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ANTENNA SYSTEM

2001 NEW

n

 Antenna for ship

Required antenna element length

Required antenna element length to achieve full 
performance varies according to the lowest frequency: 

The longer the antenna element, the better the 
antenna efficiency. 

Undesirable antenna element lengths
AVOID

  multiples  of 

1

2

λ 

(half  wavelength)  for 

antenna element lengths, since tuning becomes 
difficult.

L : Antenna element length to be avoided [m]
f : Operating frequency [MHz]
n : Natural number (n = 1, 2, 3, ...) 

L

 

=

 

300

f

×

1

2

n

×

[Example]

At an operating frequency of 16 MHz, avoid the 
following antenna element lengths:

L

 

=

 

300

16

×

1

2

n

×

9.4, 18.8, ...

1 m

39 inches

For example, if 15 m is selected for an antenna 
element length, you have no problem in the 1.6–25 
MHz marine bands range.

Insulator

Backstay operates as 
a long-wire antenna.

Insulator

Whip antenna

NOTE:

  Keep  antennas  as  far  away  from  other 

objects as possible, especially metal objects.

The lowest frequency  Required antenna element length
1.6 MHz band 

7 m; 23.0 feet or longer

4 MHz band 

3 m; 9.8 feet or longer

Summary of Contents for YPL 880

Page 1: ...HF AUTOMATIC ANTENNA TUNER AT 141 INSTRUCTION MANUAL ...

Page 2: ...minal for ground connection The mounting plate is not connected internally Ground terminal Mounting plate DO NOT operate your HF marine transceiver without running the boat s engine AVOID using the AT 141 in areas where the temperature is below 30 C or above 60 C Word Definition R WARNING Personal injury fire hazard or electric shock may occur CAUTION Equipment damage may occur NOTE If disregarded...

Page 3: ...nd antenna cables You never need to open the cover 45 memories for shorter tuning time To decrease the tune up time the AT 141 automatically stores the matching conditions for up to 45 frequencies Re tuning for a memorized frequency takes approx 1 sec Super capacitor for memory backup Even if the AT 141 is not used for approx 1 week the built in super capacitor backs up contents of the 45 memories...

Page 4: ...voided m f Operating frequency MHz n Natural number n 1 2 3 L 300 f 1 2 n Example At an operating frequency of 16 MHz avoid the following antenna element lengths L 300 16 1 2 n 9 4 18 8 1 m 39 inches For example if 15 m is selected for an antenna element length you have no problem in the 1 6 25 MHz marine bands range Insulator Backstay operates as a long wire antenna Insulator Whip antenna NOTE Ke...

Page 5: ...or electrolysis Engine block Ship s DC battery ground Electrolysis All ground cables from the AT 141 HF transceiver etc on your ship should be connected to only 1 ship s ground AVOID connection to 2 or more points Voltage difference between 2 or more ship s grounds may cause electrolysis AVOID connection between dissimilar metals where an electric current is present These connections may cause ele...

Page 6: ...6 Terminal information for details GND Use the optional OPC 1147N 1286N 1465 or assemble the desired length 4 conductor shielded cable and the connector kits supplied with the transceiver and the tuner E Black 13 6 Red STAR White KEY Green KEY Green STAR White 13 6 Red E Black Use the optional OPC 566 1147N 1465 either the connector to the AT 141 or the transceiver requires assembly or assemble th...

Page 7: ... and solder as shown below Solder Solder r Screw the coupling ring onto the connector body n Mounting Mounting on a Mast Metal pole Using U bolts U bolt U bolt plate Flat washer L Spring washer Nut Mast Metal pole Flat washer S WARNING Mount the AT 141 securely with the supplied nuts and bolts Otherwise vibrations and shocks due to waves etc could loosen the antenna tuner making if fall causing pe...

Page 8: ... the inside connections DO NOT pull the antenna and control cable receptacles This may cause disconnection in the AT 141 internal connector damaged or bad connection r Connect the coaxial cable and the control cable to the transceiver as illustrated below t Ground the transceiver AT 141 and shield cable of the control cable via the ground terminal See p 2 for grounding details IMPORTANT AT 141 NEV...

Page 9: ...tart tuning Start voltage V For tuner through operation Less than 250 msec Key voltage KEY During automatic tuning the AT 141 grounds the key voltage line and the HF transceiver reduces output power 8 6 4 2 0 Time Key voltage V Grounded Approx 7 5 V During automatic tuning Terminal Description KEY Key voltage Grounded during tuning Max current drain 100 mA 13 6 13 6 V DC input terminal Max current...

Page 10: ... supply requirement 13 6 V DC supplied from HF transceiver Current drain Max 2 A Operating temperature range 30 C to 60 C Weight approx 2 5 kg Antenna connector SO 239 50 Ω Max Input power 150 W PEP 100 W continuous Automatic tuning time Approx 2 3 sec general condition Max 15 sec Approx 1 sec re tuning for a memorized frequency Automatic tuning accuracy SWR 2 0 1 after tuning except for multiples...

Page 11: ......

Page 12: ...1 103 Garden Road Clayton Victoria 3168 Australia Phone 61 03 9549 7500 Fax 61 03 9549 7505 URL http www icom net au E mail sales icom net au Icom UK L d Unit 9 Sea St Herne Bay Kent CT6 8LD U K Phone 44 01227 741741 Fax 44 01227 741742 URL http www icomuk co uk E mail info icomuk co uk Icom New Zealand 146A Harris Road East Tamaki Auckland New Zealand Phone 64 09 274 4062 Fax 64 09 274 4708 URL h...

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