[mythtv-users] HD HomeRun 1012xxxxx vs later models (Rev1 vs Rev2 tuners)

[Brian Wood]

On Saturday 14 March 2009 12:01:54 jason maxwell wrote:

> From digging around the archives a little, I understand there are couplers
> that split the signal with more loss to one leg than the others. Should I
> use one of these for more signal to the TVs than to the modem?  Would this
> be a better approach than an amplified splitter?  What experiences have
> others had in solving this problem?
> -Jason

You are talking about directional couplers. They have an input, a "through" 
leg and a "tap" leg. Loss from the input to the through leg is typically .5 
to 1.5 db., loss to the tap leg can be anywhere from 8 to 40 db. Obviously 
the lower the loss to the tap leg the higher the through loss, since the 
device is passive and can't create signal.

Whether this would help your situation or not depends on the topology of your 
setup. If you are sending more signal than you need out of a splitter, then a 
DC might help. If your problem is you simply do not have enough signal, it 
won't help but might make things a little better.

Using an amplifier on a multi-channel cable system is frought with problems, 
you need a very high quality amplifier, preferably one that's push-pull, to 
minimize even-order products. If you use a single-ended amp the second 
harmonic from the low band signals can render the mid-band useless.

So using DCs with good design might help you out, if you need an amplifier 
make sure you get a good quality one that's rated for the number of channels 
and the frequencies of your cable system.

You might also need a bi-directional amp, if your cable modem is after the 
amplifier. The modem needs to be able to send a signal back to the cable 
system.

-- 
beww
beww at beww.org