Building a pyramidal horn antenna radio telescope - need advice

Question

I am currently trying to build a pyramidal horn antenna. The horn antenna is designed for the hydrogen line at 1420 MHz. The copper probe at the end of the waveguide is soldered onto a 4-hole SMA panel mount.

I'm using this LNA and this SDR and this SMA Connector Kit. I am struggling to find a 4-hole SMA male panel mount which I can use to solder the copper wire on to. Are there any alternatives which I can use to fix this issue?

Here is a link to the documentation I am following: https://physicsopenlab.org/wp-content/uploads/2020/07/Hydrogen-Line-Project-Documentation.pdf

Answer 1

A Google search for "panel mount sma" shows a selection of devices from major electronics distributors. (Here in the UK Mouser, Digikey, RS, Farnell. Elsewhere you may have a different selection.)

this SMA Connector Kit.

Try to minimise the number of adapters you string together especially for the weak signal connection between the horn and the LNA. If the horn is rigid enough you could use a four hole male plug on the waveguide section and attach the LNA directly to the horn.

If the horn is less rigid so that the weight of the LNA would make the waveguide to co-ax SMA probe flex you could use a four hole female jack on the horn and buy a pre-made short male-male SMA lead to connect it to the LNA.

After the LNA it's less critical to avoid adapter losses but the fewer adapters you use the more reliable your connections will be. Try to plan your cables to use the correct connectors without adapters where possible.

For readers mystified by what OP is trying to do I assume they are trying to build their own waveguide to coax transition (because commercial ones are really expensive).