The Official 169time AVX-1 Technical Status Discussion - Page 4

Does anyone have a link or part number for the 'pad'? I did a search of the forum and couldn't find it. Is it just a 3db attenuator? Thanks.

Its the radio shack part, 6 db, only one they have

dave

Catalog Number: 15-1258

Thanks guys. Is this part any different than regular inline attenuators? I've got a bunch of those from 3db-16db.

The above is an inline F connected and is 6 db.

I'm having trouble looking that up by part number. I'm also confused what it is that we're talking about and where it goes. Are we talking about putting a choke around the firewire cable, an attenuator on the satellite input into the DTC-100, or are both of those getting discussed?

Thanks

Joe

Joe- Go into any Radio Shack in your town. That is the name of the store that sells both parts. Radio Shack is in just about any city in the country but I'm not sure if you have them in Roseville Mn. If not they have a web site at radioshack.com where you can order the part. They will help you and explain how to insert the part in your cable.

The Web site is currently out of stock on that part and you can't back order it.

There are 2 versions of the Radio Shack 6dB pads:

Part number 15-1257A is the preferred version as it has a male on one end and female on the other end. Just attach it to the antenna input of the sat receiver and then connect the antenna. No adapters required. Note that this version also allows the DC to pass through--very important.

My local store had lots of these. The 15-1258 version is less common and less convenient to install because it is male on each end.

Thanks. We do have Radio Shack stores. What I'm curious about is whether people are using chokes, attenuators, or both. I'm not clear if peope are discussing one solution or two.

I'm confused because I thought people were suspecting that the problem was RF interference between the the DTC-100 and the AVX-1. If that's the case, I thought people were talking about a choke on the cable between the DTC-100 and the AVX-1. Wouldn't an attenuator be for a case where the satellite signal was too strong going into the DTC-100? I'm trying to understand why you'd want to weaken your satellite signal. Wouldn't that make you more susceptible to rain fade and other signal losses?

Anyhow, what I was wondering was:

Are people using an attenuator, a choke, or both?

If people are using a choke, which cable are they using it on?

Are people using attenuators experiencing other unwanted problems like increased susceptibility to rain fade?

What is the reason for wanting to attenuate the satellite signal?

Dave, is there any update on when a software update for the AVX-1 might be available? Does Richard suspect that might clear up the problems without the need for either chokes or attenuators?

Thanks much!

Joe

Joe Linn:

The purpose of the pad is to prevent signal distortion by reducing the amplitude of signal reflections on the dish to receiver transmission line. If the reflected signal is strong enough (i.e., above the threshold) it can combine with the desired signal to produce a corrupted signal. If the transmission line is long, line attenuation usually does the job. If the cable is short, then the pad provides the attenuation. It's kind of a balancing act, but 6dB loss for the desired signal can usually be tolerated. In my case, there was no change in "signal strength" after I installed the pad. The reason is the signal strength indicator is really a bit error rate indicator, so installation of the pad did not increase errors. Of course if the transmission line is well matched at each end, then you wouldn't have the problem in the first place. This is usually not the case with most consumer grade systems. Reason: Better matching costs more money. A few pennies over millions of units is lots of lost profit. Nothing new here.

I dont have a date of S/w from Richard. I bugged him last night when over at the lab.

I think the key to add up based on all the type off issues you read on avs here with the vcr decks, stb's, etc, is in a digital world, if something "fails", you cant point at one piece. For the same channels, why are some having basically no issues and others are. The s/w between the units is sure not different. It goes back to what I have said many many times, its the quality of the signal and enviorment that makes the difference. This is w/o any avx-1 either. So, the best Richard can do is try to mask a few more of the real life things going on. Its impossible to be "perfect", since the avx-1 cant mask the real world. Again, how can some be basically having perfect success recording lets say SHO, and others cant? Logically, seems like a pretty easy non emotional answer to me!!!!

I was ready to blame the jvc deck for a recording I made that had pixels.
Until I watch the show on the tv and it was pixels. Pixels in ,pixels out.
My modulator had gotten into a bad digital state.

So, Richard is trying to put more masking into the s/w. Will never be perfect if you dont clean up. And as I posted, the jvc, etc either put out or accept junk that messes them up w/o even the avx-1 connected.

Again, just the facts.

Dave

Robert,
Thanks very much for the informative post! That helps a lot. I never knew that the signal strength meter was really a bit error indicator. You have eased my fears that adding a pad would reduce my signal strength.

Dave,
Thanks for checking on the software. You're right. I wouldn't expect that the software could fix an imperfect signal. What seems to happen though is that after a glitch in the signal, the AVX-1 stays messed up when the signal returns to normal so that the rest of the recording is messed up. What I would hope he could accomplish with the software is that he would be able to return to tracking the signal correctly after a problem so that a glitch would only be temporary rather than affecting the rest of the recording. I'd like to have it be able to self-correct rather than requiring the user to unplug and replug the firewire, change the input, or recycle the AVX-1 to get it processing the signal correctly again. I'm so impressed with what Richard has been able to accomplish and with finally having the ability to record HD that I am hoping another little tweak will allow the AVX-1 to be as robust as recording OTA directly from the DTC-100. I'm optimistic that it will.

Thanks all

Joe

Robert explained the Pad insertion theory. For some people it helped, for others the in line amp was required and for, yet, others, like me neither did anything to change anything better or worse so I don't use either.

The RFI toroid choke is what you would put on if you have RFI. How do you tell? Generally we have found in the early beta testing that certain RF generating equipment in the home can and does cause the AVX-1 to mal function. These devices are:
2.4 Ghz digital phones,
Digital cell phone use
802.11b wireless lan WAP systems
Standard lan router/switches, broad spectrum RFI generators such as vacuum cleaners and electric drills with brush style motors that generate sparking.
All the above operating in proximity of the system will increase RFI. To reduce RFI the toroid is installed at each end of the 1394 cable just behind the connector. Some have found that adding two toroids on each 1394 cable in use but I found only the one between the AVX and the VCR was required to solve my RFI. Some have also found installing the appropriate RFI toroid on the 120v power cable just before it connects to the AVX-1 is also needed. I did not find this necessary at my location.

There were four recommendations by the early beta team to successful use of the AVX with current beta2 software.

1. keep the AVX at least 5 feet away from the VCR and the DTC-100 by using a 6 ft. 1394 cable.
2. Reduce RFI using RFI ferrite toroid snap-on chokes to the 1394 cables and the powerline cable as necessary.
3. Add an inline amp from Radio Shack to increase sat signals when signals are marginally low due to long line feed and other reasons
4. Add a 6 db pad to reduce the interferring standing waves on the sat feedline to below damaging threshhold.

What this means is you need a good quality signal and a clean environment for the AVX to work properly.

Don Landis: Good summary!

One thought I had on the amplifiers was they might have improved some systems because they provided a better match to the transmission line and thus reduced flections. In any case a trial is the only way to tell for sure.

Re toroids: I've had some experience with them. Depending the core material and other factors, they effect different frequencies more than others. Thus the effectiveness depends on the frequency of the interference. If you put 2 toroids of the same type on a cable, the attenuation is increased, but the frequency of attenuation is lowered.

If interference is supected, try several types of toroids as effectiveness varies greatly. Knowledge of the interfering spectrum would be very helpful in selecting the proper toroids. Maybe somebody can take a look at the various components with a spectrum analizer.

This digital stuff is not easy, but sure can be fun.

dave

Joe,

I found that an amplifier destroyed my signal and made it impossible to record anything reliably, which is why I was reluctant to try the pad. Seems silly now, since it costs just a buck or two. The pad has performed reliably and I have recorded several more movies the last two nights with it installed.

I had never noticed the RFI problems others had, but it seemed so prevalent at the beginning, that I got the chokes immediately ( also from RS ) and snapped them on. BUT, I have my JVC separated by a 13 foot Firewire cable from the AVX-1, so they are not in close proximity at all.

Jeff

Dave:

Does it look like Richard is walking to the airport?



Lon

'Cause of the ongoing JVC issue I've been thinking about getting a Mits D-VHS deck to continue my OTA recordings. Does the 169 timer work with the Mits deck too?

I recorded "Live From Bagdhad" last night and it was almost flawless. I was surprised because my satellite signal strength is down in the 60s now. Perhaps that is due to all of the storms out here on the West Coast.

A few glitches did occur and two were particularly interesting. The dropout caused the playback to stop entirely for a split second; I saw a quick flash of OTA programming and then the movie playback continued.

Thought that on the way to work today. I have learned working with Richard for hte last 2 years or so, when its ready, its ready, but until then, his mind is working on the problems.

JHL, how were you playing your tape? JVC output? Just for an FYI, I have recorded straight OTA with glitches that caused the JVC to lock up or go into pixels. This has nothing to do with the 169time products. Its a bug in the JVC firmware which the latest is supposed to fix. My first unit should be there so will let you know when I get back.

Dave

I was playing my tape back via the JVC 30K and the DTC-100. I was surprised because in numerous previous attempts I had never seen that particular glitch.

I did not save the tape, so I did not try it on my Mitsubishi 1100U. I was happy enough with the quality from the JVC 30K. Not perfect but close enough for satellite recording when the signal strength is relatively weak.

JHL, so if I read you comments correctly, you where playing the tape in the jvc, and watching with the dtc100?

Well, this was the lock up state I sent JVC a few ago on the tape. If I watched the jvc output, it locked on this glithed. At the same time watching the dtc100 output, it would glitch but keep on going.

Dave

That is correct. I am unable to watch via the component outputs of the JVC because of transcoder issues with my projector. I have been delaying purchasing a new transcoder and bought the Mitsubishi 1100U instead. I thought a second VCR would be more useful than using the component outputs; the DTC-100 seems to do an adequate job playing back tapes.

Dave,
Will Richard and his family be taking a cab to the airport for Christmas?

Steve

Yeh, there's not been much word here for a while.

Yea, looks like we will all be disappointed for christmas. I bug him on just about a daily basis. About all I can bug him now on is he better not introduce any new stuff, and I keep telling him hes going to have to get hungry enough soon since hes out of new dtc100s. I am as unhappy as everyone else and I have made this clear to RIchard. Its my credibility that gets beat up here on AVS, not his, and for me, a commitment is a commitment.

Dave

As a matter of perspective-
We have been using the same B2 software that is now 6 months old.
Dave- Your reports on the progress of this hasn't changed since August.
It is too bad that considering all this time, Richard cannot give you any answers as to how close he is to a resolution on the main issue, which I think is HBO timing issues. I have no problems with HDNet, as you know, and considering my personal solution was achieved with the AVX-1, I only push now so that others who are dependent on the AVX for movies will have their day too when the new B3? is released. For me, that will just be a backup if we are without the 5000/mod for HBO.
If we can't have a fix soon(meaning by the end of the year), maybe you could at least satisfy everyone's curiosity as to how close he thinks he is to improving the problem of HBO recording. Maybe a more defined answer as to what the problems are. I think after all this time everyone would like to hear from Richard, a short recap of the problem and his progress and best guestimate as to outlook for the future, eventhough I know it may be painful to do that.

Don, I have worked enough with RIchard that unless I see something, to be totally honest, words are just marketing. One the one side I stick up and support him totally, on the other its clear I only get from him what he wants me to have. I have not saying this is good or bad, I am just too much of an idealist for my own good. Since I am far from perfect, I am not judging him. Again, just being honest.

Dave

Dave,
I think I speak for many in saying we appreciate your efforts to resolve these problems.
Best wishes for a Merry Christmas,
Steve