antenna subforum? - Page 1
Forum section: electronics / projects

author: sarepairman2
author_rank: Frequent Contributor
timestamp: July 09, 2015, 01:16:59 am
content: I propose an antenna subforum be amended to this forum, I think that the topic is highly specific, and is limited to few people.I also feel that if there is an antenna subforum glaring at people then it will get people who never built an antenna before to build one.I don't think a general "HF" forum is advisable, as you can be talking about high frequency FPGA clocks, switching regulators, transmitters, so it does not really serve a good purpose.All the HAM people would probobly post alot of easy to make DIY stuff there too.

author: nitro2k01
author_rank: Frequent Contributor
timestamp: July 09, 2015, 01:39:29 am
content: If you wanted to generalize the topic outside of antennas, surely RF (radio frequency) would be more suitable than HF. Antennas as a topic on its own I unfortunately think is too narrow to deserve a subforum.

author: kc9qvl
author_rank: Regular Contributor
timestamp: July 09, 2015, 02:04:30 am
content: I also don't see any reason an antenna subforum or even RF or HF.As far as hf antenna's go there are 2 very large ham forums already.

author: Lightages
author_rank: Unknown
timestamp: July 09, 2015, 02:45:50 am
content: I don't see it neither. If there are specific needs for a specific antenna design for a specific product, it fits here. If the need is for general antenna design, as already said, there are other forums for that.

author: LaserSteve
author_rank: Super Contributor
timestamp: July 09, 2015, 05:06:29 pm
content: Concur with the idea of a microwave/HF forum. It is very much a different world then most EE areas.Steve

author: dom0
author_rank: Super Contributor
timestamp: July 09, 2015, 06:09:12 pm
content: Quote from: sarepairman2 on July 09, 2015, 01:16:59 amGood that you say yourself why an additional subforum is unnecessary.

author: Lightages
author_rank: Unknown
timestamp: July 09, 2015, 06:29:30 pm
content: Quote from: dom0 on July 09, 2015, 06:09:12 pmHe answered a call for opinions. Just like mine is just my opinion, so is his. What is the problem?

author: LaserSteve
author_rank: Super Contributor
timestamp: July 09, 2015, 09:40:18 pm
content: I'd argue, that anything over 1 GHZ starts to need considerable skill to design well. For those of us who work at the 2-10 Ghz region, be it digital clocking or radio, it would be nice to our own area.Steve

author: Lightages
author_rank: Unknown
timestamp: July 09, 2015, 10:01:11 pm
content: HF and GHz are two very different animals. I agree that perhaps GHz+ might have a place here, but HF has been done to death elsewhere.

author: mazurov
author_rank: Frequent Contributor
timestamp: July 10, 2015, 02:28:06 am
content: I'd like to see 1G+ sub-forum as well.

author: calexanian
author_rank: Super Contributor
timestamp: July 10, 2015, 03:21:32 am
content: EHam has a pretty extensive forum and HF antennas make up a good part of it.

author: Melt-O-Tronic
author_rank: Frequent Contributor
timestamp: July 10, 2015, 03:39:56 am
content: If you look over the current list of subforums, I think a general RF area could fit. Not limited to antennas, but also PCB design, transmission lines, EMI, etc. On the other hand, those would touch into existing areas. But I would personally love to see an RF subforum.

author: Stonent
author_rank: Super Contributor
timestamp: July 10, 2015, 04:18:17 am
content: I think Mike said it best:https://youtu.be/eyA2lWQrxwg?t=16m52s(Sorry can't embed it because it has a queued start)

author: LukeW
author_rank: Frequent Contributor
timestamp: July 10, 2015, 04:47:33 am
content: If anything is justified as an additional subforum, I'd make it an everything-RF subforum.

author: LaserSteve
author_rank: Super Contributor
timestamp: July 10, 2015, 02:44:25 pm
content: I VERY MUCH like the idea of GHZ plus, all the way out to 640 Terahertz. Ie Light....Right now on the bench is a 0-2.5 Ghz analog Spec An, a home made 360 pS pulse generator, a 2-18 Ghz sweeper made in the late 70s, a few home made down converters, a Programmed Test PTS-250 with 1 Hz steps, Rubidium 10 MHZ source, a couple of 5 and 10 Ghz microwave "brick" phase locked oscillators, a HP 415, a HP 432 to 12 Ghz and a 0-22 Ghz return loss bridge.I'm on 1296 Mhz, 2.4 Ghz. and 10.368 Ghz for my Ham hobby. It is a whole different world when you lay out the PCBs or make harmonic multipliers ... Don't even get me started on waveguide and feed horns.Did I mention that when I went to the one Ham Radio microwave conference near me, I felt under equipped?HF guys and Microwave Guys do not mix well on Ham forums, either... I don't know why, but we easy overwhelm the HF crowd. Its sad...Another reason for the GHZ+ forum is the Microwave Mailing list, which I so dearly love, is and has to be, so highly moderated to keep things on topic. That topic is pretty limited to narrowband SSB attempts at long distance communications, to break records... There really is not a open forum that tolerates hobbyist microwave, and has strong contributors regularly visiting.So I could make a strong argument for a very public, GHZ+ Digital and RF Comms forum. Clock frequencies are not getting any lower, and the idea of a 300 Mhz microprocessor should soon be the norm, not the exception.Steve

author: sarepairman2
author_rank: Frequent Contributor
timestamp: July 10, 2015, 04:18:51 pm
content: gonna post the schematics for the pulse generator?Unless its the jim williams one, i was interested in making the one that uses high speed logicwhat are these forums that everyone keeps referring to and why can't we borrow their users to bring more diversity to eevblog?

author: LaserSteve
author_rank: Super Contributor
timestamp: July 10, 2015, 07:07:42 pm
content: We had a build off, four of us at the College of Engineering. Discrete parts made with a small loop area won over using the coax line or T-line. Building the pulser as a 3D object, dead bug, using a mix of SMD and thru hole, was very, very, fast. Reduce the loop area... Hand select the transistor. Do what ever you can to reduce loop area and inductance. Select a cap with the right self resoance via trial and error.. We borrowed access to a 10 Ghz sampling scope... Mine was second place in the contest.One of the bottlenecks with Coax Storage Lines is the junction inductance between the coax and the transistor can be a serious slowdown. Even using tiny UT141 as the coax. Which is why the T-Line Avalanche board posted on this forum is very nice...Jim Williams design has the advantage of being something you could manufacture as a product. It will also work, every time. I had to build three trial dead bug systems to get the time down. It's not something I could mass produce/reproduce and uses hand selected parts... I switched to a Emco High Voltage voltage variable 0-500 V Module instead of using Williams' Switcher. Because I had one on the bench. Mine is free running, and Williams' external triggering is much more useful.One modern piece of say Eclipse Lite or Hittite Logic can smoke the Avalanche system. Where the Avalance circuit wins is you have a pulse with significant amplitude.There are also some tricks for a small signal with summing two logic edges slightly delayed, out of phase, but engineering that is PFM even with a really fast scope.Steve

author: G0HZU
author_rank: Super Contributor
timestamp: July 10, 2015, 09:08:45 pm
content: In the unlikely event that an antenna subforum was created and it proved popular, I offer the following info based on my own experience.Antenna design is one of those areas in the RF world where there is no shortage of quack experts making all kinds of misguided claims. There's no shortage of myths or folklore surrounding the world of antennas.Also, on some US ham forums some people have been known to argue for years and years over claims and counterclaims over antenna design and performance. Especially when it comes to the design and testing of electrically small antennas. These guys don't give up and there's not a lot of love between them.I just don't think it would be wise to have an antenna forum here because I think there could be a lot of (confusing?) disagreements. Best to read a few good books on the subject and avoid any ham radio forums unless you particularly want to witness several old men arguing the same old stuff over and over again...Maybe best to let people ask the odd antenna related question in the current Projects, Designs and Technical section.

author: sarepairman2
author_rank: Frequent Contributor
timestamp: July 10, 2015, 10:37:12 pm
content: Quote from: G0HZU on July 10, 2015, 09:08:45 pmi think this is a great reason to have an antenna sub forum, as this place has many industry professionals that can look at claims and debunk them. It's not a strictly hobbiest thing that has a strong cult of personality.

author: G0HZU
author_rank: Super Contributor
timestamp: July 10, 2015, 10:57:21 pm
content: QuoteIt would be nice if it worked out like this but I suspect that for every post containing reliable info about antennas there could be 'many' that don't. I still think that the safest place to learn about this subject is in trusted literature. There's plenty of it available.Although I've spent my whole career working with RF I'm not an antenna expert by any means. I'm not sure there will be many people on this forum who are experts in antenna theory who will also devote a lot of time contributing to an antenna subforum on Eevblog.But there will be plenty of people who 'think' they are experts...

author: Electro Fan
author_rank: Super Contributor
timestamp: July 12, 2015, 06:13:57 am
content: +1 for a RF Forum. Wireless is different, complex, important, prevalent, and growing with no end insight. It spans analog and digital domains, includes transmitters and receivers as well as antennas, and it covers a large range of frequencies, includes various forms of multiplexing and modulation, and spans both Wide Area Networking (satellite, microwave, cellular, M2M, GPS, and more) and Local Area Networking (Wifi, Bluetooth, passive and active RFID, Zigbee, UWB, and more). I think a RF forum here would be popular.

author: sarepairman2
author_rank: Frequent Contributor
timestamp: July 12, 2015, 03:24:38 pm
content: I kinda feel like the modulation/digital side of RF gets handled pretty good, the black magic design is where peoples answers start to get janky

author: cdev
author_rank: Super Contributor
timestamp: January 19, 2016, 11:36:24 pm
content: I'd like to see an antenna subforum (perhaps to the new RF forum) too.I'd also like suggest a motion control forum.

author: dadler
author_rank: Unknown
timestamp: January 20, 2016, 04:11:30 am
content: Quote from: cdev on January 19, 2016, 11:36:24 pmToo many subforums => segregates/dilutes conversation and makes the forum seem less active. More manual effort is then required to go read the separate sections.In my opinion, this forum just is not large enough to support division at this level. Certainly the new (and not very active) RF subforum should be sufficient for antenna related discussion?