Radio check please?

[jcpa]

The thread on the "new" Solent Coastguard has prompted me to ask "How can I check a problem I seem to have with my new DSC radio (installed in June)?"

I hear traffic clearly on all channels, with no obvious dropouts, though sometimes I only hear one side of a dialogue – presumably due to power/range issues.

I’ve made a few calls to harbour masters, locks and marinas, and more times than I expected got no response. I have then used my old handheld and seemed to get a better response, though sometimes been told the radio was unmanned earlier.

Just over a month ago I did make a serious call to the CG, and again found I could only get a response using the handheld (though I was told the signal was weak). Concerned, I’ve again called the CG and HM for a radio check, usually getting a “hearing you loud and clear” response, but I don’t think I’ve ever heard my yacht name copied back to me – so I am still uncertain it is indeed me they have heard.

I mentioned my problem to the radio dealer, and he suggested there was probably a problem with a dodgy connection or with my aerial – receiving was easy, but transmitting needed a better aerial. How can I check this out?

Anyway, last weekend I asked the local HM for a radio check, using 1w, and got the short “loud and clear” response. Yet when I tried the more distant Solent Coastguard on Ch 67, using 1w and 25w (I’ve been told their receiving aerial is on the south coast of the IoW) I don’t believe I got any response. However, a colleague in the neighbouring boat said he heard both my transmission and the CG’s “loud and clear” response (that I don’t believe I did receive). Trying to confirm this, I called the CG a second time, and this time did receive “Station calling CG, hearing you loud and clear”.

I am still not certain it was me they heard, and anyway, to be sure my radio is working properly, I'd like to do the check several times and get a clear response each time. but I’m too embarrassed to keep calling up to explain all this - and maybe interfere with more important callers. Should I keep calling, or can anyone suggest how else can I get to the bottom it all?

Thanks

P.S. I have thought of trying to call a fellow DSC user on the other side of the Solent, but I've not yet been organised enough to find such a user and set up a series of tests. Also, the cruising season seems to be ending, and like many in the club, my boat is being lifted this weekend, and my mast/aerial unstepped! Probably I should try this next spring.

P.S. I do know that my aerial lead runs from the radio, behind the chart table, through an area of sprayed filler behind the fuel tank, into the bilges and then up the mast – via a connector at deck level. I’ve tried to free it, but it is jammed solid behid the fuel tank. I think I’d have to take out the chart table and the fuel tank to free it!

 

[rob2]

Well, aerials can deteriorate, though not as frequently or as quickly as the feeder cable. From what you say, it is likely that the aerial and cable are the same age as the boat and probably ready for replacement for optimum performance anyway. With that in mind, I'd be inclined to replace them, choosing a new and more accesible route for the new cable. Once the mast goes back up, borrow a 2m SWR from a radio ham and test the new installation - ideally borrow the radio ham too! It's a good idea to check the standing wave ratio before switching to full power on a new installation to avoid getting too much power reflected back into the transmitter, although most new generation radios have protection. If there are any problems at this stage, you should be able to check at each junction so as to isolate which part of the antenna assembly is causing the problem.

I think most of us have called for a radio check at the start of the season, but it may be as well to arrange to call a friend some distance away at a set time, preferably with their mobile number to hand to make contact if no joy with the radio. Other potential contacts would be a marina office (although they can be slow to respond) or, if you know them, a local workboat crew. It sounds as if you usually leave the radio on scan, so some of the messages received, such as a marina , you will only hear one side of the conversation as the cannel is duplex and one side is only set as transmit on a shps radio installation (the marina has a land based set with reversed frequencies for receive and transmit).

Rob.

 

[jcpa]

Thanks Rob, I am SURE it is not the original (1984) aerial, but I don't know how old it is. It IS a replacement fuel tank!

It is the uncertainty of really knowing if I have a problem that needs fixing that I don't like.

Since making my post I've seen the thread on radio checks on the Yachting Monthly's Scuttlebutt forum, which has helped me. It confirms the need to do radio check(s) over long range and at high power, and that Marinas are often not good people to ask for a radio check (I've found they often don't answer anyway - calling them in advance on the mobile then only VHFing them when you are alongside their office seems the best plan).

I am considering replacing the aerial/cable, and I will try to find a SWR ham to give it all a once over - thanks.

And yes, I realise I would only hear one side of a duplex channel - but 11, 12, 16 and 67 are simplex channels, as I thought was the usual marina channel 80 (or should that be 80A).

Thanks again

John

 

[Laundryman]

Pm sent

 

[johnphilip]

Aerial Survey?

Last year I had fairly similar issues. After laying up I had a professional rig check, the first for some years. Rig fine but the guy came down from the masthead with my aerial stuck through his belt. The plastic base had failed, leaving the aerial perched on a half inch spigot from the base, making intermittent contact and surprisingly staying up there.

 

[Alpha22]

If the mast is down..... replace the aerial and the feeder anyway. That will eradicate any problems in that area well before next season.

 

[Jean]

Do you carry an emergency aerial, if so, worth trying this. Also, I know Foxes (Ipswich) chandlers hire out aerial test SWAR meters, perhaps south coast ones do too, if not, you may be able to borrow one.