Connecting SSB Receiver to Backstay

[Andrew G]

Hi – I am new to the forum (but not entirely new to cruising) so please “be gentle” if I ask some Civil Engineer-type questions about HF radio.

I cruise in Australia (based in Melbourne) and have used a portable SSB receiver (Sangean ATS 505, $50 from Dick Smith) for weather forecasts and warnings (in addition to VHF, and web when within range – but I can assure you that they are not in range down the Australian or Tasmanian West costs). I am sick of sitting on deck in all weather with the telescopic antenna extended listing to “tinny” forecasts. I now have an insulated backstay which I wish to connect to my SSB receiver's antenna input jack.

Some specific questions:
1) What cable should I use and what connections (eg coax/shielded/what to do with the shielding – some say connect it to the core, both ends or only one)?
2) Do I need an ATU or is manual tuning possible, if so what would you recommend?
3) If I am buying an ATU should I get something compatible with a subsequent HF with DSC installation - I am now “self unemployed” so I need to watch the $?
4) As I am only receiving does there need to be a connection to earth (there is plenty of aluminium around)?
5) If this is outside the scope of this forum can you possibly point me in the right direction, especially in Melbourne/Australia?

Some facts:
· “Brut” is an aluminium Van de Stadt 34;
· The main HF frequencies in Australia (for voice and fax weather) are 8176, 12365, 8113, 12362, 5100, 11030, 13920, 7535, 10555, 15615 (kHz);
· The length of backstay between insulators is about 40’ (12.7m). The top insulator is at least 3’ from the top of mast and the bottom one 6’ above the deck;
· I currently have the central core of RG213U cable clamped to the backstay (above the lower insulator) and after 1’ it passes inside a stainless steel frame into the hull and for about 15’ through plastic conduit to the chart table where the SSB receiver is located;
· I’ve used PL259 connectors at any joins and the core of the RG213U is soldered to the Antenna input jack;
· I’ve tried cable pulled up the mast, horizontally, specific lengths (understood to be ½ waves etc) . . . none are any better than the built in telescopic antenna.

Thanks for your help,


Andrew

[Wotname]

Just use whatever single conductor wire you have handy, you don't need anything fancy here and you don't need an ATU for a receiver. You just need a long wire (i.e. you backstay) connected to the receiver jack.

What style of jack is used on the receiver's external antenna connection point. I am assuming it is a monopole style like a banana plug.

Is there an ground jack on the receiver, if so, try connecting this to either a metal throughhull or your lifelines and see if there is any improvement.

[Celestialsailor]

I do use coax and do nothing with the shield. It acts as a shield to the inner wire so the tuner does not see it as an addition to the antenna. Works for me and provides protection from RF also.

[denverd0n]

You might want to consider one of these: Sangean ANT-60

Like Wotname said, though, this is basically just a wire that is attached to the right kind of jack for your radio. In fact, you could put an alligator clip on the end of a piece of wire, and clip that to the antenna on the radio, and that would give you just about as good of reception as you're likely to get.

[Paul Elliott]

Remember: when you connect the external antenna, if you hear an increase in the background static noise the antenna is working as well as it needs to (for receiving).

[Andrew G]

To those who have replied - my abject apologies for taking so long to get back to you. I have tried each of the suggestions and they do not appear to improve things (the jack is a 3.5mm mono but there is no earth - and it is a plastic case). I'll play around with some plan Bs.
Cheers, Andrew G.

[Lancerbye]

Usually a single any heavy conductor is used from the ATU to the backstay antenna. The ATU has a ground as a reference (often a Dyna Plate). In your case the aluminum hull will supply a good reference for ground. Since you don't have an ATU I am not sure how good your SSB tuning will be since the job of the ATU is to compensate and match the antenna wire length to the frequency you are trying to tune too. If you only wish to receive then the ATU is not needed. However you usually need a ground reference ( the shield of the coax connected to your boat hull)

[Wotname]

Originally Posted by Andrew G

To those who have replied - my abject apologies for taking so long to get back to you. I have tried each of the suggestions and they do not appear to improve things (the jack is a 3.5mm mono but there is no earth - and it is a plastic case). I'll play around with some plan Bs.
Cheers, Andrew G.

Originally Posted by Paul Elliott

Remember: when you connect the external antenna, if you hear an increase in the background static noise the antenna is working as well as it needs to (for receiving).

Originally Posted by denverd0n

You might want to consider one of these: Sangean ANT-60

Like Wotname said, though, this is basically just a wire that is attached to the right kind of jack for your radio. In fact, you could put an alligator clip on the end of a piece of wire, and clip that to the antenna on the radio, and that would give you just about as good of reception as you're likely to get.

Andrew,
Take note of the above posts, especially what Paul says about detecting a small increase in receiver noise. As soon as that happens, you really can't improve on the antenna as it is already receiving well enough for the receiver AGC (automatic gain control) to kick in.

In fact, your antenna may already be receiving well enough which means the receiver AGC is already winding back the receiver gain and no amount of antenna length will help.

Originally Posted by Lancerbye

Usually a single any heavy conductor is used from the ATU to the backstay antenna. The ATU has a ground as a reference (often a Dyna Plate). In your case the aluminum hull will supply a good reference for ground. Since you don't have an ATU I am not sure how good your SSB tuning will be since the job of the ATU is to compensate and match the antenna wire length to the frequency you are trying to tune too. If you only wish to receive then the ATU is not needed. However you usually need a ground reference ( the shield of the coax connected to your boat hull)

Please note the OP has a HF receiver only, not a SSB transceiver.