advice needed on radio range

[andrewhopkins]

Ive just discovered a problem with my radio on my Bavaria 35. I can no longer get any response from the coastguard on 16 or 67 for radio checks. I can hear the coastguard, etc ok.

However, i can speak and received calls on 06,16,67 or anything between myself and my portable VHF when someone is 3-400 yards away.

This suggests to me that there is a problem with the power or range of set. Can anyone give me any ideas how to fix this? Am i right to think that the arial must be ok as i can transmit/receive to my portable ?

Any help is appreciated

 

[Phoenix of Hamble]

These are classic symptoms of an aerial problem..... get it SWR tested....

 

[john_morris_uk]

Sadly the VSWR showing at the radio end of the transmission line is only part of the story. A bad VSWR will show that something is wrong. A good VSWR does not prove that everything is right.

Lossy and faulty coax can give a reasonable VSWR reading and /or mask faults with the antenna. Checking the VSWR at the radio end is a good start, but don't be lulled into thinking that it proves everything is ok with the antenna and coax.

 

[brianrunyard]

The fact that you can recieve doesn't prove the antenna is ok, you can receive on almost any piece of wire, but transmitting is different matter.
Check the antenna connections, most common problem is bad connection due to water getting in.

 

[Brian_Moffat]

OH! for goodness sakes peoples get your acts together:

1 Happy Chappy here does not know his left from his right! - He owns a VHF radio which originated from Merlin (of King Arthur Fame and he does not have a clue - does he?)

2 For some reason he thinks that the VHF does not work! (Whether that is correct or not is immaterial).

3.Have I done that myself? No Way! Under no circumsaances would I ever allow anyone whomsoever to observe me in a state of ultimate pratness.

4. I know that when you ask the question - that you kow the answer but you are such a shyster (Scrivener/lawyer/ politician/etc) that you want someone else to Pay ? Sorry sunshine! Get your wallet out and pay the bloody engineer> After all ? did you purchase the equipmen?

 

[starboard]

Have you accidentally changed to low power setting....i.e 5w output instead of 25w???

Paul.

 

[pvb]

Hmmm...

Yet another helpful post there, Brian. We're starting to build a mental image of you...

 

[ShipsWoofy]

The few times I do a radio check or even call the CG on routine I use 1W and they hear me loud and clear.

I am not saying this is the situation, but I was say it was unlikely to be his problem.

If I was him, I would choose a quiet time and see if he can talk to the CG with his h/h. Then I would connect the h/h to the ships aerial and confirm that contact could still be made.

50% fault splitting.

 

[mica]

We have a similar problem. What is a SWR test and how do you get it done?

Regards,
Mica

 

[Tisme]

Re: Hmmm...

[ QUOTE ]
Yet another helpful post there, Brian. We're starting to build a mental image of you...

[/ QUOTE ]

Yup!
He always seems to hit the keyboard late at night, possibly after he has hit the bottle?

 

[andrewhopkins]

Thanks to all except the drunk

Sounds like the aerial, i'll check connections and see if i can attach to the hand held.

Regards
Andrew

 

[Guest]

Re: advice needed on radio range ... Magnacarter hit the button !

Classic antennae cable / antennae problem ... all you are getting is signal from the bit of cable that is still connected ... you have two ways to check it ....

Best actually is to just disconnect cable and check for continuity in the cable .... I know its a pain if antennae is masthead based !! but is only real way to be sure.
Next is once continuity is established is SWR the set-up ... this will then tell you if antennae is working. It is possible to have cable ok - normal meter on Ohms will tell you that - but antennae be US - SWR gives you that.

There is of course another way if you have a friend with an emergency or rail based antennae ... connect that and see what happens ..... you could even on some sets connect a HH or other small Rubber duck CB aerial .... (Ok so the length ratio is not correct - but it will work well and show if range is increased ....)

 

[Guest]

Brian_Moffat .... ??????

Wrong side of bed or summit ???

Poor guy would like help - not insults.

 

[Guest]

Low Power ..... 5W ?????

3 - 400yds is not just low signal - that is appalling ....

5W or 4W or even as some sets do go down to 1W ... will give you a number of miles on average ... not yds.

Average HH is about 4 - 5W ..... and you can talk across Solent for example on average ....

 

[Guest]

SWR meter .....

Local Maplins / Elctronics emporium specialising in CB and other TX / RX equipment ....

It's a meter that is connected between radio and antenae and reads the wave ratio of output ....

To be honest - I am doubting its use in this situation as I think it's a continuity problem - not SWR ... as another says - connect antennae to the HH - see what happens then and as I suggested before - put HH aerial on fixed set ... see what happens ....

 

[Salty John]

Unfortunately you can't check the antenna cable without disconnecting both ends. However, try the following; Insert the radio-end PL259 plug into the socket on the radio but only far enough for the centre pin to connect, not the outer case. Tune the radio to a station that is weak but steady. Push the connector in all the way. If the reception improves slightly the antenna system is probably OK; if it goes away completely then you have an antenna or connector problem.
In fact, it sounds like you have a bad antenna (bird strike, corrosion) or you have at least one bad connection. Non-soldered connections, unprotected, are unlikely to last more than 2-3 years before corroding.

 

[Benbow]

Re: SWR meter .....

something like this:

AV-40 AVAIR VSWR/POWER Meter

plus a short patch lead

Will make you a very popular person in the boatyard at relaunch time. I agree its not the be-all and end-all, but SWR can be very informative, especially for identifying dodgy connections.

 

[Solitaire]

Now, where's Steverow when you want him? /forums/images/graemlins/grin.gif

 

[DrBob]

I'd put money on it being a bad connection between the feed coax and the antenna. The connectors fitted to the normal antennas are very poor considering the duty.

Best way to check is take your emergency vhf antenna out of the box and fit it to the radio. You will probably find it works fine. Your problem is then in the wire / antenna and a trip to the top of the mast to refit the wire in the antenna will probably solve it.

THis has happened a few times to me and easy to identify with an impedence bridge (MFJ antenna tuner).

Dr Bob

 

[sailorman]

Tooooooooooooo many radio-checks in the past, all radio checked-up i guess. /forums/images/graemlins/blush.gif
none of my radios have ever been " radio-checked" by H.M.C.G. /forums/images/graemlins/cool.gif