• 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.
  • Click here to find out how to win free radios from Retevis!

Sigma 4 or 5/8th, what do you think?

radioman24

Active Member
Jul 19, 2009
448
34
38
I have owned both, an original sigma 4 made with the fluted material and a workman 5/8ths antenna both were amazing than I tried out the new sirio vector 4000 antenna the sigma 4 clone and it was no good, so what should I put up an old original sigma 4 or a new workman 5/8th's ground plane?

Dan
 

I have owned both, an original sigma 4 made with the fluted material and a workman 5/8ths antenna both were amazing than I tried out the new sirio vector 4000 antenna the sigma 4 clone and it was no good, so what should I put up an old original sigma 4 or a new workman 5/8th's ground plane?

Dan

Dan, you say the New Sigma 4000, was no good. That is unusual to hear. Can you give us some details on why you feel that way?
 
To me it just did not have the receive that the older original model did I also have a cte lw-150 sitting in my backyard same witht hat one just no much on the receive side, maybe I was doing something wrong? I dunno
 
I have owned both, an original sigma 4 made with the fluted material and a workman 5/8ths antenna both were amazing than I tried out the new sirio vector 4000 antenna the sigma 4 clone and it was no good, so what should I put up an old original sigma 4 or a new workman 5/8th's ground plane?

Dan

Since you already have the Sirio V4K; then perhaps all you need to do is just go through the manual and make sure it was assembled correctly and pay special attention to the gamma match assembly and tuning...So long as all of the parts are there, it should not be all that difficult...

66-1240315020-pic.gif


66-1023877962-pic.jpeg


ASSEMBLY MANUAL:
 

Attachments

  • Id-041_08-09-2011.pdf
    1.5 MB · Views: 5
Last edited:
  • Like
Reactions: 2 people
Okay cool, yeah mine never had that top circle looking piece either, also those instructions say the new vector 4000, I wonder what they did to make it better??

Dan
 
To me it just did not have the receive that the older original model did I also have a cte lw-150 sitting in my backyard same wit ht hat one just no much on the receive side, maybe I was doing something wrong? I dunno

24, your story has an amazing resonance in my ears. Long ago I ordered three, what I though were Sigma 4, antennas from Charlies Airways near Houston. I had them sent to three guys, one that I knew personally.

The guy I knew, got his antenna and said it had a fluted bottom section as I understood it. We lost our friendship over that antenna...even though I offered him all of his money back, including shipping. He said this antenna has no ears, but it seemed to talk OK. However, he swore "...I can't hear a damn thing compared to my A99...that is mounted about 30' lower at the tip."

He never returned the antenna and I never refunded him his money. He died, way too young, hating me with a furry.

One of the other guy's also claimed the antenna was no good, but would not describe why, and he too would not agree to a return.

I often heard the third guy talking on his CTE antenna, but he never complained. I always figured he had nothing to compare.

I have though about this over the years, and have only one suggestion, based on what my one time friend Tex told at me as he described his problem.

I told him I had never physically seen the antenna he described, although it sounded somewhat similar to the Sigma4 which he wanted. He said it was about 31' feet long, and that he made it as long as possible, just because it was in the damn box. I told him I think the antenna was designed to work 10,11,12 meters, and I think it said that right on the box. So, that meant it was adjustable as to frequency and that length mattered. I then suggested that the length may be too long, but that pissed him off even more.

I often wondered if his antenna was just set too long, and I base that on an article that Bob85 posted some years ago to help him support his idea about varying the length of his modified Sirio Vector 4000. The article claimed that the current distribution of an open sleeve antenna with a length/sleeve ratio that was more than 3.2:1 wavelengths would begin producing the typical maximum high angle lobes for a 3/4 wavelength ground plane antenna.

24, maybe if your antenna is near 31' long it exceeds this ratio, and the gamma match adjustment used is not mitigating the problem for good resonance. I can't be sure, but this is what I've thought over time.

There is more considering reciprocal theory with antennas, but I'll leave that for another discussion.

I also agree with Robb. The antenna I describe above did not have the top hat circular basket either.

I believe what Sirio did was make the length of the radial cone longer, and make the radiator a bit shorter. Their claim was this provided the same gain/angle with a shorter length overall antenna. Some of the original models of this antenna were famous in parts of Europe for failing due to wind, so maybe Sirio wanted to help minimized that problem. They also made a much better set of instructions, that I think if followed to the tee, probably won't miss the mark of a good tune. Check it close, like Robb suggested.

We don't hear many reports from guys that own this NV4K, but the antenna should produce very good results.

Good luck and keep us posted
 
Last edited:
  • Like
Reactions: 3 people
I don't know where you are at? On 5/21 there was no skip rolling down here in the inland empire ; east of Los Angeles. Could it have been flat where you where at? When it's quiet around here some times I think I have no ears ether. 73's
 
Last edited:
I don't know where you are at? On 5/21 there was no skip rolling down here in the inland empire ; east of Los Angeles. Could it have been flat where you where at? When it's quiet around here some times I think I have no ears ether. 73's

Thanks for the "Likes." I'm full of old experiences and stories, but sometimes I can't remember what happened yesterday.

It is really flat here on the Gulf Coast of Texas, and I have not heard DX in weeks. I'm not on the air because of this fact, so I could have just missed it.

How is the skip for you members?
 

dxChat
Help Users
  • No one is chatting at the moment.
  • @ kopcicle:
    If you know you know. Anyone have Sam's current #? He hasn't been on since Oct 1st. Someone let him know I'm looking.
  • dxBot:
    535A has left the room.
  • @ AmericanEagle575:
    Just wanted to say Good Morning to all my Fellow WDX members out there!!!!!