SSB Receiver Target HF3

[rjlourens]

I am currently in Lanzarote and due to croos over to Caribbean in Dec. I use the "Active HF " antenna with the Target HF3.I have no ground and with the installation it does not say to connect a ground as it ahs no tuner. I use MScan software.There is a lot of interference from my laptop, more so if I use 12V power. I find it difficult to receive Boston station

Questions:
1. Any advice on interference?
2. Any suggestions on other stations for weatherfaxes?

Fair winds

 

[ShipsWoofy]

turn the fridge, lights, inverters off.

 

[MM5AHO]

When you say "active antenna", do you mean one of these that has a very short wire and an amplifier? (by short I mean perhaps less that 6 ft of wire or so, and if the "active antenna" requires a power supply its likely an amplifier type)?
If you do have an amplified short antenna, then this is likely part of the problem. Your short antenna is collecting signals very close to the radio, and close to those sources of interference, and these are swamping the real signal you want to hear.
You need to get your antenna as big as possible and as far away from those interfering devices as possible.
Could you hoist a long wire up the mast on a spare halyard? This would likely be better than an active antenna.
For a receiver, a tuner is not so important as it is in a transceiver, so don't worry about that.
Even the ground isn't so important, but a ground might help. In this case even a wire of a few metres strung overboard (uninsulated wire) might be good.
For alternative transmitters to try to receive, try
http://francisperey.com/sailing/weather_fax.shtml

 

[ShipsWoofy]

I presumed he means the nasa active antenna which is built for the set. It is actually pretty good as it happens. For a while I mounted mine at the masthead and it far out performed the wire hoisted up the mast. My worst mistake was listening to some on here suggesting it makes no difference if the antenna was up the mast or on the pushpit... Rubbish!

Up the mast it was clear of all the electrical noise I have bouncing around the saloon, I was getting a clear crisp reception of talk radio, this is one of my benchmarks as the talk radio txmitter is rubbish. There are very few radio's out there that can actually hold onto the signal.

The active aerial is great, but you really do need to mount it away from everything, location location location!

Also, the active aerial, er, being nasa, can benefit from a little help before you place it outside. I have painted the internals completely with silicon seal, and helped the seal at the bottom of the case. This is standard practice on aircraft circuits and an extremely effective and cheap way to prolong the life of something that is in a pretty harsh environment.

I suggest people do the same to their navtex aerials too!

hope this helps a little.

p.s. don't be mean with the silicon sealant, get in there and smother the components and printed circuit board. If it needs any repairs in the future it is quite easy to peal off the silicon when required.

 

[milfordman]

Hello Dog Watch, I have a NASA navtex, and I have always had the aerial mounted upside down on the pushpit, as recommended in an article in PBO. The reception in years gone by when it was in the Solent was ok. This year I have moved to Milford Haven, and the reception has been rubish. Do you think that if I move it higher the reception will improve.

 

[ShipsWoofy]

Well, at the masthead I was receiving navtex from portpatrick and niton constantly without errors.

Now it is down low although I get portpatrick ok, but do now get a few dropped characters during most messages. This in pwllheeeellllliiiii.

It is not the height that makes the difference, it is getting away from any noise, this includes all the masts of other boats in a marina etc.

I intend putting the navtex back at mast top when I step the mast this winter, but will leave my active nasa aerial on the pushpit aerial mast I intend to build and fit this winter too.

The perfect answer would be to reduce all the noise around the saloon, but on a small boat this is not always that easy.

p.s. why upside down, how do you prevent it filling with water when it rains?

 

[milfordman]

The reason the aerial is mounted upside down, is that the fixing point which is on the base is easily clamped to the top rail of my push pit, and by pointing the aerial down it means that it lies against the lower rail of the push pit, instead of sticking up where it would be vulnerable to crew leaning on it.

I do have a 2 meter high SS tube clamped to the rear of my push pit, on the top of which are 2 GPS aerials and the flux gate sensor for my auto pilot(my boat is steel).

I have been thinking of fitting a flux gate compass, but I realise I must keep the sensor as far from the hull as posible. It is getting a bit crowded at the top of the tube.

I had thought that I should extend the push pit to to form a small gantry. I could then spread out all the sensors. But I am not sure that I want the extra drag that would come with the gantry. I would appreciate opinions.

 

[Gunfleet]

It is not the height that makes the difference, it is getting away from any noise, this includes all the masts of other boats in a marina etc.>>

I think this is right. I have a NASA Navtex with the active ariel. On the river and at sea it works, in a city centre marina I get zilch.

 

[ex-Gladys]

[ QUOTE ]
The reason the aerial is mounted upside down, is that the fixing point which is on the base is easily clamped to the top rail of my push pit, and by pointing the aerial down it means that it lies against the lower rail of the push pit, instead of sticking up where it would be vulnerable to crew leaning on it.

[/ QUOTE ]

I wish I'd read this a couple of years ago. When Gladys came ashore this year the first time up the ladder I just touched the Navtex aerial with my foot and bust the flaming bracket!!! Very grumpy. Perhaps thee solution is to tie wrap it upside down to the pushpit upright!

 

[MM5AHO]

The height does help actually, but the best improvement in signal to noise ratio will be to get the antenna as far away as possible from electrical hash generated by all your onboard toys.
Of course on a yacht, getting it to the top of the mast does both - height and seperation.