__CQM10DX 2M Band Low Q Yagi Design__

I designed CQM10DX in 2016 for my own personal use at my hill top (450 feet ASL) QTH in rural Devon. It uses 5/8 Inch OD tube for the driven element and 1/2 Inch OD tubing parasitic elements. We often suffer from high humidity and very damp/wet conditions so a low Q design was a must have!

__YO7 and AOP notes__

__YO7__

To reduce screen clutter, YO7 does not label the figures displayed within the Yagi patterns. They are as follows (shown in yellow font):

1. Frequency

2. Forward Gain

3. Front-to-Rear Ratio

4. Input Impedance

5. Standing-Wave Ratio

6. Elevation Angle *or* Gain FOM

YO displays elevation angle for Yagis over ground and gain figure-of-merit for single-Yagi, free-space models.

YO defaults to a generalized definition of front-to-back ratio.

The notation 12.7-j15.4 means a resistance of 12.7 ohms in series with a reactance of -15.4 ohms.

Z stands for impedance.

The lambda symbol (λ) means wavelengths.

YO uses a generalized notion of standard front-to-back power ratio to characterize pattern quality. Conventional F/B is the ratio of forward power (at 0 degrees) to that radiated in the opposite direction (at 180 degrees).

YO's generalized F/B is the ratio of forward power to that radiated within a specified region to the rear of the antenna. This is called front-to-rear ratio (F/R).

Yagi designs maximizing conventional F/B often have large backlobes at angles other than 180 degrees. Much better patterns result when you optimize a Yagi for F/R.

The F/R region begins at 180 degrees and extends forward to a specified angle (90 degrees by default).

Finally... Element lengths shown in the tables are half lengths.

__AOP__

AO displays wire losses in dB.

AO also displays antenna efficiency in percent. This figure includes the effects of both wire and load losses.

### Gain, F/B etc seen in AOP

### Azimuth in AOP

### Elevation in AOP

### SWR 140-150MHz in YO7

### H-Plane NEC2 calibration in YO7

### E-Plane NEC2 calibration in YO7

### Element positions and half-lengths

### Element diameters

### Average Q-factor = 13