[defilm]

I have been a D* customer for 11 years. I have experienced most of the issues listed here. I do find the HR20 interface as annoying as the HR15 I returned, and LOVE my Sony SAT-T60 interface. But I hate Tivo, so I used the perfect remote with the perfect UI, but disabled TIVO. Someone said there are two types of Tivo users.
One that hate it and disable it, one type that loves it. So to each his own.
I have gotten used to some of the missing tivo features honestly, but indeed I am tired of the more annoying ones. I have seen improvement. A key issue is when I lose Signal, trying to go back and play a previously recorded show would be just as bad as the broken signal. In the latest firmware update they resolved that issue.
You can now play recorded material if you have weather related signal loss.
BUT, you are watching the recorded content, and a nice big "Searching for signal" block comes up from the opposite tuner. Now I noticed that I lose signal even during light rain. Was never the case with the dual LUN older Sony dish, or 3 LUN dish, nor my Dish 500 when I was a Disk Network customer 11 years ago. Looking at signals (which are between 80 and 100 on clear days), there seems to be low tolerance. I get light drizzle, and have some transponders at 60-70, while others just drop off the map on the 101 sat. So a work around is to find two stations on transponders that have signal. (Loved when we had rain during the baseball playoffs. Light drizzle lost YES network. YES and my son's love of the Yankees is the only reason I have not moved to Dish Network, plus I have endured much of the pain already, so I figured I would stick it out. Except for one thing I realized...

They have had techs out here to check the connections on the dish. I have also
gone and used compression fit condensation proof terminations on all cables on the 4 LUN's run in to the house, and verified the Db strength with an independent meter. (Yea, I am a EE, and PE in NYS, with all the degrees to back it. So I have a keen understanding of this technology, and in fact work in a very similar industry with Hidef Codecs (Mpeg2 and Mpeg4), but we are interactive so we don't have the luxury of latency.

However, I came to realize, even when D* resolves all the issues, I will still be left
with a fade problem. because the dish has design issues, and they are also related to where the sats are located in the orbital arc.. I will make my case, and hence why I have now decided there is no hope unless they redesign the dish, and EEk, I am going to Cablevision IO digitial Cable, and I thought I would never see that sad day, as I have a severe distaste for the Dolan's.

The simple Spherical reflector and near 30deg orbital arc is the issue. Has a general wide range of reflector area, but in it's current design is meant for individual feed illumination of the reflector surface so that a beam is formed coincident to the axis of the feed.

In multple feeds(multi-beam) geometry all the beams have similar radiation patterns and gains, although there is degredation in performance/gain in the case of multi-beam. This is because the reflector is designed such that the multi-beam overlaps each other, hence there is degradation. Even light rain has a significant effect on diffusion of the main beam, and in this case degrades signal further.
Remember that db loss is logorithmic, so -3db is 1/2 original signal. Sounds small, well it is. So how do they fix this?

Well not easily with spherical reflectors, or even paraboloidal reflectors with a larger feed / diameter ratio (f/d). A design change is answer for geosynchronous satellites for a receiver receiving a multi-beam feed with little loss for a stationary ground antenna. One such example is the Torus design. It is a dual curvature reflector that is made to serve just this purpose.This antenna has it's feed-scan plane inclined to the elipitical-arc plane like it's spherical predecessor. However unlike the spherical reflector, the Torus has a circular contour in the scan plane. and a parabolic contour in the orthogonal plane. This design has less phase aberration than spherical systems because the focusing in the parabolic plane. The circular symmetry yields identical beams from feeds received anywhere on the feed arc, hence no performance degrade when multiple beams are sent to the focal arc. I doubt this will ever happen however as this antenna type requires over-sized aperture diameters to accomadate the scan plane. Given the orbital arc of almost 30 degrees, it would have to be a bit larger. Like over 200m squared for a newar 30deg scan arc. So unless you have a big piece of land...... The similar can be achieved at 30deg with a spherical reflector at a smaller 9.5m reflector. Still a bit much for my roof though So I figure I can't wait for this. I am tired of losing signal every time it is "misty".

Thanks for all the help I have received from this site. BTW, D* is aware of it, unless they do not listen to their field techs. I have brought the issue to support many times, but I don't think they even know what I am talking about, so how can they fix it??

 

[litzdog911]

Your mathematical analysis is accurate. However, the satellites provide more than enough power to overcome these losses, provided that the dish is aligned properly. A properly aligned dish will NOT lose transponders during "light drizzle", so be sure to check your dish's alignment first.

 

[defilm]

Your mathematical analysis is accurate. However, the satellites provide more than enough power to overcome these losses, provided that the dish is aligned properly. A properly aligned dish will NOT lose transponders during "light drizzle", so be sure to check your dish's alignment first.

Yea, I did. I re-aligned the dish myself. Clear day, lowest transponder on 101 was 82, while several were at 98, 99. I am presuming based on the number of reads that this is not likely a common problem. If not, I have an issue somewhere and it is not a general dish design or DVR issue, but specific to my setup. Great, seems to always be the way. Yep, you don't want me shopping for your electronics
Frustrating on top of the HR20 issues, which I have to admit, IMHO, has come far from it's epoch in a relatively quick period of time. So hard to fault D* on responsiveness.

During a light rain, like tonight, where the rain rate my weather station 22' above the house (28' above the dish) was a mere 0.07" per hour rate (verses a downpour where one would expect to lose signal at 3-4.5"/hr, most transponders dropped
down to 40-60. Indeed on the stations mapped to those transponders, image was clean. No pixilation, artifacting at all. While 7 transponders had no signal. Rain lightened to under 0.02/hr and I got the zero's back up at 50-60%. Rain stopped, All back in the mid 80's to mid 90's.

I don't deal much with Sat professionally because as I mentioned the 550ms uplink, and downlink times are way too high for hi-def codecs used in interactive Telepresence communications. I don't think the company would like me taking home one of our pico-sec multi-trace scopes, but we have some wide-band
micro-second scopes I could borrow a few days. Get a wave across the frequence spectrum for all transponders on 101 and wait for rain. I can then measure the signal loss (if there actually is any). There is no transponder pattern either, which is a bummer. This would be a no-brainer if I lost all odd or even transponders.
Not the case. It is always the same transponders however. To really troubleshoot this I need to know the frequencies of the transponders on 101. Or at least the channel mappings to transponder mappings. (which I could then put the scope in pass-through, tune the channel and measure the frequency, isolate a waveform and measure a base attenuation level. Next rain... tune it and see what the attenuation loss is.

Unless there is a relationship to the transponders I am losing signal on that I don't know about, all this would tell me is I have attenuation loss at the dish input. But if this were true others would have the problem. I know the cables are clean. I disconnected the pairs from the dish, dropped ina barrel, and shot them (75Ohm/Unbalanced, 1Mhz - 3Ghz) on an Agilent Onmiber 718 test set). Not a bit error, no signal deviation above 6UI. I realize this frequency testing is perhaps overkill and most people just shoot for continuity, but I have the test equipment available. So if I drop the scope on each input (is Multi-trace) If I see no significant amplitude change in the wave for the monitored transponder, It would suggest that the problem may not be signal reception at the dish at all. Yet clearly the HR20-700s is seeing a loss of signal. This clearly would point at the DVR itself, and I am sure D* would replace i if I presented someone with a reasonable technical background with details of my tests...

Anyone have the transponder to channel (or frequency) mappings? I can grab
one of the Scopes and take a car home from Work Friday to run my test.
I will do anything not to have to go to CV. My humble thanks to anyone who can provide a mapping.

 

[litzdog911]

If you're sure that the dish is optimally aligned, the next thing to check is all of your exterior connections .... be sure they're snug, dry and well sealed from moisture. This includes all of the connections at the dish, including the connections between the two dish LNB assemblies, plus any exterior ground blocks or multiswitch.

Your readings really should not drop so dramatically during light rain. I live in Seattle and we've had record-setting rain amounts this month and I have not yet had any reception problems with only minor (a few points) signal reductions.