marine radio not transmitting well

[Line Dancin]

i have a galaxy 5225 antenna that i put on my boat last year. i was also using an inexpensive raymarine radio. i could recieve wellbut not transmit. this year i bought a better radio, Oceanus, and still seem to be havint the same issue. i could hear plum crazt down by saugatuck while in the holland area and also nick of time but when i tried to get them i couldnt get to them. could it be my antenna connection at the radio not installed right?? I couldtalk to people in the local vicinity, just not any distance.

[Indybleck]

How much coax wire do you have? You just need enough to get to your radio, there is a thing as having too much. You want to keep it as short as possible. Make sure the ground on the coax is soldered to the outside of the connector and you have enough of the middle sticking out to make contact.

[GLF]

Sometimes this gets overlooked. Were you on "high" or "low" power when you tried to reach them?

[Rayman96]

i have a galaxy 5225 antenna that i put on my boat last year. i was also using an inexpensive raymarine radio. i could recieve wellbut not transmit. this year i bought a better radio, Oceanus, and still seem to be havint the same issue. i could hear plum crazt down by saugatuck while in the holland area and also nick of time but when i tried to get them i couldnt get to them. could it be my antenna connection at the radio not installed right?? I couldtalk to people in the local vicinity, just not any distance.

I mount my radio on the port side away from the dash. Doesn't seem to matter where the antennae is. Or at least keep the coax away from my dash as much as possible.

I don't cut the coax, just keep the excess away from the dash.

Run power directly from the battery, not from the dash, this is important! You will have to remember to turn the radio off!!

Invest in a cheap RF meter. It will tell you when your signal is at optimal output!

Once you find the sweet spot, you're good to go!

[Line Dancin]

hi power power direct from the battery. i did cut the co ax back as i had most of it there got the connector on good, so we will have to see tomorrow on the water. thanks

[Line Dancin]

i also isolated the marine radio pos and neg wires to the Post on the battery with the post to stud connectors and the rest of the power wires are going to the studs on the battery. not sure if this will make a difference or not?

[Rayman96]

Aaron, that at the very least will give you clean power and that's a good place to start.

Mount the antennae as high as possible. Take the excess cable and form into a coil. Do not bunch it up. After that I just tuck mine somewhere out of the way. I test before I do the final install.

The RF meter comes with a chart of acceptable readings. The meter measures signal strength when you key the mic. I got my meter at Radio Shack.

When in the harbour or close proximity, I always use the 1 watt setting. I watched two guys fry their radios when they both keyed the mics at the same time on high power at dockside.

Keep at it, you'll get it.

[1mainiac]

Grounds grounds grounds. now that you know you have good power to the radio on the back of the radio near the heat sink is a ground lug run a heavy guage wire from it to the motor or outdrive or better yet a bronze or copper plate on the stern below the water line. All RF goes down basicly in simple terms you make a bank shot off the earth frequencies below 30mhz also can bounce off the atmosphere back towards earth depending on conditions this is called skip on CB. VHF radio frequencies usually pass thru the atmosphere with a few exceptions and travel into space. Antenna design can concentrate the signal and even amplfy it but the signal must bounce off the ground to be heard at a distance. 1/2 of your signal is the ground field you create that produces a repelling charge to make the other half bounce. The quality of the ground (EC) and height of the antenna determine maximum distance you can be heard. lets assume a great ground system and the base of the antenna is 6ft above the water your strongest signal would bounce between 3 and 5 miles from the boat and be workable by a similar antenna system for 6 to 10 miles away you also will have secondary lobes transmited that will bounce further from the boat which will reach further but will be lower in RF signal strength but can still be workable. Even though I am discribeing this like a rifle shot it is not it would be more like bird shot but eventually you get to a point where only one pellet makes it and the rest pass above the target and off into space.

[Nailer]

How much coax wire do you have? You just need enough to get to your radio, there is a thing as having too much. You want to keep it as short as possible. Make sure the ground on the coax is soldered to the outside of the connector and you have enough of the middle sticking out to make contact.

Yea That^^^

[Line Dancin]

i have cut the wire to about four feet long just long enough to get to the radio and leave a little left if i have to replace an end. i also added a noise filter to the power wire and with doing everything i was able to now talk to dirty dog in Port sheldon while we were in the pier heads at holland. Jim i looked the radio over and there is no ground lug on the back of this one. I have the black wire run direct to the black post on the battery should i run that to my outdrive?? and not the battery. red wire is direct to the battery also.

[1mainiac]

NO the power and ground to the radio must come from a clean power source. I have never seen a radio that transmits that does not have some form of chassis ground but there is a first time for everything. I just read the manual on it and you are right it does not have a chassis ground. Check the grounds to the engine and lower unit it is also possible your SWR is way off this will put the radio in protection mode and it will not put out full power have you checked SWR on the antenna?

[Line Dancin]

NO the power and ground to the radio must come from a clean power source. I have never seen a radio that transmits that does not have some form of chassis ground but there is a first time for everything. I just read the manual on it and you are right it does not have a chassis ground. Check the grounds to the engine and lower unit it is also possible your SWR is way off this will put the radio in protection mode and it will not put out full power have you checked SWR on the antenna?

No i havent i am not sure how to do that. i do have the power and ground direct to the battery on seperate studs that have nothing else connected to those studs. everything else to the boat is off the other studs on the battery. i also put on a good noise filter: http://www.hifisoundconnection.com/Shop/Control/Product/fp/vpid/2680902/vpcsid/0/SFV/30046

this is what they said that they sell to guys for marine radios and also install on boats when installing marine radios to get good clean power.

[Rayman96]

Here is an explanation of SWR from Wikipedia. Basically your antennae and cable need to match for best output.

My radio does not have a ground lug either but has worked fine.

Practical implications of SWR

The most common case for measuring and examining SWR is when installing and tuning transmitting antennas. When a transmitter is connected to an antenna by a feed line, the impedance of the antenna and feed line must match exactly for maximum energy transfer from the feed line to the antenna to be possible. The impedance of the antenna varies based on many factors including: the antenna's natural resonance at the frequency being transmitted, the antenna's height above the ground, and the size of the conductors used to construct the antenna.

When an antenna and feedline do not have matching impedances, some of the electrical energy cannot be transferred from the feedline to the antenna. Energy not transferred to the antenna is reflected back towards the transmitter. It is the interaction of these reflected waves with forward waves which causes standing wave patterns. Reflected power has three main implications in radio transmitters: Radio Frequency (RF) energy losses increase, distortion on transmitter due to reflected power from load and damage to the transmitter can occur.

Matching the impedance of the antenna to the impedance of the feed line is typically done using an antenna tuner. The tuner can be installed between the transmitter and the feed line, or between the feed line and the antenna. Both installation methods will allow the transmitter to operate at a low SWR, however if the tuner is installed at the transmitter, the feed line between the tuner and the antenna will still operate with a high SWR, causing additional RF energy to be lost through the feedline.

That filter is a must on older engines. Can't hurt with newer applications. Could help also when running older kickers.

[Line Dancin]

how do you adjust swr then with a marine radio?

[1mainiac]

sadly most of the time you replace the antenna as they are not adjustable you can sometimes adjust by triming the coax if you have a feedline missmatch. If you are around Muskegon some time I would be happy to hook up my analyzer and see what the antenna is doing.

[Line Dancin]

sadly most of the time you replace the antenna as they are not adjustable you can sometimes adjust by triming the coax if you have a feedline missmatch. If you are around Muskegon some time I would be happy to hook up my analyzer and see what the antenna is doing.

that would be great. I am heading for lake erie on wednesday early afternoon and am going to be packing tomorrow. maybe next week some time i can hook up the boat and come for a ride out there. I really want this thing to work well. i was able to talk to guys in port sheldon after the filter and isolating the power and ground wires which i was not able to do before. i was only getting out about a mile. so now i am up to about nine miles but they said there was some distortion.

[diesel]

on all 12 volt asserories you want the shortest possable ground the shorter the ground the better. and with coax cables you dont want to cut them or wrap them up loop them away from any power leads or else you risk interferance.

this is just common knowalage in auto/semi wiring. not saying you or anyone else is wrong i am speaking form many years exeriance as a ase master machanic i also have wired many radios and cbs and learned from major screw ups.

[Rayman96]

I work in automotive, in the assembly end of things building class 8 trucks.

Satellite, CB, GPS, radio and all cables come in standard lengths. Cab and truck lengths do not. We don't cut any!!! All are coiled and stored out of the way.

In this case, Shakespeare recommends the same installation. 8" minimum size coil. In my boat, I had to go to an 18" coil for a good signal match.

http://www.shakespeare-marine.com/pdf/5225-xt_5226-xt.pdf

Aaron, one thing comes to mind.

Did you adjust the squelch?????

If you don't, you will transmit a distorted signal.

Since you cut the cable, did you use a solder type connector? It would be best.

HIH

[Line Dancin]

I work in automotive, in the assembly end of things building class 8 trucks.

Satellite, CB, GPS, radio and all cables come in standard lengths. Cab and truck lengths do not. We don't cut any!!! All are coiled and stored out of the way.

In this case, Shakespeare recommends the same installation. 8" minimum size coil. In my boat, I had to go to an 18" coil for a good signal match.

http://www.shakespeare-marine.com/pdf/5225-xt_5226-xt.pdf

Aaron, one thing comes to mind.

Did you adjust the squelch?????

If you don't, you will transmit a distorted signal.

Since you cut the cable, did you use a solder type connector? It would be best.

HIH

yes squelch was adjusted

yes solder connection now mind you i am no electronics person so the job is dond just not pretty.