[mythtv-users] HDHomeRun(s)

[Ben Kamen]

On 1/14/2010 12:18 PM, Greg Oliver wrote:
> On Thu, Jan 14, 2010 at 12:13 PM, Ben Kamen<bkamen at benjammin.net>  wrote:
>> On 1/14/2010 12:02 PM, David Brodbeck wrote:
>>>
>>> On Thu, January 14, 2010 7:14 am, Greg Oliver wrote:
>>>>
>>>> I am just wondering how the same cable connected to a TV produced
>>>> different results when connected to the hdhomerun..  I can only assume
>>>> the TV has pretty good gain or something???
>>>
>>> Yeah, it's possible the TV's tuner is more sensitive.
>>
>> Ehhh, TV tuners are of wide quality. When it comes to your TV, they're just
>> as interested in saving $0.02.
>>
>> Of course, you could test this if you have a sig meter somehow on both
>> inputs for a given channel.
>>
>> Keep in mind, when you split the signal, you lose about 3.5dB per split.
>
>> From the antenna, there is one 4x1 splitter.

So each leg has an instant 7dB loss there. ( in losses 3dB=1/2 power, 6db=1/4power )

Is this an active or passive splitter? If it's passive, this would be a great place to put an active
splitter, then your 4way would realize no loss and possibly some gain to boost the signal down the line.

>> So if you have -10dBmV coming in and put it through a 2 way splitter, you
>> now have -13.5dBmV coming out
>> the 2 ports.
>>
>> The 3 output splitter on my house for CATV has
>> Input --->  3.5dB loss
>>        |->  7dB loss
>>        \->  7dB loss
>> And so on. So your test environment could affect your reception quality as
>> well.

So there's another split down at the bottom? Another 3.5dB?

> I live in Dallas, TX, and can pick up Houston TX channels on my TVs...
>   The HDHomeRuns cannot tune them..  Thjis is current with a TV and
> HDHR off of the same "split" antenna run..

You might consider (for investigative purposes) try to obtain the sensitivity for both receivers.

Do the manuals list this in the back of the user manuals in the tech specifications?

  -Ben