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Author Topic:   GAM SS-2 Antenna Adapters, Mast Extension, Coaxial Cable Connectors
cindalyn posted 03-05-2008 10:00 PM ET (US)   Profile for cindalyn   Send Email to cindalyn  
I'm going to buy a GAM SS-2 antenna to mount on my center console rail. I already have the rail mount adapter which is a SeaDog Nylon Rail Mount Antenna Bracket with knob PN 327149-1.

It appears that I also need a GAM ADAP-I which is a side mount cable adapter. Does any cable come with the GAM ADAP-I? Defender Indus., recommended by GAM, couldn't tell me and I e-mailed GAM but have not had a reply yet.|344|302025|320625&id=27905

If anyone is using this same combination, can you confirm this is what I need?

Also, I have read that some individuals are using a 4 ft extension. I contacted Defender Industries and they were not aware of any 4 ft. extensions. Can they be purchased or are they made from PVC tube and fittings? Is 4 Ft necessary or could it be any length e.g., 2 ft., 3 ft. etc?

If I have to buy cable I understand it should be RG58. Can this be bought from Radio Shack which is the cheapest cost that I've seen with two PL-259 connectors or is there some special requirement for the cable which I may not be aware?

I'm attaching the antenna to a Standard Horizon Phantom Series PS1000 25 Watt VHF/FM Marine Transceiver. Do both the antenna and radio use the PL-259 connector?


jimh posted 03-05-2008 11:21 PM ET (US)     Profile for jimh  Send Email to jimh     
There are many 1, 2, 4, and 8-foot extensions made which have the threaded connections on them that allow easy assembly of the antenna and the base mount . The one I mentioned in my article is the least expensive and I give details on the manufacturer and model.

I have never seen a radio with a PL-259 connector on it. Most radio sets have a SO-238 jack for the antenna connection. This is also called a "UHF Series" jack. The mating plug is a PL-259, but that connector is for RG-8/U cable. You need an adapter to use a PL-259 with RG-58/U cable. There are many other plugs which will mate with a SO-238 sold in the marine trade to facilitate easier assembly. Assembling a PL-259 is difficult for most boaters, and it is often poorly installed, leading to problems.

If you are going to use an extension mast with a GAM SS-2 I recommend you use the configuration I showed in my article. It will make the cable path cleaner.


jimh posted 03-05-2008 11:35 PM ET (US)     Profile for jimh  Send Email to jimh     
The GAM ADAP adaptors come with about 20-feet of military specification RG-58C/U coaxial cable. Cable marked RG-58C/U meets MIL-C-17 specifications for coaxial transmission line.

The crap they sell at Radio Shack or at most marine stores is inferior cable and carries some odd designators which are not standard parts or mil-spec qualified.

cindalyn posted 03-06-2008 02:21 PM ET (US)     Profile for cindalyn  Send Email to cindalyn     
Thanks Jim, I had read your article previously but being unfamiliar with antennas the information didn't stick with me. In fact, I previously contacted Ed at GAM and he supplied me with a lot of good information which also did not stick.

After going back and reading the information from both of you I think what I need to order is:

1 - GAM SS-2 Antenna
1 - GAM ADAP-II Base
1 - Shakespeare 498 four-foot extension mast
1 - *Adapter to mount to a SO-238 ["UHF Series"]jack for the antenna connection.

The only other length poly extension mast I found on the net was 1 ft. long. Other lengths were HD metal which I don't want.

*My concern now is attaching the PL-259 to the radio end of the cable. You and others have indicated how important and difficult this can be. What do you recommend?


GreatBayNH posted 03-06-2008 05:19 PM ET (US)     Profile for GreatBayNH  Send Email to GreatBayNH     
I just went to West Marine and picked up a solderless PL-259 connector. Wicked easy.


Chuck Tribolet posted 03-06-2008 06:39 PM ET (US)     Profile for Chuck Tribolet  Send Email to Chuck Tribolet     
Seth: Maybe easy to install. May not last. The Shakespeare
CenterPin connectors are pretty good. I've seen some others
that I wouldn't trust. I've had Shake CenterPins screwed
onto my radio for about eight years of 70ish saltwater days a
year. No problems with the connectors (I did have to
replace an antenna and its connector about six years ago
when I forgot to put the antenna down and drove under a tree.


cindalyn posted 03-06-2008 06:59 PM ET (US)     Profile for cindalyn  Send Email to cindalyn     
Chuck, is Shake a Manufacturer/Brand name?

What can be so darn difficult about installing a solder type connector? It's only a matter of tinning the center cable wire and then soldering it in the center pin of the connector - or is there more to it?


GreatBayNH posted 03-06-2008 07:09 PM ET (US)     Profile for GreatBayNH  Send Email to GreatBayNH     
For the cost of the solderless connector I'll just replace it if/when it goes bad. I don't keep my boat in the water so it doesn't get all that much wear and tear. It also allows me to easily remove it if I have to pull the antenna cable from the cc without cutting the cable and re-soldering another connector. Why would I need to pull the cable you ask. Good question. I may want to install a shorter Shakespeare extension if I ever get a bimini.


itldo posted 03-07-2008 09:09 PM ET (US)     Profile for itldo  Send Email to itldo     
To learn about solder PL-259 try a Google search or look at this web site
good luck Earl n6xtr
Chuck Tribolet posted 03-08-2008 05:52 AM ET (US)     Profile for Chuck Tribolet  Send Email to Chuck Tribolet     
Shake = Shakespeare.


Chuck Tribolet posted 03-08-2008 06:02 AM ET (US)     Profile for Chuck Tribolet  Send Email to Chuck Tribolet     
And Cindalyn, it's not the center wire that's hard, it's the
shield. (Though even the center wire does require a serious
soldering iron). I can solder, and I long since gave up on
soldering these. That Shake centerpin has been there for a
lot of saltwater years.

But itldo's link looks like good stuff.

BTW, anually, loosen the connector and tighten it. That applies
to solderless and soldered connectors.b


davej14 posted 03-08-2008 10:37 AM ET (US)     Profile for davej14  Send Email to davej14     

Take Tom's advice and use the Shakesphere center pin type connector:

You will not need an adapter because this connector is designed for use with RG-8 or RG-58 Cable.

Before you add a 4' extension you may want to try the installation without one. They are pretty costly and if you are only on inland lakes you might be satisfied without one. I found that a stainless extension, available in 1' and 2' lengths, saves money vs. the fiberglass Shakesphere extension.

Looking at your rail clamp, I am concerned that it may not be adequate for the antenna with a 4' extension. You may want to look at a more robust metallic clamp if you add an extension.

Another suggestion, you can cut the antenna cable to a reasonable length without affecting the antenna performance. Just be sure to leave enough for future repairs.

cindalyn posted 03-08-2008 06:46 PM ET (US)     Profile for cindalyn  Send Email to cindalyn     
Dave, I did take Tom's advice and bought the recommended connector. I'm not going to shorten the cable until I know that I'm satisfied with the performance. I may want to move it to the stern.

I already ordered the Shakespeare 4' extension. I will be running the local river, ICW which is surrounded by trees and also short distances off-shore.

I too have a concern for the mounting device I have. I hope everything is OK but if not I'll have to bite the bullet and find something else.


home Aside posted 03-09-2008 10:19 AM ET (US)     Profile for home Aside  Send Email to home Aside     
As I said in a previous post, I have this same setup (as Jimh's), it is a superior piece of equipment, with great transmission / reception. the only problem I see is mounting it to your console grab rail, you will have problems if you have or plan to have use of a bimini in the future, or if you use a console cover when the boat is not in use. On my old montauk I mounted the antenna on the starboard rear side rail....


GreatBayNH posted 03-09-2008 10:50 AM ET (US)     Profile for GreatBayNH  Send Email to GreatBayNH     
The whip antenna, if purchased from the factory, is installed on the starboard side center console. The factory install doesn't have an extention so the whip clears a bimini. Having said that, if you don't mount the 4' Shakespeare antenna extention you should be OK for a bimini down the road. That's why I recommended the solderless connector so you can easily pull the cable out for switching extentions/mounting methods as your needs change. It's much cleaner and easier to mount the antenna on the center console rather than finding ways to hide/run the cable to the stern or gunnels.

Just one man's opinion. There are many on this site.

BTW, who's Tom?


cindalyn posted 03-09-2008 02:48 PM ET (US)     Profile for cindalyn  Send Email to cindalyn     
Seth, I don't know who Tom is either.
davej14 misled me and I inadvertently followed him but the link he sent me was appreciated :)

You raise a good point about the bimini. I may just try the antenna without the extension and see how it works. With the solderless PL-259 and extra cable I'll be able to go either way without too much trouble.


GreatBayNH posted 03-09-2008 05:33 PM ET (US)     Profile for GreatBayNH  Send Email to GreatBayNH     
Sounds like a plan, Ron. Good luck.

Here are some pics of my install last year of GAM SS-2 whip and ADAP-II with Shakespeare 498 4' extention.

I think I could get away with a 1' extention if I ever win the lottery and buy a bimini.

Chuck Tribolet posted 03-09-2008 10:06 PM ET (US)     Profile for Chuck Tribolet  Send Email to Chuck Tribolet     
A downside of a console mounted antenna is the at everyone
will want to used it as a grabrail.

An upside is that it's out of the way for fishing.


davej14 posted 03-10-2008 09:24 AM ET (US)     Profile for davej14  Send Email to davej14     
Sorry about the misleading reference to "Tom", I meant "Chuck". Age is a wonderful thing, I had just gotten off the phone with my friend "Tom" when I typed my response.

Here is how I mounted the GAM SS2 on my Dauntless. It will rotate aft and allow for the boat cover and console cover. When vertical it clears the Bimini.

I have since added a 1 foot stainless extension and can still clear the cover and Bimini.

A nice feature of the GAM SS2 is that the whip and base unscrew from the mounting adapter. This allows for covering the boat in a fixed mount situation without an extension.

If you mount it to the console or rail I suggest that you mount to the opposite side of your compass. In close proximity the antenna base does influence the compass.

cindalyn posted 03-10-2008 01:57 PM ET (US)     Profile for cindalyn  Send Email to cindalyn     
Dave, that's a nice setup. My antenna will be on opposite sides from the compass. From all the responses I've received I deceided that I'm going to make my setup temporary until I get a feel for how it performs and how I like the location. I'll really have to give some thought where to drill the hole for the cable.


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