Gam Split Lead SSB Backstay Antenna

[W32Glorious]

I have an Icom IC-706MKII HF Transceiver and and need to replace the "not up to standard" wire strung next to the mast that has passed as an antenna.
Looking at the Gam Split Lead SSB Backstay Antenna instead of the Insulated Backstay route.


Anyone used this type of antenna before/
Comments welcome!

[SoonerSailor]

Originally Posted by W32Glorious

I have an Icom IC-706MKII HF Transceiver and and need to replace the "not up to standard" wire strung next to the mast that has passed as an antenna.
Looking at the Gam Split Lead SSB Backstay Antenna instead of the Insulated Backstay route.


Anyone used this type of antenna before/
Comments welcome!

I just ran some SS lifeline from the pushpit up to a small masthead block. The SS line is about 8 feet short of the masthead, with Dacron line to pull it up and tension it. I don’t use any special insulators, the Dacron line itself serves the purpose. It works well.

[S/V Illusion]

Probably the most expensive way of installing an end-fed antenna on the market. It’s pretty simple to replicate it for well under $100 with higher quality parts from any of the ham stores or hardware stores.

I use a home made version cut for a specific length based on reactance measurements with my antenna analyzer (which also costs less than this antenna).

[Brian.D]

Can you be a little more specific about "wire strung next to the mast"? Meaning, was it a specific length or just something thrown up there to get on the air?

Most antennas on boats are about 43' or 35' or 23'. These numbers are based on wavelengths to operate on the majority of the amateur and marine bands. These lengths are inclusive of the wire connected directly to the antenna tuner.

So, to answer your original question, no, I personally have not tried or used the GAM. I do know they are expensive and maybe a little thought process into installing one of the antennas mentioned above, or, an alternative backstay antenna using 1/8" coated wirerope (the same as used as lifelines on the boat).

Regardless of what you choose, make sure you have a good counterpoise, whether it is seawater, KISS, or 100sqft of copper in the bilge.

JMHO

[Russ]

I've had a GAM for years and it works great with the ICOM tuner
Yes, there are cheaper solutions but they are all in some way a PIA.
I wanted to avoid the insulated backstay fitting which is the weak point of the wire backstay and antennae arrangement.
The tuner allows the ICOM to be used throughout the SSB spectrum ( or HAM bands if that interests you)
Compared to the cost of a new ICOM 802 and the AT-120 Tuner, the GAM is cheap.

[waterman46]

Originally Posted by W32Glorious

I have an Icom IC-706MKII HF Transceiver and and need to replace the "not up to standard" wire strung next to the mast that has passed as an antenna.
Looking at the Gam Split Lead SSB Backstay Antenna instead of the Insulated Backstay route.


Anyone used this type of antenna before/
Comments welcome!

I haven't used it so you can skip reading this if you like but I do have a comment. I am trying to figure out what the Gam actually looks like - the description on the web does not give details, but understand it must be a semi-flexible metal strip formed into a long tube with a split in it so it can be "pressed over the backstay". I also assume the inner surface of this metallic strip is insulated. If this is the case, in addition to simply radiating energy, it also couples RF into the existing backstay which will then radiate some of that energy in the length that is not covered by the Gam. If this is correct, then you could get an RF burn by touching the backstay below the Gam so you still want to cover that length with insulation, and the electrical length of the antenna might be different than the physical length of the Gam. Electrical length doesn't matter that much as the tuner will match amost any load, but I assume the designers tested it and have made it a length which will work with most backstays. I also think that if you have a ground wire, say for lightning protection, connected to the lower end of that backstay or its chainplate, it may make it difficult to get a good RF match into the Gam. Wonder if the directions say anything about that.



The manufacturer claims the alloy used in the Gam is more conductive than SS, also that the connection from the lead wire can be made more securely and with less likelyhood of corrosion compared to connecting a copper wire to the SS backstay. Both points seem valid and in favor of the Gam.


Since the price of the Gam is about the same as two backstay insulators, if it makes you feel better that you don't have insulators in the backstay then the Gam is a good idea. We have twin full length backstays so I didn't mind devoting one of them to a traditional insulated backstay antenna.

[Russ]

As I said I have one. It appears to be a rubber/plastic sheath with the two leads on each side of the semicircle that pushes down onto the backstay. The web page says there are NO shock or RF concerns. I have never held on to the wire while transmitting, be kinda hard to do but I suppose a crewman might be holding on to the backstay at an inopportune moment. Here's an image address in as much as this site won't allow cut and paste a photo. Hope it helps.

https://apis.mail.yahoo.com/ws/v3/ma...id=YMailNorrin

[4kMike]

I ended up to GAM, after comparing the cost and functionality of other options. Have been climbing to masts and trees to hang several ham antennas, when younger. There is no magic in wire antennas: copper, tuned length for one freq (or use tuner).This is easy to install, mechanically robust and not a added risk for your mast. And it works as well as any during last years solar inactivity. I shall test some upper band qso:s ..btw.. now when propagation is getting better?

[SAMUELBURNS]

After completing the 2010 Single Hand Society race to Hawaii with 13 others
communicating twice daily via SSB, the general consensus was that my ICOM802 with Gam antenna had so-so reception. A post-race comparison near Drakes Bay
with another nearby boat had better reception when I hoisted a 30ft copper wire connected to bottom of tuner. I have a Dynaplate ground plane; acknowledged as one of the longest range & best reception competitors (Blue Moon) in the race had a KISS (Sea-Tech) ground plane.....new at the time.
The windage deriving from the inch-and-half width of the Gam is considerable.
To avoid having strong winds dis-attach the Gam, I used cable ties every meter of
length. I plan to install a back stay antenna at my next rigging replacement on
my 2009 Catalina 309.

[SV_Sweet_Ruca]

We have had one aboard for 2.5 years. So far so good after 10,000 sailing miles.

We rarely use the SSB but to test it and keep skills up to date as we prefer iridiumGo. The antenna has always performed to reasonable standards.

We chose it for similar reasons as others. It is cheaper than backstay isolators. It removes 2 possible failure points in one of your most important pieces of standing rigging. It is easy to install, and easily removed.

There are cheaper options, but we are not HAMs, so the hours spent researching a DIY solution would have outwighed the savings.

[HeliosJim]

I'm considering adding HF on my race boat, a 36 footer I like to do offshore races with. I really don't need it, I know, but it would be fun since I have a ham license. Anyhow, my boat has a dyneema backstay, and adding 1.5 inches of windage may not be ideal.

I'm wondering, could I just get a new dyneema backstay but bury a length of copper wire under the cover? I could fit 43 feet in there. I would love to use the existing backstay but I'm sure by now it's too tight to get a wire inside the cover.