View Full Version : VHF aerial as a radio aerial?

10-10-07, 22:24
Will a VHF aerial work when connected to a car radio instead of a dedicated car aerial? My experience of car aerials on boats is that they rust very quickly, but I do have spare VHF aerial which I could use.

10-10-07, 22:55
my car aerial for the FM radio is inside ... and works fine.

Wight Dawn
10-10-07, 23:23
Don't you have a wire coat hanger? No, seriously, as Fireball says, the modern car radio can get a signal from almost anything. In fact mine worked for strong channels with no aerial at all in most anchorages on the Clyde. To get better reception I put the cheapest VHF aeriel I could find on the mizzen and that gives a good signal even in Tighnabuaich.

11-10-07, 00:58
Some VHF antenna are a quarter wavelength ie about 20 odd inches long and consist of a rod connected to the centre of the coax with the braid connected to the Al mast. This type will work well on MF AM broadcast as well as VHF FM . The down side is that the coax cable presents a large capacitance to ground which can detune the input of MF AM. The cable used on car radios is more described as a shielded low capacitance cable.

However some VHF antenna of the 5/8 wavelength ie much longer type often in a Fibreglass tube tend to have coils and capacitors to tune them to VHF They measure a low DC resistance to the shield of the cable and will probably not work well at MF AM but may be OIK for VHF FM.

So just try the antenna. It is certainly good to have a standby VHF antenna. Especially one not connected to the mast in case of amst failure. olewill

11-10-07, 17:05
If your spare is a stainless whip it should be OK but both it and the cable won't match a car radio. I wouldn't destroy the cable or existing connector, so it could still be used in the event of a failure with the main VHF aerial.(make up an adapter cable to fit your car radio). As Olewill says, if it's a fiberglass rod it is a tuned stub "J" and will present a short to your car radio - it won't damage it, but it won't work either.
I generally connect one of the sprayhood hoops to the AE socket with a bit of coax, and it seems to work well.
P.S. do you know what Sydney Bechet was doing when he named Petitte Fleure?

11-10-07, 21:16
I have a foot long 'rubber duck' type aerial, hung horizontally in the space behind the car radio. It works brilliantly in the Solent. This goes to show how good car stereos have got!

14-10-07, 20:09
'P.S. do you know what Sydney Bechet was doing when he named Petitte Fleure? ' - What are you talking about?????

15-10-07, 08:58
a) connect wire to chainplate for car radio ... stay will be good aerial.


b) Rig aerial in locker inside cabin ... mine works fine - only piece of wire up and hooked onto curtain runner.


c) fit a splitter box between existing VHF antena and VHf / Car radio to provide both ...

Of course a rubber duck cra antena is better than a chrome jobbie ... which is what I had for years on my Snapdragon ... fitted it to the transom ...

24-10-07, 23:12
He was on the loo composing (as you do,) and the lilting notes of Petite Fleur attracted another person in the Paris flat to ask what the tune was called. Petite Fleur is french slang for a wee jobby.....(from the sleeve notes to the Chris Barber triple compilation CD)