AM Carrier Settings
understand fully what you just said about the proper operation of the AM
signal but I need to know WHERE the AM carrier pot located inside the
radio is supposed to be set. Someone has turned this pot and I had to
re-adujust it so my MP would make a carrier at all! I need to know how
much carrier the radio is supposed to make when the carrier control on
the front panel is set to max. Is it 100 watts or 25 watts or 50 ect ect?
I need someone that has a MP that knows for sure that the carrier pot
has not been messed with to check theirs with it set to max with a dead
carrier and let me know what it shows on the watt meter.
Solution 1: The Yaesu Technical Supplement quotes the following: With the watt meter and 50 ohm dummy load connected to the antenna jack, select AM mode, set the meter to read ALC. With no microphone input, preset the RF PWR control to the fully clockwise position. Key the transmitter, and adjust VR3011 for ALC meter deflect to the top edge of the ALC zone.
Solution 2: With no modulation .. Rf power level on front panel fully clockwise. AM position. Set internal carrier level pot to 15 watts output for a MP... 30 watts for a Mark 5. The 15 watts applies to any 100 watt PEP output transmitter. Now when you modulate, without a scope, crank up the Mike gain watching a watt meter on Average ( not peak ) Power, until the carrier power only occasionally kicks downward. No downward deflection would be distortion free. Without compression or peak limiting a little downward would be acceptable to keep the average up. 73 John K1DEU Ph.D. Electrical Engineering
If you monitor yourself with good headphones ( I like
Sony CD10's about $20) , as you bring up the Mike gain you should hear
the distortion as you start to kick your external average watt meter
downward. When set properly with little average downward, now observe
the Internal PO (power out) meter. You should see your 15 watts of
carrier and as you modulate your peaks of 100 watts or slightly higher
should show momentarily. Although your carrier power is only 15 watts
your PEP will be 100 watts or slightly higher. Yaesu properly disables
ALC and Compression in AM. By the manual I set my metering menu hang
time to one second (1000 ms) for all functions. For excellent modulation
reports I use a $30 dollar Radio Shack Mike #34069 with a Radio Shack
wind sock plugged into the RCA Phone Patch input on the rear and the
FT-1000 MP's internal TX EQ Menu 4-4 set to #4. 73 John
John, I set the carrier control up as you said and it now works great!
On an average reading watt meter I now show just a flicker of foward
deflection with a 15-25 watt carrier. Audio is clean, no distortion at
all. Seems it'sreal touchy about where you run the mic gain though.
Thanks to you and Sandy(w4dup) for getting me back right on this. My MP
is now 100% perfect.
This site was last updated 08/27/07