Bejasus
Well-Known Member
does the antenna wire have to connect directly to the backstay wire, or can it be connected to the stainless swage fitting above the insulator?
Connecting SSB antenna to backstay
- Thread starter Bejasus
- Start date
KellysEye
Well-Known Member
Not sure why you would want to fit it to the swaged fitting. I've only ever seen it clamped to the stay, which surely is easier?
ozcruiser
Active Member
Attach to the the swage. on the wire you have a chance of corrosion due to disimillar metals
trouville
N/A
I see what your asking
The insulated wire for receiving can be wraped around the back stay or any other stay but then should jump to the receiver
If your transmitting then the insulated wire should be the same and to,the TX
On the receiver you can try attaching the anntena to anything thats metal and going up!Depends if your boats plastic wood or metal and if the mast is wood or metal
For receive the bigge the antenna the better for TX its better tuned;rx should be tuned but try and do as best
The insulated wire for receiving can be wraped around the back stay or any other stay but then should jump to the receiver
If your transmitting then the insulated wire should be the same and to,the TX
On the receiver you can try attaching the anntena to anything thats metal and going up!Depends if your boats plastic wood or metal and if the mast is wood or metal
For receive the bigge the antenna the better for TX its better tuned;rx should be tuned but try and do as best
KellysEye
Well-Known Member
>Attach to the the swage. on the wire you have a chance of corrosion due to disimillar metals
I might be missing something here (no expert on swaged fittings we have stalok) but the wire will be copper, the swaged terminal and the stay are stainless. Thus no difference regarding corrosion.
I might be missing something here (no expert on swaged fittings we have stalok) but the wire will be copper, the swaged terminal and the stay are stainless. Thus no difference regarding corrosion.
ccscott49
Well-Known Member
Just clamp it to the wire, no worries, thats how I've seen most done here.
jerryat
Well-Known Member
[ QUOTE ]
Just clamp it to the wire, no worries, thats how I've seen most done here.
[/ QUOTE ]
Yep, agree with kellyseye and you. I don't think I've ever seen one connected to the swage. Not saying it wouldn't work, just that there's no point.
Another thought - the swage is effectively a (hopefully good!) joint between the swage and the backstay - so why introduce the possibility of increased resistance when you don't need to? /forums/images/graemlins/confused.gif
Just clamp it to the wire, no worries, thats how I've seen most done here.
[/ QUOTE ]
Yep, agree with kellyseye and you. I don't think I've ever seen one connected to the swage. Not saying it wouldn't work, just that there's no point.
Another thought - the swage is effectively a (hopefully good!) joint between the swage and the backstay - so why introduce the possibility of increased resistance when you don't need to? /forums/images/graemlins/confused.gif
HoratioHB
Well-Known Member
Clamp to the back stay works for me - dont forget to stand the aerial wire off, below the insulator. You can buy expensive ones or drink a lot of wine and use wine corks and tie wraps - this also works for me and either has a degree of yottie 'credibility' or shows I am an Alchoholic!!!!
davidbains
Well-Known Member
Good idea about the wine corks. However the diagram in Mike Harris' book shows no need for spacers. What are they for?
HoratioHB
Well-Known Member
Depends who you ask, I was advised they were not necessary by my installer. However everyone I have seen uses them and they seemed to improve my reception. I think the theory is to keep the aerial wire away from any potentially earthed source to either reduce interference and/or reduce the effectiveness of the insulation. I am sure others will know more than me.
jerryat
Well-Known Member
Yes I've seen a few boats with either home or purpose-made 'stand-offs, but far more with the feeder simply taped to the backstay - which is how ours has been since installation.
I would have thought that if you are using a high quality screened cable, as one should, there would be no discernable degradation in the signal.
I would have thought that if you are using a high quality screened cable, as one should, there would be no discernable degradation in the signal.
ytd
Well-Known Member
SSB output cable to connect to a backstay is not normally screened but it does usually have fairly thick insulation so it can be taped to the earthed part of the backstay and the ATU can compensate. But it will work better, especially on receive, if the cable is kept away from anything that is earthed. Hence spacers.
Bejasus
Well-Known Member
ok, reason for asking about the swage connection, was to enable me to trim the wire by 2 inches without having to replace the whole length. Wire is stainless, as is the swage, so why would there be a metal problem? As for standoffs when running the cable down the earthed section. Why? Cable has good insulation.
Anyhoo, cable is now connected to new swage via a small loop and two hose clamps, and wrapped at this point in rigging tape. Insulated part is tie wrapped every foot to the earthed section. Everything seems to be ok, except I haven't had time to tune it in to anything worthwhile and I am now back in the UK until the end of August. So here's hoping it will be ok when I get back to the boat.
Anyhoo, cable is now connected to new swage via a small loop and two hose clamps, and wrapped at this point in rigging tape. Insulated part is tie wrapped every foot to the earthed section. Everything seems to be ok, except I haven't had time to tune it in to anything worthwhile and I am now back in the UK until the end of August. So here's hoping it will be ok when I get back to the boat.
whipper_snapper
Well-Known Member
[ QUOTE ]
As for standoffs when running the cable down the earthed section. Why? Cable has good insulation.
[/ QUOTE ]
Because of capacitive linking. In effect, there is no insulation at radio frequencies and a large amount of the energy transmitted will be lost to the grounded part of the backstay.
Standoffs to give a few inches of air space are very strongly advised to improve performance and reduce stray RF when transmitting.
I have used short lengths of hose. I have also seen plastic spacers intended for bee frames used for the job.
As for standoffs when running the cable down the earthed section. Why? Cable has good insulation.
[/ QUOTE ]
Because of capacitive linking. In effect, there is no insulation at radio frequencies and a large amount of the energy transmitted will be lost to the grounded part of the backstay.
Standoffs to give a few inches of air space are very strongly advised to improve performance and reduce stray RF when transmitting.
I have used short lengths of hose. I have also seen plastic spacers intended for bee frames used for the job.
whipper_snapper
Well-Known Member
[ QUOTE ]
I would have thought that if you are using a high quality screened cable, as one should, there would be no discernable degradation in the signal.
[/ QUOTE ]
I don’t understand. The feeder must not be screened. Everything on the antenna side of the ATU is part of the antenna, a single unscreened conductor which radiates RF
I would have thought that if you are using a high quality screened cable, as one should, there would be no discernable degradation in the signal.
[/ QUOTE ]
I don’t understand. The feeder must not be screened. Everything on the antenna side of the ATU is part of the antenna, a single unscreened conductor which radiates RF
jerryat
Well-Known Member
Hi W-S,
Our lower backstay insulator is only about four feet above the deck on our little boat, and the feeder is the same cable as that which runs from the transmitter to the ATU. Can't remember the spec. at the moment.
As have you I'm sure, I've seen all sorts of bits of wire acting as a feeder dangling from backstays, and the sets often work superbly. However, after much debate, I was advised to cut back the inner core of the co-axial cable (both ends) and use the twisted and soldered together outer braid only as the feeder. The outer braid giving a greater 'mass' of copper conductor.
True, it's not screened very well in the sense of preventing RF but is so far as allowing any path to earth, in short it's just ordinary insulation. I initially did use 'stand-offs' on my rig as it 'seemed the best thing to do', but they were a real pain for us on our little boat ('cos we tend to grab the backstay when coming aboard using the stern ladder) so we ditched them.
According to the meters on my transceiver there is absolutely no discernable difference between the two, and certainly, the range and clarity we have enjoyed on our transats etc has been superb.
No doubt a very senitive and expensive meter might discover a reduction in reception, but as the whole rig has worked so well for the last twelve years and thousands of miles, we just have to live with it!! /forums/images/graemlins/grin.gif /forums/images/graemlins/grin.gif
As always, everyone to their own!!
Our lower backstay insulator is only about four feet above the deck on our little boat, and the feeder is the same cable as that which runs from the transmitter to the ATU. Can't remember the spec. at the moment.
As have you I'm sure, I've seen all sorts of bits of wire acting as a feeder dangling from backstays, and the sets often work superbly. However, after much debate, I was advised to cut back the inner core of the co-axial cable (both ends) and use the twisted and soldered together outer braid only as the feeder. The outer braid giving a greater 'mass' of copper conductor.
True, it's not screened very well in the sense of preventing RF but is so far as allowing any path to earth, in short it's just ordinary insulation. I initially did use 'stand-offs' on my rig as it 'seemed the best thing to do', but they were a real pain for us on our little boat ('cos we tend to grab the backstay when coming aboard using the stern ladder) so we ditched them.
According to the meters on my transceiver there is absolutely no discernable difference between the two, and certainly, the range and clarity we have enjoyed on our transats etc has been superb.
No doubt a very senitive and expensive meter might discover a reduction in reception, but as the whole rig has worked so well for the last twelve years and thousands of miles, we just have to live with it!! /forums/images/graemlins/grin.gif /forums/images/graemlins/grin.gif
As always, everyone to their own!!
whipper_snapper
Well-Known Member
any old bit of wire dangling from the backstay is likely to work perfectly as a feeder. A grounded and screened coax is likely to cause serious problems. Doing as you have and using the outer braid as the conductor is perfectly OK. I use the inner from some coax with the outer braid stripped off.
Each to his own, but I think it makes sense to use 'best practice' as far as is reasonably possible. And there is good reason to use standoffs, or at least to be aware that the lack of them is suboptimal.
Each to his own, but I think it makes sense to use 'best practice' as far as is reasonably possible. And there is good reason to use standoffs, or at least to be aware that the lack of them is suboptimal.
davidbains
Well-Known Member
Spark plug HT cable works well. I would have thought that spacers would make no discernable difference in reception but might help to transmit more power up the insulated backstay.
oldvarnish
Well-Known Member
I did quite a bit of research when I installed my SSB. The majority of the advice was against screening the feed cable, and using spacers to keep it away from earthed rigging.
Good tip for the cable - use the stuff the neon sign installers use.
Good tip for the cable - use the stuff the neon sign installers use.
whipper_snapper
Well-Known Member
I am sorry to appear pedantic here. But this is not a matter of opinion or majority vote. Screening the feed is exactly the same as screening part of your antenna and is always a bad thing. There is in fact no antenna feed from the ATU, only antenna! And the same applies to standoffs. How important their effect is depends on the nature of the boat, hull and rigging connection. But strapping your antenna to a piece of grounded wire is, to put it politely, not sensible.
People queue up here to say that's what I do and it works for me. Well I am glad to hear it, but it must be sub optimal.
People queue up here to say that's what I do and it works for me. Well I am glad to hear it, but it must be sub optimal.
