[TenTec] OCF antennas evolution
k6jek
k6jek at comcast.net
Thu Jul 11 15:40:44 EDT 2013
I found the article about the Illuminator project. It is a funny read. In 2000 he worked all continents with a TS-850S and a 150 watt bulb mounted on a four foot post fed through a common mode choke and 9913 Flex. The VSWR at the light bulb was 4:1. He started by using the internal tuner of the Kenwood but switched to a tuner near the bulb.
He later tried a 1500 watt bulb which was distinctly inferior to the 150 Watt bulb. He also built, get a load of this, a 3 bulb array selecting any two with the WX0B stack match. That cracked me up even more than the single bulb arrangement.
Jon
PS: We all know about transmission line transformers but sometimes we forget. I recently put up a sloping V with each leg about a half wavelength. I fed it with a very short piece of 450 ohm ladder line and was surprised that the Johnson Matchbox couldn't match it. I had two expert engineers helping me in this project. We all burst out laughing when we realized what we'd done. We were in a hurry, just trying to get on the air. Beer may have been consumed. Still, those guys wish to remain anonymous.
On Jul 11, 2013, at 12:03 PM, Rick - DJ0IP / NJ0IP wrote:
> Sounds to me like he was sampling the Napa Valley Produce and just dreamed
> all of that up.
>
> On the other hand, if anyone can do that, then it would be Tom!
>
> 73
> Rick, DJ0IP
>
>
> -----Original Message-----
> From: TenTec [mailto:tentec-bounces at contesting.com] On Behalf Of k6jek
> Sent: Thursday, July 11, 2013 7:08 PM
> To: Discussion of Ten-Tec Equipment
> Subject: Re: [TenTec] OCF antennas evolution
>
> Yes, Tom Schiller, N6BT, founder of Force 12, ran DX using a light bulb
> followed by a common mode choke so he wasn't cheating using the feed line as
> the antenna. I believe he later ran a phased array of light bulbs and tested
> the efficacy of different lightbulbs.
>
> I think he must have had sunspots in his favor.
>
> Jon
>
> PS: The length of a the feed line will matter a lot on how well the tuna
> does with the 260 doublet.
>
> On Jul 11, 2013, at 9:06 AM, Mike Bryce wrote:
>
>> Gang,
>>
>> I'll have to jump in here, too.
>>
>> I remember reading in one of the antenna books that some guy, to prove a
> point, worked DXCC using a light bulb as an antenna.
>>
>> But...
>>
>> Several years ago I homebrewed a OCF dipole with a 4:1 balun and stuck it
> up a tree. I've had nothing be outstanding results without a tuner. I won't
> cover 30 meters, but what the hey.
>>
>> There is currently a large antenna/tower project in the final stages
>> at this qth. One of the antennas I plan on installing is a 260 foot
>> doublet feed with 600 ohm open line feeders
>>
>> Now, I wonder how much of a problem my 238 tuner will have with the 600
> ohm line instead of the 400 ohm the tuner had been designed for?
>>
>>
>> Mike Bryce, WB8VGE
>> the heathkit shop
>> SunLight energy systems
>> J e e p
>> o|||||||o
>>
>>
>>
>>
>>
>>
>> On Jul 11, 2013, at 11:29 AM, Carter wrote:
>>
>>> On 7/10/2013 11:33 PM, Michael Tortorella wrote:
>>>
>>>> I feel compelled to weigh in here....back in the late '70s I used an
>>>> OCFD design from Ham Radio magazine which was pretty straightforward.
>>>> It was 135' long, fed with 44' of 300-ohm open wire to a 4:1 balun
>>>> and then a run of RG-11 into the shack. It was superb. Never had any
>>>> stray current problems. Worked about 150 countries using a Johnson
>>>> Navigator, 40 watts input. Would like to reproduce that next time
>>>> out. Don't pooh-pooh the OCFD design, be careful and it works well.
>>>> 73 Mike W2IY
>>>
>>> I smile when I see everybody describing their favorite wire antenna,
>>> so let me jump in with my comments (asbestos suit on). <grin>
>>>
>>> Mike, not to deny your success nor picking on you or anyone else
> describing their favorite wire antenna...but with ANY antenna, the RF has to
> go somewhere.
>>>
>>> I'm using a dipole about 130 feet long and maybe 25 feet off the ground
> fed entirely with ladder line (and a Johnson Matchbox) and worked a LOT of
> DX including Indonesia on 80, the VK0IR dxpedition and even North Korea on
> RTTY with that antenna.
>>>
>>> Heck, Kurt N. Sterba wrote in 'World Radio' magazine that he used a
> SHOPPING CART as an antenna during a DX contest and worked 17 countries!
> Again, the RF has gotta go somewhere.
>>>
>>> Bottom line: DX performance seems more attributable to the Propagation
> gods rather than what flavor of wire antenna is being used.
>>>
>>> 73,
>>> Carter K8VT
>>>
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>>
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