Direct TV, DishNet, DVR's power usage, and input power Modifications (Discussion)

Re: Direct TV, DishNet, DVR's power usage, and input power Modifications (Discussion)

try searching for 'schematic' (s) plus the model number of the receiver etc, you might hit pay-dirt.
I did on the schematic for an instant on water heater a while back, had voltages from 5 to 117v dc and ac...?? who would have guessed...

Re: Direct TV, DishNet, DVR's power usage, and input power Modifications (Discussion)

AntronX wrote: »

Try powering your LNB with variable voltage power supply and see at which voltage it shuts off. It may work way below 18V. Post pics, will be watching your progress.

One potential reason that the LNB may be specced to work at less than the normally delivered voltage is to allow for the IR voltage losses in the maximum allowed length of coax from the power inserter to the dish. If you have a longish coax already, you may benefit from adding the DC in closer to (next to) the dish using larger wires and power-insert adapter. You may need to put a DC-blocking adapter next to the box if you do this.

Re: Direct TV, DishNet, DVR's power usage, and input power Modifications (Discussion)

techntrek wrote: »

Won't work if the system is a Directv system. The LNB retransmits either odd or even transceivers on the coax based on a 13 or 18 volt input.

Basically the same technology used by the Bell system in Canada.

Re: Direct TV, DishNet, DVR's power usage, and input power Modifications (Discussion)

Wayne. Actually Bell receivers in Canada and Dish network in USA have the same manufacturer. Starchoice, now called Shaw direct and 4dtv In usa used same manufacture. Bell and direct tv have citcular polarity, Right handed for one polarity and left handed for other polarity. shaw direct and 4dtv use linerior polarity, horizontal for one polarity and verticle for other polarity. Polarity for all the systems mentioned have 14 volt for one polarity and 18 volt for other polarity. Preety simple EH. The mpeg free to air receivers pick up all the unscrambled signals that are broadcast on all satelites in the Clark Belt. The big old satelite dishes still get you lots of free tv to watch. You can also use old primestar dishes ro get free programing off KU band satelite dishes. Previously I have said satelites are my other hobby. Here is a good website to learn more about the satelite hobby for anyone that don,t know about it. http://www.skyvision.com/ Solarvic another added link http://global-cm.net/

Re: Direct TV, DishNet, DVR's power usage, and input power Modifications (Discussion)

Just happened to have a satellite receiver on the bench.
It is a Topfield TF4000F, FTA (free to air).
We got rid of Dish and Direct.
So anyway, here is what I found.

The power supply is connected to the line at all times.
There is a so called power switch but all it does is put the logic into standby
Line voltage is rectified directly then re-chopped @ approx 80 KHz.
The chopper transformer has 6 taps on the secondary.
Each tap has a half wave rectifier resulting in 3.3, 8, 15, 17, 22, and 30 volt outputs.
In addition, it looks like the main board has regulator chips generating 5 es 3.3 v for the logic.
It looks like the 30 V is being fed to the front end module.

This in not a good candidate for running directly from alternative power.
You could use a small inverter ahead of it and turn it off when you are not using it.

However, there is precedent for keeping the LNB powered at all times.
It keeps it a little warmer hence drives off water and makes it less easily damaged by lightning.
Lightening damage is the biggest problem we have with satellite systems.
I maintain about 50 of them.
We loose approx 3 a year usually in lightening storms.

Re: Direct TV, DishNet, DVR's power usage, and input power Modifications (Discussion)

Ken Marsh wrote: »

Just happened to have a satellite receiver on the bench.
It is a Topfield TF4000F, FTA (free to air).
We got rid of Dish and Direct.
So anyway, here is what I found.

The power supply is connected to the line at all times.
There is a so called power switch but all it does is put the logic into standby
Line voltage is rectified directly then re-chopped @ approx 80 KHz.
The chopper transformer has 6 taps on the secondary.
Each tap has a half wave rectifier resulting in 3.3, 8, 15, 17, 22, and 30 volt outputs.
In addition, it looks like the main board has regulator chips generating 5 es 3.3 v for the logic.
It looks like the 30 V is being fed to the front end module.

This in not a good candidate for running directly from alternative power.
You could use a small inverter ahead of it and turn it off when you are not using it.

This is what I was expecting. "it ain't simple" and it would be a huge job to start from scratch to redesign a new power supply. The results would definitely not be worth it, nor as good as the original power supply. That's my opinion anyway. I've done a lot of crazy things in electronics, but wouldn't consider this project for one second.

Re: Direct TV, DishNet, DVR's power usage, and input power Modifications (Discussion)

waynefromnscanada wrote: »

Haha Don't speak too quickly. If I remember right, it took a month or more before my programming started to be cut off a few channels at a time. That was having it off about 15 or 16 hours overnight and well into the next afternoon.
I'm trying mine on timer again, but this time only having it off from 1:00 AM, to 8:00 AM, leaving it on all day to run off solar power from PV. We'll know in a month or two if it's going to work out or will I start loosing channels again..

If your box goes out of service ("shuts down") to renew its programming information (as Dish boxes do) you may not be happy with setting it to refresh its program guide information during the period that solar power is available, but that is probably the best way to keep it up to date and happy. Does the DirectTV box allow you to choose the check-in time?

Re: Direct TV, DishNet, DVR's power usage, and input power Modifications (Discussion)

inetdog wrote: »

If your box goes out of service ("shuts down") to renew its programming information (as Dish boxes do) you may not be happy with setting it to refresh its program guide information during the period that solar power is available, but that is probably the best way to keep it up to date and happy. Does the DirectTV box allow you to choose the check-in time?

I believe my Bell system is more or less identical the the Dish system, just that it's controlled from Canada instead of the US. Mine has the option of selecting updates "during times of inactivity after 3 AM", or some such wording. I've recently unselected that option as the timer has it powered down during those hours. So far so good, but it's still way too early in this experiment to say if this will work. I'll know in a couple of months
The program guide info on my Bell system by the way, reloads each time the box is powered up, takes about 15 seconds after the box has already locked back onto the satellite and is ready to go. (I'm given the option of skipping the guide download) Whole process takes a couple of minutes. I have no problem with that, a small price to pay for saving battery power.

Re: Direct TV, DishNet, DVR's power usage, and input power Modifications (Discussion)

wayne,
i'm curious if you approached the sat company and just asked them if this will work citing that the box needs to be off at times, if they are smart enough to know?

Re: Direct TV, DishNet, DVR's power usage, and input power Modifications (Discussion)

yes, i figured as much and was why i added, "if they are smart enough to know.":roll: you gotta figure somebody somewhere should know, but how to know who to contact that knows is the tough question. i guess the effort to ask may take longer than actually just trying it because it would take forever to reach somebody who knows. shame.

Re: Direct TV, DishNet, DVR's power usage, and input power Modifications (Discussion)

Both of my system-killers were near direct hits - took out the LNBs, coax and the multiswitch but happily no farther down the line.

Odd that the LNBs would be so vulnerable to EMP. I would expect that every time a thunderstorm came through Directv would have to roll through replacing everyone's LNBs...

Re: Direct TV, DishNet, DVR's power usage, and input power Modifications (Discussion)

not sure if wayne meant this or not, but the dish and any switches/combiners outside really have to be grounded with at least #8 copper wire. was that in place? of course that ground is not a guarantee there would not be damage to the lna or lnb as the parts for these are known to blow out even just from the static electricity created in touching them improperly as they are very sensitive. remember that lightning is comprised of all frequencies up through the radio spectrum and beyond with diminishing returns the higher you go. add to that a dish that can amplify frequencies in and around that which the lna/lnb is tuned to operate at and the extreme overload alone could kill the thing even if the emp itself wasn't strong enough to do it. think of it like this, aiming a small solid parabolic dish at the sun and see what happens to anything in the focal point. btw, along these lines never paint your dish a light color, especially white.

Re: Direct TV, DishNet, DVR's power usage, and input power Modifications (Discussion)

yes, that is another way that damage could happen as the charge from either a strike or the emp from one can get transferred from the phone line outside and up into the sat box damaging it. the odds on that energy reaching the lna/lnb from the sat box through the phone line is very diminished as the dish at that point is unlikely to be in the lightning's path to ground, but stranger things have happened being it tends to do what it wants to.