OTA & PVR/HTPC, how do you make them work together? - Canadian TV, Computing and Home Theatre Forums
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post #1 of 17 (permalink) Old 2007-12-30, 09:40 PM Thread Starter
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OTA & PVR/HTPC, how do you make them work together?

Hi!

I was wondering how people handle the possibility that for some channels the antenna must be turned (using a rotor) with HTPC/PVR software like MythTV or MCE...

- Do you use a channel changer script to send IR command to the rotor control?

- Combine antennas?

- Turn the antenna in advance to the right position (kinda defeats the purpose of having a PVR/HTPC... )

- etc...

I didn't find an installer in time to install new antenna(s) before the winter (I am afraid of heights and if my approx 30 ft tower is still solid I want to use it) but I am planning in advance for next spring and I am not sure what I should be looking/asking for... I've been toying with the idea of using more than one antenna but I am still not quite sure if that's the best thing to do...

Thank you and Happy Holidays!

Nick
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post #2 of 17 (permalink) Old 2007-12-31, 10:42 AM
 
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At this time, I just use 2 antennas and more tuners of different models to assign different lineup to them. For me:

4x HVR-950: OTA ATSC, Plattburghs/Burlington (ABC/NBC/CBS/FOX/PBSx2)
2x HVR-1600/1800 (Digital): OTA ATSC, Montreal (SRC/CBC/TQS)
2x HVR-1600/1800 (Analog): Videotron Analog Cable

All configured in BeyondTV with MediaPortal as my FrontEnd that can launch BTV Link.
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post #3 of 17 (permalink) Old 2007-12-31, 01:26 PM
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Oh wow, why so many tuners? Are you really going to record 8 different programs at once? (and could a pc handle that much..?)

And Knight, it depends on your location as to how many antennas you need or what setup you need.
I'm in the GTA in such a position that I can point an antenna south at Buffalo and still pickup Toronto stations from the side in good quality.
If stations are in two opposite directions, you'd need two antennas, or a rotor, or perhaps more complex setups depending on your needs.
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post #4 of 17 (permalink) Old 2007-12-31, 03:01 PM
 
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Quote:
Originally Posted by recneps77 View Post
Oh wow, why so many tuners? Are you really going to record 8 different programs at once? (and could a pc handle that much..?)
At the moment, I am using 2 antennas because the 2 broadcast regions are separated by ~165-170degrees and I couldn't find a sweet spot between the two with my current antenna. I tried using the back lobes since I'm ~10km LoS from Montreal but it wasn't strong enough either. Therefore, I have 3 RG6 that goes to my PVR (1xOTA Montreal, 1xOTA Plattsburgh/Burlington and 1xAnalog Cable).

#1: Since I have never seen a PVR software that knows which antenna to use, I have to assign tuners to a specific market.

#2: If I were using 6xUSB HVR-950 (ie, the exact same tuners six times), neither I or the PVR software would be able to tell which is connected to what. Worst would be after a reboot, it may not recognize them in a different order and the assignation would be down the drain. To avoid this issue, I decided to go with different brands and/or models of TV Tuners to be able to simplify things. Luckily for me, the Hauppauge latest HVR series is excellent and works with alot of PVR softwares. I also picked a motherboard (MSI GA-M55Plus-S3G) with 3xPCI, 2xPCI-E (1x) and 1xPCI-E(16x) so I can expand as I need without forgetting the ~10 USB 2.0 ports available.

Do I use all 8 at once? Yes... but only during my tests! At peak, my PVR does record 4-5 shows at the same time on a regular basis, some days of the week, when the normal programming is on the air. You also have to consider that I can use those tuners remotely via BeyondTV Link (2x) to watch live TV. It'll use the proper tuner depending on the selected channel so it makes the 2 antenna setup seamless for me at this time when I use my HTPC but requires more tuners.

BTW, even if you count 4-5 of the 8 tuners I have available, it does use all the available tuners in a particular market at times (ie, using all the OTA MTL Tuners at the same time) which means I am borderline and would need to add more tuners unless I can find a way to get all my OTA reliably through a single RG6 feed. Only then could I have them all record whatever (which is my goal next summer).

Regarding my PVR, it handles all 8 feeds at the same time just fine while feeding 2xBeyondTV Link. I'm currently using an AMD X2 3800+ with 3GB RAM and 2xSeagate 320GB in RAID-0 to record shows. The only reason for 3GB of RAM is because it hosts some VMWare machines + PVR duties. The reason I have more HVR-950 is because I caught a boxing day deal at ~55$CAD tx&shipping included per tuner so I grabbed 2!

Last edited by TheIceMaster; 2007-12-31 at 03:10 PM. Reason: Clarify/Spelling
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post #5 of 17 (permalink) Old 2008-01-01, 09:56 AM
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Build a hardware interface from the rotor to the PC, and write a script to control it through the PC channel selector software. That is if I am fine with one tuner. Otherwise a buch of aimed an"cut" antannae combined to one or a couple feeds.
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post #6 of 17 (permalink) Old 2008-01-05, 01:16 PM Thread Starter
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Hi!

Sorry for the delay... Between the holidays and a few things I had to take care of I just found the time to reply to your posts... Sorry...

Quote:
Originally Posted by recneps77 View Post
And Knight, it depends on your location as to how many antennas you need or what setup you need.
I'm near Montreal... I inputted the coordinates of my home and the emitters of the stations I would like to watch in Google Earth.

- The local stations are west of my location. They are about 20 miles from here. Some (most) of them are using temporary emitters which are not operating at full strength.

- Mount Lyon and Mount Mansfield (where the US emitters are) is, not surprisingly, to the south. Mount Lyon is more to the west while Mount Mansfield is more to the east. They are around 70 miles each from my location. Mount Mansfield is more than 90 degrees from the local stations, Mount Lyon maybe around 60-65 degrees.

Quote:
I'm in the GTA in such a position that I can point an antenna south at Buffalo and still pickup Toronto stations from the side in good quality. If stations are in two opposite directions, you'd need two antennas, or a rotor, or perhaps more complex setups depending on your needs.
From reading the thread for my region I had the feeling that to get all the channels I want I would need a rotor or multiple antennas... Getting one of the tv stations in digital, WVNY, is already known to be somewhat problematic because it's not on UHF, it's on VHF (which the usually recommended CM4228 can get but up to a certain point, it's supposed to be a UHF antenna) and it's probably affected by other "local" tv stations.

Getting the signal of the temporary emitters may prove somewhat difficult from my location...

I was able to get to get, using a SIR-T451 and, of all things a Silver Sensor (a small antenna only made to get (very) local markets), a tv station from Mount Mansfield and a tv station from Mount Lyon. As soon as I was moving the antenna I was losing the signal and I had to keep it very close to the ceiling but I was able to watch both stations. These are tv stations whose emitters are 70 miles from here...

I was never able to do the same for the "local" stations (20 miles from here... ).

I guess I'll only know for sure when the antennas (and possibly the tower because I'm no longer quite sure if the current one is still ok) will be replaced but I am expecting that either a rotor or multiple antennas are going to be required...

Thank you very much for your help and Happy new year!

Nick
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post #7 of 17 (permalink) Old 2008-01-05, 01:55 PM Thread Starter
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Hi!

Quote:
Originally Posted by TheIceMaster View Post
At the moment, I am using 2 antennas because the 2 broadcast regions are separated by ~165-170degrees and I couldn't find a sweet spot between the two with my current antenna.
Gee, your situation is even worse than mine...

Quote:
I tried using the back lobes since I'm ~10km LoS from Montreal but it wasn't strong enough either. Therefore, I have 3 RG6 that goes to my PVR (1xOTA Montreal, 1xOTA Plattsburgh/Burlington and 1xAnalog Cable).
Have you looked into combining them?

Quote:
#1: Since I have never seen a PVR software that knows which antenna to use, I have to assign tuners to a specific market.
This is something I could do though I don't have as many tuners as you (I would lose the possibility of recording/watching live tv from multiple programs from the same market...

Quote:
Do I use all 8 at once? Yes... but only during my tests! At peak, my PVR does record 4-5 shows at the same time on a regular basis, some days of the week, when the normal programming is on the air.
Impressive...

Quote:
You also have to consider that I can use those tuners remotely via BeyondTV Link (2x) to watch live TV. It'll use the proper tuner depending on the selected channel so it makes the 2 antenna setup seamless for me at this time when I use my HTPC but requires more tuners.
I was planning to possibly share my HDHomerun in a similar way between my PVR (MythTV) and PCs in the home (with the provided software). For now though the HDHomerun is mostly collecting dust as the local installer I was planning to use is no longer quite interested in doing antenna installations and I couldn't find a replacement in time (before winter...).

Quote:
I am borderline and would need to add more tuners unless I can find a way to get all my OTA reliably through a single RG6 feed. Only then could I have them all record whatever (which is my goal next summer).
So you are looking into combining the signals... BTW, what antennas/kind of antennas do you have (CM4228, Yagis, XG13?)?

Quote:
Regarding my PVR, it handles all 8 feeds at the same time just fine while feeding 2xBeyondTV Link. I'm currently using an AMD X2 3800+ with 3GB RAM and 2xSeagate 320GB in RAID-0 to record shows. The only reason for 3GB of RAM is because it hosts some VMWare machines + PVR duties.
All SD or a mix of SD and HD?

Quote:
The reason I have more HVR-950 is because I caught a boxing day deal at ~55$CAD tx&shipping included per tuner so I grabbed 2!
Hmm, good deal...

Thank you very much and Happy new year!

Nick
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post #8 of 17 (permalink) Old 2008-01-05, 02:01 PM Thread Starter
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Hi!

Quote:
Originally Posted by classicsat View Post
Build a hardware interface from the rotor to the PC, and write a script to control it through the PC channel selector software. That is if I am fine with one tuner.
If I were to do this I could probably use the following script and configuration file provided in this post:

http://osdir.com/ml/hardware.lirc/2004-10/msg00045.html

Quote:
Otherwise a buch of aimed an"cut" antannae combined to one or a couple feeds.
Very interesting idea... I wonder though how massive and costly the end result would be and if all of these antennas would interfere with each other as regular antennas are known to do... The other problem would be adding antennas if a new channel gets added as I can't do it myself (I'm afraid of heights...)...

Thank you very much and Happy new year!

Nick
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post #9 of 17 (permalink) Old 2008-01-05, 02:48 PM
 
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This is getting very reception specific.. may be better suited in the appropriate OTA reception thread... I follow all QC threads so I can follow this too

Quote:
Originally Posted by Knight View Post
So you are looking into combining the signals... BTW, what antennas/kind of antennas do you have (CM4228, Yagis, XG13?)?
Yes and now not really.

I was using a CM4221 HomeMade clone for Montreal and a A-Neutronics AV-891 for the US feeds. Neither was good enough for both markets on their own. Both also had enough signal on some stations to cause major multipath/headaches so joining them would have required filters/CM jointenna which would have gotten quite costly.

Although the AV-891 is considered a crappy PoS by a few people here, it performs quite decently and was dirt cheap (less than 30$CAD incl. everything) and comes with a builtin rotor (that freezes in winter) and preamp but at at 115+km, its reaching its limit where I was still able to get 75-95% signals from the US stations. All in all, it was a decent purchase for someone who, at that time, knew nothing about ota reception but I wouldnt recommend it for long term use due to the build quality. My main gripe about it is that you cannot customize your setup by changing the preamp and the antenna itself is ordinary. You're stuck with what you have or nothing at all so I started looking for a replacement.

Moving on to this years boxing day deals, I ordered a 91XG for less than 70$CAD tx/shipping included locally (otherwise I would have gotten a CM4228 at Montcalm's). I received it yesterday and installed it aiming directly at Mt.Mansfield. At the moment, with the help of my Motorola DropAmp (15db/2.5NF), I am able to receive all the US networks at 85-95% (besides ABC on VHF) and the Montreal locals at 80-85%. The signals are stable yesterday's Friday Night Lights was without any pixelisation or dropouts. Without the dropamp, all US stations are fine except FOX at 70-75% and locals are in the 60-75%.

This was unexpected but a happy surprise as I always felt yagi antennas were VERY directional with excellent front to back. I may just be lucky, it may be my location, it may be the antenna location, it may be due to trees without any leaves... we'll see in the coming months how it holds up.

Quote:
Originally Posted by Knight View Post
All SD or a mix of SD and HD?
Mix: 6xHD and 2xSD.
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post #10 of 17 (permalink) Old 2008-01-05, 03:57 PM Thread Starter
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Hi!

Quote:
Originally Posted by TheIceMaster View Post
This is getting very reception specific.. may be better suited in the appropriate OTA reception thread... I follow all QC threads so I can follow this too
Sorry, I kinda had to explain why I thought a rotor or multiple antennas was necessary... It wasn't my idea to put it in the HTPC forum though...

Quote:
I was using a CM4221 HomeMade clone for Montreal and a A-Neutronics AV-891 for the US feeds.
The owner of A-Neutronics is nice to deal with but appears to be a very busy person...

Quote:
My main gripe about it is that you cannot customize your setup by changing the preamp and the antenna itself is ordinary. You're stuck with what you have or nothing at all so I started looking for a replacement.
Could be an interesting temporary solution for me as I'm stuck with an antenna that no longer works and the other which only partially works and there's no way I'll ask somebody to climb my tower in winter...

(If I can only find a way to put it high enough without having to climb on my roof/tower...)

Quote:
Moving on to this years boxing day deals, I ordered a 91XG for less than 70$CAD tx/shipping included locally (otherwise I would have gotten a CM4228 at Montcalm's).
Oops, I got my model number all wrong, the 91XG that was the antenna I was thinking about... BTW, sounds like the MicroInformatique deal...

Quote:
I received it yesterday and installed it aiming directly at Mt.Mansfield.
You're lucky you can install it in the middle of winter, I wish I could do the same...

Quote:
This was unexpected but a happy surprise as I always felt yagi antennas were VERY directional with excellent front to back.
That very good news for you... A little less for me since I was hoping that the fact that these antenna are directionnal could be used to my advantage to combine multiple antennas without having multipath issues...

(I was thinking of using 2-3 Yagis each pointing in a direction where there are emitters... Only problem is I don't know if the town has any laws governing this (I'll have to look into this))

Quote:
Mix: 6xHD and 2xSD.
O.k. Never though a pc could handle that many feeds at the same time...

Thank you very much and have a nice day!

Nick

Last edited by Knight; 2008-01-05 at 04:03 PM. Reason: added some additionnal details..
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post #11 of 17 (permalink) Old 2008-01-05, 04:58 PM
 
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Quote:
Originally Posted by Knight View Post
Could be an interesting temporary solution for me as I'm stuck with an antenna that no longer works and the other which only partially works and there's no way I'll ask somebody to climb my tower in winter[...]You're lucky you can install it in the middle of winter, I wish I could do the same...
Hehe, I'm crazy, its my nature but with safety precautions. I have some climbing gear laying around so I just attach them every 2-3 feet so I cant fall down. You should also have someone around when you are working in a tower but, if you dont feel comfortable, dont do it. Its not worth the risk.

The 91XG is installed in a temporary 15ft pole (grounded and al to be safe), not a real tower. I am toying with the idea of using my old 25ft tube that I was using for my solar cover/blanket reel as a temporary mast for the remainder of the winter. It would have support from the ground up to ~11ft in the air and free for the remainder (~15ft). I need to check how flexible it is before hand

I'm still enquiring to the city about tower restriction. Less than 2 years ago, someone built a self-standing ~40-45ft tower down the street so I am hoping I wont be running into issues to have something similar built next summer.

Quote:
Originally Posted by Knight View Post
That very good news for you... A little less for me since I was hoping that the fact that these antenna are directionnal could be used to my advantage to combine multiple antennas without having multipath issues...
That was my original goal going with the yagi. I thought 1 high gain for the US and low gain from Montreal to ensure I wouldnt have too much overlapping signal combined with a simple reversed splitter. I can't complain on the result though!

Quote:
Originally Posted by Knight View Post
(I was thinking of using 2-3 Yagis each pointing in a direction where there are emitters... Only problem is I don't know if the town has any laws governing this (I'll have to look into this))
There usually are municipal laws regarding the tower height. I have yet to find a city that has a limit on the number of antennas you can hook on one though.

Quote:
Originally Posted by Knight View Post
O.k. Never though a pc could handle that many feeds at the same time...
Remember the feeds are only 2-3MB/s on HD with no processing of any kind. 6x3MB ~18MB/s with the writes being shared on 2 HDs (RAID-0) so each has to be able to sustain only 9MB/s writes per second. Most modern HDs will be able to do it. I could even add a 3rd HD to the RAID-0 if that would be the bottleneck (or use faster/better HDs).
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post #12 of 17 (permalink) Old 2008-01-05, 08:39 PM
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Quote:
Originally Posted by TheIceMaster View Post
Remember the feeds are only 2-3MB/s on HD with no processing of any kind. 6x3MB ~18MB/s with the writes being shared on 2 HDs (RAID-0) so each has to be able to sustain only 9MB/s writes per second. Most modern HDs will be able to do it. I could even add a 3rd HD to the RAID-0 if that would be the bottleneck (or use faster/better HDs).
But the Bs that you are talking about are bytes not bits so that is pretty impressive!
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post #13 of 17 (permalink) Old 2008-01-06, 10:12 AM
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Quote:
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But the Bs that you are talking about are bytes not bits so that is pretty impressive!
Exactly.

The maximum data rate for MPEG2 HD from OTA, cable or Sat is only 2.375 MB/s. This is not even 1/25 of what any given modern drive will handle. If one could get enough cards installed or use firewire tuners, it would be almost possible to record between 15 and 20 simultaneous feeds.
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post #14 of 17 (permalink) Old 2008-01-13, 05:28 PM Thread Starter
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Hi TheIceMaster!

Sorry for the delay... I hope next week will not be as crazy as this one was...

Quote:
Originally Posted by TheIceMaster View Post
You should also have someone around when you are working in a tower but, if you dont feel comfortable, dont do it. Its not worth the risk.
I can't even climb my roof because I'm afraid of heights so I'm pretty sure I won't we comfortable enough to climb a tower...

(Though I never thought I would be able to parachute jump and I have done it more than once... )

Quote:
The 91XG is installed in a temporary 15ft pole (grounded and al to be safe), not a real tower. I am toying with the idea of using my old 25ft tube that I was using for my solar cover/blanket reel as a temporary mast for the remainder of the winter. It would have support from the ground up to ~11ft in the air and free for the remainder (~15ft). I need to check how flexible it is before hand
You better be sure that the thing is pretty solid...

Quote:
That was my original goal going with the yagi. I thought 1 high gain for the US and low gain from Montreal to ensure I wouldnt have too much overlapping signal combined with a simple reversed splitter. I can't complain on the result though!
I guess...

Quote:
There usually are municipal laws regarding the tower height. I have yet to find a city that has a limit on the number of antennas you can hook on one though.
I found the following cities when I was looking for info for my home town a few months ago...

Ville St-Laurent has a limit of one antenna:

http://saintlaurent.ville.montreal.q...laws/radio.asp

Boisbriand has a limit of two antennas:

http://www.ville.boisbriand.qc.ca/pa...lements.aspx#3

I did not find any information for my own town (they have a website but did not provide any information about this on it...).

BTW, I kept thinking about this:

Quote:
#1: Since I have never seen a PVR software that knows which antenna to use, I have to assign tuners to a specific market.
If there was some sort of (possibly infrared) switch like those matrix switches where multiple inputs can go to multiple outputs but in reverse it might be doable with MythTV (and possibly other PVR apps) by using the channel changer functionality...

If I'm not mistaken in MythTV the channel changer is settable per tuner and is called with the channel number one wants to change to... Using a small database (or simply ifs or cases) one could determine the antenna to switch to and the tuner could be determined by using more than one script that calls the other script but specifies the tuner the script was for...

Something like:

tuner1-changer script gets called with channel number 2 as parameter.

tuner1-changer script calls antenna-changer script with parameter tuner1 and channel number 2.

antenna-changer script sends the appropriate command to the switch to use the local antenna with tuner 1.

tuner2-changer script gets called with channel number 33 as parameter.

tuner2-changer script calls antenna-changer script with parameter tuner2 and channel number 33.

antenna-changer script send the appropriate command to the switch to use the US antenna with tuner 2.

I just wish hardware suitable existed and/or was easily available (and not too costly.... ).

I still wonder why a directional antenna works so well for you and if there's a way around it... From the sound of it avoiding the problem would require, as you mentioned, multiple jointenna (and probably many filters) which would probably degrade the signal somewhat and be pretty costly...

Once again thank you very much for your help!

Have a nice day!

Nick
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post #15 of 17 (permalink) Old 2008-01-13, 05:33 PM
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Quote:
Originally Posted by Knight
If I'm not mistaken in MythTV the channel changer is settable per tuner and is called with the channel number one wants to change to...
That is correct. MythTV runs a MySQL database called "mythconverg", and in it your scanned channels are tracked by their channel number, the PC card/device, and that card/device's inputs if there are more than one (such as RF, S-Video, Composite, etc.). If your system can access the same channel over two or more such cards, the software allows you to prioritize or change the weight of each card/device to prevent conflicts amongst scheduled recordings.



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