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Screwdriver HF Antenna for home use.

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xtatik
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Re: Screwdriver HF Antenna for home use.

Post by xtatik » Thu Apr 22, 2010 10:15 pm

2-cisco_systems_2.jpg
2-cisco_systems_2.jpg (346.6 KiB) Viewed 3361 times
Dennis, here is an example of what I was describing further up the thread. Although, this guy doesn't have his antenna mounted high enough, he is at least using physically full length resonant radials. Truth is, not only do they work better, they are actually easier and faster to set up than the Scorpion radial kit.
Obviously, being physically full-sized they wiil require more space. THe radials depicted in the picture can't be for any band lower that 20m which would be approx. 16.5' long. To give you a midrange guide, 40m radials would need to be approx. 33' long. Again, these approximations are based on an elevated mounting position. They don't necessarily have to be straight but overlapping or crossing them is a no-no.
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Re: Screwdriver HF Antenna for home use.

Post by OLLIE » Sun Apr 25, 2010 1:21 pm

Randy,

Could that same type of setup be done with our ATS antennas? How many radials does it require what is the attach point on the base of the antenna for the radials?
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Re: Screwdriver HF Antenna for home use.

Post by xtatik » Sun Apr 25, 2010 1:55 pm

OLLIE wrote:Randy,

Could that same type of setup be done with our ATS antennas? How many radials does it require what is the attach point on the base of the antenna for the radials?
Yes it can, but again it's a very serious compromise to other antennas that could be had for portable use. IMO, it's hardly worth the effort in detaching it from your truck an re-rigging as a portable unit. You might as well just work from your truck....but that's no fun and much less effective.
As for attaching to the ATAS, all you would need to do is make a small radial plate with a SO-239 connector. A short SO-239 bulkhead with jamnuts works fine for this and 1/8" aluminum works fine for the plate. The plate can be round or square and something approximating 6-8" across would suffice for the ATAS. Surrounding the connector on the plate a series of holes can be drilled for #10 machine screws and wingnuts to attach the resonant radials. You need a minimum of two per band, but four works best. You'll also need to accomodate any mounting means on the plate as well, so keep this in mind.
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Re: Screwdriver HF Antenna for home use.

Post by OLLIE » Sun Apr 25, 2010 1:56 pm

xtatik wrote:
OLLIE wrote:Randy,

Could that same type of setup be done with our ATS antennas? How many radials does it require what is the attach point on the base of the antenna for the radials?
Yes it can, but again it's a very serious compromise to other antennas that could be had for portable use. IMO, it's hardly worth the effort in detaching it from your truck an re-rigging as a portable unit. You might as well just work from your truck....but that's no fun and much less effective.
As for attaching to the ATAS, all you would need to do is make a small radial plate with a SO-239 connector. A short SO-239 bulkhead with jamnuts works fine for this and 1/8" aluminum works fine for the plate. The plate can be round or square and something approximating 6-8" across would suffice for the ATAS. Surrounding the connector a series of holes can be drilled for #10 machine screws and wingnuts to attach the resonant radials. You need a minimum of two per band, but four works best. You'll also need to accomodate any mounting means on the plate as well, so keep this in mind.
I already have the magnetic base plate (with three magnets) to put it on the roof of a truck with the connector built in. All I should need to do is drill the holes and add the radials to that.
"OLLIE"
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Re: Screwdriver HF Antenna for home use.

Post by xtatik » Sun Apr 25, 2010 2:50 pm

OLLIE wrote:
xtatik wrote:
OLLIE wrote:Randy,

Could that same type of setup be done with our ATS antennas? How many radials does it require what is the attach point on the base of the antenna for the radials?
Yes it can, but again it's a very serious compromise to other antennas that could be had for portable use. IMO, it's hardly worth the effort in detaching it from your truck an re-rigging as a portable unit. You might as well just work from your truck....but that's no fun and much less effective.
As for attaching to the ATAS, all you would need to do is make a small radial plate with a SO-239 connector. A short SO-239 bulkhead with jamnuts works fine for this and 1/8" aluminum works fine for the plate. The plate can be round or square and something approximating 6-8" across would suffice for the ATAS. Surrounding the connector a series of holes can be drilled for #10 machine screws and wingnuts to attach the resonant radials. You need a minimum of two per band, but four works best. You'll also need to accomodate any mounting means on the plate as well, so keep this in mind.
I already have the magnetic base plate (with three magnets) to put it on the roof of a truck with the connector built in. All I should need to do is drill the holes and add the radials to that.
That won't work! You either have to use the ATAS in its standard mobile setup using the vehicle as a counterpoise or isolate it away from the vehicle in the method discussed in this thread. You will have atrocious coupling problems in the method you describe in your last post. What you describe is the equivalent of laying a dipole across a tin roof and expecting it to tune......it won't!
The setup we're talking about here has to be a signifant diastance away from your truck or any other large metal object for that matter.
Last edited by xtatik on Tue Apr 27, 2010 10:52 am, edited 1 time in total.
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Re: Screwdriver HF Antenna for home use.

Post by Dennis David » Sun Apr 25, 2010 6:41 pm

Seems like what you are describing would make it all but impossible to do this in an apartment. :cry:
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Re: Screwdriver HF Antenna for home use.

Post by xtatik » Sun Apr 25, 2010 10:17 pm

Dennis David wrote:Seems like what you are describing would make it all but impossible to do this in an apartment. :cry:
Apartment dwelling has it's challenges when it comes to HF. There's no shortage of hams looking for ways to get a signal out and no shortage of opinions on how to do so. Stealth is the operative word and I've heard stories of guys tapping into and loading even raingutters in order to do so. Verticals of any type (screwdrivers included) are probably the most difficult unless roof access is available. The ParElectronics End-Fedz are probably the least conspicuous and most effective way to get on the air from an apartment or hotel room. You simply hook up a 1/4 wave section of coax, attach the matchbox end to a balcony and affix the other end to a tree or other building using the supplied insulator and dacron cord. I've even let them simply hang as mentioned earlier in the thread.
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Re: Screwdriver HF Antenna for home use.

Post by Dennis David » Tue Apr 27, 2010 12:28 am

That I have got to try. I'll be moving the first of June and getting my rig shortly after that. Will report progress.
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