VHF Aerial and FM Reception

adams1x · 13 June 2016, 18:43

Hi,

Forgive this probably very obvious question to those in the know. I have noticed on my new rib the VHF Aerial goes through a splitter to both the VHF and the Radio (Music)

Is this right that the VHF Aerial can also double up as a FM antenna? I ask the question as I cannot find any radio stations with signal.... I also did a radio check yesterday and Solent Coastguard said I was readable but weak... but then I was at the top of the Hamble river and almost under the M27!

Thanks... :-)

jwalker · 13 June 2016, 18:56

Yes, the VHF antenna can be used for FM reception with a suitable splitter but there will be a loss of gain to the VHF radio. The insertion loss is usually stated along with the splitter instructions. As a guide -3dB = half power.

adams1x · 13 June 2016, 19:18

many thanks.. wonder why there are no stations then... might get a cheapy FM aerial and plug it in to test :-)

jwalker · 13 June 2016, 21:30

Quote:

Originally Posted by adams1x

many thanks.. wonder why there are no stations then... might get a cheapy FM aerial and plug it in to test :-)

Why not get a rubber duck type fm antenna and use it permanently, remove the splitter and then get the full performance from the vhf antenna?

willk · 13 June 2016, 21:33

Quote:

Originally Posted by jwalker

Why not get a rubber duck type fm antenna and use it permanently, remove the splitter and then get the full performance from the vhf antenna?

Aye - Vtronix make a wee FM antenna in the style of the dreaded RIBfader - mine seems to work well enough offshore.

adams1x · 13 June 2016, 21:46

Good plan... on the hunt now :-)

Thanks for the advice as always! Now who is the man person to speak to about the Suzuki V6's! Need to post another thread!

boristhebold · 14 June 2016, 07:13

I have a cobra 7.5 with a shakespeare 1.2M VHF Aerial which goes into a RayMarine AIS100 splitter, the splitter has connections for the FM Signal, VHF Signal and AIS Signal, and all work very well. Having used various types of the normal vitronix, rib raider style aerials in the past I find I get much better VHF with the shaekespeare 1.2M. Its mounted on a foldable SS base for going under bridges or general dry stack issues.

If your having issues it could be a combination of splitter type, aerial type or even just bad connections, its always worth going for quality connections, cable and aerial.

adams1x · 14 June 2016, 08:12

Thanks for the advice, great choice of boat BTW :-)