Formerly I was running a MythTV box directly from analog comcast cable.

Recently I moved and got WOW-HD and when I did they also gave me an analog connection to a different TV. The analog TV terminates at an old school cable box called a "Home Communications Terminal" by Scientific Atlanta.

My problem now is that I can only view TV when the MythTV is set to channel 3. I set the preset tuner channel to channel 3. Thus, the live viewing works fine. My problem is that to record something I have to set the cable box to record and my Myth box to record as well (On the wrong channel). Is there anyway I can get around this so I don't have to connect to the cable box????


For Reference Here are the Specs of and around my system
---------------------------------------------------------------------
Cable Provider: Wow! HD and Analog
Analog Cable Box: Scientific Atlanta Home Communications System

AMD Athalon 64 2.0 GHZ
DFI Lanparty UT nf4
512 RAM
Chaintech FX5200
PVR-150
PCHDTV 3000

Which all seems to work fine with a few tweaks that can be read about in the forums.

Search for "irblaster", there is a script to set it up automatically and directions both here and on the wiki.

I saw that solution but that doesn't seem to work for my issue. THe reason is that it merely coordinates my cable box and my Mythbox but I still have to set both to record. The other problem is that I have an old box so it's not the one that has the firewire connection that most of people talk about.

An irblaster lets your KM box pretend to be a remote control for your cable box.

When it records something using one, MythTV selects the correct input on your capture card, if necessary (because you're using the tuner) presets the tuner on the card to the right rebroadcast frequency (usually channel 3 or 4), then uses an external tuner script to set the cablebox to the right frequency using an IRblaster (like your InfraRed remote control) or other means (serial cable, firewire connection, ...)

If your cable box has an SVideo output you're actually better off using that, since it avoids the generational loss from re-encoding the signal onto and decoding it from the carrier frequency for channel 3 or 4.

Hi,

Have you tried the direct cable feed? Maybe the rf is converted back to the Old School type of signals. No cost experiment

Mike

I'm having a similar problem.. except that I am using an IR Blaster.

In "setup >> input connections", I have "preset to tuner channel" set to "4" .. yet, Watch TV & Recording goes to "whatever channel" on the TV Card, so I get snow. (In Watch TV mode, I can force it to channel 4.. and I'm "watching"!)

_________________
// Brian - Hardware:
ASUS P5P800 - P4 3Ghz, 500 GB PATA HD
ASUS P5K-V - P4 Core2 Duo, 500 GB SATA HD
Hauppauge PVR-350, IR Blaster, Comcast Digital Cable
http://tech.groups.yahoo.com/group/KnoppMyth/
KnoppMyth R5F27 >> R5.5

Do you have an external tuner script defined that returns success?

Apparently not. What does that look like?

_________________
// Brian - Hardware:
ASUS P5P800 - P4 3Ghz, 500 GB PATA HD
ASUS P5K-V - P4 Core2 Duo, 500 GB SATA HD
Hauppauge PVR-350, IR Blaster, Comcast Digital Cable
http://tech.groups.yahoo.com/group/KnoppMyth/
KnoppMyth R5F27 >> R5.5

There is a couple of things that I do to make sure my capture card(s) stay on channel 3. When mythfrontend launches it sometimes changes the channel on my card itself. To solve this I created a script in /home/mythtv called set2three.sh To create. nano set2three.sh and type this:
ivtv-tune -c 3 -d /dev/video0
(3 being the channel and /dev/video0 is your capture device). Save it and as root do chmod a+x set2three.sh. Now cd to /home/mythtv/.fluxbox. Nano apps. Under the last of the items that begin with [startup] add this:
[startup] {xterm -e /home/mythtv/set2three.sh}

Second thing you need to check is that your external channel change command actually works and doesn't error. You can test it by pressing Alt-X while watching live tv, then type your change channel command. i.e. change_channel 12 to change to channel 12. (Your channel command will be different depending on what method you used to setup your irblaster). If it works then make sure that it is entered correctly in mythtv-setup. If it doesn't work then search this forum and the wiki for irblaster. There is a ton of info here to get them working.

_________________
ASUS A7N266 Micro-ATX Motherboard
Athlon 2200 processor
512K Kingston PC2100 Memory
MicroAtx Case
2 PVR250's w/remote
eVGA e-GeForce mx4000 (64 Ram with Tv/Out (Svideo))
Lite-on DVD cd-rw combo
120 GB Western Digital

I got it! Thanks for the reply.. I'll keep your suggestions in mind. "Channel drift" has not been a problem with my suggestions below..

Actually, this topic is a "Deja Vu" for me.. (oddly enough, almost a year to the day!) Here's my prior post & solution..

http://mysettopbox.tv/phpBB2/viewtopic.php?t=5659

(I was on Release 5 Alpha 16, at the time.. too bad the "signature" updates globally on these forums! At this point, I am reinstalling from scratch - R5C7)

The simple answer is ..
1. Exit the Frontend
2. Stop the Backend with Alt-2.
3. Enter the Backend Setup with Alt-S. (I'll assume that you have your Capture card and Video Sources already set.)
4. Go into the Input Device, (which is "tuner0", where my Comcast Cable box is attached)
5. Set the "External channel change command:" to
6. and the "Preset tuner channel to:"
7. Exit the Backend setup
8. Restart the Backend with Alt-3
9. Re-enter the Fronend with Alt-M

_________________
// Brian - Hardware:
ASUS P5P800 - P4 3Ghz, 500 GB PATA HD
ASUS P5K-V - P4 Core2 Duo, 500 GB SATA HD
Hauppauge PVR-350, IR Blaster, Comcast Digital Cable
http://tech.groups.yahoo.com/group/KnoppMyth/
KnoppMyth R5F27 >> R5.5

I now have a working "irblaster" .. so, I've changed my backend setup to the /etc/irblaster/channel_change.sh .. this seems work "almost" work OK.. except that my cable box (Motorola DCT2244) wants either a three digit code, or the significant digits plus and "Enter" key. the channel change configuration doesn't seem to send either the "Enter" key or a leading zero.. Upper channels (>99) work OK, the lower channels don't lock in.

(I'm on R5C7)

_________________
// Brian - Hardware:
ASUS P5P800 - P4 3Ghz, 500 GB PATA HD
ASUS P5K-V - P4 Core2 Duo, 500 GB SATA HD
Hauppauge PVR-350, IR Blaster, Comcast Digital Cable
http://tech.groups.yahoo.com/group/KnoppMyth/
KnoppMyth R5F27 >> R5.5

OK, I have a working solution.. see thread at http://mysettopbox.tv/phpBB2/viewtopic. ... c&start=60 ("Out Of Box IRBlaster Support: Contribute now! ")

I added some code to the script that will add a leading zero, if the channel is less than 100.. and a second leading zero if the channel is less than 10. Works like a champ!

_________________
// Brian - Hardware:
ASUS P5P800 - P4 3Ghz, 500 GB PATA HD
ASUS P5K-V - P4 Core2 Duo, 500 GB SATA HD
Hauppauge PVR-350, IR Blaster, Comcast Digital Cable
http://tech.groups.yahoo.com/group/KnoppMyth/
KnoppMyth R5F27 >> R5.5

Why not just format all numbers to a consistent width with one command?

That's even better! Thanks! (I'm a relative "beginner" to shell script, so I appreaciate the alternative!)

_________________
// Brian - Hardware:
ASUS P5P800 - P4 3Ghz, 500 GB PATA HD
ASUS P5K-V - P4 Core2 Duo, 500 GB SATA HD
Hauppauge PVR-350, IR Blaster, Comcast Digital Cable
http://tech.groups.yahoo.com/group/KnoppMyth/
KnoppMyth R5F27 >> R5.5

hmm, newby-operator error!

I created a test script to check it out.. test_script_fix_three.sh



results in something like

It's echoing only the original two digits!
something that I'm not seeing! THANKS!

_________________
// Brian - Hardware:
ASUS P5P800 - P4 3Ghz, 500 GB PATA HD
ASUS P5K-V - P4 Core2 Duo, 500 GB SATA HD
Hauppauge PVR-350, IR Blaster, Comcast Digital Cable
http://tech.groups.yahoo.com/group/KnoppMyth/
KnoppMyth R5F27 >> R5.5