How can I connect two small beacon transmitters (40m+30m) to one aerial?

3 posts / 0 new
Last post
LA7ZMA
Offline
Last seen: 4 years 2 months ago
Joined: 2013/12/27 - 09:36
How can I connect two small beacon transmitters (40m+30m) to one aerial?

An project taking my interest is to combine the outputs of two QRP beacon transmitters to one aerial and drive them in synchronism.
At first this was tried with DFCW transmitters on 40m +30m. I suspect each TX acted as a dummy load for the other!
Or expressed another way- from a U3 type of source to drive two generators for outputs on two bands at the same time and with the same info.
I'm uncertain as whether to have a form of matching between the TX and the combiner, or to have the combiner first and then the AMU?
And what form should / could the combiner take?

Perhaps it is easier to organise around sequential transmissions, which the U3 does open up for?

I worked on equipment with simultaneous dual freq txing at 50W levels many years ago and that used a bridge arrangement of coupling the two transmitters but I can't find my old notes from those days.