Posts by Verdonim

1) Message boards : SETI@home Science : Would we find us. (Message 1920890)
Posted 24 Feb 2018 by Profile Verdonim Project Donor
Post:
From 49:30 to 50:22
https://www.youtube.com/watch?v=vQ2sKwwhRgI
2) Message boards : SETI@home Science : Would we find us. (Message 1919624)
Posted 18 Feb 2018 by Profile Verdonim Project Donor
Post:
I would tend to say yes. They would probably pick up our most powerfull transmissions easy but this
is all just maths and physics. Lets assume they and we stop to rotate when both our Aracibos are facing
each other perfectly.

How much ERP (effective radiated power) would be needed at the transmitting ''Aracibo''
(knowing that the signal has 4 light years to cross and that it will fade to the square of the distance)
for the signal to get at the receving ''Aracibo'' with enough energy so it has an S/N (signal to noise) ratio
good enough so it can be detected ?

You have all the the info to make a quick estimate.
- The intensity the signal need to have at the receiving end in order to be detected.
- The receiver sensitivity, the antanna gain (very high) and the noise level.
- the distance.
From there you know how much ERP is needed at the transmitting ''Aracibo'' and since you know the
antenna gain you know how much RF power you need.

Its just a guess but in CW mode (continious wave) at 1.2GHz and with the perfect conditions of having
both antennas facing each other two radio operators could have a morse code converstation with no more
then a 1KW transmitter (MW ERP). And a lots of patience....
3) Message boards : SETI@home Science : The R.O.L.B (Radio Operators for a LISTEN Breaktrough) (Message 1919323)
Posted 16 Feb 2018 by Profile Verdonim Project Donor
Post:
SDRConsole is very good too. And wow this little SDR on CW is fantastic. The filters are
very good very quiet and CW sounds good even down to 5 Hz wide. Weak signals feels strong.
It is an easy to listen receiver. The spectrum is fast is software is very well put out.
There is a lot of amateur radio in mind behind this amazing little rig.
4) Message boards : SETI@home Science : The R.O.L.B (Radio Operators for a LISTEN Breaktrough) (Message 1919094)
Posted 15 Feb 2018 by Profile Verdonim Project Donor
Post:
There is a new update to SDRUNO software at SDRPlay. There are also links there for the SDR Console V3.P7 software. Between the two of them you can decide which you like best for functionality and screens layout. The control software will have to be newer versions to handle the new hardware that is the SDRPlay RPS1a.
I have installed and played with all 3 apps and so far prefer SDRUNO. I knew I had lots of birdies but to see them on the screen is pretty impressive. I have spent a good 6 hours today getting familiarise with it. Works well with the little Uniden rubber duck
for UFH. With the indoor Buddipole tuned at 7.030 MHz (with lots of patience and my AA-30 antenna analyser) I manage to receive some CW (in between birdies...). I have 4 floors of consumer electronic devices above my head... Not much I can do.
I am really happy with the purchase.
5) Message boards : SETI@home Science : The R.O.L.B (Radio Operators for a LISTEN Breaktrough) (Message 1918973)
Posted 15 Feb 2018 by Profile Verdonim Project Donor
Post:
I have received my RSP1a yesterday :)

I have an adaptor for my Buddypole BNC. Second antenna will be one from a handheld trunktracker scanner no adaptor needed and a USB type B cable.
Not shielded nor choke but I wont be transmitting anything so it should work for now.
I now I have to go search a little bit starting at SDRPlay site on how to get ready for the ''mise en operation''.

For now I am amazed by how small and lightweight the thing is and when I think about all it does it blows my mind.
6) Message boards : SETI@home Science : The R.O.L.B (Radio Operators for a LISTEN Breaktrough) (Message 1918410)
Posted 12 Feb 2018 by Profile Verdonim Project Donor
Post:
How long that wire is going to be ? I have never used a Magnetic loop but if I remember well they are quiet. Wich is a good
thing now... Is it a fixed frequency loop or you can adjust it somehow from the shack ?
7) Message boards : SETI@home Science : The R.O.L.B (Radio Operators for a LISTEN Breaktrough) (Message 1918402)
Posted 12 Feb 2018 by Profile Verdonim Project Donor
Post:
I had one similar to that before. Thats the kind of antenna I was thinking.
Of course Height is very important those are direct waves but unfortunately
I am on the first floor... It wont stop me from having fun with it.
I am watching videos... cant wait.
8) Message boards : SETI@home Science : The R.O.L.B (Radio Operators for a LISTEN Breaktrough) (Message 1918399)
Posted 12 Feb 2018 by Profile Verdonim Project Donor
Post:
I have a box full of adapters SMA BNC PL etc but yes I will by a shielded USB.
9) Message boards : SETI@home Science : The R.O.L.B (Radio Operators for a LISTEN Breaktrough) (Message 1918395)
Posted 12 Feb 2018 by Profile Verdonim Project Donor
Post:
Sounds good. Can't knock the price for what you get. Any SDR over the $20 cost of the cheap RTL-SDR dongles is a huge improvement. I started with a dongle and soon realized it is very limited in receiving bands. Think you will be very happy with the RSP-1a.
I am ready to confirm the purchase I just hesitate because of the fact it has only only one antenna connector. But at the same time its not a big deal I will only have 2 antennas. My buddypole and another one for VHF-UHF that I will have to buy or build. I am temporarily living in an apartment building at the moment and I have limitations when it comes to antenna. I will be mostly playing with UHF... Ok I go confirm the order.
10) Message boards : SETI@home Science : The R.O.L.B (Radio Operators for a LISTEN Breaktrough) (Message 1918387)
Posted 11 Feb 2018 by Profile Verdonim Project Donor
Post:
SDRPlay RSP2

Correction RSP1A
11) Message boards : SETI@home Science : The R.O.L.B (Radio Operators for a LISTEN Breaktrough) (Message 1918385)
Posted 11 Feb 2018 by Profile Verdonim Project Donor
Post:
What are you ordering if I may ask?
SDRPlay RSP2
12) Message boards : SETI@home Science : The R.O.L.B (Radio Operators for a LISTEN Breaktrough) (Message 1918368)
Posted 11 Feb 2018 by Profile Verdonim Project Donor
Post:
Primary reason is that only GBT is steerable for our current antennas. Arecibo is not. You would have to coordinate observing campaigns at each antenna. Also, we don't have exclusive access to the target observation star, we normally just 'piggyback' on the nights primary science target and have our receivers and recorders listen in as secondary. I do believe that many of the radio telescopes DO in fact do long baseline interferometry of observing targets. With bringing on the steerable Parkes array in Australia in the future there should be candidates at the celestial equator visible at both GBT and Parkes. So we theoretically could do differential listening if the hardware is compatible.
Understood. So in a perfect world we would at least have 2 steerable dish in the northern and 2 in the southern hemisphere each pair in deferential mode with primary access all year long.
13) Message boards : SETI@home Science : The R.O.L.B (Radio Operators for a LISTEN Breaktrough) (Message 1918363)
Posted 11 Feb 2018 by Profile Verdonim Project Donor
Post:
I am ordering one right now for real. I dont know why I dont already have one in my shack. Seriously.
I have not been active much in radio recently but boy I am late with new things.
14) Message boards : SETI@home Science : The R.O.L.B (Radio Operators for a LISTEN Breaktrough) (Message 1918346)
Posted 11 Feb 2018 by Profile Verdonim Project Donor
Post:
And BTW why arent we searching using 2 antennas (differential) ?
Point the 2 dish at the same star and ''look'' at the bumps. Those that appear
in just one antenna is for sure local. Local RFI problems solved. Must be a
budget and telescope time limitations I guess. It would be so much more
efficient. The scientists at SETI are far from stupid and I highly respects
them. I have watched a few Berkeley video on youtube and it looks like a
cool team. BUT ! If you tell me they have never thought about that I quit
SETI forever. No seriously it would be so much better to use two dish at the
same time.
15) Message boards : SETI@home Science : The R.O.L.B (Radio Operators for a LISTEN Breaktrough) (Message 1918331)
Posted 11 Feb 2018 by Profile Verdonim Project Donor
Post:
Well, there are hundreds available on Ebay at the normal $20 dongle cost. Just search for RTL SDR on Google. I like my:
SDRPlay RSP2 receiver for $170
Wow I dont know what to say.
The last time I had a look at those receivers was like 10 years ago... They are so non expensive !!! Long time ago receivers needed to have only
3 qualities. Sensitivity, selectivity and fidelity. How do those little SDR performs in those matters ? They are software define so I guess one can
makes it the way he wants.
16) Message boards : SETI@home Science : The R.O.L.B (Radio Operators for a LISTEN Breaktrough) (Message 1918328)
Posted 11 Feb 2018 by Profile Verdonim Project Donor
Post:
If we put a GBT dish like in space equip with an ultra wide band SDR receiver and and a 2GHz span on the spectrum what will happen when you
turn the dish towards the earth ? the spectrum analyser will be filled with bumps everywhere. It will look like a single giant wide band
transmission containing lots and lots of information. Why looking at narrow signals only ? I am just a technician but would it not be a good way
to search by just simply go from star to star ultra wide and when you pick one that has more bumps than average you investigate ?
17) Message boards : SETI@home Science : The R.O.L.B (Radio Operators for a LISTEN Breaktrough) (Message 1918316)
Posted 11 Feb 2018 by Profile Verdonim Project Donor
Post:
So all the SDR's that I am familiar with tune that band of frequencies. Most SDR's go to around 2 Ghz, some as high as 6 Ghz and then if you want to tune higher you just put a down-converter in front of the SDR receiver.
Thats the problem I am not familiar with any of them actually. Can you post a link to a SDR that would be great for the L-Band ? I could search again but since you seems to already know a few... I know that flex does SDR box that looks like a ''radio'' and I like that. https://www.radioworld.ca/flexradio-flex-6600-m That one is a transceiver but you get the idea.
18) Message boards : SETI@home Science : The R.O.L.B (Radio Operators for a LISTEN Breaktrough) (Message 1918295)
Posted 11 Feb 2018 by Profile Verdonim Project Donor
Post:
I would not have been good working at NASA I mix my acronyms all the time.
I often mix DSP and SDR...

Yes SDR would be the way to go of course with the spectrum analyser and everything.
Looking a t a few manufacturers though I cant find any for 1.2 GHz and up.
I had a look at Flex they don't have any receivers for the bands GBT is ''listening''
to.

Just for fun google image ''amateur radio seti'' there are a lots of miniature ''GBT''
antenna in back yards. That is cool. Great links I will spend some times reading and
learning SETI today.
19) Message boards : SETI@home Science : The R.O.L.B (Radio Operators for a LISTEN Breaktrough) (Message 1918110)
Posted 10 Feb 2018 by Profile Verdonim Project Donor
Post:
How many receivers at GBT ? If more than one they have to split the source somehow.
It might turn out to be very easy to do... And the more I think about it the more I am
convinced it would be very popular in the amateur radio community.
20) Message boards : SETI@home Science : The R.O.L.B (Radio Operators for a LISTEN Breaktrough) (Message 1918105)
Posted 10 Feb 2018 by Profile Verdonim Project Donor
Post:
Yes you are right it would probably be difficult to sample the RF without affecting it somehow. I know nothing
about how the RF is transport to the receivers on a radio telescope (Coax, wave guide) etc. I am not a scientist
or an engineer but there is got to be a -20dB test point somewhere... I would be fine with that.

And yes I think you are also right IP would be the best If not the only way to transport it to the listeners. Dont forget
we are only sending chunk of the total bandwidth. each listeners could receive one channel of lets say 100 KHz wide.
Nothing that internet cant handle I think.

Do you know what kind of internet bandwidth would be needed to to broadcast the GBT feed ? It would not be free
thats for sure... I wish I could go there and plug my ''very noisy'' receivers, compare to the ones they have, directly into the feed,
picnic table under the dish, a beer in one hand and the other on the radio, Just listening, Jodie Foster style.


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SETI@home and Astropulse are funded by grants from the National Science Foundation, NASA, and donations from SETI@home volunteers. AstroPulse is funded in part by the NSF through grant AST-0307956.