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Author Topic: QRP With Indoor Antenna  (Read 1715 times)

K1FBI

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Re: QRP With Indoor Antenna
« Reply #15 on: February 05, 2021, 08:13:39 PM »

Not well at all if your house has a metal roof and aluminum foil backed wall insulation.  A pretty decent Faraday Cage at HF frequencies.  ::)
Metal roof? Do they live in houses or sheds down South? ::)

Metal roofing on houses is more common than you might think. In Ohio, once you get out of the cities and into the rural areas, metal roofs on houses are pretty common. It's more expensive than traditional shingles. But it lasts twice as long (or longer) if properly installed.
Like a cat on a hot tin roof. I imagine some might make a good ground plane.
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KM1H

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Re: QRP With Indoor Antenna
« Reply #16 on: February 10, 2021, 06:34:20 PM »

Metal roof commercials are regularly on TV ads here in NH/MA/ME areas. Often seen on high end homes.

Im considering it as my original GAF shingles roof is 31 years old.
That would mean my 34' horizontal wire in the attic plus a 25' drop to the feedpoint at ground level would require a new horizontal thru tree branches.
Ive run from QRP CW to 120W of 40-10M AM on it.

Carl
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K1FBI

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Re: QRP With Indoor Antenna
« Reply #17 on: February 11, 2021, 05:12:55 AM »

Metal roof commercials are regularly on TV ads here in NH/MA/ME areas. Often seen on high end homes.

Im considering it as my original GAF shingles roof is 31 years old.
That would mean my 34' horizontal wire in the attic plus a 25' drop to the feedpoint at ground level would require a new horizontal thru tree branches.
Ive run from QRP CW to 120W of 40-10M AM on it.

Carl

Go for it. Nothing like the sound of heavy rain hitting a metal roof at nite; quite relaxing.
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K3UIM

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Re: QRP With Indoor Antenna
« Reply #18 on: February 11, 2021, 07:44:47 AM »

Actually, it isn't all that bad. We had a metal roof put on our house and because of the underlayment/insulation they install prior to the metal, it can't be heard from inside.

Outside, I'm not sure. And the attic shack is so much warmer now. We like it! I needn't huddle around my  soldering pencil anymore. LOL

Charlie
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Charlie. K3UIM
Where you are: I was!
Where I am: You will be!
So be nice to us old fogies!!

K1FBI

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Re: QRP With Indoor Antenna
« Reply #19 on: February 11, 2021, 11:13:02 AM »

Actually, it isn't all that bad. We had a metal roof put on our house and because of the underlayment/insulation they install prior to the metal, it can't be heard from inside.

Outside, I'm not sure. And the attic shack is so much warmer now. We like it! I needn't huddle around my  soldering pencil anymore. LOL

Charlie
How's your hearing young man😊?
Just teasing....
Side note: MFJ loop tuner fried the ALC circuit and damaged the finals on my FT-950. Threw the 950 in the dumpster; talk about a bad day. Done with MFJ.. lesson learned.
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K3UIM

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Re: QRP With Indoor Antenna
« Reply #20 on: February 12, 2021, 02:52:17 AM »

We had a freezing rain that we could hear, but it didn't bother us.
Charlie
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Charlie. K3UIM
Where you are: I was!
Where I am: You will be!
So be nice to us old fogies!!

KBKZ2105

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Re: QRP With Indoor Antenna
« Reply #21 on: February 12, 2021, 08:15:57 AM »

Is QRP with an indoor antenna QRPp?  Just askin'  8)

73

I believe it is.  Actually probably all lower case qrpp.  I'm guessing your a CW OP and will not have any problems making contacts with an indoor antenna.  Good luck. 
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KM1H

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Re: QRP With Indoor Antenna
« Reply #22 on: February 12, 2021, 10:09:03 AM »

Quote
We had a freezing rain that we could hear, but it didn't bother us.
Charlie

My old 80-90's Dodge full size vans with fallen headliners sure could be heard but the radio volume control compensated.
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K1FBI

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Re: QRP With Indoor Antenna
« Reply #23 on: February 25, 2021, 09:51:05 PM »

Quote
We had a freezing rain that we could hear, but it didn't bother us.
Charlie

My old 80-90's Dodge full size vans with fallen headliners sure could be heard but the radio volume control compensated. Cripes Im not that far from 90 myself......drool.....drool
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KN6SU

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Re: QRP With Indoor Antenna
« Reply #24 on: March 06, 2021, 01:12:01 PM »

Not well at all if your house has a metal roof and aluminum foil backed wall insulation.  A pretty decent Faraday Cage at HF frequencies.  ::)

More common than metal roofs around here (SF Bay Area & California in general) is stucco construction using metal lath or chicken wire, which forms a very nice Faraday cage topped off by foil vapor barrier in the attic.
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KF5LJW

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Re: QRP With Indoor Antenna
« Reply #25 on: March 06, 2021, 01:30:38 PM »

Is QRP with an indoor antenna QRPp?
 

Sure laws of physics do not apply to hams, just like sticking your head in a microwave oven. Your a ham and can get away with it.  8)
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KB9BVN

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Re: QRP With Indoor Antenna
« Reply #26 on: March 11, 2021, 09:02:17 AM »

I put an dipole for 40m in my attic in 1998.  I run QRP.  I have done WAS four times so far, I have 83 DXCC contacts logged...it's no set of beams up 55 feet but it does make contacts. 
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KU3X

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Re: QRP With Indoor Antenna
« Reply #27 on: March 17, 2021, 09:37:46 AM »

Is QRP with an indoor antenna QRPp?  Just askin'  8)

73

To answer the question to your post........NO !  QRP is not rated on ERP, it's rated on the amount of power coming out of your radio.    If you put 1500 watts into a dummy load, the ERP is ZERO. This does not mean it's QRP.

If you have 5 watts CW coming out of your radio and it's going to a dummy load, you are QRP. If you have 5 watts coming out of your radio and it's going to 6 over 6 over 6 20 meter yagi's, it's still QRP.

You were given a lot of interesting information on this post but I did not see anybody answering your question.
Barry
« Last Edit: March 17, 2021, 09:41:29 AM by KU3X »
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N4OI

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Re: QRP With Indoor Antenna
« Reply #28 on: March 18, 2021, 04:37:45 PM »

Is QRP with an indoor antenna QRPp?  Just askin'  8)

73

To answer the question to your post........NO !  QRP is not rated on ERP, it's rated on the amount of power coming out of your radio.    If you put 1500 watts into a dummy load, the ERP is ZERO. This does not mean it's QRP.

If you have 5 watts CW coming out of your radio and it's going to a dummy load, you are QRP. If you have 5 watts coming out of your radio and it's going to 6 over 6 over 6 20 meter yagi's, it's still QRP.

You were given a lot of interesting information on this post but I did not see anybody answering your question.
Barry

Thanks for the answer, Barry!  So I guess I knew there's no extra credit for QRP with a compromise attic antenna...  But all the same, I think I'll add an asterisk in my log...  Just sayin'!   8)

73
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N6YWU

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Re: QRP With Indoor Antenna
« Reply #29 on: March 20, 2021, 09:59:28 AM »

So I guess I knew there's no extra credit for QRP with a compromise attic antenna...  But all the same, I think I'll add an asterisk in my log...  Just sayin'!   8)

To bad there's no official name for the challenge of using small antennas (or RF radiation systems), as a vast number of operators are constrained by that challenge.  Maybe as many or more than have QRP radios. 

Maybe the ARRL should assign a designation for QTH operating using a single element antenna smaller and lower than X lambda, where X is a fraction less than 1/2.  For QRP, even feedline radiation can be limited to an even smaller fraction ("light bulb" must be right on top of the transceiver).
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