A Final Suggestion - Ramsey Electronics AA7B User Manual

All band hf, vhf, uhf active antenna

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Table Of Contents

Table of Contents

very carefully and see if you notice anything unusual. Since these are

pre-installed factory parts and under warranty call Ramsey Electronics

for advice on how to proceed. If you attempt to repair these devices

and damage them without contacting Ramsey Technical support you

may void your warranty.

2. Check Q2 and Q3 Drains (D) for 5VDC. If one or both of these are not

correct follow the foils back toward the regulator until you find the open.

3. Check Q2 and Q3 Gate number 1's (G1) for approximately 1.3VDC. If

one or both of these are not correct follow the foils back toward the

regulator until you find the open. Once passing the gate biasing

resistors (R1 & R6) the voltage should increase to 5 VDC.

4. Check the 2nd Gates (G2) for a voltage that varies from approximately 2

to 3 VDC. If this voltage is missing follow the foils back to the regulator

measuring the voltages as you go. AfterR3 the voltage should increase to 5

Volts. Also Check R4 for short.

No Gain Control, Gain present, LED lit

1. Check R3 for short

2. Check R4 for open

3. Check R2 for open or short

There are some characteristics associated with preamplifiers and active

antennas which do NOT mean that your AA7B is malfunctioning:

Strong AC hum: The antenna is too close to an AC cord or power line, and/

or the RF gain is set too high.

Unusual oscillations in receiver: Some portable receivers not enclosed in

metal cases may break into oscillation when connected to any RF

preamplifier. Try reducing the AA7B gain control and make sure good

grounds are on the interconnecting coax cables.

Receiver overloading, heterodynes, images: A preamplifier will intensify

any problems with selectivity and image rejection due to poor receiver design.