KC4VFP

 


 

OptiBeam's Dirty Little Secret: fudged gain and specifications

This is the picture that OptiBeam does not want you to see.  It shows the testing of the Optibeam OB18-6 Beam Antenna.  This is OptiBeam's top of the line antenna to compete with the SteppIR Monster Antenna.

Problem: A 40 meter antenna needs to clear surrounding ground and objects by 20 meters minimum, or else the ground and nearby objects will distort the antenna's resonance (tuning), SWR, pattern, and gain measurements.   If a horizontally polarized antenna does not clear the ground and all other objects within the radiation / reception pattern of its radiating element(s), the capture area, and thus the gain, is reduced.

The gain of antenna A compared to antenna B is equal to the capture area of antenna A compared to the capture area of antenna B.

The capture area of an antenna is determined by multiplying the antenna's radiator length by 1/4 lambda.  See Figures 1 and 2.

NOTE: If the antenna is placed less than 1/2 wavelength above ground, the ground and / or surrounding buildings can severely distort the antenna parameters.

The gain of antenna A compared to antenna B is equal to the capture area of antenna A compared to the capture area of antenna B.  The capture area of an antenna is determined by multiplying the antenna's radiator length by 1/4 lambda.  When an antenna incorporates linear loading or traps to reduce the length of the element(s), the capture area, and thus the gain of the antenna, is reduced.

In either case, a horizontally polarized antenna tuned for 10 meters would need to be a placed a minimum of 5 meters above ground, and a 40 meter horizontally polarized dipole, log, or beam antenna would need to be 20 meters (66 feet) minimum above ground for accurate measurements to be taken of the antenna's gain and other parameters.

When the rented telescoping hydraulic bucket (above) is fully extended on this test setup, the 40 meter through 10 meter  antenna is barely 50 in the air, and less than 30 feet above the rooftops of the buildings underneath.  OptiBeam "fudged" the gain and other measurements for this antenna.  The antenna measurements are actually only estimated guesses, as personally told to me by telephone by OptiBeam's designer, Thomas Schmenger, whose ham radio call letters are DF2BO.  This deception is a slap in the face to every ham who trusted the name "Optibeam."

Propagation is what really counts.  On Christmas day a yeay ago, OP4K used his expensive OB18-6 Optibeam antenna to talk to KD1RV, who had a booming signal with his G5RV Jr.   OPK4 had spent $5,000.00, for his antenna (+ Rotor + Tower), the other spent less than $50. The results were the same on both ends for this QSO.

 

 


 

My Day Job

 


 


Having my a free Pass and my own jacket on Game Day saves a few bucks!


GoodYear ran NTSC at the 2004 Super Bowl. Hi-Def TX was blocked by WiFi QRM.  This night I was with the Goodyear Crew.


Erin (xyl), Sean, and Eric, in Kissimmee Florida, before the FUJI launch for the 2004 Daytona 500


Erin outside the ESPN truck - Daytona 500


Around the QTH:

When I say I have QRN from FPL ( Florida Power and Light ), the local power utility, I mean it:


Click here for MPEG video
 

Click here for MPEG video of power grid RFI on a BAD day 1-29-2005

15,000 volt Lateral from 3 feeder arcs to tree and causes RF noise and faults on the utility power grid.  These power outages are totally unnecessary.

 
Excellent utility company ground splice on the pole going to my house.


This utility company ground provides excellent balance between phases.


To reduce noise, our power utility uses hollow poles.


Safety comes first with FPL.  I just avoid walking under poles so a fuse doesn't fall on my head.


Surge Protection is important to keep the Ham Shack going.  Too bad the ground is blown off.
I have a 15,000 volt BARE aluminum wire lateral going through the back of my 1 acre lot. 

The use of bare wire is extremely important.  It allows the 3 phase 15,000 volt feeders
to turn into a "Jacob's Ladder" when they come in contact with each other during
 wind gusts.  It makes for a beautiful bluish-green flash that can be seen for miles.


Our utility company always keeps my "drop" trimmed, and the wires free from vines - NOT.


I also have a little static in my phone when the wind blows. 


Don't ask for an audio check unless you want the truth:

QSC amps drive each speaker pair @ 1700 watts RMS per channel.   (I Like HEADROOM)

 


 

Sometimes the power company has a problem when I switch in my High Power Linear Amp.  CLICK HERE


The Electronic QSL Card Centre


 

The town I live in refused my proposed antenna plans.


 

I would like to also thank the manufactures of a 15 amp, 3-way adaptor that we used in our 3yr old son's room.  A potential fire was discovered because of Amateur Radio, and the QRN that I noticed on my radio equipment is credited with saving my son's life from a possible fire.

Complaint to Underwriters Laboratories: 

FIRE SAFETY ISSUE:  Device becomes hot, polycarbonate  material starts to deform after 8 hour load from space heater rated at 1200 watts.  Measured AC voltage under load was 117 VAC at the outlet, giving a current draw of 10.256 Amps.  Another tap of this device had a 16 watt, screw-in, fluorescent style bulb, used in a lamp.  This was in our 3yr old son's bedroom.  The heater was a model 633 Lakewood, with auto shut-off and tip alarm (buzzer).  The 3-way adaptor had previously been noted to be warm to the touch after a few hours of operation, and the plug to the heater was removed and checked to insure that the contacts were clean.

 

When discovered, the device was HOT, and was the source of a "burning smell" in the child's room.  The device was like putty in the center, and the circuit breaker was immediately turned off to the child's room.  The device was then extracted from the wall with the aid of an oven mitten, but the polarized neutral male prong remained in the receptacle, with the 3 female neutral receptacles from each of the 3 AC receptacles still attached, having been pulled from the overheated device that was like butter in the center.

 

Pictures of the device will be posted at http://www.WatchdogUSA.com/woods/


15 Amp, 125V rating


I am in the process of building a new tube linear from a guaranteed tube
I bought off of EBAY from a person with 0 feedback.  He says people in his
country have successfully got power outputs in excess of 2 KW from this tube,
and he personally tested it before sending it to me.

 

I am expanding my horizons by buying a used camera for SSTV:

P.S.  If you believe the last 2 items, I have a bridge for sale. 

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This is a picture of the Marconi room on the Titanic. This is the only photo ever taken of the radio room. Harold Bride (in picture) was the assistant operator. John 'Jack' Phillips died in the sinking, and his body was never recovered.

Bride, after rescued, went on to work as radio op on the Carpathia until they arrived in New York on April 15, 1912. He only suffered from frostbite for a short while.

from KI4NZU

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My Business Website:  http://TVtower.com