icom M700 ssb info please.

[chrisgee]

what is the alternative to a backstay aerial if any and how do I fit a modem ( and which type?) to receive and send small emails?
Thanks to all for the info on Catalina 42`s I just bought one after a test saIL. I was well impressed with it`s performance and build quality. Very under rated I would say.

 

[Talbot]

fit of a modem depends on which model of M700. If it is the M700 pro, it is relatively straightforward, but the older M700UK is a different matter. There is a degree of analogue interface within the machine and the older ones dont have an external connector that is suitable. It is possible to modify, but the resulting interface can prove to be incompatible with the faster modems. Great RX/TX for chat, but costs of a pactor are about the same as costs for an iridium whhich would have much better interface capability (although running costs would be higher)

 

[Talbot]

Two possible alternatives to a backstay antenna -

whip aerial

temporary wire raised on rope to just below masthead.

 

[davidbains]

You can make a whip aerial by winding some wire round a long bare carbon
fishing rod and clamping it to the pulpit. This will require a ground plane,
which can be a sintered hull plate or just radial wires in the bilge.
Alternatively hoist a dipole up with a halliard, you can use this without
a ground plane.

 

[Benbow]

Dipoles seem attractive because they don't need a ground, the trouble is that marine HF happens on lots of very different frequencies and you would need several different antennas. A whip is unlikely to be as good as a backstay and, as has been said, requires a ground.

A backstay is very hard to beat for a flexible antenna, and you have the perfect ground a few inches away if you can make a decent connection to it.

 

[SimonJ]

Alternative to a backstay aerial which I have used for 4 years is:
Obtain length of pvc covered copper wire (say 8mm)long enough to go from aerial tuner to just short of mast head. Then obtain a cored rope of say 10mm diam and remove core from all but last about 4/5 ft. Seal end of wire and thread up core of rope from a point that will allow tight securing of rope at top end to a mast head fitting and lower end to a U bolt on your quarter or similar position. Take wire to the aerial tuner. At top end seize wire to core of rope.
This is cheap, safe as it can be touched and no insulators are used. It is very efficient as wire is copper (which emits well) and not twisted as your stainless backstay is and reduces losses as it can be connected directly to the tuner.
For the earth use long length of wide copper strip concertinered in bilge and tagged to keel bolts.
For a modem you will need at least a Pactor 2 modem at about£545. Search for this on the web (sailmail.com)and you will eventually reach Bob Smith in Warsash who I believe will set you up!

 

[chrisgee]

thanks for all your info --- much appeciated

chris garraway

 

[chrisgee]

thanks for all your info --- much appreciated

chris garraway

 

[mdrifter]

I'd be a bit wary of M700 - as has been said some models more amenable than others but if I remember it could have a "duty-cycle" problem if you drive it too hard - there may be some info on www.hf.com. Most modern/recent ham rigs are easier to interface with an SCS PTC modem and are available 2nd hand at reasonable price - unlike the modems which only very occasionally appear 2nd hand. As for antenna - hoist a wire or wind around a grp whip and use a good atu such as sgc230 and ground plates ot via keel-bolts. If you lower the mast you can still email!

 

[syfuga]

Bob Smith is contacted www.yachtcom.co.uk or 01489 565100.

 

[mdrifter]

Sorry!! Should have been www.hfradio.com