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shakespeare 3 element beam

hi everyone thanks alot for the info it is very much appreciated and if their is any thing else i should know please let me know the weather wednesday was horrible so i didnt do much with the antenna im still havin trouble sizing photos so i can upload them any ways ill try again and thanks again its appreciated.
CHEERS FROM THE COLD COUNTRY
 
Hi there,

I would first confirm it is actually a 1:1 balun you need.
(just put up the antenna and verify swr).
It is possible the antenna uses a other "coax" length as a impedance tranformer.


Secondly i wouldnt "buy" a 1:1 balan.
Since it is a "single" frequency yagi there are other ways.

Like:
http://www.iw5edi.com/ham-radio/files/I0QM_BALUN.PDF
Coax Velocity Factor in Baluns, Does it Matter? Part 1 | Ham Radio Help Desk
Or a simple RF choke (not a balun but a unun)
RF Choke

Kind regards,

Henry HPSD
19sd348
 
Well I finally had a chance to snap some pictures of the Shakespeare pamphlet and edit them. I don't have a scanner so I did what I could.


Three element beam.

img2328sz.jpg


Four element beam.

img2327qz.jpg



Dual polarity three element beam.

img2329x.jpg



Element mounting details.


img2330s.jpg
 
BJ radionut said:
(y) 9db Gain for 3 elements or 14db Gain for a 4 element over what...:confused:
A Screen Door on a submarine?:LOL:
All the Best
BJ
Click to expand...

i can believe it. gain figures are so varied. is it near field or at a distance? i know if you take a 5/8 against a 2 element verticle there wont be much gain difference at 100 feet but go out 30 miles and you will see several s units improvement on the beam. theres so many factors involved but if its installed horizontle then you can add ground gain of about 6db to about 5db of a normal 3 element so 17db for a 3 element over a 1/2 wave verticle dipole is possible making sure you are using the same polarization for taking readings and add the 6db ground gain to the receiving horizontle dipole
at least these are the results i got when i did my comparisons. about 3 1/2 s units difference from my 5/8 to his 1/2 wave verticle dipole and my 3 el yagi to his horizontle dipole at 17 miles
i dont know why no comapny has offered a horizontle omnidirectional for the base. i bet it would be quiter and stronger then verticles
 
BJ radionut said:
(y) 9db Gain for 3 elements or 14db Gain for a 4 element over what...:confused:
A Screen Door on a submarine?:LOL:
All the Best
BJ
Click to expand...

Sounds like those figures are reasonable if they are over an isotropic source for the three element but the four element is a bit optimistic.


Needle Bender said:
i can believe it. gain figures are so varied. is it near field or at a distance? i know if you take a 5/8 against a 2 element verticle there wont be much gain difference at 100 feet but go out 30 miles and you will see several s units improvement on the beam. theres so many factors involved but if its installed horizontle then you can add ground gain of about 6db to about 5db of a normal 3 element so 17db for a 3 element over a 1/2 wave verticle dipole is possible making sure you are using the same polarization for taking readings and add the 6db ground gain to the receiving horizontle dipole
at least these are the results i got when i did my comparisons. about 3 1/2 s units difference from my 5/8 to his 1/2 wave verticle dipole and my 3 el yagi to his horizontle dipole at 17 miles
i dont know why no comapny has offered a horizontle omnidirectional for the base. i bet it would be quiter and stronger then verticles
Click to expand...


Just remember that when trying to figure dB gain from S-meter readings that most S-meters are NOT calibrated to the old Colin's figure of 6dB per S-unit. In fact I have yet to see one that is calibrated that way and linear over it's range.
 
well, at least the question about the matching stub was answered,.... 41 inches of RG 58.
 
hookedon6 said:
well, at least the question about the matching stub was answered,.... 41 inches of RG 58.
Click to expand...

Yeah but look at the picture again. It looks like two pieces coming from the connector up to the boom with one piece grounded to the U-bolt mount and then a single piece to lugs for connection to the driven element.Could it have been two parallel pieces of RG-58 connected at the top. I can't see why but that is what it looks like.Almost like a short phasing harness shorted together at the feedpoint end.
 
If you parallel two 50 ohm impedances you get 25 ohms, which just happens to be close to the feed point impedance of a three element beam. I didn't pay any attention to the lengths of those two lines, so what would you end up with at the connection to the 50 ohm feed line to the radio? And for that matter, that 'stub' going to the beam's feed point, what's it's length and impedance? ...you figure it, I'm too lazy.
- 'Doc
 
Captain Kilowatt said:
Yeah but look at the picture again. It looks like two pieces coming from the connector up to the boom with one piece grounded to the U-bolt mount and then a single piece to lugs for connection to the driven element.Could it have been two parallel pieces of RG-58 connected at the top. I can't see why but that is what it looks like.Almost like a short phasing harness shorted together at the feedpoint end.
Click to expand...

yeah,... both the center conductor and the shield are tied togeather

... also, I don't understand why the cable clamp just above the coax connector MUST be in contact with the MAST and CABLE. isn't the cable insulated ?

if the cable is insulated ( and I think it is), then making contact does nothing. if it is not insulated, then they just grounded the center conductor to the mast.

the bracket assy's seem to be insulated from the mast,.... why else would there be a jumper across the bracket on the reflector & director
 
ok sorry for the delay i got this antenna up all i did was run rg8 right to the driver element and the swr is 1:5 for about 10 ch and they are 27.355-27.455im going to make a matching section but i cant get my head around the fact that the shield and the common go to the lug at the boom it doesnt make sence i know if you make patch cord and the shield touches the common it screws everything up so can sum one help me out here. im gunna try one piece of rg58 and see but it just seems crazy for thr shield and comon to ground out together
 
Howdy,
Just ran across this old thread while looking for sales brochure info on my two Shakespeare fiberglass beams. I have both the 3 and 4 element versions NIB and have the original instructions with dimensions and other info if anyone needs it. The models are 4153 for the 3 element and 4104 "MegaBeam" for the 4 element.

I plan on cutting the 3 element down a bit for 10m amateur use and the 4 element will hopefully cut down for 6m amateur use. Both antennas have a coax matching section made of several chunks of parallel coax to match the driven element which will be much less than 50 ohms. I see they want you to ground one end of this harness to the boom clamp and the other end to the mast. Very poor design in my opinion.

I will be using a hairpin match on the final design and will assemble the 3 element version today and check it with the stock harness on CB first, then replace the harness with a hairpin match, test and tune, then cut down to 10m and retune the hairpin.

These antennas seem to be very rare as little info exists on the Internet. I will scan the original assy manuals and post to benefit others that come across these old antennas.

Mike
 
Last edited:

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