND

COUPLER

Repeater and Link Antennas

10T.Apel

LINK-1

927/902 MHzLINK-1

443/448 MHz

LINK-2

927/902 MHz(ALLSTAR) LINK-1(ALLSTAR) LINK-2

Dia

mo

nd

X-5

0

SCA

LA O

GB

9-9

00

Dia

mo

nd

X-5

0

Dia

mo

nd

X-5

0

Dia

mo

nd

X-5

0

SCA

LA O

GB

6-9

00

Ph

elp

s-D

od

geSt

atio

nM

aste

r-II

K5TRA

Repeaters and Links

11T.Apel

CROSSBAND

COUPLER

U

R

I

U

R

I

U

R

I

LINK-1

927/902 MHzLINK-1

443/448 MHz

LINK-2

927/902 MHzLINK-1LINK-2

927/902 MHz

LINK-1,LINK-2

K5TRA

Balun Feed for HF Loop

12T.Apel

K5TRA

HF Loop Tuning Capacitor Switch

13T.Apel

K5TRA

WEB Controlled Power-Strip

14T.Apel

• Remote PA and LNA on-off control

• HF loop tuning capacitor switching

K5TRA

Remote 902 MHz and 1296 MHz LNAs

15T.Apel

K5TRA

Loss of LMR-400

16T.Apel

0.0

1.0

2.0

3.0

4.0

5.0

6.0

0 500 1000 1500

50 MHz

144 MHz

222 MHz

432 MHz

1296 MHz

902 MHz

(100 ft, with connectors)

Loss

(d

B)

Frequency (MHz)

K5TRA

Sensitivity vs NF

17T.Apel

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

-143

-141

-139

-137

-135

-133

-131

-129

-127

-125

-123

0.0 1.0 2.0 3.0 4.0 5.0 6.0

SSB Sensitivity (dBm)

CW Sensitivity (dBm)

Degradation (%)

SEN

SITI

VIT

Y (d

Bm

)

SEN

SITI

VIT

Y D

EGR

AD

ATIO

N (

%)

NF (dB)

SSB: 2.7 KHz BW, 10 dB S/N, 50 WCW: 500 Hz BW, 6 dB S/N, 50 W

K5TRA

Sensitivity vs NF

18T.Apel

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

0.00

0.02

0.04

0.06

0.08

0.10

0.12

0.14

0.16

0.18

0.20

0.0 1.0 2.0 3.0 4.0 5.0 6.0

SSB Sensitivity (uV)

CW Sensitivity (uV)

Degradation (%)

NF (dB)

SEN

SITI

VIT

Y (u

V)

SEN

SITI

VIT

Y D

EGR

AD

ATIO

N (

%)

SSB: 2.7 KHz BW, 10 dB S/N, 50 WCW: 500 Hz BW, 6 dB S/N, 50 W

K5TRA

Remote 902 MHz and 1296 MHz LNAs

19T.Apel

K5TRA

Schottky Detector

20T.Apel

222.060 MHz Beacon

CONTROL SENSITIVITY DOWN TO +13 dBm

K5TRA

Mini-Circuits ZX60-P162 LNA

21T.Apel

222.060 MHz Beacon

0.5 dB NF and 20 dB gain

K5TRA

VHF and UHF Remote LNA’s

22T.Apel

222.060 MHz Beacon222 MHz ASSEMBLY

K5TRA

Helical BPF

23T.Apel

222 MHz ASSEMBLY

K5TRA

LNA Preselector Response

24T.Apel

222.060 MHz Beacon

K5TRA

More Helical BPFs

25T.Apel

432 MHz ASSEMBLY

144 MHz ASSEMBLY

K5TRA

902 MHz and 1296 MHz Remote PA & LNA

26T.Apel

222.060 MHz Beacon

K5TRA

900 MHz Remote PA & LNA

27T.Apel

222.060 MHz Beacon

K5TRA

1296 MHz Remote PA & LNA

28T.Apel

222.060 MHz Beacon

K5TRA

Modified 1296 MHz PA

29T.Apel

222.060 MHz Beacon

K5TRA

VHF-UHF Remote PA & LNAs

30T.Apel

222.060 MHz Beacon4

32

MH

z

22

2 M

Hz

14

4 M

Hz

K5TRA

VHF-UHF Remote PA & LNAs

31T.Apel

222.060 MHz Beacon4

32

MH

z

22

2 M

Hz

14

4 M

Hz

K5TRA

222 MHz Remote PA & LNA

32T.Apel

222.060 MHz Beacon

K5TRA

H-Polarized Omni’s

33T.Apel

CIRCULARCOLLINEAR50 MHz OMNI

FOLDED DIPOLE222 MHz WHEEL

22

2 M

Hz

HEL

ICA

L C

OLL

INEA

R

12

96

MH

z H

ELIC

AL

CO

LLIN

EAR

90

2 M

Hz

HEL

ICA

L C

OLL

INEA

R

K5TRA

927 MHz Notch Cavity with 902 MHz Omni

34T.Apel

Hi Q

¾ l

CA

VIT

YN

OTC

H F

ILTE

R

HEL

LIC

AL

CO

LLIN

EAR

H-P

OLA

RIZ

ED O

MN

I

K5TRA

Link Radios Share Feedline and Antenna

35T.Apel

Frequency 1 Frequency 2

PASS F1REJECT F2

PASS F2REJECT F1

REJECT F3UHF Repeater

SHARED LINK ANTENNA

K5TRA

Crossband Couplers

36T.Apel

(BAND SPLIT DIPLEXERS)

K5TRA

Some Attic Photos

37T.Apel

K5TRA

Summary

38T.Apel

• Location, location, location ! (elevation, elevation, …)

• Plan before you begin

• Key to performance:

Remote LAN with BPF Establish NF at antenna !

Remote PA

Filters needed for co-located links and repeaters

Crossband couplers for efficient use of coax runs

Link radios can share feed and antenna through cavity duplexer

• No rain, lightning or UV deterioration

• Easy maintenance