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FIGURE 5: FAILED TUNING RESPONSE 

The command to reset the tuner causes it to pass-thru (tuning network out of circuit).

FIGURE 6: TUNER RESET 

AH-4 Operation

K9EQ

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Содержание AH-4

Страница 1: ...garding antennas for fixed locations An overview and description is presented as well Those who are interested in antenna tuners the AH 4 in particular and those who just plain like to look into the g...

Страница 2: ...following reasons During tune the radio always sees a low SWR typically 1 1 1 or less This is because the RF is switched to a 10 1 power divider during the tune operation Only approximately 350 milli...

Страница 3: ...2 AH 4 Design FIGURE 1 BLOCK DIAGRAM OF THE AH 4 AH 4 Operation K9EQ Page of 3 8...

Страница 4: ...flat top via ladder line In both these cases the AH 4 works extremely well This is a photograph of my AH 4 It is feeding a 30 meter flat top The antenna is about 20 meters high and is fed with 450 oh...

Страница 5: ...FIGURE 3 A VIEW OF THE INSIDE OF THE AH 4 AH 4 Operation K9EQ Page of 5 8...

Страница 6: ...fies that the power is between 5 and 15 watts If not the AH 4 aborts the tuning operation 5 If the power is between 5 and 15 watts the AH 4 begins the tuning operation 6 Approximately 250 ms after the...

Страница 7: ...FIGURE 5 FAILED TUNING RESPONSE The command to reset the tuner causes it to pass thru tuning network out of circuit FIGURE 6 TUNER RESET AH 4 Operation K9EQ Page of 7 8...

Страница 8: ...s the START line to ground to assert the signal start the tuning operation Similarly the AH 4 pulls the KEY line to 5 volts through a 22 K ohm resistor diode combination The radio also pulls this line...

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