1. 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.
    Dismiss Notice
Dismiss Notice
This forum does not allow a single user to have more than one username. If anyone wants to change their username contact an admin and it will be done. Multiple accounts belonging to the same member will be deleted without warning.

Tuning 102" Whip?

Discussion in 'CB Antennas' started by buickid, Jun 3, 2013.

  1. Marconi

    Marconi Usually if I can hear em' I can talk to em'.

    Joined:
    Oct 23, 2005
    Messages:
    6,998
    Likes Received:
    1,977
    Bob, I've got these guys yealing at me now, and I finally got a yes answer from #6, a direct answer of yes, and as I promised I will not be fretting over the issue any more.


     

  2. Robert Cook Sr

    Robert Cook Sr New Member

    Joined:
    Dec 27, 2020
    Messages:
    15
    Likes Received:
    10
    Redbeard - CB handle in the Great state of South Carolina
    I have been using a 102" whip on my cars & trucks for 50 years. From imports to pickups I always had 1.1 SWR . I never used spring, I had buddy in machine shop make me Spacers 6.25" long to replace spring. out of Stainless steel and still using original on my Truck now. I use 18ft coax, tried 12 ft and SWR jumped up to around 1.3 using CB with 3-4 watts output. I have talked from South Carolina to OK state using skip no problem. can talk local for around 25miles barefoot ,haven't tried long distant using my 100 watt booster ,I also use a 2 tube Elkin linier dead keys 35Watts mod's to around 100watts, it's 50 years old also. I also have in shop a Gold Eagle 3 SSB receiver with Am transmitter. Browning only made 6 & I have one of them. You can't beat a 102" whip it works when the others don't. I'm planning on using one for a base antenna also soon. By the way I've checked SWR in my driveway and other places ,it never changes, Front yard or back yard
     
  3. Marconi

    Marconi Usually if I can hear em' I can talk to em'.

    Joined:
    Oct 23, 2005
    Messages:
    6,998
    Likes Received:
    1,977
    Robert, welcome to the forum. Your comments sound a lot like me talking back in the days when CB was a big deal.

    Here is what I call my Marconi 7x, where the hub is made with a mobile L bracket, a hub from an A99 GPK, and a short mast pipe for mounting. This setup provided vertical and slanted down radials, but just using 3 slanted down radials did the best job for me.


    upload_2020-12-26_23-9-16.jpeg

    Here it is in the air. Some times I used a 3" - 4" riser, but most of the time I just used the 102" whips. In the picture below the radials are 102" whips and in this case the 6 radials were set to both horizontal and the slanted down positions with the A99 hub I modified.

    IMO, the extra radials made little difference as I recall...and I don't think it was necessary. I could get this antenna up to 50' feet, and it worked great. With the whips the Marconi 4x did not need radial supports, which often fail due to the constant wind and weather. The match was always rock hard and steady...just like your described above.

    upload_2020-12-26_23-16-53.png
     
    #93 Marconi, Dec 27, 2020
    Last edited: Dec 27, 2020
    Slowmover and Shadetree Mechanic like this.
  4. Eldorado828

    Eldorado828 8-2-8 in the Lonestar State

    Joined:
    Feb 21, 2016
    Messages:
    1,466
    Likes Received:
    2,380
    Curious how the whip panned out for the original poster?
     
    Slowmover and buickid like this.
  5. ljh505

    ljh505 Member

    Joined:
    Nov 29, 2020
    Messages:
    30
    Likes Received:
    69
    If you think the antenna is too short, stick on a 10 inch shaft at the bottom of the spring

    https://www.wearecb.com/procomm-10-stainless-steel-shaft.html

    and then if it is overall too long, cut the crimp-on ferrule off the bottom of the whip and shorten the whip a bit at a time from the bottom, using a replacement 0.200 whip ferrule with set screws to re-mount the whip in the top of the spring.

    https://mfjenterprises.com/products/mfj-7715?_pos=2&_sid=1edc0370d&_ss=r

    To cut the whip at the bottom with a metal file, score/file about 1/3 to 1/2 of the way through the diameter of the whip, then use pliers to snap off the rest.

    If the 10 inch is way too long, stick on a 5 inch shaft

    https://www.walcottradio.com/wilson...-p-339.html?osCsid=rjuek1ufcn6ekglp8ac7ddqub1

    with some shaft nuts

    https://www.walcottradio.com/wilson-shaft-nut-for-2000-and-5000-antennas-880900908-p-2597.html

    If 10 inches is still too short, try a 12 inch shaft extension

    https://www.wearecb.com/ss34hs12-procomm-whip-shaft.html

    [Edit: Egads, I just noticed this thread is 6 months old. No doubt the OP has long ago solved his 102 inch whip SWR issues.]
     
    #95 ljh505, Dec 29, 2020
    Last edited: Dec 29, 2020
    Slowmover and buickid like this.
  6. buickid

    buickid Active Member

    Joined:
    Nov 22, 2012
    Messages:
    196
    Likes Received:
    75
    Turns out, I'm still around after all these years. I ended up running the spacer and spring as shown in the first pic. The SWRs seemed acceptable to me and I ran a 979 with a DX500 for a year or so before selling my equipment and moving onto other pursuits. Now I'm back with a different mobile, a different 979, and a different DX500. 102" and spring didn't look real good right off the bat, so I slapped on a 10K I got from a SK friend of mine for now. There's something to be said about being able to tune it with a set screw. I'll revisit the 102" when I have more free time. I still have to make time to run some wire for the DX500...
     
  7. Eldorado828

    Eldorado828 8-2-8 in the Lonestar State

    Joined:
    Feb 21, 2016
    Messages:
    1,466
    Likes Received:
    2,380
    I like many others have left the hobby before, only to return with a bigger thirst. It seems to have that affect.

    As I've said before 20201229_084709.jpg
     
  8. Marconi

    Marconi Usually if I can hear em' I can talk to em'.

    Joined:
    Oct 23, 2005
    Messages:
    6,998
    Likes Received:
    1,977
    Hello again Buickid,

    IMO the basic issue here, when installing a 102" SS Whip, like both you and 505 are describing, is the lack of an adequate ground plane mix of horizontal surfaces and vertical surfaces...that are nearby the feed point, in order to effectively resonate the 102" SS whip with a good match for CB.

    Your idea to lengthen the whip will work, but the 102" whip will only resonate in the CB band...if it has a suitable GP to work against. Mobile body shapes, sizes, and materials make for a lot of variables to work out when trying to match a whip at 102" inches, especially in this modern era of mobile design ideas.

    This is the same issue I posted to you, regarding your buddy's Van...that had a large flat roof, and the nearest vertical elements to respond to RF were a bit to far away to make the 102" whip resonate in the CB band.

    This is probably why a few operators suggested bonding. To me that would be "iffy" at best. I don't recall, but how did bonding work out with your buddy's Van project?
     
    #98 Marconi, Dec 29, 2020
    Last edited: Dec 29, 2020
    Slowmover likes this.
  9. Riverman

    Riverman Old Member

    Joined:
    Nov 12, 2013
    Messages:
    2,454
    Likes Received:
    2,279
    You should buy in bulk and sell those mounts, Eddie.
    Bet you’d sell a bunch. I’d love one.

    Rather than 102” whips, I’d use 4’ Firestiks for a perfect small attic antenna.
     
    Handy Andy likes this.
  10. Marconi

    Marconi Usually if I can hear em' I can talk to em'.

    Joined:
    Oct 23, 2005
    Messages:
    6,998
    Likes Received:
    1,977
    Yep Riverman, I think I got that idea after the first time reading a Homer Home Depot ad here on WWDX. (y)
     
    Handy Andy and Riverman like this.
  11. Handy Andy

    Handy Andy Do Your Research First, Then Decide...

    Joined:
    Apr 23, 2018
    Messages:
    4,850
    Likes Received:
    6,363
    Count me as interested!
     
    Marconi likes this.

Share This Page

  • About Us

    The WorldwideDX Radio Forum was originally established in 2001. We pride ourselves on welcoming Radio Hobby enthusiasts of all types, while offering unbiased, informative, and friendly discussion among the members. We are working every day to make sure our community is the best Radio Hobbyist's site.
  • Like us on Facebook

  • Premium VIP Member

    The management works very hard to make sure the community is running the best software, best designs, and all the other bells and whistles. Care to buy us a beer? We'd really appreciate it!

    Donate to us!