DishPro Plus 44 Switch Review

[keitheva]

Well, all I can think of has to do with some reports that the separator is sometimes not happy being on the DPP44's port 1 (with the power inserter).

I have tried all ports.

Other than that, my only other thought is a bad jumper - but you've undoubtedly checked all that.

Indeed - I've checked all the cables/jumpers on other connections with no problems (including the new 75' length of RG6 I bought).

I am left to my original conclusion, something like there is more bandwidth required to run two tuners over 1 cable, and hence the effect of signal loss causes practical limits to be reached over a shorter distance of cable.

This is empirical, I have not measured anything. But I cannot think of any other variable which can explain the behaviour I am seeing. Apart from where the separator is placed, all the other pieces of the equation are constant. If anyone is interested enough, please bring your oscilloscope and come visit me in the beautiful wine country of Sonoma County CA so we can get to the bottom of this

Those of you running the DPP44 plus separator, what roughly is the cable length between the switch and the separator?

Thanks,
-Keith

[SimpleSimon]

No, the bandwidth required to run DishPro vs. DishProPlus is exactly the same.

There's gotta be something going on that we're just not seeing.

[keitheva]

No, the bandwidth required to run DishPro vs. DishProPlus is exactly the same.

That's not what I'm saying. The issue is running the feed over 1 long cable vs over 2 long cables.

After reading some more it seems that the separator (perhaps) splits the signal into a low-freq band, and a high-freq band. If so, *after* the separator, each cable carries a narrower frequency range.

With the separator at the rcvr, 75' from the switch, one cable has to carry the full frequency range (x) over a long distance. Whereas with the separator at the switch, two cables each carry a narrower frequency range over the same distance.

Is it not possible that (assuming I have crap RG6 or something), the 2nd scenario (separator at the switch) might work whereas the 1st one doesn't because x/2 is "easier" on the cable than x/1, for the same cable length?

I am no electronics engineer so this may be complete hogwash. But I'm just trying to figure out the cause since the effect is repeatable every time I move the separator position.

If it is hogwash, got another idea?

Thanks,
-Keith

[SimpleSimon]

Your logic is reasonable, I just don't think it actually applies here.

One way to find out - take the 2 long feeds and plug each into a DPP44 port - NO separator. This forces EACH cable to carry a full 2-band load. Under standard DP "rules" the Even transponders will be on the upper band no matter what.

If it works, the (long) cables are NOT part of the problem, and your hypothesis fails.

If it does NOT work on ONE side, try using the OTHER side for the long feeder to the separator and see what happens.

Again, ANY idea here is worth exploring, beause this is a strange one for sure!

[RBBrittain]

Is the 75-foot cable you're using to feed TV1 in the "at-switch" scenario the same one feeding the separator in the "at-receiver" scenario? If so, that cable may be your problem.

The cable feeding TV1 is at a lower frequency (950-1450 MHz) than the one feeding TV2 (1650-2150 MHz); meanwhile, the cable feeding the separator handles both ranges. The higher the frequency, the harder it is to get it thru the cable. If the cable isn't rated for 2150 MHz, it may work for a separator-to-TV1 feed; but it won't work for switch-to-separator or separator-to-TV2.

[keitheva]

Is the 75-foot cable you're using to feed TV1 in the "at-switch" scenario the same one feeding the separator in the "at-receiver" scenario? If so, that cable may be your problem.

Yes, at first it was. When I first tried this, I was using an already installed RG59 cable for the at-receiver scenario, with two 1' radio-shack RG6 patch cables from the separator to the rcvr. That failed as described.

I then tried the at-switch scenario with the same cable for the satellite 1 input on the 921, and another already installed RG59 cable for the satellite 2 input on the 921, with one of the same 1' RG6 patch cables between the switch and the separator. This worked fine.

Since my curiosity was now piqued and assuming it was the RG59 that was the problem, I went out and bought a 100' length of radio-shack gold quad-shield RG6, which I cut to about 75' and then used for the at-receiver scenario instead of the already installed RG59. This also failed as described.

To test the cables I ran both the 1' RG6 patch cables and the 75' RG6 cable into a feed from the DPP44 to a 301 rcvr, which continued to work fine. This must mean that the 75' RG6 cable is able to successfully carry a full-frequency DPP signal must it not? If so then my hypothesis must be wrong, unless if the signal is marginal, perhaps the insertion of the separator itself is enough to drop the signal below some threshold?

Is it possible that this is something to do with the 921 itself and the check-switch function? I can't see how though, I go through the same process each time, and surely to the 921 it looks the same no matter which end the separator is at?

Thanks,
-Keith

[keitheva]

One way to find out - take the 2 long feeds and plug each into a DPP44 port - NO separator. This forces EACH cable to carry a full 2-band load. Under standard DP "rules" the Even transponders will be on the upper band no matter what.

I think this is moot since I have tried the new 75' RG6 cable with another receiver and it worked fine, which should mean the cable is able to carry the full frequency load right? Yet it still did not work with this cable and the separator in the at-receiver scenario.

Bizarre.

Thanks,
-Keith

[SimpleSimon]

Yes. Quite bizarre. I wonder if DP+ equipment actually does not do band-stacking when it's not needed. That would of course ease cabling issues.

Dunno - guess we've just got to build a matrix of the Check Switch results.

[farmsatguy]

As an installer, I've gotta know what type of fittings you used when you cut the Radio Shack cable from 100' to 75'? Please tell me you didn't use those twist on connectors with DP equipment - if I had $10 everytime I rolled up to someones trouble call and relaced those fittings, I could retire for a year! I prefer PPC compression fittings (Gilberts are OK but sometimes won't test for "fire" when checking for a signal with a small tester).

Have you tried running one length of cable straight from the DPP44 to the receiver area (through a window maybe for testing purposes); hook in the separator then use your 2 two foot jumpers to the 921? 75'...100'...doesn't matter at this point. Is all the cable swept tested for 2150? It MUST be at this rating. Doing this will bypass (temporarilily) any other problems that may exist such as a bad ground block, a wall plate with a low rated barrel, bad cables, crappy fittings, etc... IF you do this and still have a problem then...well, I'm stumped too. I don't see it as being the receiver as you can put the separator a foot away from the 44 and it works!

[keitheva]

The best conclusion I can come up with given that the 75' of RG6 works fine with no separator and a 301, is that the signal strength for the upper frequency band is low by the time it gets to the end of the cable, and is insufficient to overcome the additional loss introduced by the separator. This is not a problem when the separator is at the switch because the incoming signal is strong.

I guess this could be a bad separator, or poor RG6, or it could be neither of these things and simply a limitation of using a separator with long runs of cable.

If you have a separator working fine at the end of a 50' plus cable run, please post here!

Thanks for all the input,
-Keith