Скачать или смотреть Tuning the meter on a MFJ- 949D Deluxe Versa Tuner II

Illustrates the 5 tuning knobs on the circuit board of a MFJ-949D Deluxe Versa Tuner II.

There are two sets of variable resistors (pots) on the main circuit board (black) that adjust the level of the forward (high/low) and reflected (hi/low) power meter.

There is also a small variable capacitor between the forward/reflected power diodes near the current torroid / transformer on the main transmitter wire. This capacitor adjusts the "balance" between the forward/reverse, and is most useful to make the reverse needle "dip" exactly in line with the SWR of the reference meter you are using to tune with. [i.e. when tuning an antenna, you want the SWR needle on your reference meter to go down while the reflected power meter on your 949D is going down, and you want both meters to hit their "lowest" point at the same time, and then start to go back up together. [Don't worry so much about the lowest point not being at the SAME watt level, you can adjust this later with the reflected power adjustment pots.]


I recommend adjusting the forward/reflected pots (if needed), then adjust the forward/reflected balance with the capacitor, and then go back and re-adjust the forward/reflected power to really zero things in.

NOTE: You MUST have the cover in place (no need to screw it down) when taking measurements, especially for adjusting the capacitors. [The power levels can also change slightly when the cover is off...] So be prepared to take a reading, remove the cover, adjust the pot/cap, put the cover back on, take another reading, etc...