February 8, 2025
I was able to obtain a prototype of the new lightweight OK1DFC 23cm septum feed for the 2.4 meter W2HRO folding dish. Initial testing revealed a very significant improvement on receive as expected, and even a boost on transmit. With 400 watts at the feed my echoes are consistently averaging -20.5 db near perigee. The dish with the patch feed was never better than -24 db. Bitter cold temperatures precluded too much testing or adjusting to find the exact focus sweet spot, never-the-less we have a winner!
Two representative contacts just past perigee: KB2SA (1.9m dish, 400 watts) -20/-20, W1FKF (2.0m dish, 400 watts) -21/-21.
As a bonus the new feed is 24% lighter than the patch feed so mast deflection is not an issue.
More details here. Kudos to Bill, KB2SA for the concept, and Zdenek, OK1DFC for making it a reality!
Note that the W2HRO folding dishes have used two different mast diameters - originally 1.25 inches and currently 1.5 inches. If you order one of these feeds from OK1DFC be sure to let him know which diameter mount to 3D print for you.
 |
| Made from 1mm sheet aluminum the OK1DFC septum feed is lightweight. |
 |
| Echo testing near perigee, with 400 watts at the feed. |
| OK1DFC 23cm septum feed ready to mount. 1.184 kilograms or 2 pounds 9.7 ounces |
