background image

Measuring VSWR

This useful function allows to accurately measure amplifier load VSWR. To enable 
VSWR measurement, press SHOW SWR button while transmitting. This mode will 
persist as long as amplifier is in transmit mode. Display returns to normal operation 
(power measurement) after releasing transceiver PTT button.
Actual VSWR is represented as single „moving dot”. Lowest reading is 1.20, below 
this value respective LED starts blinking, indicating underrange. Highest reading is 
1.90, crossing 2.00 will cause respective LED blinking, indicating overrange.

Built in VSWR meter is of good quality, compensating for detector nonlinearities, 
what makes measurement result fairly independent on output power. It also offers 
exceptional directivity, with residual VSWR reading in order of 1.10.

Error signalling

To signal error in amplifier operation, multifunction display bar LEDs change color 
to red. Apperance of any error denies power amplifier transmit operation.
 

Error LED

Meaning

Amplifier reaction

HIGH SWR

 Excessive VSWR (over 2.1) 
detected. Typically caused by 
faulty antenna.

Deny transmitting, resume 
after PTT release

OVERDRIVE

Excessive input power (>7Watt)

Deny transmitting, resume 
after PTT release

DC VOLTAGE

DC supply voltage out of 
permissible range (10.5V to 14.8V)

Deny transmitting, resume 
after PTT release and voltage 
restored

HIGH TEMP

Chassis temperature over 60 ºC

Deny transmitting, resume 
after cooling down

PA FAIL

Amplifier electrical failure

Deny transmitting, resume 
after PTT release

Summary of Contents for PA-85V

Page 1: ...VHF POWER AMPLIFIER PA 85V User Manual ...

Page 2: ...s actual power limit 25 45 65 85 Watt SWR measurement Green Dot No Shows VSWR Error indicator Red Dot s No Indicates error condition Blinks on under overrange Pushbuttons function Name Function RX LNA Toggles operation of receiver pre amplifier LNA TX PA Toggles operation of transmit power amplifier SSB ON Toggles SSB mode SET POWER Displays changes transmit power limit SHOW SWR Enables SWR displa...

Page 3: ...ier exits power setting mode if SET POWER button is not pressed again within 2 seconds Automatic Level Control is of saturated nonlinear type only suitable for FM modulation While using amplifier with AM SSB modulations set ALC threshold to maximum power 85W then adjust transceiver power to yield appropriate power displayed on bargraph For AM modulation carrier power should not exceed 20 25W to ac...

Page 4: ...surement result fairly independent on output power It also offers exceptional directivity with residual VSWR reading in order of 1 10 Error signalling To signal error in amplifier operation multifunction display bar LEDs change color to red Apperance of any error denies power amplifier transmit operation Error LED Meaning Amplifier reaction HIGH SWR Excessive VSWR over 2 1 detected Typically cause...

Page 5: ...SFET PUSH PULL Specifications Receiver preamplifier In band gain 18dB 21dB 24dB 138 MHz 174 MHz Out of band gain 19dB 108 MHz 8 dB 88 MHz 50 dB 30 MHz Noise figure 2 4 dB 3 dB Specifications General DC supply voltage 10 5 V 12 6 V 14 8 V Operation at low end of range may not yield specified maximum power Transmit supply current 10 A 13 A Transmitting at maximum power Frequency dependent Standby su...

Reviews: