SatSig topic:

problem establishing transmit

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Aug 5^th, 2009 at 10:14am

hello,
please am having problem establishing transmit of hns7740s while having SQF 76.i have tried cable swaping and even change to new buc but still having my tx code on 13. also i reconfigured the modem and tried to re-range but can't range.i tried to deconfigure the modem but eachtime i put command "rd" instead of deconfiguring the modem it will come up with "connection to the host lost".what next will i do?
thanks
edwin

Aug 5^th, 2009 at 10:38am

That means that The transmitter cannot communicate with the GTWY

This condition can indicate any of the following:

•This may indicate a transmit problem at the GTWY and should resolve itself within a few minutes.

•The transmitter is sending incorrect timing data because incorrect ZIP code or incorrect latitude/longitude information was entered during installation. Contact your installer.

•The outdoor transmitter unit is not operating properly or is not properly connected to the remote terminal. Ensure that the transmit cable is securely fastened to the satellite out connector

Tell me what happened

Aug 5^th, 2009 at 10:51am

in the first place the connectors are well crimped and fasten to the buc and tx port of the modem.secondly the immeadiately after tracking on connecting cables the transmit starts to blink (flashing), sometimes it will come up after like 7-10 mins it will go off.when i preseted tru the preset button and reboots the modem established a transmit with tx 8 and start downloading files.suddenly the transmit led went off and couldn't come up again.i preset again and it remains the same way.don't know what again to do.

Aug 5^th, 2009 at 10:54am

(TX=8) means that The transmitter is available
This is the normal operational state and indicates that the transmitter is ready to transmit .

contact your Noc Operator.

Aug 5^th, 2009 at 11:05am

More specifically, it means the transmitter is unable to perform the ranging process - because it cannot communicate with the NOC. That usually means not enough RF energy is making it to the satellite. This can be caused by
1. Problem at your NOC
2. Bad weather
3. weak/defective transmitter
4. Incorrect POL angle
5. signal loss on the IFL
6. incorrect geoloco installed in modem
7. defective/incorrect power adapter

Since the problem sounds chronic - and since you've already swapped out transmitters - I think we can rule out the first three. Relative to the others:
4. verify/correct POL angle, to include inclination error if any
5. swap TX and RX cabling end to end
6. verify/correct latitude/longitude in modem interface
7. use minimum 64w power adapter (80w for 2 watt Tigris). My information suggests you should be using Hughes part number
1031105 or 1500089 (both 64w)
or 1500185 or 1033374 (both 80w)

//greg//

Aug 5^th, 2009 at 12:08pm

Problem at your NOC
2. Bad weather
3. weak/defective transmitter
4. Incorrect POL angle
5. signal loss on the IFL
6. incorrect geoloco installed in modem
7. defective/incorrect power adapter
thanks greg,
but according to our NOC they said that at their end no problem, and we have a very clear weather,correct pol, no signal loss, correct lat/long installed on the modem,good power adapter.
NOTE: we have established a transmit previously which makes the modem to be able to download file,but suddenly the while still on the process of downloading files the transmit went off and couldn't come up again.

Aug 5^th, 2009 at 1:30pm

Quote:

NOTE: we have established a transmit previously which makes the modem to be able to download file,but suddenly the while still on the process of downloading files the transmit went off and couldn't come up again.

As I said before, items 1 through 3 can likely be discounted. Unless/until you post otherwise, items 4 through 7 remain germane.

And FYI, your connection is in the form of a segmented loop. The segments are typically
a. modem to cable block
b. cable block to ODU
c. ODU to satellite
d. satellite to NOC
e. NOC back to satellite
f. satellite back you your ODU
g. ODU back to your cable block
h. cable block back to your modem.
A problem on any of those segments will break the loop. That's why your connection drops despite having what looks like a usable receive signal. Segment c is generally the weakest link in the entire loop. But when ANY segment or segments are broken, the entire loop goes down.

This is what's happening when your TX light goes out. I suspect that the TX signal from your ODU is not making it to the satellite with sufficient strength to be relayed properly down to your NOC. One or more of items 4 through 7 above may be contributory.

//greg//

Aug 6^th, 2009 at 1:11pm

is it possible to have signal lock from a particular satellite with a particular frequency and having the dish pointing to a different satellite. (ie) receiving with an nss7 frequency on a different satellite and yet having all the nss7 data on the modem.

Aug 6^th, 2009 at 1:38pm

I don't actually understand the question the way it's worded. But I'm pretty sure the answer will still be not possible. I say this because of the "two degree rule".

//greg//

Aug 6^th, 2009 at 4:38pm

Tell Greg what Rx code you see.

If there is a similar carrier on a nearby (wrong) satellite (similar frequency, symbol rate and polarisation) and you are pointed at the wrong satellite then your modem will not complete the lock up process successfully. It will do fine tuning (perhaps +/-2MHz to get freq lock), then adjust the AGC level, then fine adjust the symbol rate (to get symbol lock) then look for the wanted unique data word, framing and try to decode the data stream to check for correct carrier ID or other code (it will fail to find the wanted data).

On Linkstar symptom: slow flashing green and pcr=false
On Hughes symptom: No idea, but maybe the fact that the SQF goes above 30 means that it is Hughes carrier perhaps ?
On iDirect symptom: No idea

Best regards, Eric.

Aug 10^th, 2009 at 12:22pm

on i have rx 5-- tx 13. SQF 76. and yet can't still establish transmission even when moved the dish to 4 different position and still having a very good SQF.someone said it maybe interference but if it is interference what could be the possible solution?

Aug 10^th, 2009 at 1:11pm

RX5 simply represents "The receiver is operational". Whereas it's not actually an error, it's included in the Error Codes to let you know there's no problem detected on the receive half of the connection loop.

You already know what TX13 represents, and I listed the segments of the transmit half of the connection loop. You're problem is in that half somewhere. Interference can be an issue, but it's more often on the receive side. If there was interference on your TX side, it would likely be way up in the 12-14GHz range. The exception to that might be L-band interference entering the TX cable through an improperly installed connector.

To help narrow this down, I recommend that you exchange TX and RX cables. Identify your cables with tape - both ends. I use red tape on both ends of my TX cable, blue tape on both ends of my RX cable. Or you can simply write TX and RX on the tape. Your choice. Power down the modem, remove coaxial cables at the rear. Reconnect TX to Sat In, reconnect RX to Sat Out. Go outside and move the TX cable to the LNB, and the RX cable to the transmitter. Then power the modem back up.

//greg//