[mythtv-users] Coax splitters - how painful are they?

R. G. Newbury newbury at mandamus.org
Sun Sep 30 22:27:45 UTC 2007

Brian Wood wrote:
> R. G. Newbury wrote:
>> Brian Wood wrote:
>>> R. G. Newbury wrote:
>>>> Well I DO NOT FEAR a visit from the FAA....it would be the DoT up here 
>>>> in the 'frozen north' (that describes our bureaucracies not our weather!)
>>> Actually I believe it would be the DoC, at the behest of the DoT.
>>>> Seriously, I want to combine a cable feed and an antenna through 
>>>> combiner, and feed one coax to the TV. Either feed alone is fine and I 
>>>> can switch them, but through a (cheap) combiner I get nothing watchable.
>>>> Both signals have already been split: the cable coax to feed the 
>>>> mythbox, and the antenna has already been boosted (by a medium-cheap) 
>>>> amp, and split three ways, 2 of which feed the HDHR unit,
>>>> This may not be the best setup.. I do not know. I do suspect that I need 
>>>> better splitters than the el-cheapo's I had in the bottom of a box of junk.
>>> Combining OA and cable is frought with problems, you not only can't have
>>>  the same channels on both feeds, but adjacent ones can pose problems as
>>> well. You need to balance levels, taking into consideration that the
>>> levels from a CATV system can vary as much as 12 db. in a 24 hour period.
>>> If it were me I'd use two different capture devices, one for OA and one
>>> for cable, as a capture card is probably cheaper then the gear to
>>> properly do such a combining.
>>> But that's me, and the "land of the cheap (capture cards that is).
>>> beww
>> It's not a capture card problem. I have 4 tuners: 2 analog in the 
>> PVR-500, and 2 digital in the HDHR.
>> My wife wants to channel surf. Although she appreciates the advantages 
>> of the mythbox over the VCRs, there are still ocassional problems which 
>> cause her to want to avoid using the mythbox directly.
>> What I was attempting to do, was feed the antenna and the cable into the 
>> single coax input on the TV. Like most TV's it only has a single coax. 
>> While cyber-shopping, I found a page which stated that the Sony 
>> KDL-37XBR4 had two coax inputs. A physical examination dashed that hope.
>> The LG treats Antenna and Cable as just 2 different input sources, so I 
>> can switch using the remote...IF I can actually switch or combine the input.
>> Since combining is a No-Go....anyone have any ideas for a remotely 
>> controlled switch?  (Lirc is expandible and can do so much!)
> I have cable going into 2 capture cards and satellite into a third.
> Since the channel numbers do not overlap (cable is all <100, satellite
> all >100) I have no problems, the system automatically switches to the
> proper card for whatever channel I select.
> I wonder if you could edit the channel numbers of the OTA channels so
> they were outside the range of your cable channels (perhaps just prepend
> a "9" or something like that)?
> Just a thought.
> beww

In order to separate the channels in the EPG I had the channel scan use 
'0' as a separator, and then I multiplied all of the OTA channums by 
100. This give me OTA channels like 201, 4302 etc for 2.1 and 43.2 etc. 
and all the OTA channels are 'above' cable channel 61. This involved NO 
changes to any other field in the channel list.

update channel set channum = channum * 100 where sourceid = 3;


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