Pre-amp & distribution amp layout confusion!

66ninetyeightls · 2-Mar-2015, 3:36 PM

Good morning.

I currently have my antenna setup with a (TITAN 2 HIGH GAIN PREAMPLIFIER CM7777) as follows:

(Antenna > CM7777 > 2 Way Power Pass Splitter > 2 Televisions)

I would like to install an (ULTRA MINI 4 CM3414) so I can add 2 additional TVs for my children’s rooms.

Both the Pre-amp and Distribution amp would need to be in the attic away from a power supply. This was not a problem with the pre-amp as I was using the supplied power inserter and I understand that I can also use a power inserter for the distribution amp. I am having trouble figuring out how to power both amps without splitting the feed from the pre-amp at least once. I would prefer that 100% of the pre-amp signal be input into the distribution amp but can't see how when using power inserters.

Any help would be greatly appreciated.

GroundUrMast · 2-Mar-2015, 4:19 PM

It's rare that more than one amplifier is needed. You can very easily overload a second amplifier when driving it from the output of another amp... especially a high gain preamp like the CM7777.

Please post a link to your TV Fool Report. It would be very helpful to know what sort of signal levels are in the air. Also, what make and model antenna are you using?

I'll be a bit surprised if there is actually a need for a second amplifier. I'd expect a passive splitter to be more appropriate.

66ninetyeightls · 2-Mar-2015, 6:16 PM

Thanks very much GroundUrMast

Maybe I will just try a passive splitter first. They are the easiest and cheapest option.

See below for My TVFool Report. My antenna is pointed at the cluster S-SW

GroundUrMast · 3-Mar-2015, 1:11 AM

Thanks for the TVFR image... The signal levels shown actually indicate that the CM-7777 is an appropriate choice in your situation. If the signal levels were stronger, I'd be less inclined toward the CM-7777.

If your antenna is in the attic and you're still getting reliable reception, you're doing remarkable well. I'd expect to get better results mounting outdoors, clear of obstructions. The preamp will provide best results if mounted near the antenna, using no more than a few feet of coax to make the connection. So, If your antenna is outside and the preamp is in the attic, you're likely loosing some performance.

Tim · 3-Mar-2015, 11:51 PM

Not to get into the discussion of whether or not you need a preamp and a distribution amp, let me answer part of your question. You can isolate one portion of your antenna system from another portion as far as the DC voltage is concerned by using a DC Voltage Block. Winegard used to make one and I think Pico Macom does also. Less than 1 dB loss on the old Winegard VB1000 I have in my junk box. They look an F connector on one end and are threaded on the other end to accept an F connector.

GroundUrMast · 4-Mar-2015, 3:04 PM

At first glance, I think the OP was asking how to power two amplifiers via the same coax down-lead... While a DC block would be an element in a theoretical solution, one would have to consider a few additional factors.

1) What are the voltage and current requirements of each amplifier?

2) If the voltage requirement is the same for both, would a single power supply have the continuous output capacity to carry both loads without overheating?

3) If the voltage requirements are not the same, how would you go about stepping down or stepping up the voltage to safely drive each amplifier?

As these cursory questions illustrate, it's almost certain that a custom designed power supply and power insertion/distribution arrangement would be needed. That's not an impossible task, but I would expect such a project to require the skills of someone who has more than a beginning-hobbyists knowledge and experience.

For ease of service and to avoid possible damage to the preamp units, I'd simply run a second RG-6 coax to the attic... from a location that has an available outlet to power the new amp.