AM FM Hidden In-Cabin Antenna

[cghubbell]

I just installed a sweet little Fusion MS-RA200 stereo head in my CS27's main cabin. I installed one of those cheap pieces of wire that has an antenna bayonet on one end. I would consider the reception to be "OK", but not great. AM seems worse than FM. It also seems very sensitive to orientation and placement, neither of which is easy to control behind the panel.

I have a few requirements for the antenna, which I recognize may not be optimal for anyone else, but here they are:
- I don't want anything mounted (suction cup/sticky) on the cabin ports.
- I don't want to pierce the deck or bulkhead for this.
- I'm not interested in a VHF splitter.
- No additional mast antenna - this has to happen in the cabin.
- Must be possible to hide behind panels.

Seems to me it should be possible to get good reception under these conditions because I've had portable radios in the boat with telescoping antennas which worked fine. I'm ok with making something, or buying something.

Are there any recommendations on antenna orientation (does horizontal/vertical matter for AM/FM?), length, cabling from stereo to antenna, etc? There has to be a HAM expert out there who knows how to make a good antenna work in the cabin...

Thanks in advance,
Chris

[hellosailor]

Chris, for AM you want a plain vertical mast/whip. For FM...one of those "T"s made up from some twin lead, often packaged or sold with home stereos. But as a compromise for both you'd use a vertical whip because anything horizontal will be directional.

Go to a junkyard, for five bucks get an old fashioned car whip antenna complete with cable and plug it in. Find a way to keep it vertical. Compromise on whatever you need to, ti won't get any better unless you buy one of the new amplified (needs power) shorter whips or something fancy.

Maybe you forget, radios with whip antennas, portable shortwaves, tv sets, you always have to fiddle around with pointing the antenna whip. Cars with plain vertical whips? Best compromise.

[shogan50]

I've not actually tried this, but intend to at some point. http://www.wryr.org/Antenna_instructions.pdf

[MarkSF]

How long is the piece of wire? Consider making it longer. You could run it all the way forward as far as I can see.

[Oaksail]

I have the very same stereo head in my CS30, the antenna is just a plain wire led to the nearest stanchion base thru bolt and nut. I'm surprised at how good the reception is just by using a stanchion.

[Faster]

Mine is a piece of coax antenna extension wire, about 6 feet long and the stripped core attached to a shroud chainplate fitting inside a cabinet. Works great.

[cghubbell]

Originally Posted by Oaksail

I have the very same stereo head in my CS30, the antenna is just a plain wire led to the nearest stanchion base thru bolt and nut. I'm surprised at how good the reception is just by using a stanchion.

Now that's a creative idea! I think to maximize reception the goal is be at 1/2 or 1/4 wavelength as measured from the center of the FM band. That works out to about 31-33 inches from what I've been able to read. I wonder if you're close to that between the wire and stanchion.

[cghubbell]

Originally Posted by hellosailor

Go to a junkyard, for five bucks get an old fashioned car whip antenna complete with cable and plug it in. Find a way to keep it vertical. Compromise on whatever you need to, ti won't get any better unless you buy one of the new amplified (needs power) shorter whips or something fancy.

That's what I was sort of gravitating towards. I figured I could pick one up cheap and mount it along the bulkhead in the wet locker which is right next to the cabinet I've mounted the stereo in.

What I'm wondering is, will the thicker & stiffer wire of the car antenna receive signals any better than the flexible wire I currently have? If not, then I may be better off just extending my wire and doing a better job of mounting it so that it's extended and not curved anywhere.

[CapnBilll]

This is a sailboat right? You've got to have a metal guy wire somewhere? The higher the better. get a piece of coax. You will get the best reception with height, and an even multiple of 1/4 wave. The spacing between the wires in a coax or twin pair lead is the impedance. In an antenna you are converting from infinite impedance to usually either 75 or 50 ohms. that is what the antenna is for. The easiest way to do this, (barring the desire to to a lot of calculations), is to connect the shield to ground, and slowely move the inner conductor along the spreader, or whatever you are using until you get the best signal, permanently connect it to this point, job done.

[cghubbell]

Originally Posted by CapnBilll

This is a sailboat right? You've got to have a metal guy wire somewhere? The higher the better. get a piece of coax. You will get the best reception with height, and an even multiple of 1/4 wave. The spacing between the wires in a coax or twin pair lead is the impedance. In an antenna you are converting from infinite impedance to usually either 75 or 50 ohms. that is what the antenna is for. The easiest way to do this, (barring the desire to to a lot of calculations), is to connect the shield to ground, and slowely move the inner conductor along the spreader, or whatever you are using until you get the best signal, permanently connect it to this point, job done.

Certainly is a sailboat, and it certainly has wire rope standing rigging. Maybe one of the shrouds is close to a 1/4 wave multiple? The catch is, I have a deck-stepped mast and I really, really, really do not want to create another deck piercing for an AM/FM antenna.

I can get good reception below decks with a cheaper portable radio using its built-in telescoping antenna, so I know that I don't need to go all the way to the spreaders to meet my needs (although it may well do a much better job up there!).

The goal here is to figure out the best options for hiding antenna somewhere within the cabin and improve upon the reception my cheapo wire is capable of.