The Official AVS Dish DTVPal DVR Topic! - Page 508

Thanks; ed_in_tx and Chuck44 agree, cool air flows IN from the left (cooling fan location), so cool air flows over HDD first. My fan is in backwards! It's only been three days and it has worked fine all that time, so there is no apparent damage as yet, but I'll turn it around right now.

I used the link to RabbitEars posted here recently.

http://www.rabbitears.info/oddsandends.php?request=tsid

That's why I said "Both mine blow IN..." I've read some came reversed to exhaust warm air out rather than blow cool air in. Makes sense to me to blow cooler ambient air over the HDD first.

if you do a "factory reset" you have to disable the updates again and reset any other changes you made.

Look at the dirt on the old fan.

I have 2 units and they came with the fans installed differently so that one blew air in and the other sucked air out. We can argue this all we want but I see advantages to doing it either way. The important thing is to keep the fans clean and the unit inside clean. As long as this is done and the fans are working then it really should not matter.

Sorry, I've been off the grid for a couple of days, so a little late on the response.
I believe you are correct (install wizard will wipe your timers), and Chris C confirmed. So, yes, that may be overkill if your issue isn't really causing any significant scheduling problems for you. If I resort to running the install wizard, it probably means my DVR is messed up to the point that I am OK with losing the existing timers and rescheduling. For example, in the days/weeks following daylight savings time change, my guide data never seems to correct itself (on some channels) without my intervention. But at least the wizard won't wipe out my "permanent" preferences/options, such as text size, sorting options, etc. Also, TV scheduling being what it is (changing constantly), I have to review and adjust my repeating timers once a week anyway, so if my guide data is missing or otherwise corrupted, that is a good time to do the install wizard and (hopefully) set things straight. Not something I do very often, but it has "fixed" some issues for me on occasion.

Not only that, I no longer believe my idea would work anyway. After spending several days reading much of this thread, and experimenting with my own CM-7000PAL, I now believe the PAL actually stores all the stations it ever receives - even ones you delete. That's the only way it could "know" not to keep adding them back.

The apparent 19-station limit is probably just an artifact. When you go to the 3-2-6 diagnostics screen, the PAL appears to write diagnostics info into a rather small buffer; if you have 19 or more stations the buffer fills up and that's all you see, but there's more data that simply isn't displayed.

Apparently, the only way to prevent a station from being included in the PSIP calculation is to prevent the PAL from receiving it (perhaps with a notch filter on the RF input). Of course, that would also prevent you from watching or recording that station, which might be OK for KBOP but probably not for KDFI or KERA.

Even 12 PSIP lines will overflow the the diagnostics text buffer. The last line on the last screen on my DTVPal is truncated but at least the calculated local time infohas been displayed...

There is a hex number on the ident line. It appears to have two values: 0x2203 (the station has not been received recently) and 0x4404 (received -use for time calculations??)

In the last two weeks I have noted the the following errors: 61, 67, 89, 22, 18 seconds and some time during that period two distant stations changed state to 0x4404.

That may be another (thankfully minor) bug in the firmware. The last line on my 19th PSIP is also truncated. Apparently the last line gets truncated whether the buffer is full (>19 PSIPs) or not

My guess is that these diagnostic screens were intended for the software designers so they could debug their time calculating algorithm. It was never intended to hold more that a few "elements" or for consumer use. I wounder if I'm missing anything interesting...

From my observations I totally agree. I also believe the number of "elements" in the diagnostics screen is the total number of stations that you have received since the last time you did a complete initial setup/install procedure or did a restore to factory defaults. The number of elements would include all of your local stations that you receive all of the time as well as all of those out-of-area stations that you only receive when the weather conditions are just-right.

I had 36 elements in my diagnostics screen prior to going through a new install procedure with 16 out-of-area stations listed in my diagnostics screen. After wiping the PSIP memory clean I had 19 elements right away and then 20 elements showing the next day, which just happens to be my total number of local stations that I receive all of the time. Why it took a day to get up to 20 is anybody's guess. Maybe it can only handle 19 initially and then bumps the last one in the list to add an additional one to the beginning and at the same time increases the number of elements by 1?

It does seem that the first one in the list is the last one that was added; another reason my original idea wouldn't have worked. Even if the hypothesis that it calculates time using only the 19 stations displayed were correct, you'd still have to add the stations with the most reliable times last, not first. I can't think of any easy way to do that.

I wonder about the purpose of letting you set the time manually if it's calculated from PSIP data. Maybe it saves the difference between the PSIP calculation and the time you enter, and applies that "correction" to future PSIP calculations.

Should be easy to test, at least if you're not recording anything for a day or two: just set the clock off by 30 minutes or an hour, then see if/how long the incorrect time "sticks."

Did anyone read point two? The DTVPal might only use stations that have been received recently?

I read it. I don't know if you're correct but in light of point 3 it sounds like a good guess.

I'd love to know more about the time calculation algorithm. If I'd written it, I'd probably have done something simple, like:

1. During the initial setup, sort all the stations by time, and pick the strongest of the middle three or four as the default to use as a reference.
2. Give the user an option to choose another station for a time reference, in case the one picked during setup was a poor choice.
3. On an "advanced" setup page, give the user an option to enter a +/- offset from the chosen station's time.

But my guess as to what it's actually doing is more complex:

1. During the initial setup, calculate the median time.
2. Assign each station a weight based on factors such as signal strength, difference between station's time and median time, etc. Weak stations or outliers would likely receive a weight near zero.
3. Calculate a weighted average of the stations' times. Repeat during each overnight scan for new stations.
4. If the user corrects the time manually, calculate an offset, and apply that offset to the time from (3) thereafter.

The x2203 or x4404 flags may indicate things like whether the station was received during the previous night's scan, and whether the station has been deleted.

Any reason to believe that a weak stations or outliers have PSIP clocks that are less accurate? Maybe DTVPal calculates an average time from all the received channels. Another thought, without TVGOS how does the DTVPal determine the current time zone? All my TV's ask that question during set-up.

I do not believe the DTV needs to know the time zone if it is only collecting PSIP data. It is getting exactly what the station in question is broadcasting and using its' time clock.

Not that they are inhehently any less accurate, (after all your outlier station is someone else's strong local station), just that your DVR is hardly ever receiving that outlier station and so the PSIP clock "element" that was initiated WITHIN YOUR DVR when it first picked up that station hardly ever receives any OTA updates to "re-sync" it to the broadcaster. Over time, that particular PSIP element WITHIN YOUR DVR drifts quite a bit and has the potential to mess up you DVR clock.

Jrpastore addressed your question about weak stations. If you don't receive a station consistently it won't be a useful time reference no matter how accurate its PSIP data is.

Outliers are by definition stations whose time differs greatly from most other stations. Of course it's possible that an outlier is correct and the other stations are all wrong, but it's not very likely. Usually you'll see a bunch of stations within a minute or two of the correct time, and a few others that are way off. Those are the outliers, and usually it'd be safe to ignore them.

An outlier could have the most accurate time if all you get is a few stations, though. That's why I would've let the end-user pick the station to use as a time reference if I'd written the PAL's firmware. Since I didn't, I hope the PAL's software engineers tested scenarios like that, but I wouldn't bet the farm on it.

As for time zones, you enter your time zone during the PAL's initial setup. (PSIP times are sent in UTC, fka GMT, and so are independent of time zones.) There's an option on the setup menu to change your time zone setting (particularly helpful for PAL owners in Indiana, which seems to delight in moving a county or two back and forth between Eastern and Central time every few years).

My guess about the PAL's time averaging algorithm is just that: an educated guess. Dish called it a weighted average, and those seem to be the most reasonable factors to use in assigning the weights.

If you have a large number of PSIP entries and therefore do see the "Local Time" entry on the diagnostics screen you can back into to that number fairly easily.

Identify a couple of local stations whose PSIP time is correct (or very close)

Find their TSID's at rabbitears.info and then locate them on the DTVPal diagnostics screen

The number in in parenthesis (times -1) is the DTVPal calculated time error.

I wonder if the PSIP time sent by each station is also the timer for their programs on the EPG when there is no TVGOS? If you select a program off the EPG on a particular station does it use the PSIP from that station to synchronize for the start time or does the DTV always use the average time assigned by the DTV for the start? Has anyone had program recordings that are set with only PSIP that actually start at the wrong time, like several minutes off? It might be interesting to see when the severe outliers actually start a recording.

I believe firmware F208 uses the time that the DVR is currently displaying as the time for all programs being recorded. The difference of an individual station's PSIP time should not change the start and finish times of a recording on that station.

Previous versions of the firmware were not as kind. Those who did not have a TVGOS time signal lock in their area with the original firmware F201 had all kinds of problems with their clocks varying with each station's PSIP time. I believe this also led to locked-up DVRs because the time was changing constantly as you changed channels and would "confuse" the DVR especially if a recording was in progress.

Firmware versions F206 and F207 actually made things worse (IMHO) as they would allow PSIP times of individual stations to change the time in your DVR even if you had an accurate TVGOS time lock. Fortunately that was fixed with firmware F208.

The bottom line is that if anyone is still running an older version of the firmware (prior to F208) I believe it will be a necessity to update to F208 when you have to run with PSIP times only. I still have one DVR at F201 that I have had since December 2008 and I have never updated it. I have had TVGOS since day 1 and it has worked fine with no major problems at all other than the standard "quirks" reported in this thread. I've kept it at F201 (if it's not broken don't fix it) so that I can directly compare that firmware to my other DVR that is at F208. Once TVGOS goes away I'll update it to F208 so that it will work better in the PSIP-only environment.

The phase out of my DTVPAL DVR begins.
Picked this up last week when it was on sale.
http://www.newegg.com/Product/Product.aspx?Item=N82E16856173007
Currently waiting for a sale on an HD Homerun Dual.

I get the same thing from some people. It seems they are resistant to the idea of getting local reception free when there is an opportunity to pay for it.

It is their problem if they want to pay for local TV broadcasts when they can easily get them OTA. However, I can understand that they have to pay to get non-broadcast stuff though. But whatever. All we can do is tell them about it. For us who use OTA, we will enjoy it being free (ads.) and save money!

I'll keep mine in service - in fact I just bought a 1TB drive for it - but I can't really blame you. It seems the HTPC route is the only alternative for those who don't want to buy a subscription and/or watch ads just to get TV guide info.

I did look at the CM-7400. It has some nice features, but it's been discontinued also, has its own bugs/quirks, and you still have to pay for the damn guide!

The good news is that these DVRs are still selling for $300 and up on eBay even w/o a warranty, so you'll probably get most or all of your money back once you're ready to sell.

Most puzzling are the folks who only subscribe to "basic" cable. They really don't get much beyond what they can get OTA, and often less (fewer subchannels or LP stations). We've been talking with a Hispanic viewer in Houston who can't get MundoFox because none of the Houston cable or satellite providers (except AT&T U-Verse) carries the LP station that it's on.

In the analog era, basic cable often made sense for folks who just wanted good reception of their local stations. But now, cable and satellite often provide a worse picture than OTA! Their loss, I guess; but that's also why our OTA DVRs never found a market.

Yeah, I guess their minds are still in analog days. Whatever. Also, satellite and cable don't show ALL foreign stations too like in L.A. with all those foreign stations. :/

I'm keeping my two DTVPal DVRs in service also but I have my "fingers crossed" that they continue to function well when they are only receiving the time and program info from PSIP. I can live without a guide that goes out for a full week but if the clock is not relatively accurate and stable that will be a deal breaker for me.

When I got mine in December '08 the local CBS station was waiting on the equipment to start broadcasting TVGOS.
It was several weeks before they were up and running. During that time my DVR functioned fine with only PSIP.