Homemade 137mhz - 138mhz Weather Sat Antenna? - Page 1
Forum section: electronics / rf-microwave

author: Lord of nothing
author_rank: Super Contributor
timestamp: May 13, 2018, 04:09:18 pm
content: So witch Design should I pick? The Traditional Helix?https://www.motherearthnews.com/nature-and-environment/satellite-weather-images-zmaz93onztakhttps://www.dxzone.com/dx30769/double-cross-satellite-antenna.htmlhttps://www.aeronetworks.ca/2017/12/http://tinhatranch.com/how-to-build-a-qfh-quadrifilar-helix-antenna-to-download-images-from-weather-satellites/I got some Thick and Stiff Wire who should do the Job.

author: CopperCone
author_rank: Super Contributor
timestamp: May 13, 2018, 07:57:11 pm
content: build a giant horn antenna which you can aim at satellites

author: dazz1
author_rank: Frequent Contributor
timestamp: May 13, 2018, 10:49:37 pm
content: HiQuadrifilar Helix but not the short fat version. These are designed to be on a satellite.You want the taller version like this:which are designed for terra location.Dazz

author: tautech
author_rank: Super Contributor
timestamp: May 13, 2018, 11:20:13 pm
content: Quote from: dazz1 on May 13, 2018, 10:49:37 pmAnd yet I guy I knewwasusing squat versions for weather satellite reception to get sea surface temps for the commercial fishing industry and selling his package worldwide. Handmade the antennae were too.Admittedly his squat versionwasfor marine use but he had test setups on poles in a paddock.Think he's passed now as I can't find any record of his package on Google now.

author: hendorog
author_rank: Super Contributor
timestamp: May 19, 2018, 12:44:16 am
content: You might get away with one of these, it is a very simple way to start:https://www.rtl-sdr.com/simple-noaameteor-weather-satellite-antenna-137-mhz-v-dipole/I built one, and then a low pass filter to try and knock down the very high levels of FM BCB radio here - as I'm quite close to the transmitter.It does bring in the signal, but not quite well enough to work well in my location. I have a cheap LNA from eBay now and need to try it with that.

author: Lord of nothing
author_rank: Super Contributor
timestamp: May 19, 2018, 08:06:00 am
content: I have this for the Air Band:http://www.sirioantenne.it/en/products/vhf/gp-lb-seriesSo I would guess just and "specialised" Antenna for the Sat would bring some additional Gain.

author: Fraser
author_rank: Super Contributor
timestamp: May 19, 2018, 12:03:29 pm
content: I started out by building, then buying, crossed dipole + reflector antennas for my 137MHz WESAT work. That was back in 1992 when I was in Darwin N.T. When I returned to the UK, the biggest problem was interference from Pager signals at 139MHz. That required better receiver disign rather than a better antenna though. Crossed dipoles work well and are easy to build accurately. The down side of them is that the have a null directly above them.Over the years the QFH has become popular. I have made them and they do work well. As a first antenna build they can be a little daunting though. I was happy that I started with crossed dipoles and proved my comp,eye receiving system, before trying a QFH. Commercial QFH antennas used to be very expensive when compared to crossed dipoles.My commercial maritime WESAT system from ICS uses a very high quality crossed dipoles antenna rather than a QFH. That ICS crossed dipoles performs very well indeed, but was very expensive new. There are pro's and con's to both antenna types.A decent receiver with the correct IF bandwidth is also important for best results. Normal NFM and WFM IF filters found in commercial scanners are far from optimal. A 50kHz IF filter bandwidth is about right.Fraser