CG VHF reception

[sahona]

We noticed we could always hear the chan16 invitation to listen to the maritime safety information broadcast on chan XX, but when we went to chan XX or, in fact YY or ZZ, we couldn't hear so well - even with squelch at 00.
This problem was the same on multiple marine sets and some Ham gear, so not 'at this end'.
Clyde CG offer an explanation : The dedicated aerials for ch16 are at the top of the towers, then chan0, then the switchable aerial for 'working channels' lower down. (thanks to Rosie at Clyde for prompt response)
This gives us a "dipping light" scenario, with smaller 'circles of reception' as the aerial heights lessen.
I think the explanation is valid, and explains the difficulties I was seeing.
I wasn't given the dimensions involved, so can't hazard a guess at the difference in range between Chan 16 and the
worst case working channel (depending on which mast we are talking about of course....)
So there we are. we just have to be aware of the reasons.
- It'll all be obsolete soon anyway, I'm sure. (but will I be able to afford the alternative?)

[Silkie]

That's an interesting piece of information. I had noticed the same but had put it down to differences in the propogation of different frequencies, in a wooly-minded, BSc. Physics (failed) kind of a way.

[Yotter]

That is interesting and could explain this common problem. I was told many years ago that CH16 has twice the bandwidth of the other channels, and I have presumed that this the reason for the better reception.