Originally posted by Rooster
View Post
Announcement
Collapse
No announcement yet.
best antenna
Collapse
X
-
Last edited by andyk1; 2013-11-26, 22:20.
-
Originally posted by peterhr View PostTest plots - I used ADSBscope on windows, after persuading dump1090 on the Pi to work in a mode compatible with it..
Sent from my GT-P5110 using Tapatalk
Sent from my N762 using Tapatalk 2Last edited by abcd567; 2013-11-26, 23:19.
Comment
-
When used with inLine Amplifier, my fullwave Franklin Collinear works better than 1/2 wave dipole and 3-and-half element Coco.
When working without Amplifier, 1/2 wave dipole is #1, Coco is #2, and Franklin is #3. This seems to be due to very high impedance of fullwave Franklin.
I wound an impedance matching, air-core, auto-transformer 1:6 turns ratio (= 1:36 impedance ratio) and connected. Phooosh!!! The inductor in my power injector fried! I forgot that transformer winding will short-circuit core & braid and did not insert a capacitor.
I removed amplifier & power injector and ran two tests (1) with transformer & (2) without transformer. The range with transformer is far less than range without transformer. This is contrary to my expectations! Cannot make out the reason. Can anyone explain why?
Sent from my N762 using Tapatalk 2Last edited by abcd567; 2013-11-28, 01:05.
Comment
-
Originally posted by Rooster View PostI'd bet that's an error with sdr#!
Sent from my ZX81Last edited by andyk1; 2013-11-28, 01:43.
Comment
-
Originally posted by andyk1 View Post...... The best was no protective tubing and antenna hanging from a tree using fishing line....
Sent from my N762 using Tapatalk 2
Comment
-
Originally posted by andyk1 View PostNot sure it was. I tried the antenna inside Electrical grade PVC, Water grade PVC and fiber glass. All gave be different tuning results. The best was no protective tubing and antenna hanging from a tree using fishing line. Of course that's not practical considering the weather in mid-western and southern US. Even with just the antenna hanging from a tree it wasn't dead on... 1089.993 mhz. Using Electrical grade PVC it was 1089.925 and water grade PVC was 1089.956. Fiberglass tube showed. 1089.965. mhz. These where all tested a few times back and forth to verify the results. For me anyway... Elec grade PVC is the worse to use for weather proofing. Fiber glass tubing had the better result.
Sent using Tapatalk from my ZX81
Comment
-
Originally posted by Rooster View PostThe tuning of the antenna has NOTHING to do with the frequency displayed in the software... You could stick a 6 inch nail into the reciever as an antenna and you would still receive 1090mhz!
Sent using Tapatalk from my ZX81
Sent from my N762 using Tapatalk 2Last edited by abcd567; 2013-11-28, 05:52.
Comment
-
Originally posted by Rooster View PostThe tuning of the antenna has NOTHING to do with the frequency displayed in the software... You could stick a 6 inch nail into the reciever as an antenna and you would still receive 1090mhz!
Sent using Tapatalk from my ZX81
In it, it shows all the materials we have all been using and testing. PVC, water and electrical grade and fiberglass. In it he uses a professional freq spectrum analyzer, a freq generator or whatever it was called. He demonstrates how the material used for weather proofing affects the incoming freq around 140 mhz. I don't remember the exact freq. He very carefully demo's everything including the distances from other objects that would affect the incoming signal. i.e two times the distance compared to the length of an antenna.
Considering how cheaply made these sdr dongles are made and my own tests to verify that... I'm inclined to agree with what I saw on my own tests also. For me... different weather proofing material did matter for my range and distance. To compensate for the freq shift I simple changed it to the center of whatever SDRsharp.exe waterfall in Windows showed me as the optimum incoming 1090 freq then used that freq in my RPi's dump1090 software as --freq 1089.9whatever and it seemed to help a lot. Also --gain 32.9 had to be used or no incoming signal . This is after a lot of testing that was both frustrating and bothersome and hours and hours of wasted time. I also tested local FM signals with stock antenna that came with dongle and it was dead on for 104.1 reception using SDRSharp. It was also close but not dead on for 1090 MHz but closer than my home built antenna.
I also understand I can still receive 1090 MHz even though the signal is off a bit but that is because both RTL1090 and dump1090 use a wideband signal on both side of 1090 to capture the incoming freq by 20.000 or 200.00 mhz. I don't remember which.
Sorry to say but I never tried a 6" nail to test as I never thought about that but have used bare metal coat hangers before . Maybe next round of testing when the weather warms up... next spring...Last edited by andyk1; 2013-11-29, 01:30.
Comment
-
Originally posted by abcd567 View PostThis reminds me of the old days when death punishment was given by hanging. The standard way a judge will write the verdict was: "To be hanged till death"
Sent from my N762 using Tapatalk 2
Comment
-
Can anyone else here... just out of curiosity... use SDRShape.exe (SDR# is same program) for Windows and test your 1090 MHz income freq and see how close it is to 1090 if not dead on. And mention which SDR dongle you use.
I for one have been using Nooelec R820T SDR &DVB-t ver 2 ($22.99 US ) and also 3x DVT-T + DAB +FM (R820) also ($12.00 US). All 4 brought from amazom.comLast edited by andyk1; 2013-11-29, 19:28.
Comment
-
Originally posted by andyk1 View PostCan anyone else here... just out of curiosity... use SDRShape.exe for Windows and test your 1090 MHz income freq and see how close it is to 1090 if not dead on. And mention which SDR dongle you use.
I for one have been using Nooelec R820T SDR &DVB-t ver 2 ($22.99 US ) and also 3x DVT-T + DAB +FM (R820) also ($12.00 US). All 4 brought from amazom.com
Sent from my N762 using Tapatalk 2
Sent from my N762 using Tapatalk 2Last edited by abcd567; 2013-11-29, 02:32.
Comment
-
Originally posted by andyk1 View PostCan anyone else here... just out of curiosity... use SDRShape.exe for Windows and test your 1090 MHz income freq and see how close it is to 1090 if not dead on. And mention which SDR dongle you use.
I for one have been using Nooelec R820T SDR &DVB-t ver 2 ($22.99 US ) and also 3x DVT-T + DAB +FM (R820) also ($12.00 US). All 4 brought from amazom.com
1) 2 x Nooelec Newsky v2 RTL-SDR DVB-T+DAB RTL2832 (Receiver chip) + R820T (Tuner chip). Each Canadian $22.60 (cost+shipment+sales tax).
2) 1 x KDQ23 NEW RTL-SDR FM+DAB DVB-T Dongle Stick RTL2832+ R820T SPC-155. Each Canadian $ 9.94 (free shipment, no sales tax).
Sent from my N762 using Tapatalk 2Last edited by abcd567; 2013-11-29, 15:26.
Comment
Comment