EME - Power, Power, and More Power

Gear acquisition mode continues...

As you can imagine, trying to get a signal to the Moon is going to take some power. I can't remember what the distance is, but it's so far, that your classic 10w 1.2 GHz transmitter is probably not going to make a mark. 

Additionally, as we start to try to listen for signals, the reflected signals coming back from the Moon are going to be rather weak, so... Again, probably going to need a amplifier for that. 

So here we are, trying to figure out how much power we need on the transmit side, and also looking at options for low noise amplifiers, or pre-amplifiers on the receive side. 

The fact that we have to have both of these in line with the transmit and receive is going to add some complication and require some switching, which I will talk about in a later post....  Particularly, if we have a low noise amplifier in line with the transmit sequence, And we don't switch it out of line, it will more than likely burn it out. 

So, where do we go for amplification at the 1.2 GHz range?  Seems like the no-brainer approach might be to get one of those really cool, well made, finally machined amplifiers (and Low noise amplifier for the receive) from Kuhne. 

One of the challenges was to determine how much power on the transmit side we would need. I think that was easily calculated by the amount of money that would need to be spent, and how complicated things may need to be with a power supply to support very high power output - so both Eric and myself went with the 250 w power amplifier - the MKU PA 23CM-250: https://shop.kuhne-electronic.com/kuhne/en/shop/power-amplifiers/MKU+PA+23CM250W+CU++Power+Amplifier/?card=971

This amplifier gave us what I think will give us enough power to reach the moon, and at least allow some of the big gun stations that are already doing Moon bounce a chance to catch our signal.  It was also considerably cheaper than the next step up which was 1.5 KW. (Although, as you can tell it really was pretty expensive)

On the receive side, we chose the MKU LNA 132-ah: https://shop.kuhne-electronic.com/kuhne/en/shop/MKU+LNA+132+AH+SMA++Low+Noise+Amplifier/?card=316

Looks like this is the super low noise pre-amplifier that will go near the antenna feed point.

Eric is going to explore a little bit about building his own amplifier at some point in time, but this gives us a quick method to entry into the EME space.

We do have 12 volt power supplies available, but with this power amplifier using ldmos technology, it's going to require about 50 volts.  We were able to jump on amazon.com and find plenty of options (like Meanwell) that will give us 48 volts DC, which should be plenty - and if luck has it, there are probably some adjustments we can make to get that 48 volts closer to 50 if we want.