Navtex antenna connection?

[BobnLesley]

Hello folks,

after your pointing me in the right direction when our GPS antenna 'died' a few weeks ago, I'm hopeful you can come up trumps on our latest breakage - my own fault, I forgot to follow the cruisers addage: 'If it's not broken, don't use it!'

Today's problem: We have a NASA Marine Target Pro-Plus Navtex Unit on which the terminal at the unit/screen end of the antenna cable has broken in half; it looks similar in size/profile to the terminal of a traditional TV Aerial, though I'm sure it's not. So is it possible/practicable to get & fit a new terminal to one of these antenna cables or is it a complete new antenna job?

 

[prv]

I think actually it is just an ordinary belling-lee, as used on tellies, and you should be able to fit a new one. The cable may not be the same, though, so don't be tempted to extend it with a bit of TV aerial cable at the same time.

Pete

 

[FullCircle]

It is a common or garden TV plug.....

 

[prv]

Pure quality, these NASA boxes

Pete

 

[FullCircle]

I think (from memory) it is a bog standard 75 ohm cable too..... need to check that though.

 

[ithet]

The Nasa Navtex Pro and Series 2 aerials I have here on my desk both have 75ohm cable and a 75ohm co-ax plug on the end. Incidentally, I have opened up both aerials and they contain about £2 of components, including the single transistor that makes them "active".

 

[smartcom]

Well, you get what you pay for, and with NASA you aren't paying much!

 

[Leighb]

Well, you get what you pay for, and with NASA you aren't paying much!

They generally work perfectly well though!

 

[winsbury]

I have a brand new series two Navtex antenna bought in error if anyone wants to make a sensible offer. It turned out my Navtex Pro is an early one that uses the standard 518 antenna.

 

[shaula]

I was wondering if a Navtex antenna can be connected to any of the AIS units?

 

[prv]

I was wondering if a Navtex antenna can be connected to any of the AIS units?

Nope, completely different. Navtex works a little way either side of 500 KHz and AIS works either side of 162,000 KHz.

Pete

 

[pagoda]

The Nasa Navtex Pro and Series 2 aerials I have here on my desk both have 75ohm cable and a 75ohm co-ax plug on the end. Incidentally, I have opened up both aerials and they contain about £2 of components, including the single transistor that makes them "active".

Agreed, though the transistor is a fairly high gain JFET if I recall. I had one active antenna killed by the yard person plugging it into the sounder output. A new antenna was about £25. The JFET, once identified was under £2. Five minutes with a small soldering iron was all that was needed

 

[ithet]

Agreed, though the transistor is a fairly high gain JFET if I recall. I had one active antenna killed by the yard person plugging it into the sounder output. A new antenna was about £25. The JFET, once identified was under £2. Five minutes with a small soldering iron was all that was needed

Pagoda, I would be interested in the ID of that transistor, as that is what I need to replace. Have not found it from the markings.

 

[BobnLesley]

Thankyou Gentlemen, but a back-handed complement i'm afraid...

I got myself a TV socket (not easy out here - they use US ones) and all's working well again.

I commented to Lesley about how useful the forum is: 'I can ask any question and get the answer, the forum's full of people who know far more about boats then me.'

The reply: 'Come on, you could write to a forum for camel farming Bedouin and they'd probably know more about boats than you.'

Oh, how the truth can hurt!