Awwww you are all being rotten
To be totally fair here.... there have been line powered wideband RF line amps around for decades in the satellite industry. They do work if used correctly. I used to be heavily into TVRO prior to the days of easy to use 'direct to home' mini dish stuff. I had a 1.2m Ku band Dish & LNB at the end of a long cable run at the bottom of my garden. Line amplifiers are a valuable asset on long cable runs whether you are using Satellite or lower frequency feeders. In the professional world you use slope gain corrected line amplifiers to compensate for the slope loss characteristics of coaxial cable. As the frequency gets higher, the more loss and so the more gain that is required to counter such losses on long cable runs. The advert correctly identifies this issue and the level compensation required when splitting a feeder cable two or more ways.
Where this amplifier is amateur is in its claims to cure all problems as this simply isn't the case with RF feeds. For a start, if this is a lab grade flat response 30dB gain amplifier(it isn't but lets be generous) it would actually over amplify lower frequencies and likely cause all manner of overload issues at the receiver input. 30dB is one heck of a lot of gain for a simple line loss amplifier. More gain is not always a good idea and you need tight control over the gain slope and associated noise figure for the complete system.
It should be stated that in many cases, such a simple non 'slope adjusted' amplifier MAY work on a very long coaxial cable run as receivers have become more tolerant of excess signal levels. The advertised amplifier is no different to a two stage Minicircuits MAR-6 MMIC gain block....great if used appropriately
For the price its cheap enough to try. A MAR-6 MMIC costs around $2 so to build this amp using two of them would cost you around $4 + PCB + connectors + Case. Mini-Circuits take one of their MMIC's mount it on a small PCB with some passive components and then charge a significant sum for the ready to install gain block....it isn't rocket science to use an MMIC so the cheap price shouldn't be an indicator that the amplifier is no good. If it turns out to contain a pair of Bipolar transistors on a crap PCB with similarly crap passive components, then that is another matter
I have seen such coming out of China but they are usually limited to terrestrial TV and only 80-890 MHz bandwidth which isn't too demanding and analogue TV tuners were very tolerant devices.
This isn't a professional device, but lets not call it crap either....unless that is , we buy one and prove it to be so
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