Posts by pe1chl

With all LNB types (especially the unspecified ones) it appears to be customary to change the electronics while still selling them under the same brand name and type number.

So when person #1 buys and determines to be a PLL LNB with 25 MHz reference, person #2 may find a DRO based LNB and person #3 may find a PLL LNB with 27 MHz reference.

All with (about) the same external appearance and sold under the same name.

I would think the trend is towards PLL type, and it seems also towards 25 MHz reference. So whenever you buy an LNB try to get new stock by ordering from a company with high turnover or close to the source.

Especially when searching all the internet for an LNB no longer produced or hard to get, you probably have increased risk of getting an early type that is not usable.

It could be that they were switched to the MENA beam or maybe even a narrower spot beam.

It would be valuable to get reports in the MENA area or closer to Qatar.

That sure looks like the correct signal, but it is strange that you have a polarization issue as the signal from the beacon is RHCP (circular polarization).

I do receive it both H and V here. Cannot turn the LNB but I can switch it.

The frequency instability is similar to what I have here, i.e. not as bad as some people write.

More important than the attenuation of the coax is the quality of the shielding!

There are usually other services on the frequencies used for IF in the system, and you may get interference from that.

E.g. when using normal satellite TV there is interference from "cordless telephone" DECT devices. When you put the base station of the phone near the settopbox or the cable towards it, you may have interference on some channels.

When using an unmodified LNB (9750 MHz LO) the narrowband transponder IF will be 739.xxx MHz. This used to be in the UHF TV band (channel 54) but this band is being repurposed as a 5G mobile band. So there may be very strong signals or they could appear later.

So make sure you used good quality coax with foil+braid shielding and apply the connectors in the correct way.

W.r.t. the dish size: we don't know yet, as our objective is not to receive the beacon but to receive the amateur transponder. When it was on for testing, it was very strong. But we would have to see that in operation.

Also, now that the satellite is in position, the situation is worse then when it was at 24e. There is noise from other satellites at the 10.706 beacon. Similarly this could affect the amateur transponder.

So it may be that you require 60cm or 80cm just for the directivity, not as much for the gain. To attenuate the signal from Astra3 at 28.2e.

This depends on your location. In the UK the situation is of course much worse than in southern Europe.

I have looked at SDRangel before but it wasn't possible to install it on my machine, the CPU is too old and lacks some modern instructions that this program requires.

So it is worth to check that before you spend a lot of effort!

Many years ago (about 25 I think) I won a KR-500 elevation rotor at the tombola.

Then had to devise some way to smuggle it back home on the plane

Fortunately the security checks were not so rigid back then...

Quote from DB8TF

I don't think that NB SSB receiving with unmodified PLL LNB would be fun.

Just try to demodulate the EB with SSB and see how you must constantly adjust the VFO for a steady audio frequency.

It depends on the weather and the stability of the LNB in question. What I read and see here about the Octagon LNB is considerably worse than what I experience with my cheap Chinese SR-3602. But it could vary more between devices than between those two manufacturers, after all they all use the same cheap crystals.

The question of course is, do you modify the LNB with a better oscillator or do you then immediately go to the "full solution" of using an external GPS-locked reference.

Quote from DB2OS

pe1chl no Serial numbers on my NEWGEN-RTL-SDR's

RTL-SDR sticks have an electronically readable serial number. On most if not all devices I have seen the number is 00000001

(also on those NEWGEN-RTL-SDR sticks that I recently ordered)

So even more exclusive than your Funcube dongle

But you can change it. E.g. on Linux do this (with a single stick plugged in):

rtl_eeprom -d 0 -s 12345678

You will see the current serial number and the proposed new one, and answer y to the question if you want to write it.

Then unplug and re-insert the stick and it will be serial number 12345678 now.

When you have several sticks you can use this to know which one you are accessing in your program (at least when it supports the serial number).

Quote from DB2OS

my Funcube Pro+ Dongle (Serial 00000002)

Did you already check the serial number of your RTL-SDR dongles?

Quote from G4SDG

I've been using a Funcube Pro dongle and SDR-Sharp which seems to limit my visible bandwidth to ~+/-75KHz but when I checked with an analyser I can see sidebands on both beacons at ~+/-250KHz but only the additional sidebands at +/-15KHz on the 11205.5MHz beacon at the moment.

That is correct. The 15kHz sidebands are not always there and at the moment they only appear on 11205 and not on 10706 but this can also be the other way around.

The 250 and 500 kHz sidebands are always there.

Of course even with a Funcube you should be able to see them by tuning around, just not in a single picture as with the RTL-SDR or other SDR receivers that can sample at 1 or 2 MS/s.

Quote from ha7dcd

Dear All,

Made my first reception attempts and looks like got the 11205 MHz beacon (Hungary, Budapest). I see something on the 10706 MHz part as well but suspicious that not seeing side bands (may just my signal too weak?).

When you see signals but not the expected patterns or only one of the two, you are likely pointed to the wrong satellite. This can easily happen as other satellites used beacons on almost the same frequencies, and are located e.g. at 31.5e and 19.2e.

It is easier when you have a DVB-S(2) receiver as you can verify the satellite you are pointed to by checking the TV programmes you receive.

When you are checking from Europe (i.e. not from the target area of these satellites) you cannot receive most programmes, but e.g. on 11996 MHz Horizontal 27.5MS/s 3/4 FEC you can receive a strong transponder with Arabic versions of news programmes. This is not from Es'hail-2 but from another Arabsat at 26e.

Quote from G4SDG

Hello all,

I am a bit confused about the polarisation of the two beacons.

The beacons are RHCP. So not suitable to set the skew angle of your LNB.

Yes I remember that from my first experiments with RTL-SDR sticks...

At first I could receive only the local FM radio stations.

But once you have fixed that it actually works quite well for a 15-euro radio

Yes, when you first use RTL-SDR sticks in software you should search for the gain setting that can be set to something between 0 and 50dB or "automatic" and make sure it is either on "automatic" or you change the setting to something reasonable for your setup. Try 20dB or so.

Yes, there are two of them, but there is only a single crystal between them.

I would like to convert one half to external reference (1 connector for ref in and one for IF out) and the other half to remain on the crystal.

My hypothesis is that the crystal is used with the oscillator in one of the chips, and the resulting signal (probably one pin of the crystal) is linked to the other chip.

That is the connection I want to cut.

But it would be helpful to know the local circuit for the crystal used in standalone mode and which pin is input and which is output.

(usually the crystal oscillator in such chips takes the form of an amplifier to which the crystal is connected from output to input, and a capacitor on the input)

I am always interested in affordable PLL LNBs but I prefer the 4-port type so I can use one connector for reference input, and still have output for Ham Radio and for normal satellite usage.

I have one here: SR-3604 or clone (unsure).

I still need to convert it to external reference input. I'd like to find some solution so that it continues to work from the internal reference when no reference is supplied.

(so I can watch TV with the reference turned off)

I would be nice to have the datasheet of the chip (KTD1051 see http://www.ktdel.com/en/Product/Details/1653 ) but the manufacturer does not reply to mail, as seems usual in the far east.

Those dongles are fine, I received 2 as well up to now (ordered 3 at different shops, 1 still in the mail).

I tried it on Es'hail-2 although there are intended for extra bands in our WebSDR http://websdr.pi1utr.ampr.org/

(now we have 430-434 1296-1297 2320-2321 5760-5761 and 24048-24049 MHz already QRV)

I can't help you with Windows 10, the sticks work OK in Linux (and should work in Windows as well I hear from others)

Nice, I want to make something like that as well.

For now I have a WiMo/SHF-design SHF-1340

Quote from Frank DL9DAC

How are DXpeditions going to work via the satellite? Split operation is not desired on the satellite. Is there a plan for this case?

Due to the fullduplex nature of satellite operation the calling stations can judge by themselves if they are being heard or if another station is stronger so they can stop calling for now. So at least part of the reason for operating split is not valid on satellite.

Quote from YL3AKC

Another idea for monitoring: BATC will provide webSDR, so you can always monitor downlink from webSDR.

I'm afraid people who now worry about the roundtrip delay ( = no experience on Phase3 satellites) will not want to listen to a WebSDR which has even more delay.

However, it could be considered to make LEILA behave so that when a station repeatedly triggers the LEILA and does not appear to reduce power, the siren tone also continues for some time after the transmission has ended, so at least they are warned when they switch to receive.