Dual-band 2-element Yagi antenna for SOTA/POTA, 50/144MHz, DS62

This is the DS62, a dual-band Yagi antenna designed to be usable on both 50MHz and 144MHz bands, based on the DS6-C, a 50MHz 2-element Yagi specifically designed for mobile operation (SOTA/POTA, etc.).

We built 10 units last year, and only 3 remain. We are currently designing a 3-element option for the 430MHz band for those already using the DS62. We plan to release the DS62 with this option once it is complete, if there is demand.
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While 2-element HB9CV type antennas are commercially available, they are quite troublesome to assemble. The DS-62 incorporates features that allow for immediate use after mobile setup. Assembly is quick and easy.

Generally, there is a discrepancy between MMANA simulation values and actual measured directivity, which is a challenging aspect of DIY antennas. The beam pattern has been adjusted to match actual operating environments.

Because it is dual-band, during mobile operation, if conditions are poor on the 50MHz band, you can change the element positions and switch to the 144MHz band. This type of dual-band antenna, with such significant shape changes, is unprecedented.

When using on 144MHz, set the element spacing to the stopper positions and extend only the top two elements. The directivity characteristics in this configuration are as described in the manual.

Even though it's the VHF band, 50MHz has a longer wavelength and is slightly affected by the ground depending on the height above ground.
The feed point incorporates an impedance matching circuit that operates on both bands, with values chosen to be usable with typical tripods of 1m to 2m.

Furthermore, it can be transported in a small case as shown in the image during mobile operation.
The instruction manual is attached, so you can check the specifications. This listing is for the antenna unit only. Four 1.4m rod elements are included. (Tripod, etc. are not included. Includes U-bolts for mounting to a mast.)

The image quality of the instruction manual has been improved.

We brought it to the Shikoku Ham Fair, and based on questions asked there about the orientation of the BNC connector, we have added information to the manual.