Doug,
Our town uses shipping containers in the recycling center. The floors are steel.
Maybe they modified your container for land use by installing plywood floors so that flooring can be applied.
You have a nice installation by the way.
Mike N2MS
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On June 12, 2017 at 8:50 PM Epignathus <doug@...> wrote:
Hi Hans,
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Yes, my mobile phone says, ¡°Loss of Service¡± when I go inside way in the back with the doors open, but here is something most people don¡¯t realize about these containers, and I found out the hard way when I wanted to enclose all the switching noise from my solar plant in another one of these ISO containers; that the floor is marine plywood with steel struts to support it, but otherwise the floor is completely open! In my solar plant, I had to lay sheets of aluminum diamond plate to complete the 6th side in order to form a Faraday shield. I suspect the GPS signals are simply getting in through the floor¡
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73, Doug
W6DSR
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From: [email protected] [mailto:[email protected]] On Behalf Of Hans Summers
Sent: Saturday, June 10, 2017 01:26 PM
To: [email protected]
Subject: Re: [QRPLabs] Mounting the QLG1 inside the case.
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Hi Doug
Thanks for the info and the amazing photo. Great location!?
The wavelength of GPS is something around 18cm. I guess is sneaks in through the cracks along the door of your container. Still amazing. Hard to imagine. I've been in one of these shipping containers and it's hard to imagine that any radio signal would get through that when it's closed up. I bet a cellphone wouldn't work inside. So I'm amazed!
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On Fri, Jun 9, 2017 at 9:23 PM, Epignathus <doug@...> wrote:
I am in the process of setting up a QTH out in the country where I can control the man made noise. I have the requisite antenna installed, and pulled in an inexpensive surplused, refurbished, 40 foot container for my shack. On my last visit, I completed an underground cable for power to the shack from my solar plant about 400 feet distant, and an underground heliax cable to the antenna. I thought I would just try the U3S from my new shack to give the idle antenna something to do. I have the amazing QLG1 GPS receiver on a 20 foot shielded cable, and hung it out the side door, where obviously it was working just fine.
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As I packed up to come back to Sunnyvale, I pulled in the QLG1, and closed all the doors with me inside to watch it lose the GPS satellites. It didn¡¯t ¨C stayed locked with plenty of sats in view. The U3S is powered 24/7 from a simple 5 VDC supply, and with no power amp. All the containers are locked up for security reasons. Because I get some pretty severe winds on this mountain location, I stow the antenna with its butt into the prevailing winds which unfortunately leaves it pointing almost south into the Pacific. Even so, there are more than a hundred independent spots every day from the WSPR.net site using W6DSR as the call.
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I conclude that at 1500+ MHz where the GPS signals reside, an ISO container is far from a Faraday cage. Also, my Garmin hand-held GPS receiver does not find any sats inside the container, so the newer GPS receivers must be much more sensitive.
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I attached an image of the site, but I don¡¯t know if it will survive on this reflector¡
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73,
Doug W6DSR
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From: [email protected] [mailto:[email protected]] On Behalf Of Hans Summers
Sent: Friday, June 9, 2017 02:40 AM
To: [email protected]
Subject: Re: [QRPLabs] Mounting the QLG1 inside the case.
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Hi Doug
That's quite interesting. Faraday will be turning in his grave. Why did you install it inside a shipping container? I assume it is a retired shipping container??
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On Fri, Jun 9, 2017 at 1:26 AM, Epignathus <doug@...> wrote:
I have mine in a 40¡¯ ISO shipping container with the doors sealed shut, and to my amazement, the very sensitive receiver is always locked on multiple sats. I think it would be rather difficult to stop it from receiving under any circumstances¡
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-Doug W6DSR
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From: [email protected] [mailto:[email protected]] On Behalf Of Ron Carr
Sent: Thursday, June 8, 2017 06:20 AM
To: [email protected]
Subject: [QRPLabs] Mounting the QLG1 inside the case.
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I know it won't work without modifications, but I am considering cutting a square hole in my case and mounting the GPS just below the top cover.? About the only thing holding me back is my poor metal working skills.?? I have a house with a metal roof and this GPS works so well that it receives 7 to 10 satellites anywhere I put it.?? I don't think there is a need to have it on a long cable mounted where it can see the sky.
Has anyone tried something like this?? And did it work ok?? I suppose the extra metal above the ground plane could de-tune the antenna.?
Ron? K1URC
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