Base SPT-500

[Greg T]

The Workman W-58, Maco V-58, and Jetstream JVT-10 are all the same antenna made on the same assembly line. They are a loose knock off of the Avanti AV-170 Sigma 5/8. They use what is called a "Beta" match (the hoop with feed point) along with changing the vertical radiator length to tune the antenna. In my experience, they are fairly easy to tune especially if you have an analyzer (adjust the feed point first for best reactance, then adjust length for lowest VSWR; rinse repeat).

Like most things, you get what you pay for so if you have mild winters and no ice buildup, you will probably be good to go. If you do have conditions for ice buildup on the antenna and high winds, the antenna isn't going to make it too many years. I have those conditions and have had 3 come down in the last 30 years (along with other antennas too). And that is even after I had "ruggedized" them.

I think the general consensus is that the SPT-500 uses a bit better quality aluminum and is more rugged. But even it isn't able to handle my conditions. So I run something a bit more sturdy (and yes, more expensive) for my ground plane. YMMV

I'm in the U.P. of Michigan. It doesn't get much worse. We can get snow, rain, ice and wind all within an hour. Heavy, wet snow. Downed power lines, etc. That's why I was looking at the penetrator. Seems much less delicate. I've had a Sigma Silver rod 5/8 up for about 5 years now and aside from a little bow, she's pretty good. But I always seal and reinforce all the joints and shit, too.

 

[Christopher17]

The Workman W-58, Maco V-58, and Jetstream JVT-10 are all the same antenna made on the same assembly line. They are a loose knock off of the Avanti AV-170 Sigma 5/8. They use what is called a "Beta" match (the hoop with feed point) along with changing the vertical radiator length to tune the antenna. In my experience, they are fairly easy to tune especially if you have an analyzer (adjust the feed point first for best reactance, then adjust length for lowest VSWR; rinse repeat).

I think the general consensus is that the SPT-500 uses a bit better quality aluminum and is more rugged. But even it isn't able to handle my conditions. So I run something a bit more sturdy (and yes, more expensive) for my ground plane. YMMV

My home brew 5/8 uses a beta match, 6 foot copper water line, adjust feed point for best resonance like the maco or shockwave, putting up a spt 500 myself , I liked the shockwave or the zero5 , but went with the hygain for price and reputation , I've seen some pretty old ones still in use

 

[Dr_DX]

My first 2 basically failed in the same spot - about half way up the vertical radiator at one of the joints.
On the way down:

A day later:

For my 3rd one, I used rivets on the vertical radiator in an effort to reduce wind load and weight.. These are much stronger and each one has over 300lbs of clamping pressure (I use 3 per joint - 900lbs). Used in a line, you can clamp the whole length of the overlap (4"), not just the 1" or so that a hose clamp would. So this time, the joint didn't fail, but the whole radiator snapped off just above the feed point. If you are observant, you will see that I reversed the hoop - it works better that way.



I have also had 3 of the Italian Sigma 4 copies come down in the same way too over the years. It is a bit better performing antenna than a 5/8 (its a 3/4wave) but the Italian aluminum is worse than the stuff Maco uses. I didn't get a picture, but I had one forming a giant horseshoe in the sky with the tip pointing at the ground. Didn't break, but was kinked beyond repair.

I was told that the newest version of the Sigma 4 clones, the Sirio New Vector 4000:

https://www.sirioantenne.it/en/products/hf/new-vector-4000

was built better than it's predecessors, so I picked one up last year. When it came in, I was disappointed. The aluminum didn't look any better and the vertical radiator uses swagged sections which I don't like, so I didn't put it up (you know, the definition of insanity...).

Luckily (for me), a member on the forum gave me a screaming deal on a NIB ZeroFive Colossal 10K which I am in the process of ruggedizing and putting up. If it can't handle my weather, then I give up.


My advice, if you live in a harsh environment, cry once when you spend the $$$ on a quality, well built antenna, using thick wall aviation rated aluminum and all SS fasteners. I highly recommend using aviation style closed end "Blind" rivets where tubing is being joined together and something like Morgan Systems M-602 (not Penetrox or Noalox) wherever you have 2 surfaces connecting and one of them is aluminum. Once everything is all put together, I put a couple of layers of conformal coating on to slow down the oxidation process of the aluminum.

Rivets:
http://www.mcmaster.com/
I use the three following part numbers:

97524A020 (1/8" .063 - .125 thick)
Used for double wall thickness (.058 x 2 = .116" thick) on all your standard element joints.

97524A021 (1/8" .126 - .187 thick)
Used for triple wall thickness (.058 x 3 = .174" thick) on main radiator joints.

97524A106 (3/16" .063 - .125 thickness)
Used to replace small screws or connections made with small bolts, nuts, and lock washers.

Grease: https://surgestop.com/mounting-hardware/m-602.html

Conformal coating: I use the clear gloss version of https://www.krylon.com/products/fusion-allinone/

 

[Marconi]

Good report Dr_DX.

 

[Greg T]

My first 2 basically failed in the same spot - about half way up the vertical radiator at one of the joints.
On the way down:
View attachment 40655
A day later:
View attachment 40656
For my 3rd one, I used rivets on the vertical radiator in an effort to reduce wind load and weight.. These are much stronger and each one has over 300lbs of clamping pressure (I use 3 per joint - 900lbs). Used in a line, you can clamp the whole length of the overlap (4"), not just the 1" or so that a hose clamp would. So this time, the joint didn't fail, but the whole radiator snapped off just above the feed point. If you are observant, you will see that I reversed the hoop - it works better that way.
View attachment 40657
View attachment 40658

I have also had 3 of the Italian Sigma 4 copies come down in the same way too over the years. It is a bit better performing antenna than a 5/8 (its a 3/4wave) but the Italian aluminum is worse than the stuff Maco uses. I didn't get a picture, but I had one forming a giant horseshoe in the sky with the tip pointing at the ground. Didn't break, but was kinked beyond repair.

I was told that the newest version of the Sigma 4 clones, the Sirio New Vector 4000:

https://www.sirioantenne.it/en/products/hf/new-vector-4000

was built better than it's predecessors, so I picked one up last year. When it came in, I was disappointed. The aluminum didn't look any better and the vertical radiator uses swagged sections which I don't like, so I didn't put it up (you know, the definition of insanity...).

Luckily (for me), a member on the forum gave me a screaming deal on a NIB ZeroFive Colossal 10K which I am in the process of ruggedizing and putting up. If it can't handle my weather, then I give up.


My advice, if you live in a harsh environment, cry once when you spend the $$$ on a quality, well built antenna, using thick wall aviation rated aluminum and all SS fasteners. I highly recommend using aviation style closed end "Blind" rivets where tubing is being joined together and something like Morgan Systems M-602 (not Penetrox or Noalox) wherever you have 2 surfaces connecting and one of them is aluminum. Once everything is all put together, I put a couple of layers of conformal coating on to slow down the oxidation process of the aluminum.

Rivets:
http://www.mcmaster.com/
and type "3157" in the search box on the left. I use the three following part numbers:

97524A020 (1/8" .063 - .125 thick)
Used for double wall thickness (.058 x 2 = .116" thick) on all your standard element joints.

97524A021 (1/8" .126 - .187 thick)
Used for triple wall thickness (.058 x 3 = .174" thick) on main radiator joints.

97524A106 (3/16" .063 - .125 thickness)
Used to replace small screws or connections made with small bolts, nuts, and lock washers.

Grease: https://surgestop.com/mounting-hardware/m-602.html

Conformal coating: I use the clear gloss version of https://www.krylon.com/products/fusion-allinone/

When I do get my old one down I'll take some pictures of how I do the joints. I use hose clamps, and Tiny sheet metal screws. Then I wrap about 3in above and 3 in below the actual joint with electrical tape, and then give it about three coats of clear polyurethane. So far have not had anything break on me because the taped up and sealed up joints kind of acts like a strain relief.

 

[Van Lifeson]

When I do get my old one down I'll take some pictures of how I do the joints. I use hose clamps, and Tiny sheet metal screws. Then I wrap about 3in above and 3 in below the actual joint with electrical tape, and then give it about three coats of clear polyurethane. So far have not had anything break on me because the taped up and sealed up joints kind of acts like a strain relief.

I used sheet metal screws on my new Penetrator and we had some 80 mile an hour winds here in the Chicago area about a month ago and she is just fine.

 

[Hilltop]

According to the MFJ website..."This antenna is illegal for 11 Meters use."

https://mfjenterprises.com/collections/hy-gain/products/spt-500

Waiting for the antenna police to arrive..

 

[Tokin]

http://www.palcoelectronics.com/p1005081.aspx - $84.99 Cheapest 5/8 you can get. Identical to the Maco V-58, Jetstream JVT-10. Comes off the same assembly line as the Maco (instructions are for the MACO).

Made on the same line but are they made from identical materials?
Greg is dealing with Michigan UP weather which is no joke many times throughout the year. The worst is October thru May with snow, ice and wind all at the same time.
I knew of several folks in the mountains where i lived who had the maco ground plane and they seemed to survive the weather with a little help depending on the ice/wet snow situations.
I wasn't impressed with how the radials mount to the ring by sliding the radials over what i consider to be short nipples. Id be concerned about falling snow from any trees. That tuning ring is fairly easily jolted out of position.

 

[Greg T]

Thats why I reinforce every joint with a screw and tape. Keeps them dry and acts like a strain relief. So far so good. Never had a penetrator so I want to try one. Will fortify it as well.

 

[Marconi]

I prefer slotting and using good SS hose clamps. Most of the old antennas I've taken down over time that had broken elements were right at the screw or bold holes.

Swagging construction like HyGain used, has some good qualities in that idea, but all of the antennas I removed, that had breaks or bends in the tubing, were broken at the base of the swagged end, and the screw holes were all-ways wollered-out from wind and weather.

I don't ever recall any of the antennas with Sirio type construction using sheet metal screws, and or swagging ever falling down inside the other tubes, unless the setup used slotting and hose clamps...sheet metal screws mess up the tubing so much that often the tubing would not even come apart, and IMO that is likely due to garbage shards of small metal filings getting in-between the tube surfaces.

Just my opinions.

 

[Dr_DX]

Made on the same line but are they made from identical materials?

Yes, they are the same antenna just sold under a different name.

 

[Dr_DX]

I prefer slotting and using good SS hose clamps. Most of the old antennas I've taken down over time that had broken elements were right at the screw or bold holes.

Swagging construction like HyGain used, has some good qualities in that idea, but all of the antennas I removed, that had breaks or bends in the tubing, were broken at the base of the swagged end, and the screw holes were all-ways wollered-out from wind and weather.

I don't ever recall any of the antennas with Sirio type construction using sheet metal screws, and or swagging ever falling down inside the other tubes, unless the setup used slotting and hose clamps...sheet metal screws mess up the tubing so much that often the tubing would not even come apart, and IMO that is likely due to garbage shards of small metal filings getting in-between the tube surfaces.

Just my opinions.

IMHO, any kind of slotting, swagging or flaring weakens the aluminum. Taping and hose clamps add weight and more surface area for ice to form on. Screws will vibrate loose (unless you use a lock washer), pull metal from the inner tube into the outer tube - hence not being able to get the tubing apart, and will have galvanic corrosion due to dissimilar metals.

Sirio New Vector 4000
Bottom of tubing is flared:

Smaller tubing is thinner wall:

Top of tubing is swagged:



Screws don't have lock washers. Hardware is not SS.

Sirio, Maco, and Hygain SPT-500 do not come with SS hardware.

 

[bob85]

Sirio screws rotting & sections dropping inside only happens when they have been up for a good length of time & wind & rain gets time to work its majic,

if somebody suddenly has high vswr on a vector, first thing i tell them is go count the sections,
second thing i ask is did you file the corners off the gamma so it can't twist in wind & short on the hub,

i had it happen to one of my old 7/8 vectors about the same time a radial snapped at the bottom where its squashed flat & never noticed i lost a section apart from higher vswr,
i changed the broken radial without taking the antenna down & the antenna worked ok with a full section dropped inside.

 

[Marconi]

second thing i ask is did you file the corners off the gamma so it can't twist in wind & short on the hub,

Bob, I never considered such a problem, but I see what you mean. The same situation might could of happen with the Siro New Top One, but I never experienced the issue. I know the gamma base connection flat tube did have square corners and may have come in contact with the hub if it twisted...like you said.

Thanks for the info.

 

[r carl]

IMHO, any kind of slotting, swagging or flaring weakens the aluminum. Taping and hose clamps add weight and more surface area for ice to form on. Screws will vibrate loose (unless you use a lock washer), pull metal from the inner tube into the outer tube - hence not being able to get the tubing apart, and will have galvanic corrosion due to dissimilar metals.

Sirio New Vector 4000
Bottom of tubing is flared:
View attachment 40794
Smaller tubing is thinner wall:
View attachment 40795
Top of tubing is swagged:
View attachment 40796
View attachment 40797

Screws don't have lock washers. Hardware is not SS.

Sirio, Maco, and Hygain SPT-500 do not come with SS hardware.

You can't expect an antenna with loose fitting tubes like that to last.