Updated Feb 21, 2019, 9:53 PM
As many you do today i am also using a web SDR system. It stated around 4 year ago when globaltuners was them main way of tuning to a remote HF system, and I m sure that someone from you alreday tested one of them so far .
Here i will post some of my thoughts adn reviews regarding these remote systems in draft due to medical parent resaons . that grab me more than 3/4s of my life. Im uncertain if i will find thetime to revise that . Plase accept my apologies.
Yu may also coments below for amndments or anything other you think necesary
The fist to notice here is the globaltuners facility which unfortuntely i don't remember so well. the only ican remember is the feeling of using a remote receiver that is controlled by an computer. Fortuntely these computers perform better than mine which is a full noise receiver . The radio is in between the computer tower and the 23" monitor adn the times the PC does not operate (ie 95% the time ) the secondary mains power splitter uses a switch to turn off all the connected equipnment. The router is over the PC and is connected to the main power splitter that also connects the receiver a LED lamp and the secindary mains power slpitter.
MY tablet is also the same . This F&U tablet and its adaptor have also quite strong noise levels . The adaptor dicsonected can also trasmit some noise if a radio is vey close to it . To add to the topic i spend too much time using the tablet then the PC . The PC is used only once or wice per week for just 3 hours max wehn the tablet can be used as long as ...12 hours per day. The reason is that I am jobless and my most time was spent in writng till my father's sickness problem .
Parenthese stops here with the noises caused by computers.
Globatuners as idea was very good and was relatively easy thought the sole process was very time consuming ifyou want to monitor the band . IN contrast just working with preset frequencies is much better and faster. THis is one of its major drawbkacks .Dont forget , it is a netwirk of recveivers conected into PC in contrast to the newer systems with PCB receivers or external interfaces.
Web SDR was the next option on around 15 or 16. I m unsure onwhen they started . I used the Twente Sdr since then which is the best among all others and the only one that uses the full band. I have tested more than 10 spots acrodd the globe but Twente is surely the best due to its full span tha tcovers all the SW bands adn still has the higher payload. I could prefer if at least 4-5 spots used the full frequency span so that i can makie my own comparisons to several stations around the world that include my favs from Msia or any other useful SW stations.
Memories is its best feature something that Kiwi still lacks. hurryngly waiting when they will add it
The web version is very simple self explaining. Just the basics :
-Spectrum , freqs etc
-very few adjustments for waterfall with 3 speeds and 4 sizes .waterfall can be changed into spectrum.
-AM FM SSB and in several spots with AMSync
-recording facility with freq and time ID file.
-keyboard usage of most oprations .
-S-meter plots . for unknown reason the plots are not linear as i remember from the analog system of the 90s but a series of dotted lines thast seem as a kind of chaos. Possibly faster tracking could help more in a opration i lked very much older times.
One great drawback: Once you visit the Sdr centers you on the 14 MHz band thjen you have to change the frequency. I ahve never given a callsign to know if the radio can restart from an older session as with kiwi.
KIwi Sdr iis now its main rival.I have used it around 17 adn then stuck with it adn its nice inetreface that seems more professional adn rich than its rival,and continuously updated .if you dont know Kiwi SDR is a 'commericial' SDR priced around 300USD and ofered via ebay and direct from their web page and connects into your router. Their philosophy was not to be a one's SDr sut rather a shared system,. It uses a built in microcomputer and the main radio card adn everytihng is made via a web browser . Its interface and control panel are better than the simplistic of WebSDr
Too many featues are used comparing to WebSDr as the decoders with I-Q except the FM.SSB, and AM that WebSDR (WSDR then ) uses . KIwi Sdr haa also the features below that Web SDr does not have:
-IQ demod does but seems a very funny demod to listen to a 'point that moves between the two earphones ' Actually it is used for providind raw signal for external decoding programs as DREAM , MultiPSK etc. similar to other standalone SDRs of the market (RSP models , Airspy ec)
-full Swband in all SDRs tested It is also nice to listen to the local MWs in all sites .
-More than 350 spots in 10 Dec with less than 100 for narrow band or in VHF etc .
-seprate spectrum graph with amplitudes from the main consele A newer version of the OS adss smoothing and max levels
-retune to the last station you visited the page.
-adjustable bandwidth for all decoding modes ,mouse controlled for both sidebands and 'memorized' if you return back later
-many adjustments for the waterfall including auto and 14 levels of zoom. in the same tab.These parameters can clean the noise from the waterfall. Also some options to change the colurs
-audio filters with NB and autonotch, decay and more from the audio tab of the consile
-separate tab to watch other users and clik on other's basic rececption parameters
-usage also with other SDrplay or spacifiued card mounted into the motherboard that costs around 100Eu (good price same as RSP1)
-various very useful extensions (plugins ) that can be usd to decode rtty fax sstv loran navtex and cw modes. However if there is any unlisted FSK (RTTY) station from its database you need to adjust manaually arond 8 parameters for rtty and never be assured .The fax mode is closed project but works fin . CW is not 100% sure and cant be used for poor signals navtex worked 80% well even if the signal was very good. Ther is a very interesting feature called TDoA that can be used as a radio direction findind mecahnism of unknown signals
-Ther are several separate useful extensions as IQ and S meter. S meter can show a trace of the signal per the time as with the plot in WSDR but its traces are much more 'analog' han its rival. . I wish this opration installed as a button inside the console The IQ meter reminds me the use of oscilloscope to analyze the spatiality a stereo sound in 'orthogonal view'.
-easy programing from the URL for some options very similar to DOS command line from the adress bar. .
-wish also later to include ISB decoding (3325RSG?itis bad that station closed down two moths after )
-and also a simplifid version for mobiles
Some draqwbaks of the Kiwi :
-recording doesnt work in all kinds of tablets as tested with other than mine tablet.
-no memories as with WSDR . This is posibly the most forgoten thing
-up to 4 or 8 users max by design That lowers the usageof waterfall and other paneloptions WSDR can handle unlimited users. BUt you can check what others monitor.I found a random frequency for pirate greek operators while i checked on a spot in Italy .
-a 'fake' chatbix with someone via a userID.Thay happned once with a radio pirate.WDSR has more capabilities between its users
-time limits in most spots today. I dont know on how is defined ut the limits can be either for a given frequency (30 mins ) or by use (5 hours as one example ).
-easy to freeze temporarily regardless of the operation system ie tablets or PC if you operate your broswer with more tabs . Happeens also sometimes with WSDR
-smartphones are too small to use for Kiwi and the browser seems to freeze or cant start the engine . In contrast tablets above 7' can be used well but most times freq change keyboard controlerd requires the tablet to turn laterally. WebSdr mobile can be used in smarthones and even in chrome as in my xiaomi witout any problem ecept rare cases of noise.
As for result i pefer the kiwi system in my tablet abd PC that has much more useful operations then WSDR . WSDR is now used very rarely and only in the smartphone Both systems hav good audio but sensitivity varies depedent to the antenna used
There is a common problem for both systems: they very easily can break reception. Thi can be hapened either by the abrupt stop of DSL coenction or if somethin happens to the "rig's" system be from computer or by the sdr card in case its mother board 'freezes' ..
Another importnat problem comes from the reception system. I have tested more han 40 spots and understood that:
1. not all systems have the optimal configuration so computer noises or other noises pass the system
2.most antnnas have not fully tested to provide noise rejection.Ther are some spots that have more nose than signal !
3. Also by the time evral clear systems degraded their noise deletion!
4. Suposedly also the sun increasrd ...its noise as read in a FC group
And another personal feeling here :
One of my "wettest radio dreams" on 90s was the usage of a ficntionary 4D micro display or 'space hole' in which you could look interactively to any point 'live' in the world. This 4D dispaly is detemined by the basic coordinates of the point that include LAat/ Lon/ height /3-angle and zoom Using a wire as antenna, passed it thru the display or space hole it is a perfect way to listen radio stations in allbands if not also for watching TV. And with crystal clear noise free sound
THis idea is now relizal ble with both SDR systems for HF bands and with streaming radio as replacing the remote space hole reception.>Howeer there are stil man omisions fom my perfect or ideal example as there are so many places in the wird that are not eovered with Kiwi sdrs on South America or Africa and Oceania . A goo example si Benin1566kHZ that can be head in my house ocasionaly when the local pirates are off but cant be heard in any other online system with better signal. Anyway the sense of listening to a very remote station that soul never be heard before is a marvelous experience!