DK3WE

In order to use the spiderbeam @DL2LSM in parallel on several bands I’ve been looking for a triplexer. Looking at several approaches both commercially as well as homemade, I stumbled across the work of Pavel, VA6AM. He has been developing a triplexer with respectable performance numbers. Additionally, he provides printed circuit boards, parts, as well as entire triplexers. I opted for a full assembled board. It arrived in good conditions. DL2LSM did his usual mechanical magic to mount it in a suitable enclosure.

On air testing with QRP power level has been done during the CQ WWDX SSB and CW contests in 2015. It worked pretty well despite the fact that the unused ports haven’t been terminated correctly with 50Ω but grounded and no additionally band-pass-filters were used. It is pretty amazing to listen to a station on 15m while transmitting on 20m at the same time.

System Pictures:

The triplexer mounted below the 6-by-2 antenna switch. Please note that the description labels are not mounted, yet.

Top view. The triplexer board is mounted to the box top cover.

Another top view.

Box cover aka front panel w/ the description labels in place.

Front panel w/ standoffs for mounting the triplexer printed circuit board.

side view of the front panel circuit board combo.

Printed circuit board bottom side w/ the connector sockets mounted.

System Performance (as measured by VA6AM):

Numbers for the stop band attenuation are worst case. The appropriate notches are pretty narrow. Thus, exact attenuation changes drastically across the bands. See plots for details.

VSWR and Impecance of the triplexer.

Insertion loss and VSWR: 20m (wide frequency sweep)

Insertion loss and VSWR: 20m (narrow frequency sweep)

Insertion loss and VSWR: 15m (wide frequency sweep)

Insertion loss and VSWR: 15m (narrow frequency sweep)

Insertion loss and VSWR: 10m (wide frequency sweep)

Insertion loss and VSWR: 10m (narrow frequency sweep)