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considering an M400 starduster. whats the deal?

Discussion in 'CB Antennas' started by loosecannon, Sep 3, 2009.

  1. loosecannon break on through

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    just want to know the inside scoop on this antenna.

    are they made by workman? or sirio? both?
    if so, which one is better?

    what improvements need to be made to make it sturdy?
    SS hardware etc...?

    should it be isolated from its mast?

    i am thinking that a choke balun would not be needed, but im open to opinions on that.

    thanks for any and all input you can provide on my prospective birthday present.
    LC


     
    Last edited: Sep 3, 2009
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  2. n0zna W9WDX Amateur Radio Club Member

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    not sure about the new ones,but ran astarduster back in 1967 till 1982....never had a problem.I out talked my neibor,and out heard him....a astroplane go figure...73s de JW
     
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  3. palco sells their workman version for $50 =S&H .
    Workman M-400 Starduster - Palco Electronics

    theyre not as well made as the origional starduster from what ive read . but its cheap and all aluminium , and isnt mostly coil like those balcony antennas .
    on my wire starduster copy it was suggested that i should have done a second coax choke 9 foot below the feedpoint to help prevent induced (i think??) mode currents . the choke at the feedpoint it for common mode currents . i forgot to do the lower choke but i dont have any CMC's if wildly shaking the slack coax in the house around while i hold a deadkey and my ess wubba ares dont move around means anything . other than i musta looked like an idiot . LOL

    a pipe/sleeve choke may be useful , better , worse ????????

    ill let others comment on isolating it from the mast or ground .
     
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  4. Railham W9WDX Amateur Radio Club Member

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    I have a Sirio Starduster M-400 and she is loud . Sirio Antenne - Products
     
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  5. Antenna Notes

    some good info there LC
     
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  6. MisterFatty Poppin Fresh!

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    Starduster was my very first Base Antenna, purchased back in the early 70's from AES in Milwaukee, worked great, never had any issues with stray currents/RF anything like that, though back in them days 150 watts was about my max. Later in the years I ran quite alot more through the original AS M400, never had any issues, even with the old Two Piece D&A Warrior I ran, other then melting my Moms wire core clothes lines (y). And the mysterious deaths of more then one small bird :eek:, that was back in the last Solar Cycle Peak :D

    The Antenna was always a decent performer, had some issues with it breaking the plastic spreaders, made up some of my own and never had another problem. While I did prefer the Hygain, and Avanti antennas it was a solid performing anenna which was much less prone to performance changes due to weather. I do remember one though that apparently the radiator filled with water over the winter months and it split/burst from expansion as it froze, never broke, worked fine other then that.. Had one fall over on 40 feet of water pipe during an Ice Storm, a little straightening, raise it back up and it was good to go...

    I did sell a few Larrys clones back in the early to mid 80s, never had any complaints on them the 90s Sirio version were very similar, one thing I did learn about the original Starduster is it worked best threaded onto the waterpipe with plumbers sealant, the original matched the pipe threads for somewhere around the 1 inch water pipe, and my Father (master plumber) always had the sweet ass HEAVY DUTY old school water pipe around which came in 21 foot lengths, and was the best you could get for antenna masting (y) I think at least one of the clones threaded on as well, no need to isolate from the mast...

    Not sure who is actually making the current bunch of clones, my guess is someone over in Italy, and imported By H&Y. I'm sure they've lost some quality over the years, just use a bit of common sense when putting it together, if it looks weak, it probably will be, improvise/replace from there.

    All that said and done I wouldn't hesitate to choose a Duster Clone over glass...
     
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  7. MisterFatty Poppin Fresh!

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    Here is a page from an old CB Center of America Catalog I have...

    [​IMG]
     

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  8. loosecannon break on through

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    thanks for all the input guys.

    probably going to pick one up in the next few weeks.
    LC
     
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  9. 15minigrass Active Member

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    They are great antennas for the price. Only thing I would do is lose the screws that came w/it and use better ones or find some way to really hold down those ground planes and the sections too.

    I dont think it needs to be sepsrated from the mast(GROUNDING). A choke would be a good Idea too.

    Small but really performs.....

    Aloha, James....
     
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  10. AkBowtie Active Member

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    Like James said (15minigrass) change the screws or secure them better. I've had the original StarDuster and the Workman or Sirio Clone or I should say I still have the clone.
    The clone, the screws fell out of the tip top after a few years and the tips fell off. I redid the tip and all with new screws and tapped over the screws to make it all hold together better. I've had zero problems since and the Clone seems to work quite well.
     
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  11. dont forget . you can put a coil and a top hat on it and .......... well ............. nevermind :( .

    never herd bad things about the old starduster . replacing its hardware with SS is always recomended , but i know you know that ;) . im sure at some point marconi will see this thread . i wonder if hed suggest two coax chokes on it , one at the feed point and one 9 feet below , or just one ?
     
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  12. RickC. Hopeless antenna junkie

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    Funny!

    Why two chokes though, and why 9 feet? A 1/4 wave of coax at 27 MHz isn't 9 feet...


    Rick
     
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  13. Marconi Supporting Member

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    Well BM, you can't add a choke at the FP on the Starduster inself, due to the design, but in your design similar to the Merlin YES---if needed I would added chokes as you note.

    In my last work recently with my Marconi I removed the bazooka balun that I had previously attached and the antenna really seemed to work just as well without the 1/4 wave sleeved balun. I have changed my mind a little on this issue with the SD'r needing such feed line shielding, but before I get all categorical on you guys regarding this new idea for me, I will need to be more convinced and do more testing. At the moment I'm not doing any antenna work. I have my Avanti Sigma IV up about 40' to the base and it is working well for me getting back on-air.

    I have not reported my recent testing results to the Internet yet, but maybe I will do that soon. I really wanted to compare a Merlin to a couple of my better performers, but I was not able to get one without buying the antenna new. I can say that the Marconi X6 that I built recently with 6-102" 1/4 wave GP elements and a 102" radiator, using a mobile L-bracket, and a A99 hub preformed very well when compared to my A99, Imax, AstroPlane, and my I-10.

    Issues like CMC and chokes are complicated and without some complicated testing of cause and effect their use is arguable. BM what are you basing your need for such modifications to your particular antenna?
     
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  14. loosecannon break on through

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    the more i think about it, the more i think that a choke balun, or a bunch of ferrite at the feedpoint might be beneficial with this antenna simply because we are feeding a balanced antenna with an unbalanced feedline.

    it is a balanced antenna isnt it?
    i hope im right on that. LOL

    maybe thats why they want the coax to go up through the mounting pole.

    hmmmm...

    there is a part in the manual that says the mast should be over 10 feet long.
    why would they put that in there?

    hmmm...

    were they thinking the same thing you were Marconi?
    about the sleeve balun idea i mean.

    so, if we decide that we need a balun; the question becomes where?

    yes, a choke balun at the feedpoint is impractical because of the design, but what about snap on ferrite chokes? 10-15 of those might work.

    do we want to stop the currents at the feedpoint or do we want that first 1/4 wave of coax to "radiate" so to speak.

    marconi, i am very interested in your opinion about isolating this antenna from the support structure.

    could this antenna be mounted with plastic/fiberglass mounting pole?
    does it need that first 10 feet of metal?

    can we agree that this antenna is in essence a quarter wave vertical dipole and then base our theories off that?
    if its not, what is it?

    thanks to all who have participated in this discussion. i am a big fan of beating a subject into the dirt, and i suppose this thread should be no different. LOL
    LC
     
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  15. Marconi Supporting Member

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    I agree LC that the Marconi X6 that I built recently (2009) is maybe a bit more balanced than the original SD'r simply because the Marconi uses all 102" elements and the Starduster is fed a bit off center. Now with this information I can only guess as to the effects on pattern and that there are likely some differences. I am not able to actually measure the results, but if I could that might suggest some technical differences. When operating purely as a radio operator, I could see no differences with the limited testing I have done recently. More must be done and I may try that this fall.


    I consider both antennas to be vertical 1/2 wave dipole antennas, but I would not argue with someone calling them a 1/4 wave ground plane with slanted down GP radials either. Both of these antennas appear to be balanced or somewhat balanced, but I can't define this small physical difference as it might apply to performance. BTW, I did not do Field Strength testing and that may have been a good thing to include. My goals in building the Marconi was to make comparisons as I added GP radials to the antenna and see what affects that it also had on tune and resonance.

    For years I figured the purpose of running the coax down the center of the support pipe to be a feed line shielding advantage with the Starduster and still do. The old Avanti Sigma IV also configured a mount that allowed for a sleeved mount as well---so there must be some importance in the idea.

    Some years ago (late 80's) a CB buddy came up with an idea he read in an ARRL article entitled “An Analysis of the Balun” and a discussion of a Bazooka Balun (sleeved). This article can be located on the Internet. His idea was to make the 10’ SD’r mast section a true 1/4 wave length and use a barrel connector and a tuned 1/4 wave jumper from the feed point to the base of the tuned mast where the shield was then directly attached using a hose clamp to a grounded supporting mast or tower. We did not isolate the top of this mast at the hub however, so I'm not sure how much, if any, good this idea really was. But, based simply on my buddies on-air results of reducing his TVI we really believed there were improvements to be made with the idea. I later mounted my own SD’r and discovered while using a mobile Field Strength meter directly below my Starduster antenna---that when TX'ing the FS meter indicated full scale while my buddies SD'r did not make the meter even budge. Only difference was the modification he made to the mast and feed point connection. We were not aware of any other noticeable differences in performance as both antennas worked exceedingly well---even when compared to other buddies larger and more up-to-date antennas in the Houston area. Back then however we did not really do antenna testing or comparing as a rule. Soon after I modified my SD’r and I saw the same results using the FS meter---regarding the TVI as my buddy did.

    Some time later I was made aware of a patent related directly to the ideas we used and maybe even the principles used by the creator of the Starduster antenna back in the early days of CB radio. You can reference this patent at the US Patent Website see Patent # 2,184,729 which is dated in 1937. Click on: http://patft.uspto.gov/. So the concerns for destructive radiation on the feed line with a vertical dipole or any vertical antenna with a counterpoise system was evident even back then.

    Concerning the over 10’ mast issue in the manual you mention LC, I can’t recall ever seeing a real manual for the SD’r. I could be wrong though, so could you post a link or the text of the manual you referenced?

    I’m also not sure how to really determine how or why we need a balun or choke on a verticle, but I hear CB’rs say all the time that they know exactly what is going on and some are quite categorical about their claims. I’m still waiting for a definitive and convincing answer though.

    Concerning isolation of an antenna from the supporting mast. There are many arguments on this issue and I’m still not convinced that I can discuss the issue with confidence. I did conduct a test on one of my A99’s and I did the same when I installed my I-10K. I think I could see some improvement in the performance of my A99, but it was not significant---nothing like my friend Bob95 noted when he insulated an A99 for a neighbor. However, I insulated the brackets from my mast and left the antenna mounted to the side of the mast and not above the mast like Bob85 and Multimode 200 did. So, to be fair that could have made the difference.

    At the time I was testing and comparing here, the conditions were mixed with some DX at times and the local conditions varied considerably in my area out to at least 50 miles. I did not try and test with DX rolling, but I did make some observations under those conditions.

    At first I tried comparison testing using only one antenna setup using the same mount, line, and radio. When testing I tuned all antennas as best I could to 27.205 mHz. That was just a control measure for me, but in doing so I could notice RX changes due to changes in tune and for me that was somewhat remarkable and I have never observed that before. I may discuss this later after I have compiled all of my results in my mind and on paper, but in the mean time you can check out what Bob85 has posted regarding similar experiences with his modified Vector 4000 in the past. I refer to that process as a Super Tune, but I'm not sure about how it really applies to performance. You might check the forum for clarification of Bob's work and see what that is all about. Bob85 carried his work well beyond mine with regards to performance in his area of the radio world. I was disappointed of course, but in our discussions on the issue we concluded with the possibility that the very high conductive soil in my area make be mitigating the responses among the different antennas I tested. Had I tested over poor, very poor, or extremently poor soil, I likely would see very different results.

    Since I only considered RX signals as reliable for my work, I make no claims regarding the Super Tune having a positive affect on TX, but I believe Bob when he tells me of his experiences. So LC, regarding insulation and this Super Tune idea---I still need more convincing and more work. When I do post some of my Signal Reports you can check for what I saw during the hours and hours of testing I did. I have to add Field Strength testing the next time I test.

    You have to consider that my work recently was just what it is and nothing more. I use to think that my results had to be similar in all areas, but that is far from correct. Mother nature and Mother Earth exert a profound affect of RF and how and why antennas respond as they do. That might help explain all of the different results we hear all the time.

    LC you post: “can we agree that this antenna is in essence a quarter wave vertical dipole and then base our theories off that? if its not, what is it?” Do you mean ½ wave vertical dipole? See above where I discuss this issue.

    My thoughts on all ideas of others are---CAN I DUPLICATE THOSE RESULTS AND DO I HAVE ENOUGH INFORMATION TO TRY! In the past it has been almost universally impossible to try, because of a lack of good information regarding process. I attribute much of that to BS ideas unfortunately.
     
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