FTA and 4DTV 920 Receiver on one Dish

[JacksBack]

Hello,

I have an FTA receiver with a GBOX dish positioner driving a (fairly old) C- and Ku-band dish. Everything works.

With the return of 4DTV on W5, I dusted off the DSR-920 receiver and got a proper 2400 MHZ splitter with DC pass on both legs. I installed the splitter between the GBOX and the dish. One leg goes to the GBOX (that then connects to the FTA receiver) and the other leg goes to the 920.

Pointing the dish to AMC 18 (105 deg. west) with the FTA receiver allows the 920 to receive 4DTV, and all is well.

The problem is that with the 920 connected to the splitter, the FTA receiver stops working - no signal. If I disconnect the 920 from the splitter, the FTA receiver gets a signal, and works fine.

Turning off the 920 doesn't solve the problem, as the power switch on the 920 just switches off the front panel; the receiver is still powered. I could unplug the 920, but this means it will lose its program guide.

I'm guessing that the FTA receiver or the GBOX doesn't like seeing DC from the 920.

I really hope I'm not the only one to encounter this situation, and that there's an easy fix.

Thanks.

::JACK

 

[Anony55]

...and got a proper 2400 MHZ splitter with DC pass on both legs. I installed the splitter between the GBOX and the dish. One leg goes to the GBOX (that then connects to the FTA receiver) and the other leg goes to the 920...

You need to pull that splitter out immediately! Hopefully, you haven't already fried anything. By using a splitter that passes voltage to both legs, you are allowing the voltage from both receivers to meet / fight.

You need a splitter that only passes power to one leg, and blocks the other.

Cheers

 

[tvropro]

Put a DC block on one leg. A ceramic disc capacitor will achieve this. Thats all there is to a DC Block.

 

[Mr Tony]

if all he wants it for is W5 why not just salve it using the loop out? Since he mentions a GBox and the 920 being added the FTA receiver is the item moving the dish, not the 4DTV so using the loop out would work too

 

[JacksBack]

Thanks.

Okay; nothing is fried. (I thought about the DC affecting the other receiver but the guy at the place I bought the splitter said that was the correct device, and he had been using them for years in this sort of application. You just can't trust anyone!)

At the moment, I have replaced the splitter with a mechanical antenna switch, pending the correct splitter. (That's not going to fry anything, I hope.)

If I understand it correctly, I would use the one-leg-pass splitter so the 920 receiver, which is always on, powers the LNBF. The RF from the LNBF would split to both receivers, and both receivers could send control signals back to the LNBF. And nothing would get fried. Is that correct?

Thanks again.

::JACK

 

[tvropro]

You send power pass to the DSR and RF only to FTA.

 

[radio]

But, don't we have to have only ONE receiver controlling polarity here? Only one polarity will scan/show at a time on either receiver in the usual FTA/4DTV setup with shared feed. Depending on which unit is powering the dish's LNBF.

 

[scottxray]

But, don't we have to have only ONE receiver controlling polarity here? Only one polarity will scan/show at a time on either receiver in the usual FTA/4DTV setup with shared feed. Depending on which unit is powering the dish's LNBF.

This is the problem with a shared setup. One receiver or the other has to be the master for polarity since the voltage has to change with an LNBF, or the polarotor on a co rotor.
I am facing the same dilemma. Controlling the polarity is a pain.

I REALLY wish that someone would come up with a dual C-band lnbf that also has a Ku feed. Sort of like a Dual C band DMX 741. Run one cable to the FTA receiver, one to the
4D and use a 22 khz switch to select the KU for the FTA on the same coax.

 

[radio]

I REALLY wish that someone would come up with a dual C-band lnbf that also has a Ku feed. Sort of like a Dual C band DMX 741. Run one cable to the FTA receiver, one to the
4D and use a 22 khz switch to select the KU for the FTA on the same coax.

A dual "C"/ DUAL "kU" would be a dream come true. There used to be such feeds at skyvision, and you could even buy them for fitting on a Birdview. They were bulky, and very expensive, but that was before the days of the voltage controlled LNBF, too...I wouldn't mind some bulk on the dish if it dual fed both bands!

 

[jaray]

I'm assuming the problem with 2 receivers controlling polarity is that many receivers are not truly off when the power button is pressed and they'll still control polarity? I know I have a 410 on the loop-out of my traxxis and I have to turn the master power switch on the Traxxis off or some channels don't come in on the 410. Same the other way around too, watching the traxxis with the 410 still on and some channels don't work.
Is this still an issue with a dual lnb where I run a separate cable to each reciever?

 

[radio]

Correct on your understanding. They'll fight for polarity based on whichever one is powering the LNBF. Dual LNBF off one dish will not cause any problems and give full single-band coverage to each receiver. They're inexpensive and very effective these days.