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Old 05-18-2006, 08:02 PM   #16
tw
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Quote:
Originally Posted by MaggieL
It sure is addictive. I'm working on a model of 30th Street Station. Why, I'm not exactly sure...
Previously you were considering a Ham antenna. What happened to that and what frequencies? Is there neighbor opposition - existing or potential? I don't see an antenna on that picture.
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Old 05-18-2006, 10:44 PM   #17
Kagen4o4
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Quote:
Originally Posted by glatt
Nice job, Kagen.

Is that round thing on the deck in back a hot tub or something?

(2 weeks late with reply)

no, garden.


i bet that was worth waiting for
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Old 05-19-2006, 07:40 AM   #18
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Awesome!
A garden!!

Yes. It was well worth it.
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Old 05-19-2006, 07:59 AM   #19
MaggieL
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Quote:
Originally Posted by tw
Previously you were considering a Ham antenna. What happened to that and what frequencies?
It's up. The 3D model I posted wasn't the one my lifepartner used; my HF and satellite antennas are already up. The antenna is an offset-fed wire dipole, good on 80m through 10m as I recall...so the frequencies would be roughly 4 MHz though 28 MHz.
Quote:
Originally Posted by tw
Is there neighbor opposition - existing or potential?
No. And since we're not subject to C&Rs here, even if there was there wouldn't be much they could do.
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Old 05-19-2006, 10:12 PM   #20
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Quote:
Originally Posted by MaggieL
It's up. The 3D model I posted wasn't the one my lifepartner used; my HF and satellite antennas are already up. The antenna is an offset-fed wire dipole, good on 80m through 10m as I recall...so the frequencies would be roughly 4 MHz though 28 MHz.

No. And since we're not subject to C&Rs here, even if there was there wouldn't be much they could do.
That offset dipole - also called a Zep - is featured in a Reading PA WWII airfield and encampment reenactment. In WWII, the offsett dipoles used a ladder line - 600 ohm impedance - where the ground wire did not attach to the antenna.

I was never familiar with Zep antennas. In the Canadian camp, a ham had an interesting setup using principles common in WWII. He explained the concept of tuning antenna impedance by moving the offset. It just never occurred to me that impedance could be tuned by simply shifting the offset. Also interesting his how he support the antenna so high using interconnected fiberglass poles (similar to what is now used on tents) AND adjust zep offset from the ground.

Show is soon; the first weekend of June. It had many ham operators using WWII style techniques and equipment - and lots of old guns and planes.

Some are using flagpoles as a support for the dipole that will not 'offend' neighbors. However, I always thought a J antenna inside a fiberglass flagpole would be a rather interesting way of doing an omnidirectional antenna discretely. Have never seen one. But then they would be discrete.

Satellite as in communication via amateur satellites on 145 and 435 Mhz, or just Geosynchronous conventional satellite receiever?
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Old 05-20-2006, 08:50 AM   #21
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Quote:
Originally Posted by tw
That offset dipole - also called a Zep
Of course a true Zepp is end-fed, by definition. They're called that because they were originally developed for use as trailing-wire antennas on dirigibles.

Quote:
Originally Posted by tw
Some are using flagpoles as a support for the dipole that will not 'offend' neighbors. However, I always thought a J antenna inside a fiberglass flagpole would be a rather interesting way of doing an omnidirectional antenna discretely. Have never seen one. But then they would be discrete.
We had a nice dual-band J-pole made from copper pipe on our balcony when we were living in an apartment. Gwennie painted it with brick-texture spray paint and set it in a big flower pot and it was freaking invisible. We also had Moxxon squares built into woven-wood privacy screens, and had used a slingshot to loft magnet wire Zepps into the nearby trees...also invisible. Stealth antennas are an art. But we don't need to be invisible anymore.
Quote:
Originally Posted by tw
Satellite as in communication via amateur satellites on 145 and 435 Mhz...?

Yes.
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Last edited by MaggieL; 05-20-2006 at 08:58 AM.
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Old 05-20-2006, 09:25 AM   #22
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Quote:
Originally Posted by MaggieL
Now that's a nice high gain (Yagi?) antenna. Ever try for signals from the Mars satellites? I have seen home brew creations for that, but yours looks like it has even better gain. 15? elements on the 400+ Mhz antenna with both verticle and horizontal polarization.
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Old 05-20-2006, 05:59 PM   #23
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Quote:
Originally Posted by tw
Now that's a nice high gain (Yagi?) antenna. Ever try for signals from the Mars satellites?
Yagi with circular polarization. Never tried for the Mars sats; the pointing accuracy probably isn't really up to that kind of work.

"Spiny Norman" satellite antenna array: on Yaesu G-5400-B az-el rotor
2m: 20 element CP yagi (Cushcraft A144-20T) 11.1 dBd gain
70cm: 30 element 70cm CP yagi (Hygain 7030SAT) 14dBdc gain
2.4GHz: Millicom S-band RX downconverter, 27dB gain, 3db NF 18-turn K5OE helix
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Old 05-20-2006, 06:42 PM   #24
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Been trying to understand the underlying purpose of Google Sketchup. If used as a preliminary package to enhance existing or future Google products, then I understand why Sketchup would be free. For example, use MaggieL's 30th Street Station as the preliminary sketches to design a building (and maybe it's decorating) AND then feed that data into a decorator software package or an AutoCAD architects package. But Sketchup does not seem to do that. It features a proprietary data file.

Sketchup does not seem to 'feed' other products. It does offer some connection to import from Google Earth. But I don't get it. What is (or might be) Google's intent with this free software package?
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Old 05-20-2006, 08:59 PM   #25
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The Pro version exports models in 3DS, DWG, DXF, OBJ, XSI, VRML, and FBX file formats It also exports animations and walkthroughs as MOV or AVI files. I've already imported stuff from Blender as 3DS. The user interface is *vastly* easier to use than Blender's. You can also export models from the free version to a service Google runs for sharing them.
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Last edited by MaggieL; 05-20-2006 at 09:02 PM.
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Old 05-21-2006, 09:29 AM   #26
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Old 05-21-2006, 04:07 PM   #27
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Quote:
Originally Posted by tw
snip~ But I don't get it. What is (or might be) Google's intent with this free software package?
You're not supposed to see the hook, only the bait.
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Old 05-21-2006, 05:20 PM   #28
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The roof of 30th St. station was designed to be load-bearing to allow small aircraft to land...probably at the urging of Harold Pitcairn, (early developer along with Juan de la Cierva) of the autogyro and airmail advocate.

(This is his airmail aeroplane design)

Today, derivatives of the V-22 Osprey might take their place implementing one heckuva commuter service.
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Old 05-21-2006, 05:25 PM   #29
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nice mug. or oddly shaped and unclean pool
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