DV27S modification for amateur radio bands

description: the DV27 is a Λ/4 CB antenna for the 11 meters with loading coil and DV mount. VSWR is adjusted using a movable 2mm ø whip. Overall lenght of the antenna is ~1,30 meters. It comes with a special coax connector and RF cable. Maximum usable power is 50 Watts.

The small top whip can be completely removed, so it is possible to replace it by other whipa of different lenght. 2mm ø brass tubes or similar copper welding rods are working perfectly.

To cover the amateur radio band, the whip must have approx. the following dimension:
  1. 10m ..... 14 cm
  2. 12m ..... 28 cm
  3. 15m ..... 42 cm
  4. 17m ..... 62,5 cm
  5. 20m ..... 117 cm
  6. 40m ..... 525 cm

It is recommended to leave the whip 10 mm longer and to shorten step by step to best VSWR in the middle of the respective amateur band. TRX with VSWR graph are sufficient (e.g. ICOM 706 MK 2 G). All external antenna tuners are, of course, also helpful to further improve VWSR.

This antenna needs a good RF ground. In case of unsufficient ground conditions, a radial must be connected to the antenna mount.

gd dx !