LNB Offset Testing (sorry, no more free LNBs)


#21

re-adjusted the skew… back to great snr at +7
made the yellow jackets very unhappy… (the flying wasp type)

skew adjustment was quite dramatic… from -13 at off worse
to +7 when corrected.


#22

So +7 is better than the MK1, right?
You made me really nervous…we have 1000 of these sitting on a shelf in Shenzhen, with another 10,000 on order.


#23

Let’s wait on test results to see what they can do, and what the defect rate is.

It is important that Othernet works on satellites covering different parts of the world in a reliable fashion. New satellites such as Astra are coming to fruition. Ken


#24

I recently received some Peltier cooling modules to mess with on other projects here at home. It is possible I could try for some colder testing if that would be useful (and I can get something rigged together). About how much power does this new LNB consume/dissipate? To have an idea if I have a chance using TEG modules. And/or I could rig it for elevated temps.

What sort of temp range would be useful, if I can come up with something other than using ambient?


#25

For internal heat dissipation.

two data points I have… spec’s on the MKI are power 13 or 18 vdc max 135ma

my system with the new lnbf is voltage 14.2 and current “0x23” (what that is I don’t know)

For a ‘performance’ spec … I think -40F to +180F would cover it…
(my black-colored dish acts like a real ‘solar oven’)

Edit: my test lnbf is outside exposed to the ‘sometimes black body sky’. So it will experience some real fast cool downs in the next couple of clear nights … ambient will only drop to the low 30’sF

from our local NOAA weather:
Traverse City Memorial Day Climate Extremes (1897-2018):
Warmest High Temperature: 93 degrees (2006)
Coldest High Temperature: 51 degrees (1983)
Coldest Low Temperature: 28 degrees (1992, 1961)
Warmest Low Temperature: 68 degrees (1962)


#26

After 18 hours in observation on the new lnb. I noticed in Skylark 5.5 that the Frequency Offset (Hz) and Frequency Offset (post-AFC) are always the same. It appears no AFC is being applied. In older version of Skylark I observed that if Freq Offset was high, then an AFC was applied and a smaller (post-AFC) was reported.

I tried to ‘force’ a correction by using a custom setting - no post-AFC change. This is on both my dreamcatchers’ (with different lnbf’s)


#27

-30C to 60C would be great. It is the startup temperature and initial offset that we want to log. Once we have lock the AFC can track the carrier add the temperature and offset changes, so that kind of test is not as important.


#28

Need some clarification. I have been testing the Maverick and the new Universal LNB on my Dreamctcher indoors 500 feet away from my LNB/Dish, and outdoors at the LNB/Dish as this pic illustrates with the Maverick live, and the universal and Invacom hanging below waiting their turn - -

For the Dreamcatcher indoors and outdoors tests, the Maverick has provided higher SNRs than the Universal by about 3 dB. Both are receiving the same Rssi levels (indoors they both receive -103 dBm and outdoor they both receive - 69 dBm). No problem getting lock, and my bitrates climb rapidly to 20,000 bps.

It’s the frequency offset and temperatures I need clarification on:

  1. Do I start with a dormant LNB that has not been powered for say 1 hour, or do I just do a reboot? The case of both LNBs never seems warm like my running Dreamcatcher.
  2. My Dreamcatcher sits without being in a case, so it will be at the ambient temperature. If it has been running for awhile before I do a reboot, the center of the board is warmer than it be if it sat un powered for several hours. Is the key to these test starting with cold LNBs and Dreamcatchers, and observing Freq Offset right after boot?
  3. My tests are not showing any significant Freq Offset or Freq Offset (Post-AFC) difference from start up thru 3 hours operating. I am not letting any gear cool down when I do swap outs. They have been running about 1000 Hz on both the Maverick and the Universal at an ambient temperature indoors and outdoors of average 68 deg F.

Ken


#29

What’s most important is the temperature of the LNB. More precisely, it’s the temperature of the crystal inside of the LNB. When the LNB is running, the temperature inside of the device will warm up a bit–and the ambient temperature will have an impact on that internal temperature.

  1. Yes, test at a cold start. A 1-hour shut-down period should be sufficient.
  2. The temperature of the Dreamcatcher is not important, as we are seeing how the crystal inside of the LNB responds across a range.
  3. I’m not surprised by sub-1 kHz offset on the Universal, but I am surprised by that on the Maverick.

Maybe put the Universal in the freezer for a few hours? And then another test would be to get the LNB up to about 130 degrees F.


#30

Good information. I will redo the test from a cold start out of the freezer tomorrow. Ken


#31

Filled the interior of my test lnbf with water and taped the joints to semi-watertight it… it is in the freezer doing a good four hour freeze before the next test. Hope it doesn’t expand/rupture in the freezing process.

Result: lnbf was really not affected by having it filled / frozen in ice. I monitored it as it melted/ dripped out for about an hour. no real changes. Temperature when I pulled it out of my freezer was +18F.


#32

@Syed
@kenbarbi
@ac8dg
Hey guys, I think I got a dead LNB. The mail arrived at 11:55 MST, and I have been working for two hours trying to get the new Universal LNB to work. Have set it to Othernet Dual Band, connected to both my 3.02Q and 3.03 Dreamcatchers using two different known good RJ6 quad jumpers. No indication on Status. Aimed it several times using instruments for accuracy, but it does not see the birdie. I watched as Ken changed his unit at 1555 EST from the Maverick to the Universal, and my readings in both diagnostics and tuner match to the letter, excepting that there is no status, no twittery receiving lights on the boards. It is 50 degrees F here and sporadic light showers. Have I possibly missed a step here? I am leaving it on the 3.02Q for a while this afteernoon if anyone wants to look at it. …Jerry


#33

Did you reboot after changing to Othernet Dual Band?


#34

Maverick vs Universal LNB Test Results

Both my Maverick and Universal LNB were placed in a freezer at -1 deg F for 12 hours. They were removed and installed on my offset 80 cm dish. Maverick in the morning; Universal in the afternoon.

Maverick (removed from freezer) was installed when ambient outdoor temp was 69 deg F. Freq Offset during first minute was -1,000 to -3,000 Hz with signal lock. After 5 minutes Freq Offset was -720 to +2,700 Hz. Later in the day after running for 6 hours, Freq Offset was steady at about - 200 Hz.

Universal (removed from freezer) was installed when ambient outdoor temp was 80 deg F. Freq Offset during first minute was a repetitive +719 to +1,463 Hz. After 5 minutes Freq Offset was a repetitive +620 to +1,711 Hz. The SNRs on the Universal were about 3 dB lower than there Maverick with the same Rssi levels.

Feel free to view my Dreamcatcher working with the new Universal LNB at http://71.206.20.63/ later today. Just click thru the Tuner App to get to the Status Tab. Ken


#36

I did notice a strange quirk when I first connected my Universal that caused no receive. It was the connection to the F connector on the LNB. I had to wiggle it a bit and loosen it a bit - - rather than make it finger tight. Seemed to me the F connector was not making good center pin contact. Ken


#37

@kenbarbi Are you reporting values without AFC?


#38

The numbers for both are exactly the same on my Status tab. Ken


#39

With my installation.
watch the skew … the ‘orientation’ was different between my MK I and the new lnbf. It didn’t work with the coax output terminal in the original setup. When I was way off axis of skew. I got no signal.

About a full 90 degree’s different in skew alignment.

Note: I am running about 15 feet of good quad rg-6 … but I may still have some voltage drop… or as @kenbarbi mentioned… connection at the F terminal could be causing the Vdc to drop … that could affect the Horz / Vert oscillator selection circuitry. Checking the diagnostic lnbf current might be important.


#40

Yes, rebooted and checked connectors several times for each change. Re-tested with a Maverick, same cables, no problem acquiring in the Maverick mode. Skew did not make a lot of difference, from nothing to nothing. Incidentally, the skew + and - markings are backwards on the universal.
Interesting to note that on both DreamCatchers, the LNB reverted to the Maverick after the re-boot. Could this be part of the problem, if so, how to overcome it?


#41

Those markings may be off, but treat the LNB the same way as you do this the Maverick since that’s how it orients itself. Ken