FM aerial orientation?

[jabirugpa]

Hi Folks

I hope one of you experts can help: I recently had an FM radio aerial installed and the fitter insisted on mounting it vertically. He said that polarisation was circular now and that vertical was the recommended postion. (My old aerial was mounted horizontally.)

The BBC stations are fine but we often experience poor reception from the Classic FM station and I'm beginning to wonder if the fitter was right. Any thoughts on this?

Our local transmitter is Talconesten in Norfolk.

 

[Diamond Joe]

I can't definitively say whether Classic FM is horizontally or vertically polarized from Tacolneston, however, if you have a portable radio with an extendable aerial, try comparing the relative reception with the aerial vertical and then horizontal (or vice versa, it's entirely up to you!) that should clear up your question.FWIW BBC transmissions are mixed polarity from Tacolneston, i.e. equal Horizontal and Vertical polarization. I'm assuming Classic is the same, but I couldn't find any information to support this assumption.

 

[Anonymous]

I would have thought that seeing as most FM transmissions are optomised for either car aerials or extendable portable aerials, then I would tend to agree that vertical polarisation would be the way to go. (ie it would be in the same plane as a car aerial).

 

[Diamond Joe]

tegmen:I would have thought that seeing as most FM transmissions are optomised for either car aerials or extendable portable aerials, then I would tend to agree that vertical polarisation would be the way to go. (ie it would be in the same plane as a car aerial).I wondered who'd be the first to spot that one Pike!

 

[visionary]

but lots of cars now use the heated rear screen element as an aerial and that's horizontal

 

[chebby]

The new 206m Tacolneston mast is currently under construction and I have read reports about varying performance whilst this is going on. (Mostly dated early - late October)

I cannot link them here due to WHF forum rules.

Here is a recent quote.....

"Having been to TAC over the past few weeks I can tell you that the new
mast build has been in progress for 3 weeks now. Some engineering work
is being carried out to the current in-use mast too. The new mast build
work will last for around another 7-14 days.

Depending on which side of the TX site you live will depend on
reception at the moment, because while the new mast is being
constructed and riggers are on site, the TX powers are reduced. Also
some reflections/shadowing from the new mast will cause a few problems."

 

[jabirugpa]

Thanks to everyone for your help: the reason for the vertical orientation that the fitter gave me was based on the vertical car aerial too, but because of the poor reception I reckoned that your input would be valuable - and it has been.

I have been watching the new Talconeston mast construction (I fly a light aeroplane close to the Talconeston area) and did wonder if it might be affecting the signal. Chebby's comments do help explain a lot!

Thanks again

 

[Anonymous]

excellent