No odd transducer channels

[SkipF]

For the past month or so, I've been having troubles receiving (what I believe to
be) channels from ODD transducers. Once and a while, it seemed to go away.
(Like I could see SciFi on NewYearsDay) but now several channels post a
'searching for Sat Sig' box. Seeing 15V DC on the coax for the odd (bad)
channels, and 19V on the good ones. Yesterday I even plugged the coax
into the other LNA Block port, to no avail.
some Good ones:
241
245
248
269-279
500-503
505-508
521
locals channels
some Bad Ones:
212
232
236
242
244
247
249
504
520-529 (except 521)
It's just a single receiver installation, with the coax feeding straight to the Dish.
Where should I look next?
Thanks,
Skip Flem
Hull, Massachusetts

 

[damaged]

Loss of half the transPONDERS usually means a bad LNB, since you seem to have no multiswitches in play. Check the coax for wear and tear, kinks, corrosion at the connectors, etc. too.

Posting your signal levels (from meter screen) and type of dish (dual/triple) may help further analysis.

 

[SkipF]

I don't have a signal meter; the signal levels displayed on screen are in the low
90s on the Even Xducers, 0 for the Odds.
And I'm using an 18" round dish with a dual LNA B. Coax 'looked' fine; I wrapped
the connector up with silicon rubber tape, and the typeF SnapSeal connector
also 'appeared' good.
Another funky aspect was... it used to find the signal after 5 minutes of waiting;
while the image 'developed' and the sound would snap, pop and click.
But no more. Just a black screen.
Perhaps I'll ask a neighbor for his LNA, he's no longer a subscriber. (I'll hook
my box up to it, first)

 

[charper1]

Just FYI so others know exactly what is being discussed:

A transducer is an electronic device that converts energy from one form to another. Common examples include microphones, loudspeakers,thermometers and pressure sensors. Although not generally thought of as transducers, photocells, LEDs, and even common light bulbs are transducers.

A transponder is a wireless communications, monitoring, or control device that picks up and automatically responds to an incoming signal.

DBS dishes use an LNBF (“LNB + feedhorn”), which integrates the antenna’s feedhorn with the LNB. LNA is old tech.

The item in question here is a transponder.

 

[Mr Tony]

and its a LNB too

but yes transponder signal strengths will help start narrowing it down

 

[dragon002]

what kind of IRD (reciever) do you have? the hughes models were known to lose one set of transponders or the other. just a thought.

 

[SkipF]

Thanks for the clarifications. I once worked in the Polaroid
'transducer' lab, where they made 2000 units a day. I'm
sure that's where the word comes from.
My 'current' problem is the LNB (or Low Noise Block ?);
the 'electronics' sitting on the end of the boom, as opposed
to an aiming issue? The evens are in the 90s.
Thanks!

 

[dragon002]

i really doubt the lnb is bad.

 

[damaged]

_If_ your coax is good, and all your connections are good, and the receiver is good (it could be that too), and there is no line of sight issues (trees, etc.), _and_ you are getting 90s on the evens, it most likely is an LNB issue. (yes, it is a Low Noise Block(er) downconverter)

If you have a dual lnb dish (round type, only one LNB on the face (referred to as a dual lnb)), then you could just call D* and ask for a dish upgrade to a triple LNB dish, it is 50 bucks delivered, and installed/peaked all for that same 50 bucks, or, you can buy a replacement dual LNB (about 30 bucks) and replace it yourself, or, if you have the D* protection plan, D* should be able to get you fixed up with a new LNB for free.

 

[dragon002]

If your coax is good, and all your connections are good, and the receiver is good (it could be that too), and you are getting 90s on the evens, it most likely is an LNB issue. (yes, it is a Line Noise Block(er) downconverter)
If you have a dual lnb dish (round type, only one LNB on the face (referred to as a dual lnb)), then you could just call D* and ask for a dish upgradem to a triple LNB dish, it is 50 bucks delivered, and installed, and peaked all for that same 50 bucks, or, you can buy a replacement dual LNB (about 30 bucks) and replace it yourself, or, if you have the D* protection plan, D* should be able to get you fixed up with a new LNB for free.

it is a LOW NOISE BLOCK

 

[damaged]

Thanks dragon, corrected. brainburp

 

[benj]

Loss of EVEN transponders could be caused by damaged cable, corroded connectors, selective short. Loss of ODD transponders (but still getting the EVEN ones) can be a little harder to track down. On a one outlet system like yours, it can only be so many things. What it is NOT: LNB, LOS or a connector.

How old is your electrical wiring? What model of receiver? Is it one of the newer D10/D11s? If it is, even money says it's a ground loop caused by a floating/mismatched ground.

With DirecTV's newer boxes anytime you have a ground loop, in most cases, it becomes physically impossible to lock into the 13v transponders.

 

[SkipF]

The box is a Sony SAT-B55, with a RCA dish/LNB. Single outlet? The LNB has
2 Type F connectors, and I just switched 'ports' yesterday. No luck.
Nothing has changed with the box, it's wiring, TV, VCR or DVD. Cable (inside)
looks fine- I removed the wall plate and checked that cable/connector.
I'm curious of the reason it's not the LNB. Internally, there has to be a switch
that senses the DC levels and selects a different antenna phase? I'd love to
pop it open and re-flow everything, but it's the 21st century, and we're NOT
supposed to fix broken consumer items any more...
I'm hoping that there won't be too many alignment issues with a different LNB.
Do they ALL fit the same mount? At least by brand?
The good news (and probably the biggest impediment) is I get all the local
stations, History Channels, and HBOs (except West); the only one I really miss
is NFL...
Thanks, Everyone!
Skip

 

[dragon002]

find the ground block and take the fittings off, look inside. any water, is it all black inside??

if so , change the fittings and ground block.

a sony 55 huh, im really surprised it lasted this long.

 

[SkipF]

13v?

I'm getting 15 and 20V, with the coax disconnected.
Could this be an issue?
What if...I put a DC isolator on the cable and put 12 V on the antenna lead with a 2.5mH choke?
Or 3 1N4148s in series across the DC blocking cap?
15V --------------| |-----------------LNB 13.2V
@ box ^--->|--->|--->|---^
That way I'd know if it's the box or the LNB

 

[jmshillito]

No EVEN transponders!!

I work in the Cayman Islands (south of Cuba). Can get a 80% signal on some of the ODD transponders with my 2meter dish (I used to use it for Direct TV, but changed to a "legal" subscription to BEV from our Canadian address.) There are some odd transponders I can't get at all.
I had to replace the LNB recently, and the only one I could get here has a single coax "plug" - does that mean it is a single LNB? Is that why I only get half the transponders?
What I understand of the above discussion is that unless I use a "dual LNB" I will only get half the transponders, and this far south I will not even get all of them.
Is that correct?
Can anyone recommend the correct LNB to buy, and a supplier near Toronto?
Many thanks

 

[SkipF]

Single or Dual refer to the numbers of 'antennas' in the LNB. A Dual will let you
use 2 'boxes' with the same Dish. It's just a coincidence that the LNB also
has 'dual' modes.
As to 'our ODD' problem, I'm wondering if my BOX is putting out TOO much
voltage (15.5V) to be detecting a 'low' voltage mode Transponder?
The Even Transponder Mode Voltage is 20.1V.

 

[jmshillito]

Number of antennas in the LNB

When I click on "check switch", I get the message that this is a single switch. I take it from your reply this is nothing to do with the number of coax plugs I can attach to it? The old LNB had 2 coaxes.

What we would REALLY love is to be able to activate transponder 8 ( with sport for me and HGTV for my wife!!) If we could get the even channels, is it simply luck if we can get 8, or would we be able to get different transponders by repositioning the dish?

Thanks again

 

[Smith P.]

Single or Dual refer to the numbers of 'antennas' in the LNB. A Dual will let you
use 2 'boxes' with the same Dish. It's just a coincidence that the LNB also
has 'dual' modes.
As to 'our ODD' problem, I'm wondering if my BOX is putting out TOO much
voltage (15.5V) to be detecting a 'low' voltage mode Transponder?
The Even Transponder Mode Voltage is 20.1V.

Yes, 15 VDC is little high for ODD transponders, but you must measure under load, so insert temporary T-connector or open your receiver and do new measures.

 

[benj]

Yes, 15 VDC is little high for ODD transponders, but you must measure under load, so insert temporary T-connector or open your receiver and do new measures.

Measure under load? That's all well and good for appliances but that's not what's going on here.

Check the voltage coming out of the coax up at the dish. If the voltage is >15.5v, the odd transponders will never be able to be selected by the LNB. Whatever you do, DON'T open up the receiver.

20.1 volts is a little high for an IRD to be putting out right at the box. Most DirecTV receivers put out just a little more than 18v at the sat input, allowing for some voltage loss going all the way up to the dish still puts you right at the 18v mark. It doesn't matter what voltage inside the box or coming right out of the box; all that matters is the amount of voltage up at the LNB.

It could be that the ic voltage regulator is going out in which case a new box would be in order.