Message	Date	From	Subject
6520	2011-07-31 08:45:21	Ron McCurdy	FW: [emrfd] low output IRF510
John, Here are the instructions for a popular kit that uses two of the IRF510: PA Idling Current Adjustment: 1. Connect an ammeter in series with the power lead that supplies 12 volts to your transceiver. 2. Disconnect the microphone, or short it's audio output so that no audio is going to the microphone amplifier. 3. Key the transmitter (use a dummy load please) and note the idling current. Unkey the transmitter. 4. Key the transmitter and slowly adjust R-91 until this current increases by 50 ma. Unkey your transmitter. Note the new idling current. 5. Key the transmitter and slowly adjust R-2 until the idling current increases by another 50 ma. Unkey the transmitter. You might try that. Ron, KE5QDA _____

John,

Here are the instructions for a popular kit that uses two of the IRF510:

PA Idling Current Adjustment:

1. Connect an ammeter in series with the power lead that supplies 12 volts
to your

transceiver.

2. Disconnect the microphone, or short it's audio output so that no audio is
going to

the microphone amplifier.

3. Key the transmitter (use a dummy load please) and note the idling
current. Unkey

the transmitter.

4. Key the transmitter and slowly adjust R-91 until this current increases
by 50 ma.

Unkey your transmitter. Note the new idling current.

5. Key the transmitter and slowly adjust R-2 until the idling current
increases by

another 50 ma. Unkey the transmitter.

You might try that.

Ron, KE5QDA

_____