Cruisers Forum
 


Join CruisersForum Today

Reply
 
Thread Tools Rate Thread Display Modes
Old 24-02-2011, 17:06   #31
Senior Cruiser

Cruisers Forum Supporter

Join Date: Jul 2006
Location: Chesapeake Region and Maine
Boat: 42' Bob Perry sloop
Posts: 4,038
Images: 4
Re: SSB Counter Poise

Quote:
Originally Posted by ON3CHD View Post
.....

I suppose that the coax coming out of the beast will have to be connected to the antenna terminal screw from my AT 140 (which is 3 meters apart from my radio) and that no other connection ( i.e. the radio) has to be done?
....
NO, NO NO! If you already have an AT140, you don't need an UN-UN!

Just position the AT-140 near the base of the wire antenna, connect it to the antenna with GTO-15 high-tension wire, and run coax from the tuner to the radio.

Then, connect the KISS-SSB radial ground system to the ground lug on the tuner. ONLY. Do not ground the radio itself.

Bill
__________________

__________________
btrayfors is offline   Reply With Quote
Old 24-02-2011, 17:36   #32
Senior Cruiser
 
AfterHoursNLCT's Avatar

Cruisers Forum Supporter

Join Date: Nov 2010
Location: Quaker Hill, CT (just above the US Coast Guard Academy)
Boat: Silverton 34 Convertible
Posts: 190
Re: SSB Counter Poise

Quote:
Originally Posted by ON3CHD View Post
Hello AfterHours,
what do you mean by added ...Is that KISS cable not originally designed for 2 to 29 MHZ WL?
Cheers.
ON3CHD
The KISS-SSB counterpoise is cut for the marine freqs and 20 meter ham. I had them add 17 and 30 meters so if I didn't have a tuner and the antenna was for, say cut for 17 meters, it would load. I use a Kenwood TS-440SAT down on the boat with a Shakespeare 23' Marine antenna and a MFJ tuner and I'm happy with that. I wouldn't worry about the other bands too much if you have a tuner. It's just easier on the tuner if the impedance is closer... Hope that made some sense. I'm ready for bed........LL
__________________

__________________
AfterHoursNLCT is offline   Reply With Quote
Old 24-02-2011, 17:42   #33
Senior Cruiser
 
AfterHoursNLCT's Avatar

Cruisers Forum Supporter

Join Date: Nov 2010
Location: Quaker Hill, CT (just above the US Coast Guard Academy)
Boat: Silverton 34 Convertible
Posts: 190
Re: SSB Counter Poise

The only reason I promote the KISS-SSB is that my knees aren't too good anymore and I really didn't want to crawl around the bilge with the old copper strapping and stuff, so I took a chance on their counterpoise and was sold on it in 5 minutes. It loaded well, and I made contacts........LL
(p.s., sucks getting old)
__________________
AfterHoursNLCT is offline   Reply With Quote
Old 25-02-2011, 05:19   #34
Registered User

Join Date: Jun 2009
Boat: Elan 37,Racing version
Posts: 42
Re: SSB Counter Poise

Quote:
Originally Posted by btrayfors View Post
....
Then, connect the KISS-SSB radial ground system to the ground lug on the tuner. ONLY. Do not ground the radio itself.

Bill
Hi Bill,
thanks fy comment.
Had a look at my present configuration.
Icom Transceiver M802 has been furnished with a control cable to connect it to the AT-140. Name of this cable is OPC-1147/N.
Both end of this cable are finished with a little green wire to be connected (as per Icom diagram ) to the Ground screw on one side of the transceivrer and on the other side of the at-140.
If I do understand your hereabove comment I should DISCONNECT this ground cable?
Thanks once more.
73
Claude.
__________________
ON3CHD is offline   Reply With Quote
Old 25-02-2011, 06:44   #35
Senior Cruiser

Cruisers Forum Supporter

Join Date: Jul 2006
Location: Chesapeake Region and Maine
Boat: 42' Bob Perry sloop
Posts: 4,038
Images: 4
Re: SSB Counter Poise

Quote:
Originally Posted by ON3CHD View Post
Hi Bill,
thanks fy comment.
Had a look at my present configuration.
Icom Transceiver M802 has been furnished with a control cable to connect it to the AT-140. Name of this cable is OPC-1147/N.
Both end of this cable are finished with a little green wire to be connected (as per Icom diagram ) to the Ground screw on one side of the transceivrer and on the other side of the at-140.
If I do understand your hereabove comment I should DISCONNECT this ground cable?
Thanks once more.
73
Claude.
The green wire is probably OK...it's meant to help reduce transients on the control wire between the radio and the tuner.

What is a NO-NO is running a ground wire direct from the main unit of the 802 (or any other SSB for that matter) to DC ground. That is what can create annoying and disruptive ground-loops.

Bill
__________________
btrayfors is offline   Reply With Quote
Old 25-02-2011, 07:02   #36
Registered User

Join Date: Sep 2008
Location: Camden, ME
Boat: A Thistle and a Hallberg-Rassy 36
Posts: 661
WRT the KISS SSB counterpoise, and with all due respect to btrayfors, whose opinion I highly respect in these matters; I am still not convinced that this item is any better than a handful of wire thrown into the bilge - except that it is water proof which counts for something.

Maybe Bill or some other technically qualified person could do some simple RF field measurements comparing the KISS SSB to a copper strap run to a thru hull, with the KISS coiled and uncoiled. At least we might see if this thing is in the ballpark, even if a comprehensive test is impractical.

I guess I'm just tired of seeing endorsements like "I get a tune in all bands" and "I made contacts a thousand miles away", which are almost meaningless. My QRP transceiver makes contacts thousands of miles away with 3 watts, but that doesn't mean it's every bit as good as my boat's m802 radiating 150 watts. And I don't think I have to argue that you really want a safety system like a SSB radio to effectively radiate all the power it is designed to deliver.

There. I feel better now.
__________________
SoonerSailor is offline   Reply With Quote
Old 25-02-2011, 08:10   #37
Senior Cruiser

Cruisers Forum Supporter

Join Date: Jul 2006
Location: Chesapeake Region and Maine
Boat: 42' Bob Perry sloop
Posts: 4,038
Images: 4
Re: SSB Counter Poise

Quote:
Originally Posted by SoonerSailor View Post
WRT the KISS SSB counterpoise, and with all due respect to btrayfors, whose opinion I highly respect in these matters; I am still not convinced that this item is any better than a handful of wire thrown into the bilge - except that it is water proof which counts for something.

Maybe Bill or some other technically qualified person could do some simple RF field measurements comparing the KISS SSB to a copper strap run to a thru hull, with the KISS coiled and uncoiled. At least we might see if this thing is in the ballpark, even if a comprehensive test is impractical.

I guess I'm just tired of seeing endorsements like "I get a tune in all bands" and "I made contacts a thousand miles away", which are almost meaningless. My QRP transceiver makes contacts thousands of miles away with 3 watts, but that doesn't mean it's every bit as good as my boat's m802 radiating 150 watts. And I don't think I have to argue that you really want a safety system like a SSB radio to effectively radiate all the power it is designed to deliver.

There. I feel better now.
Well, I hope so :-)

And, I agree with most of your points.

Unfortunately, a meaningful test and comparison of the KISS-SSB with other common forms of RF grounds on sailboats is a lot more difficult and time-consuming that it would at first appear. "Simple field measurements", it turns out, aren't simple at all, at least not if you want anything reliable. I, and my ham colleagues, have thought about this and talked about it for some years. One of these days, maybe, we'll find the time to draft a meaningful protocol and actually do the tests.

Meanwhile, we go with what we've got: an open mind, experience, some measurements, "apparent observed performance", and hunches. Mostly.

What sets the KISS-SSB radial ground system apart from other common solutions is:

1. it is designed to achieve a fast tune on all the usual marine and ham HF bands (and does so very nicely, right out of the box);

2. it is compact...only 10' long plus a 4' AWG10 pigtail....and can be arranged in almost any configuration on your boat;

3. it can be installed by anyone, and can be done in just a few minutes;

4. there are no direct connections to seawater -- thus no worries about galvanic corrosion or cleaning bottom plates, etc.;

5. its on-the-air performance is very good; and

6. its construction is top-notch; no way the average person could match the design and construction -- including the "tuned" radial lengths -- without expending a great deal of time, which would most likely be more expensive than the cost of the system.

Disclaimer: I am a dealer for this system, have installed a bunch of them, and like it very much. It does what it claims to do and, in some situations, helps to avoid troublesome RFI.

Anti-disclaimer: I still like, advise on, and install other RF ground systems: radials, copper straps to thru-hulls, aluminum toerails, s/s rub rails, s/s rudder complexes, etc., etc. I'm not wedded to the KISS-SSB system, or any other for that matter.

There are many workable solutions to the RF ground dilemma. The important thing is to choose one which best suits your boat, your temperament, your biases, and your pocketbook :-)

Bill
__________________
btrayfors is offline   Reply With Quote
Old 25-02-2011, 09:21   #38
Registered User

Join Date: Nov 2009
Location: USA
Boat: Cape Dory
Posts: 439
Re: SSB Counter Poise

Can any of you guys rec a good antenna set-up (non backstay cutting) to pair with a 700PRO (beastly thing I have no idea where to put it . . . and I need disconnect access) a AT130 and the KISS counterpoise? Is this gam twin lead antenna viable? I have heard some say you could make it better and significantly cheaper. Thx.
__________________
Mambo is offline   Reply With Quote
Old 25-02-2011, 09:40   #39
Senior Cruiser

Cruisers Forum Supporter

Join Date: Jul 2006
Location: Chesapeake Region and Maine
Boat: 42' Bob Perry sloop
Posts: 4,038
Images: 4
Re: SSB Counter Poise

Mambo,

If your boom isn't too long, or your mainsail roach too high, you might be able to fit an "alternate backstay antenna". This is an excellent solution...very robust (made of insulated s/s lifeline) and doesn't require cutting your backstay.

Many posts on this Board, on SailNet, and on the SSCA Forum. Just search for "alternate backstay".

Bill
WA6CCA
__________________
btrayfors is offline   Reply With Quote
Old 25-02-2011, 18:20   #40
Registered User
 
nv5l's Avatar

Join Date: Dec 2010
Location: Liveaboard
Boat: Allied Luders 33, Hull 98, 1971
Posts: 393
Images: 1
Re: SSB Counter Poise

Bill, what's your experience with radiation patterns and directivity of various marine antennas?

The Antenna Book has examples of radiation patterns for insulated backstays on 40 meters that show a maximum gain from 1.12 dBi, lower insulator only, to 3.53 dBi, both upper and lower insulators, and even a whopping 4.29 dBi if the latter also includes an uninsulated forestay -- that's getting close to a yagi, though I doubt anyone would do it.

It sure seems like the mast and rigging, whether grounded or not, should act as reflectors, as opposed to interference, when not connected directly to the antenna. I'd be curious to know if this is consistent with what you've seen in the antennas you've worked with. And if so, what guidance would you give, especially as pertains to grounding and counterpoise systems and rigging?

Btw, this information was taken from an article written by Rudy Severns, N6LF, however, it wasn't clear which modeling program was used to generate the radiation patterns.
__________________
don
NV5L
S/V Aurora
nv5l is offline   Reply With Quote
Old 25-02-2011, 18:47   #41
Senior Cruiser

Cruisers Forum Supporter

Join Date: Jul 2006
Location: Chesapeake Region and Maine
Boat: 42' Bob Perry sloop
Posts: 4,038
Images: 4
Re: SSB Counter Poise

Don,

All modeling programs are suspect because each boat is different. Sometimes you get lucky and sometimes you don't.

The effectiveness of any antenna system on a boat very much depends on what you're intending to do. Which bands do you wish to favor? Which distances do you hope to optimize for? What time(s) of day?

I very much doubt that any backstay antenna, however insulated, is going to show anywhere near the gain of a yagi. By the way, DBi is different from DBd, the latter being the usual measurement for a yagi's gain. A three-element yagi will show about a 6-7db gain over a dipole (DBd), which is on the order of 8-9 DBi if I remember my math correctly.

Let's take a couple of examples:

1. You wish to optimize for the 40-meter band, to communicate with other boats and land stations at distances between about 300 and 1,000 miles. In this case, you'd want to cut your backstay fairly long....say over 40', since shorter lengths would tend to favor the higher bands. You could even eliminate the LOWER insulator and feed the backstay from the below-decks chainplate, with a very short run of GTO-15 to the automatic tuner. Simple, effective. All you'd need to add would be an effective RF ground or counterpoise. This could be a tuned radial system or just copper foil to the nearest bronze thru-hull. If your boat has an aluminum toerail or s/s rubrail, these could also be used effectively.

2. You're going to be crossing the Atlantic or the Pacific oceans and you wish to communicate regularly over long distances. In this case, you'd want to optimize for the 20-meter band....the day-in-day-out workhorse DX band. The best antenna you could fit to a true seagoing boat to be really effective on the 20m band would be a vertical dipole, constructed of s/s lifeline. This antenna, rigged with the lower insulator close to the deck, requires no RF ground or counterpoise, radiates well in all directions and, most important, has a very low angle of radiation. That is, it puts out most of its power in a lobe close to the water....exactly where you want it for DX contacts!

Now, every ham knows that a dipole doesn't have "gain". However, DX contesters and other affectianados of this antenna have found that it sometimes exhibits a very substantial "gain" of as much as 18-20db!! How can this be? It's because of the low angle of radiation which, over great distances, eliminates one or more "hops". I've used this antenna for over 40 years with great results, both from seaborne platforms and from my home.

Bottom line: you really have to experiment sometimes, adapting what you know and what you think you know.

For some years at my home QTH I had several vertical dipoles (on 20m, 30m, 15m, and 40m) and, as well, I had a commercially built 120' long folded dipole for all bands. With a coax switch, I could easily switch between antennas as needed or to check propagation. Nine-and-a-half times out of 10, the vertical dipoles beat the big horizontal folded dipole in both reception and transmission. You could really hear the difference as you switched between them. Signal reports from others confirmed this difference which was sometimes astonishing.

However, once in a while -- that other "half" time -- the horizontal dipole was equal to or even better than the vertical dipoles. Why? Clearly, it was because of the vertical angle of radiation, and the vertical angle of incoming signals.

Sorry to ramble on so long.

73,

Bill
WA6CCA
__________________
btrayfors is offline   Reply With Quote
Old 25-02-2011, 19:57   #42
Registered User
 
nv5l's Avatar

Join Date: Dec 2010
Location: Liveaboard
Boat: Allied Luders 33, Hull 98, 1971
Posts: 393
Images: 1
Re: SSB Counter Poise

Not long at all, thanks!

The literature I've seen has mostly used dBi, not dBd, when referring to Yagis, starting at around 7 dBi, but I do realize they can go up much, much higher. However, I've only ever used verticals and dipoles myself.

As for modeling programs, and programs in general for that matter, they're only as good as the assumptions they rely on, and sailboats might be a bridge too far for all but the most sophisticated ones. But it's still better than just relying on anecdotal evidence, which is basically just guessing. Though the guesses get better with more data.

I'm on the hard with my mast down, so I can't really do any tests right now, but would be surprised if the mast, forestay, and shrouds didn't have some parasitic effect and act as reflectors. And even if they don't, you should still have better radiation aft than forward, which is what Rudy described. Though he does explicitly state that an ungrounded forestay acts as a reflector.

Oh, btw, I took a look at the photos of your boat, antennas, and nav station on the link from your QRZ page. Hope you don't mind if I steal some of your ideas... ;-)

73...
don
__________________
don
NV5L
S/V Aurora
nv5l is offline   Reply With Quote
Old 25-02-2011, 23:38   #43
Registered User

Join Date: Dec 2009
Posts: 3,016
Images: 4
Re: SSB Counter Poise

Quote:
Originally Posted by btrayfors View Post
Disclaimer: I am a dealer for this system...
Heh. Folks. It's complete snake oil. There's 3 clues. First it's breathlessly promoted. Second, the website has snake oil and hack written all over it. Third any RF engineer with any experience will know it's no better or worse than any old piece of corrosion-proof wire tossed into the bilge. That said, at least it's a reasonably priced swindle.
__________________
daddle is offline   Reply With Quote
Old 26-02-2011, 05:43   #44
Registered User
 
nv5l's Avatar

Join Date: Dec 2010
Location: Liveaboard
Boat: Allied Luders 33, Hull 98, 1971
Posts: 393
Images: 1
Re: SSB Counter Poise

Hi daddle,

You've mentioned RF engineers and best practices in at least a few posts. Am I to understand you are an engineer? Are you also a ham? No worries if you're not, I'm just trying to judge your expertise in this area, but if you are an RF engineer, I'd love to get the modeling results for your antenna system.

As for me, I am both an engineer and a ham, Extra class, although I'm not selling or endorsing anything. I'm mainly just a retired programmer, but I got really interested in radios while working on DARPA and DoD projects involving Manets over radio networks, which included multiple waveforms. I was involved in some of the simulation work.

And now that I have a boat, I'm trying to gather more info on current sailboat antenna systems and grounds, especially those from fellow engineers and hams. I certianly agree with you that there's a lot of snake oil out there, probably due to the small market and lure of large amounts of disposal cash (true or not -- not in my case). Bill has identified many of the myths out there -- you know, the stuff people swear is based on "best engineering practices." It's actually sorta funny. Who would have thought that physics stopped at the waters edge?

Even if you don't fit into one of those categories, your experiences, although anecdotal, would still be helpful. For instance, your 7,000 mile email contact (transequatorial no doubt) was interesting, though without details on your antenna system, orientation, date and time, it doesn't do me much good.

cheers and 73...
don
__________________
don
NV5L
S/V Aurora
nv5l is offline   Reply With Quote
Old 26-02-2011, 06:06   #45
Senior Cruiser

Cruisers Forum Supporter

Join Date: Jul 2006
Location: Chesapeake Region and Maine
Boat: 42' Bob Perry sloop
Posts: 4,038
Images: 4
Re: SSB Counter Poise

Quote:
Originally Posted by nv5l View Post
.......

I'm on the hard with my mast down, so I can't really do any tests right now, but would be surprised if the mast, forestay, and shrouds didn't have some parasitic effect and act as reflectors. And even if they don't, you should still have better radiation aft than forward, which is what Rudy described. Though he does explicitly state that an ungrounded forestay acts as a reflector.

Oh, btw, I took a look at the photos of your boat, antennas, and nav station on the link from your QRZ page. Hope you don't mind if I steal some of your ideas... ;-)

73...
don
Hey, Don...steal away! But, be careful to steal only the good ones :-)

Re: masts and standing rigging acting as reflectors, yes, I think they sometimes do. But I also think they can act to de-tune the radiators, and to reflect or absorb radiated signals in undesired ways!

One thought re: being on the hard: you might wanna try a simple mobile whip on the pushpit. If you look closely at this picture:
DSC_0028

...you'll see a fitting on the stern pushpit just between the outboard mounting board and the s/s radar pole. It's the base of a Hustler mobile antenna. It's connected to a coax switch below near the radio.

Most of the time I keep the antenna and resonators belowdecks, but can mount it in an instant. Great backup antenna for when you're on the hard or if you get dismasted!

Bill
__________________

__________________
btrayfors is offline   Reply With Quote
Reply

Tags
ssb

Thread Tools
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
New Counter Tops Gallivanters Construction, Maintenance & Refit 27 26-06-2011 10:04
SS Counter Tops Charlie Construction, Maintenance & Refit 33 07-12-2010 10:07
What's the best top for Galley counter Lesmusic1 Construction, Maintenance & Refit 49 21-12-2007 20:58
Post counter Vasco Forum Tech Support & Site Help 6 22-11-2007 02:11
Rev counter Marauder Engines and Propulsion Systems 9 19-01-2007 19:27



Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 18:18.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.