Search found 51 matches
- Thu Apr 09, 2020 10:29 pm
- Forum: Antennas
- Topic: Antenna Coax Question
- Replies: 4
- Views: 2191
Re: Antenna Coax Question
Rg174 should have less than 2dB attenuation for shortwave
- Thu Apr 09, 2020 6:43 pm
- Forum: Antennas
- Topic: Antenna Coax Question
- Replies: 4
- Views: 2191
- Mon Feb 24, 2020 9:35 am
- Forum: Antennas
- Topic: Simple but effective DIY Civil and Military Airband Antenna
- Replies: 8
- Views: 12882
Re: Simple but effective DIY Civil and Military Airband Antenna
There isn't much material in this build that is likely to add loss(at this frequency) to the antenna, so in this case, I would expect S11 to be a fairly good proxy for the true performance.
- Mon Feb 24, 2020 6:26 am
- Forum: Antennas
- Topic: Simple but effective DIY Civil and Military Airband Antenna
- Replies: 8
- Views: 12882
Re: Simple but effective DIY Civil and Military Airband Antenna
Hi Mike, Great writeup. I haven't seen this style of antenna before. It's a very interesting design. The only thing missing from your blog is any final measurements of the antenna performance. The frequency is right in the sweet spot for a £50 nanoVNA. The S11(vswr) will give you an excellent idea o...
- Thu Jan 09, 2020 6:35 am
- Forum: Antennas
- Topic: a quick queation about atennas
- Replies: 1
- Views: 3650
Re: a quick queation about atennas
Hi It's difficult to know the exact length to tune a telescopic antenna. The cable and ground plane play a big part. 1/4 wavelength is a good start point. Unless you have a VNA, you can just tweak for optimal reception. It all depends on how critical it is to extract those last few dBs of sensitivit...
- Sun Nov 17, 2019 9:35 am
- Forum: Antennas
- Topic: Looking for recommendations for mobile, wide band, rx only antennas.
- Replies: 2
- Views: 3127
Re: Looking for recommendations for mobile, wide band, rx only antennas.
Is this an antenna array? For DF for instance.
Or do you just need multiple channels that don't need to be coherent? Kerberos would seem like overkill.
Or do you just need multiple channels that don't need to be coherent? Kerberos would seem like overkill.
- Fri Nov 08, 2019 8:05 am
- Forum: Antennas
- Topic: Suggestions for antennas to use with four channel coherent RTL-SDR
- Replies: 8
- Views: 6216
Re: Suggestions for antennas to use with four channel coherent RTL-SDR
Dipoles would work fine. Or you could have a sleeve dipole, if you only want the antenna to protrude out in one direction(to avoid snarling up on landing for example). One thing worth thinking about for use with Kerberos is that you need to have the antenna well isolated from the cable. That is, you...
- Thu Nov 07, 2019 1:49 pm
- Forum: Antennas
- Topic: Suggestions for antennas to use with four channel coherent RTL-SDR
- Replies: 8
- Views: 6216
Re: Suggestions for antennas to use with four channel coherent RTL-SDR
Can you elucidate on 'airborne platform'? Is this a fighter jet, microlight or a hot air balloon for example? Where on the platform do you envisage placing the antennas?
- Sat Sep 14, 2019 6:07 pm
- Forum: Antennas
- Topic: Antenna for SDR
- Replies: 3
- Views: 3932
Re: Antenna for SDR
I sell some ultra wide band antennas that cover a whole variety of interesting frequencies. I think they are a good start for exploring a while range of bands, but if you have any specific target applications you will probably be able to find a better narrow band antenna. https://www.tindie.com/stor...
- Sat Aug 24, 2019 9:55 am
- Forum: Antennas
- Topic: antenna related information and guidance for asking questions to improve chances for an answer
- Replies: 7
- Views: 14242
Re: guidance for asking antenna questions improves chances for an answer -proposal for a sticky post
All seem reasonable to me. I'm sure there lots of other info people could volunteer too. Just telling us the frequency ( in Hz) is a big help. Don't make us research that esoteric signal that may even be specific to your country. Cable lengths and types used is also worth knowing. What type(RG numbe...