David Tyler wrote:I'm not an SSB user, so this may be a dumb question, but why can't the standing part of one of the topping lifts be used? Made of load-bearing wire, with insulators, like a backstay antenna, or made of wire inside braid, but using a strong braid, not polypropylene?
It would be a great idea, David! Unfortunately the way SSB antennas work, there is an antenna tuner at the base of the antenna which matches the ground portion and the radiating portion to reduce reflected power back to the radio unit. If we were to use a topping lift (or any other portion of the rigging where the "starting point" is at the top of the mast), a radiating part of the antenna must go all the way up the mast, then come back down the standing rigging. This part going up the mast will likely be out of phase with the part coming back down and, for those of us with metal masts, will dissipate a large portion of it's radiated energy into the mast and/or develop nasty frequency-related side effects. SSBs are a bit weird when it comes to antennas and it's definitely best to keep them spaced out a bit from any other metal that is parallel or roughly so to their path.
The other option is to put the tuner at the top of the mast, which would both add weight and probably put the tuner out of commission relatively quickly from exposure to the elements.
So, since neither option is very good from an SSB perspective, we tend to avoid them.
However, there are other problems as you pointed out, with the usual locations. If I cannot clear the luff of the sail when the sail is swung well to port, then I'll have to consider other options such as a "temporary hoist" antenna and/or the "forestay" antenna shoved out on a pole to clear the luff of the foresail. I'd rather not have the antenna run and tuner be all the way in the bow, though, but that seems to be plan B for a permanent mount. It might make more sense to integrate the antenna into a "running backstay" type system which can be eased when on a run to allow the sail to come well forward, but taken in a bit on the opposite gybe to clear the luff.
I'll ponder it for a bit more. Keep up the interesting thinking!