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Old 05-08-2010, 08:37 AM   #1
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Default AM not working.

I just installed a new jenson radio and the am is not working. my last radio also had no am. I have a shakespere ant. The fm is fine. Better than both of my cars. If the ant. is bad why would the fm be working? I'm going to google this but if anyone knows about this please reply.. Thanks in advance.
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Old 05-09-2010, 06:34 AM   #2
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AM requires a different antenna than FM.

The FM on my radio works just fine with my VHF antenna (via a splitter). For AM to work I need to use a long wire antenna.

Same crap at my house. FM comes in fine. AM not so much so.
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Old 05-09-2010, 01:18 PM   #3
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AM requires a different antenna than FM.

The FM on my radio works just fine with my VHF antenna (via a splitter). For AM to work I need to use a long wire antenna.

Same crap at my house. FM comes in fine. AM not so much so.
I know house stereos have a separate ant. but the marine stereo does not have an input for a second ant.
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Old 05-09-2010, 05:46 PM   #4
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I know house stereos have a separate ant. but the marine stereo does not have an input for a second ant.
The marine (or auto) stereo uses the same antenna for AM and FM.

By "not working", do you mean no sound or static but no stations?
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Old 05-09-2010, 06:38 PM   #5
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The marine (or auto) stereo uses the same antenna for AM and FM.

By "not working", do you mean no sound or static but no stations?
Static only. No stations or even close to hearing them. On my last stereo I heard the station very very little. The only thing I can come up with is a bad ant. but I dont get how the fm can work but not the am..
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Old 05-10-2010, 05:03 AM   #6
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Static only. No stations or even close to hearing them. On my last stereo I heard the station very very little. The only thing I can come up with is a bad ant. but I dont get how the fm can work but not the am..
Fist of all, make sure the antenna is intended to pick up AM stations. That is, it's an "AM/FM" antenna. Check with the manufacturer or look it up on their website or a catalog.

Second, make sure there are AM station signals available where you boat. Bring along a portable radio and see what you can pick up with it.

Also, some radios have a "local/distant" switch or setting. Set it on "distant".
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Old 05-10-2010, 03:57 PM   #7
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Fist of all, make sure the antenna is intended to pick up AM stations. That is, it's an "AM/FM" antenna. Check with the manufacturer or look it up on their website or a catalog.

Second, make sure there are AM station signals available where you boat. Bring along a portable radio and see what you can pick up with it.

Also, some radios have a "local/distant" switch or setting. Set it on "distant".
Thanks for the replies. I checked the ant. It is am/fm. Shakespeare 4351. I also am within 12 miles of NY City so I deffinately am in range. The directions for the stereo don't say anything about am and switching settings. I guess I will try to find a cheapo ant to just use to test ant. Thanks again. Keith
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Old 05-11-2010, 04:06 AM   #8
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You have come to the right place young grasshopper....
AM and boats is a tough install. The problem is that unlike your car which has a huge steel body that acts as a ground plane, your boat made of fiberglass has none.

I went round and round trying to get AM stations and I live in the Washington DC area with tons of stations nearby. One day while in a parking garage I noticed that AM reception in this garage was just as poor as on the boat. That's when it struck me.

Being a bit of an inventor, I decided to take a car antenna and do what they do on Battleships, that is make a ground plane. Here's the result:


The shorty phono plug on the back of the radio is used for FM, and when I am out by myself and want AM I pull this out. Each of the radials is a threaded rod that screws into the base plate. They easily unscrew and the whole assembly can be stored away.

Here's another shot:


The base is a piece of brass with 6 nuts soldered on, then 3 suction cups, a "U" bracket for the Car antenna.

Let me know if this works for you. For me the results were nothing short of phenomenal! I pull in stations from as far away as Baltimore (WTNT).


KKKKFL
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Old 05-11-2010, 04:12 PM   #9
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You have come to the right place young grasshopper....
AM and boats is a tough install. The problem is that unlike your car which has a huge steel body that acts as a ground plane, your boat made of fiberglass has none.

I went round and round trying to get AM stations and I live in the Washington DC area with tons of stations nearby. One day while in a parking garage I noticed that AM reception in this garage was just as poor as on the boat. That's when it struck me.

Being a bit of an inventor, I decided to take a car antenna and do what they do on Battleships, that is make a ground plane. Here's the result:


The shorty phono plug on the back of the radio is used for FM, and when I am out by myself and want AM I pull this out. Each of the radials is a threaded rod that screws into the base plate. They easily unscrew and the whole assembly can be stored away.

Here's another shot:


The base is a piece of brass with 6 nuts soldered on, then 3 suction cups, a "U" bracket for the Car antenna.

Let me know if this works for you. For me the results were nothing short of phenomenal! I pull in stations from as far away as Baltimore (WTNT).


KKKKFL
WOW. So lets get this straight. You unhook the fm an.t and add this to the phono or is this hooked up to your grounding system on the boat?
I just want to get the football games in the fall. Do other people have this problem??? Please chime in.
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Old 05-11-2010, 04:52 PM   #10
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........................ AM and boats is a tough install. The problem is that unlike your car which has a huge steel body that acts as a ground plane, your boat made of fiberglass has none.
................
And yet, a portable AM radio with a coil antenna works fine carried in your pocket or by a handle. On land or on the water. Years ago I often used one to orient FM and TV antennas on roofs with no direct access to the receiver.

If this is the second radio connected to this same antenna that hasn't picked up AM stations, I would begin to suspect that the antenna is defective. A call to the manufacturer might be in order.

A temporary test antenna can be made from a nail the same diameter as the inner conductor on the antenna plug and a 3' or so piece of wire. Any wire. Insert the nail into the antenna socket on the radio, strip a couple inches of insulation off the wire, and wrap it around the nail. Now, see if you can pick up AM stations. If you can, the antenna is defective. If not, it's the radio or there are no available stations in the area. Test with a portable radio.
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Old 05-12-2010, 09:16 AM   #11
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When I want AM, I just unplug the phono jack that is a small rubber duckie antenna inside the cabin. Instead, I plug in the Car radio antenna jack from my super ground plane antenna that's pictured. It pulls in stations that my little portable does not get. Originally, I tried taking the portable radio audio output and putting that through the Jensen Aux input, but the performance was poor. The pictured antenna array works solidly. I use the Aux input for my iPod.

Incidently, I have 2 monster cable (1/4 inch each) ground cables that run along the gunwhal back to the engine. These are attached to a solid grounding spot on the engine. I'm talking zero point zero ohms resistance. All electronics are double grounded with these cables. I also have a Super Filter on the Positive side of things that came from a company that installs different comms equipment on Trucks, tractors, and all kinds of heavy duty vehicles. This knocked out any ignition noises that were getting into the radio on weaker FM signals.

KKKKFL

KKKKFL
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Old 05-12-2010, 01:05 PM   #12
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Couple things:

1. Some radios have a US / Euro setting on them for setting the frequencies for AM and FM service. Make sure yours is set to US, should be in manual.

2. Jensen radio's are well known for POOR AM reception. Not sure why. They generally have fine FM reception, but I've had allot of problems with their AM side.

3. Try plugging in a wire antenna, the kind that come with most radios and steroes, looks like a T shaped peice of speaker wire about 6' long. That should get 1010 wins just fine where you are. If that doens't, then it's the RADIO.


makokeith
To answer your question, "I just want to get Football games.... Do other people have this problem?" No. I just fire up my KVH M1 Direct TV receiver!!

Last edited by Birdman; 05-12-2010 at 07:55 PM.
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Old 05-12-2010, 05:14 PM   #13
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........... Jensen radio's are wll known for POOR AM reception. Not sure why. They generally have fine FM reception, but I've had allot of problems with their AM side.
I don't think the manufacturers pay much attention to AM radio reception anymore. Most folks listen to FM if they even listen to broadcast radio at all. It's all IPod and satellite anymore.

I wouldn't be surprised if the entire tuner section was a single chip and I wouldn't be surprised if most of the manufacturers used the same chip.
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Old 05-13-2010, 04:04 AM   #14
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Rwidman,
You are exactly correct on the "Chip" being the same one across multiple manufacturers. I searched and searched for a radio that had Analog tuning. hahahahahah what a joke.. What was happening to me was that no matter which radio I tried, when the signal got weak, it would go into search mode. It was during these tests that I discovered the real problem was signal strength and that most radios used the same AM front end. My guess is that the chip being used is also used in Automotive radios.
I started experimenting, first with a good Car Radio antenna that I bolted to a clip and then clamped to the aluminum frame of the windscreen. This was a marginal improvement, but klunky. Signal engineers I talked with really pointed to ground plane as the culprit and suggested making the brass plate with radials.

The results have been astonishing.

KKKKFL
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Old 05-16-2010, 03:47 PM   #15
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Default shakespeare 4350

Just installed a Jensen mcd5112 reman deck,hooked it to a shakespeare 4350 lift and lay mount am/fm antenna. Works great! Got it online from Manventure Outpost for $34.95 plus shipping. Incredible pulling power, it also has it's own lift and lay mount so there is no need to purchase a seperate mount.
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