Re-vhf radio problems

[King mustang]

I just intstalled a new uniden um525 vhf radio on my boat and I receive the weather stations on land so I think everything ok. But I went out yesterday 10/18/08 and being confident that the radio would work I went out 48 miles to get cought in what I would say the worst weather I ever encountered yet. Swells were from 6 to 8 feet maybe 10' about every 2 sec.
( boat is 26' ) I try to contact the coast guard becuase the water is comming over the bow. I key up the radio no one can hear me not even the weather channels work. So I keep on trying to get to shore thank to my dual bilge pumps working on overtime I manage to make it back to shore within 6 hours. now on shore the weather channel works but I can't contact no one for radio checks.

Ps I put the old radio back on everything works weather / radio
also the antenna is brand new ( shakespear ).

This is a day i'll never forget it reminded me of the deadliest catch.

The radio shows on a meter that there is wattage going out swr are low 1.2

The radio shows the cord. & time distress didn't work either

Thanks Aj

 

[mthieme]

Re: Re-vhf radio problems

Did you old one work 48 miles out?

 

[King mustang]

Re: Re-vhf radio problems

Yes it did.

But I replaced everything to newer gear ( ie. dsc. ) GPS ( Garmin 3006C ), RADIO ( Uniden UM 525 ) & Antenna ( Shakespear 8' with 6 DB gain ) all hard wired with each other radio displayed gps ok. out in the water not even the weather channels worked but on land the weather works not the radio channels. Are only 1 week old .

 

[King mustang]

Re: Re-vhf radio problems

Just got off the phone with e-angler they said return the radio for a full refund no questions asked.

 

[waterinthefuel]

Re: Re-vhf radio problems

Wow. That doesn't make any sense. Something is wrong. But I've never heard of a VHF radio working 48 miles out anyway.

I hate to throw a monkey wrench in the gears, but VHF radio is not like stone, nothing is written in stone. I have a HAM radio license and in studying for the tests I learned a lot about VHF radio. There are atmospheric conditions that will help and hinder a VHF signal, they vary from day to day.

For instance, one day I was in my truck and with my little thru-window mount 2 meter antenna, I was hearing a repeater 20+ miles away. I don't normally hear it so I tried to reach it. I could...with 50 watts of power I was able to communicate with people almost 100 miles away. The next day I went out to my truck and tried to hit that repeater, unable. Nothing but static. Things change day-to-day. You can actually look online at HAM radio sites and they give the atmospheric conditions day-to-day. Those are more useful to HAM DX'ers but VHF people can still use it for daily estimations of range.

 

[King mustang]

Re: Re-vhf radio problems

Wow. That doesn't make any sense. Something is wrong. But I've never heard of a VHF radio working 48 miles out anyway.

I hate to throw a monkey wrench in the gears, but VHF radio is not like stone, nothing is written in stone. I have a HAM radio license and in studying for the tests I learned a lot about VHF radio. There are atmospheric conditions that will help and hinder a VHF signal, they vary from day to day.

For instance, one day I was in my truck and with my little thru-window mount 2 meter antenna, I was hearing a repeater 20+ miles away. I don't normally hear it so I tried to reach it. I could...with 50 watts of power I was able to communicate with people almost 100 miles away. The next day I went out to my truck and tried to hit that repeater, unable. Nothing but static. Things change day-to-day. You can actually look online at HAM radio sites and they give the atmospheric conditions day-to-day. Those are more useful to HAM DX'ers but VHF people can still use it for daily estimations of range.

@ 48 miles I was able to contact other boats in the area I figure if it works I should be able to talk to someone at least 10 miles away.

I'm also a ham radio operator I have my Kenwood 430s @ home and I also know about conditions for talking as I run 2k in my truck to talk skip while driveing to work.

This just has me puzzled.

 

[King mustang]

Re: Re-vhf radio problems

Problem solved the element inside of the antenna boake off at the base. New antenna was installed Shakespear 5225XT GALAXT 8' 6DB GAIN now it works perfect.

 

[Boatist]

Re: Re-vhf radio problems

The element inside a 5225 XT broke. Wow was there any apparent damage on the outside? Also even with it broke you got a SWR of 1.2 to 1?

Most boats with the a 5225 XT mounted 3 feet above the water will have a range of 4.71 miles plus the range of the other stations. If the other station is another boat with a antenna 11 above the water then his range is the same so you could talk at about 9.42 miles.

If the other station is someone like the Coast Guard with a high mounted antenna them much more range is normal. Example out here on the west coast the Coast Guards antennas are up on top of 3000 foot high mountains and they can be reached form 80 miles out. I talked to them several time from 80 miles away with no problem. Out here they also have many antennas linked together, like in the San Francisco Bay area I think they have 9 antennas or more to cover the whole area.

As a Ham you know that VHF is line of Site Comm and that is the reason for a 11 foot high antenna being good for 4.71 miles. Some ducting can occure but it is very rare and in very special contition. The signal can bounce off and object and get more distance but with 25 watts of 100 ERP that is also rare. I mean they bounce 2 meters off the moon but with very large beam antennas and much more than 25 watts.

You were lucky and must have learned a lot from your trip. My boat is only 21 foot and we will not launch for open water if the seas are over 8 feet or less than 8 seconds. We have been out in 9 foot every 6 seconds and building and we got no water on board but not any fun.

I would love to know more about your antenna failure as I also have a 5225 XT and it is many years old. It has been out in very rough contidion and on land hit trees and removed branches but still works perfect today.

Thanks for the information.

 

[waterinthefuel]

Re: Re-vhf radio problems

@ 48 miles I was able to contact other boats in the area I figure if it works I should be able to talk to someone at least 10 miles away.

I'm also a ham radio operator I have my Kenwood 430s @ home and I also know about conditions for talking as I run 2k in my truck to talk skip while driveing to work.

This just has me puzzled.

What is your call sign?

 

[dingbat]

Re: Re-vhf radio problems

I would love to know more about your antenna failure as I also have a 5225 XT and it is many years old. It has been out in very rough contidion and on land hit trees and removed branches but still works perfect today.

It?s a pretty common problem. I had to replace one out of my pair last fall for the same problem. The constant chop around here just beats them to death. Four to five years and they're toast.

 

[King mustang]

Re: Re-vhf radio problems

The element inside a 5225 XT broke. Wow was there any apparent damage on the outside? Also even with it broke you got a SWR of 1.2 to 1?

Most boats with the a 5225 XT mounted 3 feet above the water will have a range of 4.71 miles plus the range of the other stations. If the other station is another boat with a antenna 11 above the water then his range is the same so you could talk at about 9.42 miles.

If the other station is someone like the Coast Guard with a high mounted antenna them much more range is normal. Example out here on the west coast the Coast Guards antennas are up on top of 3000 foot high mountains and they can be reached form 80 miles out. I talked to them several time from 80 miles away with no problem. Out here they also have many antennas linked together, like in the San Francisco Bay area I think they have 9 antennas or more to cover the whole area.

As a Ham you know that VHF is line of Site Comm and that is the reason for a 11 foot high antenna being good for 4.71 miles. Some ducting can occure but it is very rare and in very special contition. The signal can bounce off and object and get more distance but with 25 watts of 100 ERP that is also rare. I mean they bounce 2 meters off the moon but with very large beam antennas and much more than 25 watts.

You were lucky and must have learned a lot from your trip. My boat is only 21 foot and we will not launch for open water if the seas are over 8 feet or less than 8 seconds. We have been out in 9 foot every 6 seconds and building and we got no water on board but not any fun.

I would love to know more about your antenna failure as I also have a 5225 XT and it is many years old. It has been out in very rough contidion and on land hit trees and removed branches but still works perfect today.

Thanks for the information.

NOT ON THE 5225 thats the new one I bought. the old one must have been like the cheapest one made by Shakespear. I saw a cut out of the 5225XT I was sold on it way better in thickness of walls compared to the old one.

 

[King mustang]

Re: Re-vhf radio problems

It?s a pretty common problem. I had to replace one out of my pair last fall for the same problem. The constant chop around here just beats them to death. Four to five years and they're toast.

Well this antenna came on the boat no telling how old it was so I just got rid of it I bought a brand new one with a brand VHF Radio 1 "Standard Horizon STD-GX1500SB Quest-X Fixed-Mount VHF Radio (Black)"

I see how it goes from here.

 

[Boatist]

Re: Re-vhf radio problems

King
Thanks for the reply. I think you will have a great rig for many years.

 

[jay_merrill]

Re: Re-vhf radio problems

If the other station is someone like the Coast Guard with a high mounted antenna them much more range is normal. Example out here on the west coast the Coast Guards antennas are up on top of 3000 foot high mountains and they can be reached form 80 miles out. I talked to them several time from 80 miles away with no problem. Out here they also have many antennas linked together, like in the San Francisco Bay area I think they have 9 antennas or more to cover the whole area.

You talked back to the USCG from 80 miles away? What is the output rating on your radio?

 

[waterinthefuel]

Re: Re-vhf radio problems

You talked back to the USCG from 80 miles away? What is the output rating on your radio?

Probably the same as the rest of us. Using my radio range calculator, at 3000 feet for the shore antenna and 8 foot tall boat antenna the range is 77 miles. If its ON TOP of a 3000 foot mountain, say on a 250 foot tower, that would make it 81 miles. He's at the edge of his range, but it's doable by all means.

One thing that you must remember. VHF has no range limit. It's only limited by the curvature of the earth. If you could put a boat on the moon and the moon was in view from your location you'd be able to talk easily, probably on 1 watt, certainly on 25. It's a well known fact that HAM radio enthusiasts (like myself) use 5 watt handheld radios to talk to the international space station.

 

[jay_merrill]

Re: Re-vhf radio problems

Interesting. I haven't thought about such distances in a long time. As I think about it now, I shouldn't be surprised because I used to sail quite a bit many years ago, and we used to maintain pretty decent coms from long distances on our boats. In that case, the increased ability came from having the antennas mounted atop 45 ' masts

 

[Boatist]

Re: Re-vhf radio problems

Jay
My radio is a Standard Omni with the standard 25 Watts Output. I have a
5225-XT 6DB gain output for a ERP (Efective Radiated Power) of 100 Watts.
My boat to boat range is about 10 miles. Power makes very little difference as VHF is line of site. Even with a illegal 1000 watts would not get more than another mile unless the signal bounced off something higher up. On the open ocean would still be close to 10 miles.

The time that supprised me was From Sacramento California to San Francisco Group. We were Salmon Fishing on the Sacramento River in Sacramento and copied the old Automatic SOS sent out by someones radio.
Coast Guard San Francisco also copied it and replied vessel sending SOS
what is the nature of your distress but got no reply. They repeated this twice more with no reply. Then they put out a request for any other vessels that heard to respond. I did not think they would here us but I responded.
They wanted to know my location and I gave it to them. Since there antennas are mounted so high they had no idea where the signal came from.

That automatic SOS system on the first radios that had a distress button was a bad idea. All it did was send out a SOS with no location and vessel identification. Out here in California with thoundsands of boat out every weekend and kids that like to push buttons it was a cnostant problem.

New system when fully in use will be much better as they will know who is sending the signal and there location so can catch the one that like to send false distress signals.

 

[jay_merrill]

Re: Re-vhf radio problems

I understand the points made about LOS, but have to disagree somewhat on signal output strength. VHF transmissions are affected by atmosphere and attenuation does occur, so there is a point at which reception is lost, even if LOS is maintained. The fact that you can transmit at 100 effective watts explains the distance to some degree, but the height of the tower that the CG uses, is the other part of the "equation."

I know the area that you are speaking of because I flew SAR missions and training flights out of CGAS San Fran (located at SFO) for several years. I'm not sure exactly where the SF area tranceiver antennas are currently located for Group SF, but there are obviously many very high locations in the area. That said, you probably were not hitting the SF tower, when you communicated from the Sacremento River. My guess is that the Guard has a repeater antenna somewhere closer to where you were.

I am kind of a cheapskate boater and operate an old boat with an old motor on it. I also use basic electronics, including a handheld VHF. Even though I do SAR missions for the Guard and LA DWF, I have not upgraded to a dash mounted VHF, because most of my SARs are in areas that have cellular coverage. This is true because the cell phone companies figured out a long time ago that mariners operating on the Intercoastal Waterway want to be able to use cell phones, so they have antennas in places that you wouldn't normally think there would be. I have the direct line number for the SAR controller's desk at CG, Sector New Orleans, and find that the communication is more effective via phone. One thing I can tell you, however, is that I can almost always hear the CG on my handheld, but can't get back to them. This is true even when LOS isn't the issue - its a transmission power issue.

I am still glad that you have provided this info, though, because I hadn't thought much about the kind of distances that I might achieve with a good dash mounted VHF. Based on this thread, I just might upgrade, because its pretty much inevitable that I will end up on a SAR sometime that is out of cellular range, and won't be working with a CG HH65 (helo) either. In that case, I would be out of luck regarding coms.

 

[jay_merrill]

Re: Re-vhf radio problems

In order to follow up on this, I have been doing some reading. I used to be better versed on this stuff, because I once had to study it in order to get a Restricted Radio Operators Permit. That was, however, about 30+ years ago, so I needed a little review.

Line of site is not the only determinant in reception range of a marine VHF transmission. Other factors are:

Transmitter Power
Transmission Line Loss to Antenna
Transmit Antenna Gain
Path Loss (aka path attenuation)
Receive Antenna Gain
Transmission Line Loss to Receiver

The more technically savvy here can probably explain how each of these things is affect by various situations.

One of the big issues in reception of marine VHF signals is radio frequency noise or interference. This can be caused by a number of things, from non-resister type spark plugs in a running outboard motor, to running GPS and radar units, to competing radio signals, both on band and off band. A weak battery will also degrade range capability because it reduces the rated output of the radio.

 

[Boatist]

Re: Re-vhf radio problems

I agree Line of Site is one limiting factor in VHF Radio.
I always recomend the first VHF be a fixed mount radio with 25 Watts of power and a good 6 db gain antenna.
A handheld radio starts with 5 watts out then goes to a rubber duck that is likely a -3 to -6 DB loss giving you efective power of 2.5 or 1.3 watts.
The antenna is also not 11 feet off the water.

The fixed mount starts with 25 watts out into a 6 db gain antenna for effective 100 watts out. The antenna is also higher than the handheld antenna.

On boats the Coax loss most of the time is small as many boat are useing Coax lines only 3 to 6 feet long. Sail boats do use longer coax and should use a low loss Coax with a 3 DB gain antenna.

One place where higher effective power out is a factor weather you get thru or not is in places like San Francisco Bay Area.
On a nice summer weekend their may be more than 1500 boat within range of the Coast Guards antenna.
On My boat I can here boats within about a 20 mile circle 10 miles in any direction. Coast Guard can here boats within about a 200 mile circle. So If you are going to call them you listen and here nothing so Make your CALL. However there may be many station that they can here. Many may be much closer to them than you are. Since there signal is stronger they will capture the receiver. If your useing a hand held on a busy weekend then your chances of being the strongest signal and reaching the Coast Guard is not too good.

The Coast Guard in San Francisco Group I do not belive use any repeaters. The antennas are linked by microwave yo the Group. When I call them from Sacramento I belive I hit either the antenna on top of Mount Tamelpias or Mount Diablo. They have no Antennas Near Sacramento for San Francisco Group. There is a station about 25 miles south of Sacramento but can not be raised from Sacramento. Also on busy Summer Weekends the Coast Guard Aux sometimes maintains a radio watch but olny contact the Coast Guard via Land line.

I have also talk to the Coast Guard Group San Francisco from the Pacific Ocean North of Salt Point. Salt point is about 30 Miles North North West of Bodega Bay. Bodege Bay is about 30 miles north of San Francisco. I Called Bodega Bay Station but after the second call San Francisco Group responded.
They then dispatched Bodega Station to help the boat that we had called in. They ask us to stay on station until Coast Guard out of Bodega bay made contact on 22A.

I like you have Study Electronics since I was 16 back in the 60's. Built a CB Walki Talki, a CB, a 2 meter Ham radio. I took a 2 year long Master course in communiction Electronics and built a signal generator, VTVM, Signal Tracer, Tube Tester and a 27 inch Color TV with all the test equipment to maintain it.

I had a Operators licence and a VHF Marine licence, and a Ham Advanced Class licence. Should go for Extra Now that do not need 20 word per minute code. I also have forgotten a lot of stuff but since I still work with all the gear still remember a lot also.

One thing that I really dislike is how dishonest so many fields have gotten.
As a example you see the FRS and GMRS radios saying 30 mile range when there usefull range is really about 1 to 2 miles.