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Input drive and power output: 

 

The amplifier should give full output with approximately 25W input.  Excessive input power 
should be avoided and the amplifier should always be operated in a responsible manner. 
 
The KL503 HD features an input attenuator 

a

 

that may be used to reduce the output of the am-

plifier if the drive radio does not have the facility to reduce its output power.  
The input attenuator should NOT however be used to reduce the input power level of the drive 
radio if it is greater than 25W! Otherwise the attenuator may be damaged from overheating. 
There are 5 levels of input attenuation and position 6 is direct input, with no attenuation. So 
setting to position 1 will provide the lowest output power from the amplifier, and position 6 the 
maximum output. 
 
 

Maximum output power considerations: 

 

All amplifiers have a maximum output and this occurs shortly after gain compression where by 
Pin no longer produces a proportionate increase in power output . The amplifier should always 
be operated at a point below its saturated output. Trying to extract every last watt by overdriv-
ing the amplifier will not actually help your signal to be stronger, you will in fact cause higher 
levels of distortion which will make your signal less intelligible at the distant receiver station. 
 
Running the amplifier a little under max output will also allow the amplifier to run cooler and 
make it more reliable for many years of use. 
 
As an example consider the following situation. 
 
1 ‘S’ point on a receiver is usually approximately calibrated at 6dB so for example the differ-
ence between S5 and S7  2 ‘S’ points is 12dB. 
 
The difference between 25W and 300W is about 11dB a healthy increase to your signal 
strength, almost 2 ‘S’ points, with the same antenna. Now lets say for example you run the am-
plifier at a moderate 250W output by slightly reducing the input power, the difference between 
250W and 300W is less than 1dB which when you compare this to 6 dB per S point is actually 
very little and  as the amplifier is not running at its absolute maximum will give a cleaner out-
put with less distortion that will actually make a difference at the  distant receiver for the bet-
ter!! 
 

8  

 

0

2

4

6

8

10

12

25,000

26,000

27,000

28,000

29,000

30,000

G

a

in

 (dB

)

Frequency (MHz)

Typical Gain vs Frequency

0

50

100

150

200

250

300

350

0

5

10

15

20

25

30

35

40

O

ut

pu

t P

ow

er

 (W

)

Input Power (W) 

Typical Output Power KL503 28.000 MHz 

Содержание KL503 HD

Страница 1: ...rtant Ver 1 0 May 2018 2 Quick Start Guide A more complete guide to the installation is featured later 1 Connect the RTX input connector to transceiver with 50 Ohm patch cable 2 Connect the ANT Output of the Amplifier to SWR Bridge Wattmeter If required and then the Antenna 50 Ohm load Impedance 3 Connect the Amplifier DC power Cable to a suitable 13VDC 1V Power Supply or Auto Battery Pay at tenti...

Страница 2: ...n SSB mode the front panel switch should be set to SSB This adds a short delay to the release time of the RTX relays so that pauses in speech do not cause the RTX relay to drop out In AM or FM mode the SSB delay switch should be set to AM The amplifier must be connected via the input power connector to a suitable power supply of the correct voltage output and sufficient current rating The output s...

Страница 3: ...ust use an antenna tuning unit between the output of the amplifier and antenna It is recommended to check that the antenna to be used is sufficiently rated for at least 500W power handling before connecting this product It is also recommended to check that the VSWR does not change considerably with increased power as this would indicate that the antenna was not suitable for high power use Cable lo...

Страница 4: ...mplifier will not actually help your signal to be stronger you will in fact cause higher levels of distortion which will make your signal less intelligible at the distant receiver station Running the amplifier a little under max output will also allow the amplifier to run cooler and make it more reliable for many years of use As an example consider the following situation 1 S point on a receiver i...

Страница 5: ...9 Typical Harmonic Output 10 Schematic Diagram KL503 Att1 7dB ...

Страница 6: ...ely the responsibility of the user The manufacturer declines any responsibility from unlawful use Warranty This product is covered by a 24 month warranty commencing from the date of purchase The original purchase receipt will be required for any claim This warranty does not cover aesthetic damage or damage to the RF power transistors from incorrect use ...

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