-
You can now help support WorldwideDX when you shop on Amazon at no additional cost to you! Simply follow this Shop on Amazon link first and a portion of any purchase is sent to WorldwideDX to help with site costs.
sigma/alpha v5/8
- Thread starter undertaker
- Start date
The Sigma (from Avanti/AS) is an awesome antenna. The V58 is a good antenna. While they both sport a loop, they are completely different antennas.
The original Sigma 5/8 (right) was NOT DC grounded. The main radiator was ISOLATED and ELEVATED above the ground radials by the use of a fiberglass tube.
When Antenna Specialist bought out Avanti, they made a few design improvements to the antenna. One improvement was the small coil (left) which made the antenna DC grounded. Showing here:
Here is a picture of what the feed point looks like next to the fiberglass tube:
This is the assembled feedpoint, ring, and ground radial bracket. Notice that the Sigma 5/8 ring is NOT tapped:
As I stated above, the main radiator is elevated above all the metal materials used for the ground plane. The Maco V58 and even the Hygain Penetrator can NOT say this!
Now let's look at the Maco feedpoint and loop:
Notice the ring on the V58 shorts to ground and you have to "tap" the 50 ohm point on the ring. What you don't see in this picture is where the main radiator extends down into the base tube. I have seen where high power stations actually ARC through these insulators! That can't happen on a Sigma 5/8.
There is only one other antenna that uses an elevated main radiator......the I-10K! You won't find a better antenna anywhere!
When Antenna Specialist bought out Avanti, they made a few design improvements to the antenna. One improvement was the small coil (left) which made the antenna DC grounded. Showing here:
Here is a picture of what the feed point looks like next to the fiberglass tube:
This is the assembled feedpoint, ring, and ground radial bracket. Notice that the Sigma 5/8 ring is NOT tapped:
As I stated above, the main radiator is elevated above all the metal materials used for the ground plane. The Maco V58 and even the Hygain Penetrator can NOT say this!
Now let's look at the Maco feedpoint and loop:
Notice the ring on the V58 shorts to ground and you have to "tap" the 50 ohm point on the ring. What you don't see in this picture is where the main radiator extends down into the base tube. I have seen where high power stations actually ARC through these insulators! That can't happen on a Sigma 5/8.
There is only one other antenna that uses an elevated main radiator......the I-10K! You won't find a better antenna anywhere!
good pics chief,
i had a copy of the avanti called an electronica special,
it had the exact same feed arrangement but the loop was flat bar and the boss for the groundplanes was a cast lump with screw in radials, no coil,
it worked very well but they would not withstand our weather like my old sigma2.
i had a copy of the avanti called an electronica special,
it had the exact same feed arrangement but the loop was flat bar and the boss for the groundplanes was a cast lump with screw in radials, no coil,
it worked very well but they would not withstand our weather like my old sigma2.
Thanx MC, I never was quite sure about the sigma 5/8 back then. The most popular around our parts was the A/S Starduster, then the Super Mag. We only had 1 guy in town that had the Sigma 5/8.
Ronnie
Ronnie
show us pictures when you get it. i was thinking of getting one from there aswell. ive been told its a maco but they advertise it as a sigma. so would like to see when you get it. not that a maco is bad or anything.
There is only ONE Sigma 5/8. Any use of that name for another antenna is nothing more than an attempt to camp on to a good reputation in order to make money.
Antenna Warehouse was selling "Sigma 5/8" antennas and wasn't happy with me when I told them that stealing a good name for a so-so antenna was a bad business plan.
Antenna Warehouse was selling "Sigma 5/8" antennas and wasn't happy with me when I told them that stealing a good name for a so-so antenna was a bad business plan.
Master Chief said:
Surely you don't think these Biz's are doing something like that on the 5/8 and the Starduster do ya?
Ronnie
Well, at least the antenna industry isn't as bad as the CB AMP manufacturers! How many "Palomar" amps have been made. Or how about "Messenger"?!
My only point was that you will NOT get a real Sigma, so don't expect one!
My only point was that you will NOT get a real Sigma, so don't expect one!