Архив за 12.10.2017

137MHz transportable measuring tape turnstile antenna

Hi /r/RTLSDR :-)

im planning to build a transportable 137MHz antenna for NOAA/Meteor reception. At first i thought about building a V-diople antenna, but then i saw /u/VA7EEX measuring tape turnstile and i think this will be a perfect design for me with folding the measuring tapes while transporting the antenna.

But i do have a few questions about the antenna and hope you all (and hopefully /u/VA7EEX himself) can help me with them.
(Please bear up against my ignorance in antenna theory, im still learning).

In /u/VA7EEX antenna there is a bit vertical distance between the two orthogonal 2x0.25λ-diople elements (see here).
Does this matter? Would it be better to have them all in one level plane? Would i have to consider this distance when calculating the length of the 0.25λ-delay line?

I ve found different versions to create a balun for this (or at least i think these things are there to act as a balun):

What would be the best method?

If i add also reflector elements:
How to calculate the distance between dipoles and reflector and the reflector lenght itself?
(measurements here and here are roughly the same ((39cm, 106cm) vs (46cm, 114cm)), but here its much different (3λ/8=82cm, 120cm, with 4 reflector elements instead of 2 though)).
And where to set the 0 of the distance between dipoles and reflector if the dipoles arent at the same height? On the upper one with the feeding cable?

Greetings and thanks :-)

submitted by /u/ecocapi
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Comment on Simon Brown Compares the Airspy HF+ against the RFSpace NetSDR on SDR-Console V3 by Simon Brown

Reflock – 10MHz reference for locking the internal oscillator so that the SDR is spot-on frequency-wise. I have rubidium and GPS reference locks, for example http://www.leobodnar.com/shop/index.php?main_page=product_info&products_id=234 which I can recommend.

RTL-SDR Discussion • Adding a Heatsink to The Aluminum Body

I have a lot of heatsinks salvaged from old PCs, and was wondering, if anyone tried putting a small one on each side of the aluminum case, with some heatsink paste? You could use a rubber band to hold them on, or get fancy with it, either way. Anyone tried this?

Statistics: Posted by k4lmp — Thu Oct 12, 2017 3:18 pm


Meteor M2 10/12/2017

submitted by /u/jeffreypkelly
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Если нужен звук, я лично не пробовал, но судя по роликам в youtube, GQRX на Raspberry Pi запускали Да, GQRX устанавливае…

toxa1983 пишет:
Если нужен звук, я лично не пробовал, но судя по роликам в youtube, GQRX на Raspberry Pi запускали Да, GQRX устанавливается запускается и работает на PI 3. Только надо в настройках поковырятся чтобы з...
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Широкополосный приёмник из DVB донгла - Страница #525

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Found out what happened with weird signal interference.

I'm referring to this post if you don't know what I'm talking about:

https://www.reddit.com/r/RTLSDR/comments/6z1mbl/what_just_happened/

The beepong at the airport was completely unrelated. Turns out it was my CPS smart meter. Every 8 minutes it transmits data on 850mhz and 100-150mhz.

submitted by /u/Tech2025_
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Comment on Simon Brown Compares the Airspy HF+ against the RFSpace NetSDR on SDR-Console V3 by Robert

I don’t know , I have a problem raping my head around some of the new terminology that people are coming up with like ultra low noise reflock . Reflock ??????????????????????????????????? When is see something like that I just bang my on the desk . Back in my miss spent youth the first thing that was on top of the list of SPECIFICATIONS was receiver sensitive and noise floor . Just try and find that in list now a days .

Друзья! Помогите подружить SDRSharp (RTL-SDR) c UR5EQF-логом. Не могу разобраться со звуком и настройками. Кто помочь может?…

Друзья! Помогите подружить SDRSharp (RTL-SDR) c UR5EQF-логом. Не могу разобраться со звуком и настройками. Кто помочь может?

Comment on Buy RTL-SDR Dongles (RTL2832U) by admin

It was supposed to be in stock at the start of October, but it’s currently delayed by US customs hold ups. They’ve selected the shipping container with our and other’s goods for a randomly selected intensive exam…We’re expecting them to release them in a few days though, then they should be on Amazon within 1-2 weeks from then.

У меня тоже первое время была тишина… Оказалось, не те частоты слушал) сейчас уже 100 групп в итоге и 1500+ радио…

smiledj пишет:
У меня тоже первое время была тишина... Оказалось, не те частоты слушал) сейчас уже 100 групп в итоге и 1500+ радио...
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Широкополосный приёмник из DVB донгла - Страница #525

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