Carl Reade

Hi you will also need to know where and when the Milky way will pass through the horn. Stellarium software etc. Carl

Hi maybe a factor maybe not I had read that the PI itself like most computers can cause interference via RF and needs to be a good distance from the LNA and antenna. Maybe the bump issue especially if it's using WiFi as well.

Excellent post. That's how small it is. Software is half the battle. I am also not sure what the humps are Peter on your last post, that is an issue in the receive end.

Hi all yes I would recommend using the sdr Averager plugin to start with and take a calibration about an hour before the galaxy comes into view of the scope. Bear in mind the H line will usually only be 2db above the noise very weak. I would also ensure the dB increments on the left are as low as you can set, I think the most it goes down to is 3 dB. If aiming for the sun there will be no humps etc the entire noise level will rise. Software settings can be half the battle.

Hi yes it can be difficult to know if a H line dedicated LNA is working but you should see a rise in the noise level when switching on. A wideband LNA is much easier to test as you can just test it on any signal in SDRsharp to see if it's working. If your H line Freq is clear of spikes you should get away without a filter. I found it easier to use SDRsharp with the IF Averager plugin. It can be calibrated flat. As per one of your links. The hump can be easily seen when using it. Then go on to the more complex software.

Hi, if you have the software running, when you turn on the amp the noise level should jump up. Will give you an indication things are connected. The last thing you want to use in calibration is the ground. The noise from the ground is far higher than cold sky hence would wipe out any readings. Top tip we have a convenient large orange noisy ball in the sky 😁 your entire noise level should rise when pointed at it. If your system can't see the sun it's unlikely it will see the H line. Go for the sun first. Keep at it you will get there.

Hi here a link to a really useful site which helped me enormously. http://www.parac.eu/ Take a look in the project section especially project 3 and 9 in the list. Regards Carl

Excellent results! Keep posting👏

Yes there are three peaks in there here's what I got a while back. Working well!!

Another way would be to feed the system with a dummy load instead of the antenna for a period of time while recording. Straight into the LNA then reconnect the antenna feed. Carl

Hi good work! There is a plugin for SDR# called IF Averager which will bring out more detail. There is another which flattens out the spectrum but can't remember what it was. Carl

Can be a any type of metal, but needs to be weather resistant.

Have a look at this link from the PARAC site. http://parac.eu/projectmk3.htm

Hi probably around a minimum of 5 meters of distance from radio gear to PC. It would also be beneficial to have the receiver in a metal box. I have had the receiver beside the PC without any problems but depends on your rf environment. You won't know what interference, if any, until you look at the band. Regards Carl

Hi if you have a read through the thread most of what you are asking is in there.

Hi not sure who the youngest would be. Not too many magazines on the subject it's a small sport. SARA group is very good to join. This site has been invaluable for me the CFRAD software works great. Have a read at the projects section particularly 3 and 9 to see what is achievable with the basics. http://parac.eu/

Hi there are quite a few options on eBay at that price. Wideband LNAs with a bias tee circuit or screw terminals for power. Why do you think yo destroyed your current one? Carl

Hi I can vouch for G8FEK LNAs. Very professional and solid. I have the 1300 -1700 and has easily allowed me to observe the hydrogen line. I would definitely add the wideband LNA to your gear if using an SDR as they are not the most sensitive devices and won't overload it at all. Without going deep into the dark art of antenas my favourites for HF are the Cobweb or the doublet which is fed with ladder line to an MFJ tuner. A lot of long wire users tend to use a 9:1balun to match Carl

It will work fine. I think what UR is saying is the plate on the feed is a reflector which it is but not the main reflector. Copper will need sprayed with a coating to protect it from the weather. Keep us updated on the build.👍

Love to see some spectrum guys results here. It does look dim to the naked eye. Are we in for a big bang?

As long as the sides are 90 deg to eachother I'm sure you can have a small curve.

Looks like you will be up and running soon. What size of dish are you using? Carl

Ahh it is thin so was able to bend it into shape.

Hi Fedor basically I had to cut a hole in the centre of the plate and screw a small price of copper circuit board to a female N connector. So the screws go through the plate and N connector. The. I soldered a small price f hard coax to the copper plate using the correct spacing from the plate. Then I soldered the "bow to the coax. The top middle of the bow to the centre core and the bottom centre to the outer coax. As I used hard coax its outer is like copper tube and was enough to support the bow. It is far easier if you can get a piece of copper plate and solder a small copper pipe to it and then you just feed coax though it. The second pic is an easier way. I would also mention that you need to solder with a blowtorch to get enough heat and plumbing solder. Hope this makes sense. Carl.

Have a read through the thread there are lots of links and diagrams to get you started. Carl