Search found 200 matches

by snn47
Wed Oct 09, 2019 8:17 pm
Forum: Antennas
Topic: antenna related information and guidance for asking questions to improve chances for an answer
Replies: 6
Views: 4363

Guidelines for choosing coax cable for use >1000 MHz

Guidelines for choosing coax cable for use >1000 MHz possibly not complete, but that should suffice for a start: Know which impedance receiver has and you know what impedance your coax cable and connector should have Decide if you desire low loss, max. shielding or both While low loss per dB/m (or ...
by snn47
Wed Oct 09, 2019 7:57 pm
Forum: Antennas
Topic: antenna related information and guidance for asking questions to improve chances for an answer
Replies: 6
Views: 4363

Re: guidance for asking antenna related questions improves chances for an answer -proposal for a sticky post

@nizz -freq scan noob I tried to rephrase and provid an example. Does this explain it better? - transmisson line loss (cable and connectors)vs. antenna gain guidance for choosing coax cable can be found here https://www.rtl-sdr.com/forum/viewtopic.php?f=6&t=4861&p=12432#p12432 All transmission lines...
by snn47
Wed Sep 25, 2019 6:05 am
Forum: Antennas
Topic: What is a good wide range antenna for desktop sdr
Replies: 5
Views: 1398

Re: What is a good wide range antenna for desktop sdr

As said before what is the frequency range you are interested in, which polarisation have the signal you want to receive? I suggest you look at https://www.rtl-sdr.com/forum/viewtopic.php?f=6&t=4861 for more information on what you might want to ask and which information you should provide to get th...
by snn47
Mon Sep 23, 2019 3:19 am
Forum: RTL-SDR Discussion
Topic: Compare field strength
Replies: 3
Views: 714

Re: Compare field strength

and you have to know the transmission line loss(cable& connectors), The attenuation differs with frequency, the higher the frquency the higher the attenuation. Furthermore the antennaazimuth and elevation pattern. The elevation pattern varies among other factors with frequency antenna height, above ...
by snn47
Fri Sep 06, 2019 10:19 am
Forum: Antennas
Topic: Signal Splitting?
Replies: 17
Views: 5010

Re: Signal Splitting?

I just tried and the link works.

I don' know if Minicircuits does mailorder, if not you You have to locate and contact a distributor for prices.
by snn47
Thu Sep 05, 2019 6:19 pm
Forum: Antennas
Topic: Signal Splitting?
Replies: 17
Views: 5010

Re: Signal Splitting?

Since you want to buy how about trying SAT-TV splitter e.g. http://www.schwaiger.de/en/4-way-distributor-12-db.html these cover VHF? Comercial splitter combiner are more expensive and price increase with power handling capacity. Another option are directional couplers for providing additional output...
by snn47
Thu Sep 05, 2019 5:07 pm
Forum: Antennas
Topic: QFH Antenna
Replies: 3
Views: 792

Re: QFH Antenna

Assuming that you are looking for receiving 137 MHz, did you try searching? Have you checked these pictures https://www.qsl.net/l/lu7did//docs/NOAA ... LU2HAM.pdf ?
by snn47
Thu Sep 05, 2019 4:44 pm
Forum: RTL-SDR Discussion
Topic: Identifying a Device's Transmisssion Frequency
Replies: 3
Views: 855

Re: Identifying a Device's Transmisssion Frequency

Sorted in order of price
absorption meter,
frequency counter,
oscilloscope or
spectrum analyzer available can detect or meassure transmitt frequencies.
by snn47
Thu Sep 05, 2019 4:37 pm
Forum: RTL-SDR Discussion
Topic: mute on transmit
Replies: 4
Views: 846

Re: mute on transmit

How much power do you transmitt and on which bands do you have problems? Have you considered that it is direct RF getting directly into your setup somehwere after you muted the audio that is generating the hiss? I know in todays totally solid state envrionment it is an old fashioned advise, but have...
by snn47
Mon Sep 02, 2019 5:42 pm
Forum: Antennas
Topic: Antenna Element Wire Gauge Effect
Replies: 4
Views: 1985

antenna resistive loss vs. diameter vs. bandwidth (capacitance)

I assume I understand what you are asking now. You are asking about the effect of conductor diameter onto bandwidth and antenna efficiency. Those are all related to antenna efficiency and bandwith but different effects are involved. It is always a tradeoff what is sensible to do for a given frequenc...