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Carl
Joined: 15 Jan 2009 Posts: 159 Location: Quebec city, Canada |
Posted: Fri Dec 18, 2009 10:11 am Post subject: IR carrier frequency Echostar 3100? |
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Does someone know the IR carrier frequency of Echostar 3100 Sat receiver.
It's a bell express VU receiver.
I'm having a hard time to make it work with my IR remote repeater.
The JP1 remote work fine but for some reason my repeater do not work with this equipment.I have tested my repeater with all my equipment and it's working fine.
Could this be because it's 56 KHz? |
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The Robman Site Owner
Joined: 01 Aug 2003 Posts: 21237 Location: Chicago, IL |
Posted: Fri Dec 18, 2009 10:33 am Post subject: |
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Which setup code are you using? If it's SAT/0775 or SAT/1200, they are both 57 kHz, so that could well be the problem.
If it's SAT/1005, which is used by the Dishplayer, that runs at 38 kHz, which is a very normal frequency. _________________ Rob
www.hifi-remote.com
Please don't PM me with remote questions, post them in the forums so all the experts can help! |
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Carl
Joined: 15 Jan 2009 Posts: 159 Location: Quebec city, Canada |
Posted: Fri Dec 18, 2009 11:59 am Post subject: |
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I'm using SAT/0775 |
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johnsfine Site Admin
Joined: 10 Aug 2003 Posts: 4766 Location: Bedford, MA |
Posted: Sat Dec 19, 2009 10:26 am Post subject: Re: IR carrier frequency Echostar 3100? |
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Carl wrote: | I'm having a hard time to make it work with my IR remote repeater. |
Does "hard time to make it work" mean so far it doesn't work at all? Or does it mean it works badly (some signals work some of the time)?
There is normally a very wide tolerance for IR frequency. All the way from 38kHz to 57kHz might or might not be too much for that tolerance.
So if it works badly through the repeater, then it probably can be made to work better through the repeater by tweaking the protocol.
If it doesn't work at all through the repeater, it is more likely beyond the reach of any adjustment, meaning you need a better repeater.
If it works badly, that could be the device not liking the signal the repeater sends (which is hard to improve) or it could be the repeater not liking the signal the remote sends, which could be fixed by lowering the frequency. (If the device itself is less picky about frequency being too low than the repeater is about frequency too high, then the answer is to reduce the frequency). |
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Carl
Joined: 15 Jan 2009 Posts: 159 Location: Quebec city, Canada |
Posted: Sat Dec 19, 2009 11:23 am Post subject: |
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It works badly,some signal work but I would say 1 out of 10 try.
I'm pretty sure the repeater is good.
It is home made but the signal has been verified with a scope many times and like I said every equipment that I have tested work with the repeater (projector,Tv,Amplifier,DVD player). The repeater I made use a 4093 instead of a 555 so the carrier frequency is very clean and stable.
The only thing I can think of is the IR receiver which is 38KHz.
I have ordered a 56 KHz IR module.
As soon as I get it I will test the repeater again and see how it goes. |
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johnsfine Site Admin
Joined: 10 Aug 2003 Posts: 4766 Location: Bedford, MA |
Posted: Sat Dec 19, 2009 12:16 pm Post subject: |
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I'm just guessing at the operational details of your repeater, but that guess is:
1) The repeater's 38kHz IR receiver does a poor job of seeing the 57kHz signal.
2) The repeater resends that signal at 38kHz.
3) The actual device's IR receiver does a poor job of seeing the 38kHz signal (since it expected 57kHz).
Issue (1) can be fixed with a JP1 cable by loading a custom version of the protocol executor that sends at 38kHz. If the device's IR receiver is less picky than the repeater's the problem might be solved.
I assume the extra module you ordered solves issue 1. Hopefully it also solves 2 and 3 (again I don't know design details of your repeater). So waiting for the extra module is easier than trying a maybe fix via JP1. |
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jetskier
Joined: 09 Dec 2003 Posts: 287 Location: Nevada |
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Carl
Joined: 15 Jan 2009 Posts: 159 Location: Quebec city, Canada |
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johnsfine Site Admin
Joined: 10 Aug 2003 Posts: 4766 Location: Bedford, MA |
Posted: Sat Dec 19, 2009 2:28 pm Post subject: |
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Carl wrote: |
Here is the repeater circuit for those who are interested.
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That isn't at all what I expected and I don't entirely understand it.
Is that top section of the schematic just power supply? (Converts 12 volt AC to 12 volt DC and 5 volt DC)
The bottom section makes sense, except I don't know how to look up what part is represented by "RC5_IR". A web search on that or the "I.R.RC5" you have inside that part all hits just RC5 decoders. Obviously the part in your schematic should not be an RC5 decoder.
I see that D2, R1 and C2 demodulate the received IR without regard to its modulation frequency. That would imply "RC5_IR" is a raw IR receiver. That is very unexpected, because raw IR receivers don't work nearly as well as IR receivers with built in demodulation (and that looks like a very lame design for demodulating raw IR). It also means changing the original frequency via JP1 would not help at all.
The design then remodulates at a frequency determined by the setting of VR1.
So when you said "I have ordered a 56 KHz IR module." you mean an entire new repeater with a different setting for VR1?
I think I'm missing the whole point of the repeater. I thought you would have an IR receiver in one location connected by wire or RF to an IR emitter in another location. |
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Carl
Joined: 15 Jan 2009 Posts: 159 Location: Quebec city, Canada |
Posted: Sat Dec 19, 2009 2:49 pm Post subject: |
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Yes the top section is a power supply for the IR module.
My whole circuit runs fine on 5 Volt only.
Well I have modified the circuit a bit.
I use a TSOP34338 module for receving the IR signal.
Also, I do not use 3 IR LED but only one.
The IR led and the IR receivers are both wired and connected to the circuit.
Yes I have to adjust the potentiometer to modify the carrier frequency to 56 KHz once I put my new IR module in place. |
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mr_d_p_gumby Expert
Joined: 03 Aug 2003 Posts: 1370 Location: Newbury Park, CA |
Posted: Sat Dec 19, 2009 3:05 pm Post subject: |
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Carl wrote: | I use a TSOP34338 module for receving the IR signal. | If that is the case, then I would remove R1/D2/C2 and connect the module output directly to U1. The module already demodulates the IR signal, and the time constant of the extra circuitry may be corrupting the timing of the demodulated IR signals. _________________ Mike England |
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johnsfine Site Admin
Joined: 10 Aug 2003 Posts: 4766 Location: Bedford, MA |
Posted: Sat Dec 19, 2009 3:08 pm Post subject: |
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Carl wrote: | I use a TSOP34338 module for receving the IR signal. |
That is a very good device for receiving 38kHz IR. If you look in its data sheet, you can see the "relative responsivity" goes down to 20% at 49.4kHz. At higher frequency they don't spec it at all, but you would expect it to be down around 6% at 57kHz.
I've never been entirely clear on what "relative responsivity" actually measures in that and similar data sheets, but from experience 6% is rather marginal, but not hopeless.
Quote: | Yes I have to adjust the potentiometer to modify the carrier frequency to 56 KHz once I put my new IR module in place. |
1) Will the new one have a separate TSOP34356 to receive 57kHz IR? Or will you share the existing 34338? If you share the 34338, then you probably want a different executor via JP1 to make the initial carrier 38kHz.
2) How will you physically isolate the emitters? Even with separate IR receivers, the two repeaters would see and repeat each other's signals, which would interfere unless you have appropriate isolation of the emitters. |
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mr_d_p_gumby Expert
Joined: 03 Aug 2003 Posts: 1370 Location: Newbury Park, CA |
Posted: Sat Dec 19, 2009 3:18 pm Post subject: |
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johnsfine wrote: | I've never been entirely clear on what "relative responsivity" actually measures in that and similar data sheets, but from experience 6% is rather marginal, but not hopeless. | For the most part, it specifies the bandpass of the carrier amplifier within the chip. _________________ Mike England |
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Carl
Joined: 15 Jan 2009 Posts: 159 Location: Quebec city, Canada |
Posted: Sat Dec 19, 2009 3:30 pm Post subject: |
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Well, if I can make it work with the 56 KHz module I will do another circuit dedicated to the echostar SAT.
As you can see the circuit cost almost nothing and is really simple to do.
Here is a picture of what mine look like:
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Carl
Joined: 15 Jan 2009 Posts: 159 Location: Quebec city, Canada |
Posted: Sat Dec 19, 2009 3:47 pm Post subject: |
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mr_d_p_gumby wrote: | Carl wrote: | I use a TSOP34338 module for receving the IR signal. | If that is the case, then I would remove R1/D2/C2 and connect the module output directly to U1. The module already demodulates the IR signal, and the time constant of the extra circuitry may be corrupting the timing of the demodulated IR signals. |
You are right about this, I'm not sure why they put a diode and a resistor in the first place since the original circuit also use a IR module that takes care of demodulating the signal.The original design use a SFH506.
But I think I have also tried with the IR output connected directly to the 4093 with no sucess. |
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