Search found 9 matches

by swarl3s
Tue Jun 18, 2019 10:04 am
Forum: Antennas
Topic: Another Double Cross Antenna build (went wrong)
Replies: 16
Views: 4076

Re: Another Double Cross Antenna build (went wrong)

Hey guy's, sorry that it took me that long to answer, i was busy doing other stuff! So, i did try to extend the antenna away from the satellite dish, sadly that didn't help either. No, it made it even worse! The reception got so bad, that i decided to remove the antenna from the roof. The satellite ...
by swarl3s
Fri Apr 26, 2019 6:07 pm
Forum: Antennas
Topic: Another Double Cross Antenna build (went wrong)
Replies: 16
Views: 4076

Re: Another Double Cross Antenna build (went wrong)

If the lower part would not be needed, it would have been a waste of material right? Like i said, i know the lower parts are needed, but did not quite understand why. But that might explain why the satellite dish is messing with the reception. I'll try to extend the pole, it seems to handle that ex...
by swarl3s
Wed Apr 24, 2019 3:31 pm
Forum: Antennas
Topic: Another Double Cross Antenna build (went wrong)
Replies: 16
Views: 4076

Re: Another Double Cross Antenna build (went wrong)

Assuming that your dish is pointing to South (Astra?) Astra 19.2 East, yes. If we assume it's the dish that is causing problems, how could this be possible? - The Dipoles are only connected on the upper half, the lower one "isn't really connected to anything". I did never understand how dipoles in ...
by swarl3s
Mon Apr 22, 2019 11:27 am
Forum: Antennas
Topic: Another Double Cross Antenna build (went wrong)
Replies: 16
Views: 4076

Re: Another Double Cross Antenna build (went wrong)

Did you use this double cross antenna design https://www.qsl.net/l/lu7did/docs/NOAA/DoubleCross_137Mhz%20AntennaMARTES.pdf ? Hi, thanks for the answer. Yes i used the guide from qsl, beside of some others. Details about the dipole length/etc. is in my first post. The frequency band at 137.9mhz is n...
by swarl3s
Sun Apr 14, 2019 3:00 pm
Forum: Antennas
Topic: Another Double Cross Antenna build (went wrong)
Replies: 16
Views: 4076

Re: Another Double Cross Antenna build (went wrong)

Its rare for a satellite to actually be directly overhead. Most commonly they will acutally be at a lower elevation. The Lindenblad (double cross) is designed to give circular polarisation as a replacement for a linear dipole. For coverage at 90degree elevation you can use a turnstyle(crossed dipol...
by swarl3s
Sun Apr 14, 2019 2:07 pm
Forum: Antennas
Topic: Another Double Cross Antenna build (went wrong)
Replies: 16
Views: 4076

Re: Another Double Cross Antenna build (went wrong)

I would expect this antenna to have a null directly above and below. https://www.amsat.org/articles/w6shp/lindy.html Thanks for the link. So a double cross dipole is known to have a null at 90 degrees? But why does everybody else using a double cross get a strong signal directly over head? Even my ...
by swarl3s
Sun Apr 14, 2019 11:49 am
Forum: Antennas
Topic: Another Double Cross Antenna build (went wrong)
Replies: 16
Views: 4076

Re: Another Double Cross Antenna build (went wrong)

Sorry it's just not easy to troubleshoot antenna issues. How does the signal look like when you're receiving it? Also what exactly is the Nooelec LNA that you have? AFAIK they haven't actually released a 137 MHz LNA yet. Are you sure that the LNA you have is for 137 MHz? Got a link to the one you h...
by swarl3s
Sat Apr 13, 2019 5:16 pm
Forum: Antennas
Topic: Another Double Cross Antenna build (went wrong)
Replies: 16
Views: 4076

Re: Another Double Cross Antenna build (went wrong)

EDIT: After climbing on the roof a second time, to turn all four dipoles around (center cond. up), nothings changed. Still same inconsistent signal when receiving meteor. Does anyone have a clue about what is going on? Many people have been reading this thread since it was uploaded, but nobody wants...
by swarl3s
Wed Apr 10, 2019 12:39 pm
Forum: Antennas
Topic: Another Double Cross Antenna build (went wrong)
Replies: 16
Views: 4076

Another Double Cross Antenna build (went wrong)

Hello guy's! Since im from germany, my english is not the best but i hope you can help me with my problem! First of all, this isn't the first double cross antenna i've build. The first one was a one day holiday project, meant to last only a few days, so no expensive materials were used. I even forgo...