The neighours think I'm nuts... - Page 1
Forum section: electronics / general

author: SteveyG
author_rank: Unknown
timestamp: February 23, 2015, 10:36:16 am
content: I've installed a GPS antenna for my GPSDO. New video on my YouTube channel-https://www.youtube.com/user/sdgelectronics/

author: Warhawk
author_rank: Frequent Contributor
timestamp: February 23, 2015, 10:37:53 am
content: Nice clean work, nice picture, I like it.

author: VK5RC
author_rank: Unknown
timestamp: February 23, 2015, 10:44:06 am
content: Nyah, just move next door to a Ham! HiHiSeriously nicely done, I like the drip loop.To minimise visual impact I have painted the bit below the guttering/roof line the same colour as the walls etc. It does make quite a visual impact reduction.Keeps the neighbours on side and not complaining that "your antenna broke their TV".

author: SteveyG
author_rank: Unknown
timestamp: February 23, 2015, 10:47:44 am
content: Quote from: Warhawk on February 23, 2015, 10:37:53 amThanksI've not really looked into how these are normally installed, so possibly OTT...Quote from: VK5RC on February 23, 2015, 10:44:06 amYeah I could possibly paint the pole, although the neighbours aren't really bothered but just thought I was trying to bring down aircraft. I may be switching the antenna over to a slightly different one at some point as it seems some are geared more towards timing operation rather than generic GPS use.

author: Towger
author_rank: Super Contributor
timestamp: February 23, 2015, 10:51:57 am
content: QuoteBut it is only tiny GPS antenna... I was expecting a 100+ foot tower with huge array in a small back garden.

author: Rerouter
author_rank: Super Contributor
timestamp: February 23, 2015, 10:52:46 am
content: Its about on par with how they would fit location antennas to council vehicles, (the first thing to hit a low entry point....)also "your antenna broke there TV".... people always look to blame what they dont understand dont they...the only time i can say i have seen one antenna do that to another was when a 15W CB antenna was zip tied to one of my units GSM antenna's, it lost all reception for a good few minutes after anything was transmitted (think it crashed the modem), and it ended up killing it after about 6 months of that abuse,

author: Dr. Frank
author_rank: Super Contributor
timestamp: February 23, 2015, 11:02:58 am
content: They ".. think .." ??Actually, you ARE going nuts.. "Time-Nuts". Nice assembly!We also have a GPS antenna on the roof of our house, but I simply attached it to the rain gutter..Main thing, that it has free sky-sight, 25° above the horizon ..Frank

author: Fred27
author_rank: Unknown
timestamp: February 23, 2015, 11:33:29 am
content: My neighbours thought I was nuts when Ross Noble and a TV crew turned up at my house to ask me about the NFC implant that lets me into my workshop. (It was for Freewheeling Series 2 - on the Dave channel in about a month.)A bonus is that with a GPS antenna on your house you'll always know exactly where it is.

author: madires
author_rank: Super Contributor
timestamp: February 23, 2015, 11:51:39 am
content: My cheap GPS receiver works fine when placed on the window board. No problem with tracking several satellites, around 7-10 with a good/strong signal plus about 3-5 with a weak signal, even at a cloudy day. BTW, I'd suggest to add a proper grounding for the pole in case of a lightning. A 16mm² solid copper wire plus grounding rod should be sufficient. The ground of the antenna cable should be grounded too. Simply connect it to the grounded pole using a L-shaped metal with a patch connector for the antenna cable (sold by antenna shops, optional over-voltage protection) and connect the metal with a solid copper wire (4-6 mm²) to the pole. The L-shaped metal should be mounted where the cable enters the house (inside the house). If you got a grounding system for the house, you could also use that instead of the dedicated grounding rod. If you'll use a grounding rod and got a grounding system for your house, connect both to keep the potential the same. And please check out local regulations regarding grounding and lightning protection for antennas. Might be also a requirement by the building/fire insurance.

author: John Coloccia
author_rank: Super Contributor
timestamp: February 23, 2015, 12:06:56 pm
content: Could someone explain why anyone would attach a GPS antenna to a house? I'm sure there's a good reason, but I can't figure it out.

author: SteveyG
author_rank: Unknown
timestamp: February 23, 2015, 12:08:17 pm
content: Quote from: madires on February 23, 2015, 11:51:39 amI had an antenna sitting on the windowsill, but the GPS receiver was unable to lock reliably at certain times of day. It was a cheap antenna though, but as this thing is going to be constantly powered I figured it was worth doing a more permanent arrangement for the antenna.The antenna is actually mounted to a lower roof section than the main part of the house, however an in-line lightning arrestor is something I'm considering. In the UK there are no requirements for any kind of lightning protection on domestic properties.

author: SteveyG
author_rank: Unknown
timestamp: February 23, 2015, 12:08:58 pm
content: Quote from: John Coloccia on February 23, 2015, 12:06:56 pmSee the videoa GPSDO for 10MHz frequency reference in the lab

author: John Coloccia
author_rank: Super Contributor
timestamp: February 23, 2015, 12:20:44 pm
content: Quote from: SteveyG on February 23, 2015, 12:08:58 pmAh. I never would have thought of that.

author: madires
author_rank: Super Contributor
timestamp: February 23, 2015, 01:30:59 pm
content: Quote from: John Coloccia on February 23, 2015, 12:06:56 pmFor example to feed your ntpd.

author: aroby
author_rank: Regular Contributor
timestamp: February 23, 2015, 06:38:27 pm
content: I have one too! My house hasn't moved since I've been tracking it ...

author: cosmicray
author_rank: Frequent Contributor
timestamp: February 24, 2015, 02:38:09 am
content: Quote from: madires on February 23, 2015, 01:30:59 pmYeah, for the time base signal. I asked guys installing the WiMax base station why they had a GPS antenna on top of the rack cabinet, and that is how I learned that.

author: xrunner
author_rank: Super Contributor
timestamp: February 24, 2015, 04:05:39 am
content: Quote from: SteveyG on February 23, 2015, 12:08:58 pmSubscribed - interesting channel.

author: Richard Crowley
author_rank: Super Contributor
timestamp: February 24, 2015, 04:27:15 am
content: Quote from: John Coloccia on February 23, 2015, 12:06:56 pmIf he lives in a flood plain and the house breaks loose, he can track it downstream for the insurance company.There are a dozen or so fixed points around the planet where they monitor and control the GPS constellation of satellites. They compare what the GPS says their location is with their actual location to establish an error factor to send the correction back into the system. Well, it is probably much more sophisticated than that, but you get the idea. Many of these monitoring points are out on exotic tropical islands. Must be a really tough assignment to run the GPS monitoring station in Tahiti or Hawaii or even Diego Garcia or Ascension Island.

author: VK5RC
author_rank: Unknown
timestamp: February 24, 2015, 04:49:22 am
content: Putting your GPS antenna up high I recall also has some benefits if you get all "time-nut"ish due to some timing / reflection issues.My GPSDO antenna is clamped to the base of a VHF, UHF antenna (it gets 50W at 440MHz or 147MHz), note the UHF antenna starts above the 3 radials (2 v difficult to see), coax up the centre of the pole.My shack hasn't moved much yet.

author: matseng
author_rank: Frequent Contributor
timestamp: February 24, 2015, 05:13:38 am
content: I've also got one, just one neighbour recognised it as a GPS antenna and asked about it :-)

author: GK
author_rank: Super Contributor
timestamp: February 24, 2015, 01:15:50 pm
content: With a GPS-disciplined clock you could set up your own backyard seismic station. One of my roles for the last ~11 years has been in the upgrade and maintenance of the states seismic monitoring network. We even built our own GPS-disciplined clocks to provide the timing pips for the old analogue pen-and-paper recorders when they were still in service. However there are a growing number of amateurs over here now getting in on the action with modern digital recorders streaming data over the internet. Virtually all seismic recorders these days have their timing synchronized by GPS.At least your little GPS antenna is a lot less bother than HF dipole for WWV.I'm still searching the local market for a 10m lattice tower to support a 630m (HAM band) antenna for my little AWA transmitter:http://www.glensstuff.com/ctm2k/ctm2k.htmThe 3.4kW air con I installed into the shack on the weekend offsets the heat pumped out by the four 4CX1000A's reasonably well.

author: coppice
author_rank: Super Contributor
timestamp: February 24, 2015, 01:34:24 pm
content: Quote from: aroby on February 23, 2015, 06:38:27 pmAfter the earthquake which broke Fukushima we found our GPS position in Hong Kong had very clearly moved.

author: SteveyG
author_rank: Unknown
timestamp: February 24, 2015, 02:29:33 pm
content: Some great pictures on here. At the moment I have a fairly generic L1 antenna, but I notice some are specifically marketed as being for timing applications or even mission critical timing applications. Is there actually any basis for this or is it just to marketing purposes?

author: aroby
author_rank: Regular Contributor
timestamp: February 24, 2015, 03:26:31 pm
content: Quote from: SteveyG on February 24, 2015, 02:29:33 pmL1 is one of the GPS frequencies. My understanding is that the information / codes originally available for civilian access are transmitted on this frequency. L2 and other (L5?) frequencies are now more commonly supported on widely available GPS units, so by monitoring several frequencies you can get better positional accuracy. I don't think the time accuracy is affected at all.

author: Dinsdale
author_rank: Regular Contributor
timestamp: February 25, 2015, 12:11:44 am
content: I have a key fob.My porch lights flash and the burglar alarm chirps.

author: hammy
author_rank: Unknown
timestamp: February 25, 2015, 01:10:50 am
content: Quote from: Towger on February 23, 2015, 10:51:57 amA red and white painted mammoth antenna. 330 feet high and fully rotatable with a large gear from an old tank ...-> like OH8X in Finland

author: TopLoser
author_rank: Unknown
timestamp: February 25, 2015, 01:23:32 am
content: Quote from: hammy on February 25, 2015, 01:10:50 amhttp://www.k3dav.com/Arkala%201.jpg

author: VK5RC
author_rank: Unknown
timestamp: February 25, 2015, 09:05:20 am
content: Didn't that (OH8X antenna) go down in a storm, would't have wanted to be close. Hopefully it is up again.@GK that is some transmitter, what are your grounding plans?

author: GK
author_rank: Super Contributor
timestamp: February 25, 2015, 09:58:16 am
content: My shack, garage and house roofs are steel so perhaps that will provide some kind of ground plane. However there isn't much else I can do. I am certainly not going to rip up my backyard to run earthed wires under (or above) the soil. My plan ATM is to just string up as long a wire as high as I can and build a very(!) large loading coil and hope for the best. Aiming for that elusive 1W EIRP I don't think I'll be able to put the full 2kW rated carrier into it before arcs start flying.

author: VK5RC
author_rank: Unknown
timestamp: February 25, 2015, 11:13:28 am
content: I recall a presentation at Gippstech 2014 by VK7TW re LF, if you can find the proceedings, it may be of some help, he spoke of and had pictures of some of the inductors, wheelie bin sized!73

author: GK
author_rank: Super Contributor
timestamp: February 25, 2015, 11:39:15 am
content: Quote from: VK5RC on February 25, 2015, 11:13:28 amThat's the plan!

author: VK5RC
author_rank: Unknown
timestamp: February 26, 2015, 11:09:12 am
content: Please 'show and tell' when you have some pics, the VK7 guy had some good stories of electrical arc-ing! O0

author: SteveyG
author_rank: Unknown
timestamp: March 15, 2015, 07:19:11 pm
content: Looks like a nice HP 58503A is going on eBay:http://www.ebay.co.uk/itm/HP-58503A-GPS-TIME-AND-FREQUENCY-REFERENCE-RECEIVER-RARE-/201303577353Quite tempting to bid on it