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Author Topic: HOA restriction...Would a "shortened" Cushcraft R7 work in an attic ?  (Read 3402 times)
KF9ZA
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« on: October 15, 2011, 02:44:47 PM »

I am just getting back in to HF after 13 years off to raise a family and run a business.  In the interim I moved into a house with a no antenna HOA.  I've been getting my HF fix doing mobile but with the weather getting colder would like to move inside permanently.  The good news is that I have a high peaked roof and my attic has a inside peak of 18 feet.  I put in a inverted V dipole, but it's not working for me.  I have a few more things I can try before giving up on it.  But....

Back in the 90's in a non restricted neighborhood I had lots of fun on HF with my Cushcraft R7 on 10 meters down to 40 meters. It's been sitting in a box since then.  The overall height of the R7 is 22.5 feet.  I'm no antenna guru by any means, but I think the overall length is to get down to 40 meters.  So I have two questions...

If I left out one of the bottom "boom" sections to shorten the overall height so that it would fit in the attic, would it work?  I could give up 40 meters if I could get on the air with 10 meters down to 20 meters.  But would an R7 work at all in an attic?  Would I be wasting my time to put it all together.  The R7 is a "no radials" vertical.  Am I crazy or could it work?
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ONAIR
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« Reply #1 on: October 15, 2011, 03:25:59 PM »

I am just getting back in to HF after 13 years off to raise a family and run a business.  In the interim I moved into a house with a no antenna HOA.  I've been getting my HF fix doing mobile but with the weather getting colder would like to move inside permanently.  The good news is that I have a high peaked roof and my attic has a inside peak of 18 feet.  I put in a inverted V dipole, but it's not working for me.  I have a few more things I can try before giving up on it.  But....

Back in the 90's in a non restricted neighborhood I had lots of fun on HF with my Cushcraft R7 on 10 meters down to 40 meters. It's been sitting in a box since then.  The overall height of the R7 is 22.5 feet.  I'm no antenna guru by any means, but I think the overall length is to get down to 40 meters.  So I have two questions...

If I left out one of the bottom "boom" sections to shorten the overall height so that it would fit in the attic, would it work?  I could give up 40 meters if I could get on the air with 10 meters down to 20 meters.  But would an R7 work at all in an attic?  Would I be wasting my time to put it all together.  The R7 is a "no radials" vertical.  Am I crazy or could it work?
   It might, but probably not as well as if it were outside.  Why don't you try putting it up at an angle so that it will fit in your attic, before actually "shortening" it?  I once mounted an A99 at an angle in my attic, with somewhat decent results on 10 Meters.
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WB6BYU
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« Reply #2 on: October 15, 2011, 08:32:24 PM »

The top part is only used on 40m, so you could take off anything above the highest trap.
I suspect that you could replace the top section with horizontal wires of an appropriate
length and get it to work on 40m as well, but that would require some experimentation.

Would it work?  You won't know until you try it.  Attic antennas are highly dependent on
the building construction (stucco is particularly bad as it contains wire mesh) and the
presence of wiring, metal ducts, and how much noise you pick up sources in the building.

But if you tried a resonant dipole and it didn't work well when the bands were open, I don't
know if you will see much improvement with a vertical antenna, especially one of the
"no radial" type that tend to be sensitive to nearby metal and other objects.
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ND6P
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« Reply #3 on: October 16, 2011, 08:15:43 AM »

Just trying to think about what I would do if I were in your situation. Undecided

I might try to end feed a thin wire that runs from the house to a tree.  Easy to take down if anyone complains and hard to see. 

Or, using a radio that supports Internet remote operation such as the the Kenwood TS-590, I would reach out to a relative or friend who lives in a good, radio-friendly location.  Then I would set up the radio and antenna there and operate over the Internet from home. I would pay their Internet bill to compensate.

Or both  Smiley
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ONAIR
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« Reply #4 on: October 16, 2011, 11:36:11 AM »

Just trying to think about what I would do if I were in your situation. Undecided

I might try to end feed a thin wire that runs from the house to a tree.  Easy to take down if anyone complains and hard to see. 

Or, using a radio that supports Internet remote operation such as the the Kenwood TS-590, I would reach out to a relative or friend who lives in a good, radio-friendly location.  Then I would set up the radio and antenna there and operate over the Internet from home. I would pay their Internet bill to compensate.

Or both  Smiley

   Interesting concept!  Could that be doable using a vehicle such as a van or SUV?
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W6RMK
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« Reply #5 on: October 16, 2011, 03:32:29 PM »

More than one ham has operated inside the house to an antenna mounted on the car in the driveway. 

But to your original question, it's really a matter of try it and see.  I can almost guarantee that the tuning will be all screwed up, but if you've got a tuner (ideally at the antenna end of the feedline) you can probably make it work.

Off hand, more metal is better, so the suggestion to angle it in there (or even put it horizontal) is a good one.


By the way, attic antennas are legion for RFI problems, both stuff getting into your radio, and your radio getting into other stuff.  Putting a radiating element a few feet away from phone, cable TV, and power lines is a good way to have good RF coupling.
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ND6P
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« Reply #6 on: October 16, 2011, 04:54:48 PM »

Just trying to think about what I would do if I were in your situation. Undecided

I might try to end feed a thin wire that runs from the house to a tree.  Easy to take down if anyone complains and hard to see. 

Or, using a radio that supports Internet remote operation such as the the Kenwood TS-590, I would reach out to a relative or friend who lives in a good, radio-friendly location.  Then I would set up the radio and antenna there and operate over the Internet from home. I would pay their Internet bill to compensate.

Or both  Smiley

   Interesting concept!  Could that be doable using a vehicle such as a van or SUV?

I suppose if you had a VHF link to your home, where you had a PC connected to the Internet, it could be made to work.
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KI4SDY
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« Reply #7 on: October 17, 2011, 06:29:41 AM »

Why don't you try to disguise it? Put it inside a PVC pipe and either put a flag or a birdhouse on top? Bury the cable run to the house (hopefully close). It will perform much better outside!  Grin
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KF9ZA
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« Reply #8 on: October 17, 2011, 06:54:49 AM »

Why don't you try to disguise it? Put it inside a PVC pipe and either put a flag or a birdhouse on top? Bury the cable run to the house (hopefully close). It will perform much better outside!  Grin

This is a picture of a Cushcraft R7:

http://www.telusplanet.net/public/telwest/R7/R7-4.jpg

Not much chance I could disguise it as anything but an antenna.
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ONAIR
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« Reply #9 on: October 17, 2011, 08:21:28 AM »

Why don't you try to disguise it? Put it inside a PVC pipe and either put a flag or a birdhouse on top? Bury the cable run to the house (hopefully close). It will perform much better outside!  Grin

This is a picture of a Cushcraft R7:

http://www.telusplanet.net/public/telwest/R7/R7-4.jpg

Not much chance I could disguise it as anything but an antenna.
    Hmmm...  Looks like it could make a nice tree?  Heard of a guy with a vertical inside an artificial tree, who has been operating for 10 years incognito!  Smiley
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KI4SDY
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« Reply #10 on: October 17, 2011, 07:52:36 PM »

With the appropriate size PVC tubing and a bird house on top, the short static hats look like bird perches to me. A little imagination goes a long way. The tree idea is not bad either. Hang some moss on it!  Wink   
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K9RQ
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« Reply #11 on: October 27, 2011, 07:49:26 PM »

Yes, it will work.  But don't remove anything from the bottom, remove the top section of aluminum above the 30 meter trap to shorten the antenna.  You will lose 40 meters.  However, you can restore 40 by running a wire from the 30 meter trap horizontally to make up for the removed section.  Make the wire approximately the same length.  You might have to play with the various sections to get swr down on the individual bands or maybe your antenna tuner will do just fine with it the way it is.  Good luck and have fun experimenting.  That's what the hobby is all about.
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W4VR
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« Reply #12 on: October 28, 2011, 01:52:51 PM »

Anything will work in the attic as long as you don't have a steel roof!
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