Counterpoise for SSB

[haydude]

Finding it hard to be pedantic - I cant remember which is the Americanism, capacitor or condenser.

It really does not matter. Both words actually come from Italian where condensatore = is something that concentrates something else into a "denser" (denso=dense) state inside a contained space, for example a vapour into liquid or a small electrical charge, as in our case, into something more concentrated that can then be released at once. Capacita' (=capacity) instead is the "measure" of a volume quantity.

In Italy we name them "condensatori" because that describes best "what" they do, whilst "capacitatori" or "capacitanze" are a words that do not exist and really do not make sense because they would indicate a way to measure something.

In English where the etymology of the word really gets lost and lose its sense, condenser or capacitor are both valid generic terms used to describe this electrical component, although talking to English speaking they normally refer to it as a "capacitor".

 

[ffiill]

Suggest you look at Furuno manual attached-it offers a variety of alternatives for counterpoise including engine block;fuel tanks etc
http://www.furunousa.com/ProductDocuments/FS1502 Operator's Manual U 6-13-98.pdf

 

[wotayottie]

interesting manual ffill but it begs the question of how do you know if your counterpoise isnt working well? how do you measure it?

I have a clear problem with my ssb that has been there since installation on this boat and I've never got round to tackling. Signal strength both on receive and transmit is weak and on transmit I am getting loads of feedback. Set up is that the aerial is the backsaty with proper insulators though the tiop one is just 6 inch or so from the mast itself. Connection at the bottom is maybe 4 ft of multi strand copper wire ( old fashioned spark plug wire actually - worked well on last boat) fastened to the backstay with a jubilee and protected against water. The auto ATU is just below the bottom of the aerial and has an earth cable running forwards under the engine to a keel bolt that is maybe15 ft away. The cablke is insulated multi strand battery cable. There is no connection between the earth terminal of the ssb and the atu other than the outer wire of the RB58 coax. The SSB is by the chart table so again maybe 15 ft from the ATU. All connections are clkean and good but the receive signal on 80m rarely gets above band noise.

 

[Conachair]

Do the LRC not the Ham exam, Hams use different LSB frequencies but Marine SSBs have both LSB and USB bands so you get the Ham frequencies too.

No actually true, a modern ham radio will receive lsb & usb on all HF bands, opened up it will transmit on all freqs lsb & usb. Not legally though, you're supposed to have a type approved radio to transmit on the marine ssb bands(& LRC).

Which license to go for comes up quite often, Ham is certainly goes into the technical side much more than the LRC, but takes longer to get, 3 exams to sit to get the advanced license, which you need to get the maritime mobile call sign needed on a boat at sea.
Marine ssb wouldn't be much use on the ham anyway, no one would talk to you without a ham call sign.

 

[Conachair]

interesting manual ffill but it begs the question of how do you know if your counterpoise isnt working well? how do you measure it?

If you have a ham license and can transmit on ham bands you can use WSPR to check as you tweak or change antennas.. http://wsprnet.org/drupal/
Not perfect as propagation varies so much but a start. I've had my laptop speak to a laptop in Aus transmitting less power than an incandescent anchor light uses.

 

[Gerry]

We fitted a counterpoise known as KISS-SSB http://www.kiss-ssb.com/ prior to our last Atlantic crossing. IT cost $149, slides anywhere under the coach roof, we have it under the aft berth. Its about 12 feet long and can be curved to fit, tube shaped and attaches to our tuner. NO copper foil, wiring etc. The thing is amazing, our radio has never worked better. We were regularly stopped by other cruisers to say that the transmission from our radio was fantastic and we managed to pick up Herb all the way from Florida to Falmouth!

 

[Rossynant]

Now, Rampage has an iron keel and it occurs to me that actually, this might offer an effective counterpoise to a backstay antenna. Is it of any use or do I need to think in terms of copper plates fixed to the hull? Can anyone offer any explanations as to why it might or might not be effective? Also, if a copper plate is used, does it go inside or outside of the hull?
Look forward to hearing peoples thoughts on this one.

Not reading what was said above, maybe explained already.
Best ground for SSB is copper plate, same kind as for lightning protection and usually the same one; or in GRP copper mesh laminated into hull shell, in outside layer.
Such things were made during production of boats, which had steel keels anyway. In fact I recall a copper plate on a steel hull boat.

 

[whipper_snapper]

In fact I recall a copper plate on a steel hull boat.

Such total insanity is not unknown and perfectly illustrates the voodoo nonsense that is often propagated on the subject.

 

[Rossynant]

Boat is in her fifties now, so guess it worked...
This boat has copper mesh laminated in hull shell for SSB, having iron keel anyway http://mantra28.pl/asia/index.php?option=com_content&task=view&id=76&Itemid=37

 

[MM5AHO]

I have an ssb on a Rival 32.
I tried various connections to the sea for a counterpoise, and ended up with no connection working well.
I have 5 wires from the "earth" side of the antenna tuner. The ATU is located about a metre from the lower end of the backstay which has insulators top and bottom. These 5 wires (about 1.5mm2 copper in insulating plastic - real basic single strand domestic house wiring stuff) run roughly parallel from stern to bow. One runs up the centre line and there's 2 either side of it. Under bunks, behind cupboards, etc etc. They're not precisely straight, and not event the same length exactly.

This works for me. I know it works by the signal reports I've had from others on boats and land internationally. (perhaps 2000 contacts) Testing on receive is only telling part of the story, its the transmitted signal that's harder to get right.

I did an extensive test one year, with an alternate copper plate hung over the side, and switching between the two I could tell no difference, and neither counld those I was talking to. So the wires have stayed, and use them each summer.

 

[wotayottie]

Testing on receive is only telling part of the story, its the transmitted signal that's harder to get right.

Yes and thats the bit that puzzled me. Reception is cr*p and whilst youi cannot directly compare reception with tranmission, I am having more difficulty hearing pals on 80m than they are hearing me

 

[wotayottie]

If you have a ham license and can transmit on ham bands you can use WSPR to check as you tweak or change antennas.. http://wsprnet.org/drupal/
Not perfect as propagation varies so much but a start. I've had my laptop speak to a laptop in Aus transmitting less power than an incandescent anchor light uses.

Thanks but having looked at that link its far from obvious how I do what you suggest.I have no experience or knowledge of digital modes. Help!

 

[Conachair]

Thanks but having looked at that link its far from obvious how I do what you suggest.I have no experience or knowledge of digital modes. Help!

For a start at digi modes you could have a look at PSK31, download fldigi and tune into 3.580Mhz USB from early evening onwards. Lots of pointless low bandwidth chatting going on
I just had a moment of pointless typing with Zolken from Slovak Republic.

Do you have a ham or marine ssb radio? Dunno about digi modes on SSB or if they even exist apart from pactor email.

 

[William_H]

Yes and thats the bit that puzzled me. Reception is cr*p and whilst youi cannot directly compare reception with tranmission, I am having more difficulty hearing pals on 80m than they are hearing me

Almost certainly bad receive is caused by local noise source. Yet surely you know that? Anyway try to turn everything off on the boat except the receiver. If that improves reception then try the different devices. So many have switch mode power supplies in them including LED lights fridges and power converters. Then there is the depth sounder which can cause interference.
Another trick is to disconnect the antenna at the receiver. Does the noise disappear? If it does it is coming via antenna. If it does not disappear then it is coming in via the 12v line or from the receiver itself.
Filters and bypass capacitors are used both at the receiver 12v input and the offending device 12v supply to reduce interference.
A bad antenna seldom hurts receiver performance much. good luck olewill

 

[MM5AHO]

SSB is very poor at handling low supply voltage, and the voice distortion is one of the first symptoms.
I run engine when transmitting on full power (100W), but 20W off the batteries does OK.

 

[Beadle]

No actually true, a modern ham radio will receive lsb & usb on all HF bands, opened up it will transmit on all freqs lsb & usb. Not legally though, you're supposed to have a type approved radio to transmit on the marine ssb bands(& LRC).

Which license to go for comes up quite often, Ham is certainly goes into the technical side much more than the LRC, but takes longer to get, 3 exams to sit to get the advanced license, which you need to get the maritime mobile call sign needed on a boat at sea.
Marine ssb wouldn't be much use on the ham anyway, no one would talk to you without a ham call sign.

Quite right. its many years since the USB for high bands and LSB for low existed. The reason was that when amateurs were first using SSB transmission a lot of 9Mhz filters were available on the ex-military market. If you made a 5 - 5.5 MHz oscillator you have 20 mtr band and 80 mtr band transceiver very cheap and reasonably easy to build. It simply became a convention that one uses USB above 5Mhz and LSB below

A thought on counterpoises:

The objective is not so much achieving resonance rather to offer a very low impedance at the frequency in use. The problem with is that you really need a different counterpoise for each frequency (another problem is getting very nasty RF burns if you use the frequency at which it is a half wave)

What really is required is a very low impedance. A copper plate achieves this at a wide range of frequencies. A further point is that a single counterpoise can make the antenna system directional in the direction in which the counterpoise runs. Can be a good thing or a bad one I guess.

Nothing wrong with using a counterpoise - so long as there is a basic understanding of the their strengths and weaknesses.

 

[tawhiri]

If you need a different length counterpoises for each band. Can they be all connected at the same time?
Also, for the 80 band the counterpoises will need to be 40 metres long. How do you you fit this into a 10m yacht?

 

[MM5AHO]

In theory you need different length antennas for each band. If using dipoles they could all be connected in parallel. (I once had a "nest of dipoles" as its called). Counterpoises can be the same. (mine 5 are not all the same length)

40m long for 80m band? They don't have to be what is best in theory, as that isn't always practical.
I use my 10m long counterpoise on 160m. It works well enough. Not as well as an 80m long one might perhaps, but I'll never know the difference as I cannot do it.

 

[yachtfunk]

This year in Las Palmas for the ARC-2013:

We are supporter for communication by World cruising club and install a ssb radio in the hotel for make test calls with the ARC boats. The different between a counterpoise like "KISS SSB" and a normal ground like Dynaplates or ssb ground paint is about 9 to 12db on 8 Mhz .We mean the KISS SSB Counterpoise is absolute rubbish. The most boat´s are arrived in St.Lucia an tell me the experience with the KISS SSB. At half of the way from Las Palmas to St.Lucia, they have no contact to other boat´s in the fleet and also no chance to download grib file via sailmail.
The last year i saw 4 boat´s with the rubbish, this year i saw 15 boats with the rubbish. The most owner´s understand the different but it was to late to solve the problem in las Palmas. :-(

I hope 2014 ist a better year and not more owner follow and buy this grounding idea

fair wind

joerg from yachtfunk.com

 

[ffiill]

For those who do not understand it the ground is not an earth but acts as a counterpoise.Connecting together the engine blocks,steel e
Water tanks,laying copper gauze over the water tanks,guardwires/rails can equally make a good counterpoise.Similarly an encapsulated keel so long as you are well connected to it or laycopper gauze over it.I have a link to one of the ssb manufacturers installation manual which thoroughly goes thru these various options that work successfully without the necessity of an expensive ground plate