Shopping for an Spectrum Analyzer - RF Explorer

[digiblur]

you should check out the smallnetworkbuilder reviews. He has the best test process/methodology.

 

I would go with the Asus RT-AC66 - there is a reason why netgear is suing Asus over it (and why it out-performs every other AC router out there).

Have the N version of the 66u. Best router I have ever bought.. Auto updates ad/malware site blocking, vpn for my phone, ftp, multi networks, network storage, you name it, it does it.

[WiWavelength]

you should check out the smallnetworkbuilder reviews.  He has the best test process/methodology.

 

I would go with the Asus RT-AC66 - there is a reason why netgear is suing Asus over it (and why it out-performs every other AC router out there).

Have the N version of the 66u. Best router I have ever bought.. Auto updates ad/malware site blocking, vpn for my phone, ftp, multi networks, network storage, you name it, it does it.

 

Asus makes great tablets and now great routers?  Why cannot Asus make a great handset?  PadFone, seriously?  Maybe Asus and HTC should merge.  Call it HateSeuss.

 

 

AJ

[S4GRU]

Asus makes great tablets and now great routers?  Why cannot Asus make a great handset?  PadFone, seriously?  Maybe Asus and HTC should merge.  Call it HateSeuss.

 

 

AJ

 

I think I would prefer HauteSeuss, myself.  

 

Robert

[WiWavelength]

I think I would prefer HauteSeuss, myself.  

 

I guess that depends upon whether you like oeufs verts et jambon.

 

AJ

[gnoj]

you should check out the smallnetworkbuilder reviews.  He has the best test process/methodology.

 

I would go with the Asus RT-AC66 - there is a reason why netgear is suing Asus over it (and why it out-performs every other AC router out there).

 

I'm still rocking a now 8-year-old Linksys WRT54G (v 2.0), which still manages to pump out about 20 Mbps of my 25 Mbps cable connection. It has great range (I lose the signal about half a block down the street), and thankfully I have hardly any interference from the neighbors. That said, the next time my ISP bumps up my speed I'll have to finally retire it, although I'll probably keep it around as a repeater.

 

Linksys went downhill pretty quickly after the WRT54G series, and now that Belkin has bought them I don't hold out any hope that that will change. Everything I've read confirms that Asus is essentially the new Linksys. It's funny that even Netgear is jealous- they claim that if consumers knew that the AC66U's Tx power was too high they'd buy a Netgear instead, but I daresay that would actually make me more inclined to nab it while I can..

 

Given how long I've put off an upgrade already, I'm holding out for the so-called "Wave 2" 802.11ac routers, which will add MU-MIMO, 160 MHz channels, and use 4-8 spatial streams. A tri-band router that adds 802.11ad ("WiGig") on the 60 GHz band is also supposedly in the works. I do wish they'd knock it off with the staggered release schedule and just release routers that implement all the features the AC spec calls for today, but it is what it is. However, for anyone needing a new router this year, I'd definitely put the RT-AC66U (or the newer 67/68U) at the top of the list.

[BenChase7]

I say we start a S4GRU donation for Robert to pick up one of these budget spectrum analyzers (similar to one that was going on for his LTE hunt in Denver), since I'm sure he could put it to good use for us all.  If others think this is a good idea, I'll be first in line with a donation towards this.    

[MacinJosh]

I say we start a S4GRU donation for Robert to pick up one of these budget spectrum analyzers (similar to one that was going on for his LTE hunt in Denver), since I'm sure he could put it to good use for us all.  If others think this is a good idea, I'll be first in line with a donation towards this.    

If I had the extra money, I would, but in October I can donate $5-10 toward this cause.

[miguell2]

To get off the stand up comedy stage and return to digiblur's observations from the field, a primary limitation of the RF Explorer seems to be its inability to adjust sweep time.  Whether an FFT or swept filter based analyzer, two things affect the detail in an RF sweep:  resolution bandwidth (RBW) and sweep time.  The smaller the RBW, the greater the detail.  The longer the sweep time, the greater the detail.

 

To illustrate, as I did on Twitter for Milan and Neal, look at two sweeps from my analyzer that I took a few seconds apart.  These are from inside my house, but fortunately, I have a VZW site located on top of a university residence hall just a few hundred feet from my backyard.

 

Both sweeps are set to an RBW of 30 kHz, but the first has a sweep time of 200 ms (to emulate the RF Explorer), while the second has a sweep time of 3000 ms (which is my established default).  Note how much better defined the VZW LTE 750 carrier is in the second sweep than in the first sweep.

 

 

 

AJ

 

Apparently you can adjust the sweep time on these devices. No?

 

http://micro.arocholl.com/index.php?option=com_content&view=article&id=71:accuracy-precision-and-resolution&catid=42:faq&Itemid=68

[miguell2]

In one of your pics or videos, I saw that the antenna port is 50 Ω.  That is quite standard.  So, nearly any directional antenna with the right frequency range should work.  The minor issue is calibration, but I do not think that we are concerned with absolute amplitude accuracy.

 

AJ

 

It looks like calibration is not a big issue.

 

http://micro.arocholl.com/images/stories/RFExplorer/Calibration/CalibrationPC.html

[WiWavelength]

Apparently you can adjust the sweep time on these devices. No?

 

http://micro.arocholl.com/index.php?option=com_content&view=article&id=71:accuracy-precision-and-resolution&catid=42:faq&Itemid=68

 

No, I have read through that page previously.  Nothing there indicates that sweep time is adjustable, nor have our users reporting from the field found a way to adjust it.

 

AJ

[WiWavelength]

It looks like calibration is not a big issue.

 

http://micro.arocholl.com/images/stories/RFExplorer/Calibration/CalibrationPC.html

 

Ah, I see.  So, like all of the rest of us, you possess a known, accurate RF test source?

 

No, you are still missing the point.  Calibration RF test sources are not found outside of labs.

 

AJ

[Nickel]

Ah, I see.  So, like all of the rest of us, you possess a known, accurate RF test source?

 

No, you are still missing the point.  Calibration RF test sources are not found outside of labs.

 

AJ

AJ, can Spectrum Analyzers tell how much a frequency is "loaded" or does it merely show the presence of signals? 

[WiWavelength]

AJ, can Spectrum Analyzers tell how much a frequency is "loaded" or does it merely show the presence of signals? 

 

Yes and no.  Some of the $20,000 pro spectrum analyzers have the capability to capture and demodulate (but not decrypt) live traffic.  That can certainly be used to assess loading.  As for my basic $1500 analyzer, I can use it to discern when an LTE carrier is live but not active -- only the reference signal bearing subcarriers are present.  But I cannot glean much about loading beyond zero loading.  I am looking only at raw RF, not demodulated LTE, CDMA1X, EV-DO, W-CDMA, or even GSM.

 

AJ

[MacinJosh]

Yes and no. Some of the $20,000 pro spectrum analyzers have the capability to capture and demodulate (but not decrypt) live traffic. That can certainly be used to assess loading. As for my basic $1500 analyzer, I can use it to discern when an LTE carrier is live but not active -- only the reference signal bearing subcarriers are present. But I cannot glean much about loading beyond zero loading. I am looking only at raw RF, not demodulated LTE, CDMA1X, EV-DO, W-CDMA, or even GSM.

 

AJ

AJ, have you taken that analyzer over by Sprint HQ lately to see if LTE 800 is broadcasting by there?

 

 

Sent from Josh's iPhone 5 using Tapatalk 2

[WiWavelength]

AJ, have you taken that analyzer over by Sprint HQ lately to see if LTE 800 is broadcasting by there?

 

No.  Generally, nothing cutting edge RF wise happens at the Sprint campus in Overland Park.  The Lenexa lab is a far more likely target.

 

AJ

[MacinJosh]

No. Generally, nothing cutting edge RF wise happens at the Sprint campus in Overland Park. The Lenexa lab is a far more likely target.

 

AJ

Have you tried there? I'm hopeful.

 

 

Sent from Josh's iPhone 5 using Tapatalk 2

[WiWavelength]

Have you tried there? I'm hopeful.

 

Yeah, I *want* to be arrested for corporate espionage.

 

AJ

[MacinJosh]

Yeah, I *want* to be arrested for corporate espionage.

 

AJ

No, we don't want that. I wasn't implying going into the lab property, but if that's the only way to test, then no, I don't want you risk espionage.

 

 

Sent from Josh's iPhone 5 using Tapatalk 2

[Jeffrey_J]

AJ any idea what this is

 

1965 - 1970 MHz and 1971 MHz

PCS 1X is CH 425 and EVDO is CH 475.

[WiWavelength]

AJ any idea what this is

 

1965 - 1970 MHz and 1971 MHz

PCS 1X is CH 425 and EVDO is CH 475.

 

Is this in Mount Pleasant?  For Sprint, 1965-1970 MHz is not relevant, as that is the downlink of the PCS E block.  In the Dallas-Fort Worth MTA, Sprint is licensed the PCS B block, which has its downlink at 1950-1965 MHz.

 

Prima facie, what you have in the PCS E block looks like a W-CDMA carrier.  Then, at 1971 MHz, that would be in the PCS F block, and it looks like a GSM channel.

 

I would say AT&T or T-Mobile for one or both, but I would have to check my spreadsheets and/or the FCC ULS to know for sure.  Do you happen to know whether you are in the Dallas-Fort Worth, Paris, or Texarkana BTA?

 

AJ

[Jeffrey_J]

Is this in Mount Pleasant?  For Sprint, 1965-1970 MHz is not relevant, as that is the downlink of the PCS E block.  In the Dallas-Fort Worth MTA, Sprint is licensed the PCS B block, which has its downlink at 1950-1965 MHz.

 

Prima facie, what you have in the PCS E block looks like a W-CDMA carrier.  Then, at 1971 MHz, that would be in the PCS F block, and it looks like a GSM channel.

 

I would say AT&T or T-Mobile for one or both, but I would have to check my spreadsheets and/or the FCC ULS to know for sure.  Do you happen to know whether you are in the Dallas-Fort Worth, Paris, or Texarkana BTA?

 

AJ

Yes it is in Mt. Pleasant, Tx.

 

BTA? The SID is 4120.

[WiWavelength]

BTA? The SID is 4120.

 

Unfortunately, the SID does not help.  The DFW MTA is huge.  Sprint uses the same SID all the way to Amarillo and beyond.  What is your county?  I can use that to track down the constituent BTA within the DFW MTA.

 

AJ

[Jeffrey_J]

Titus County

[WiWavelength]

Titus County

 

Okay, thanks.  Titus County is part of the Dallas-Fort Worth BTA, which is one of the many BTAs that make up the Dallas-Fort Worth MTA.

 

From your RF Explorer sweep, these are the relevant PCS 1900 MHz licenses:

 

http://wireless2.fcc.gov/UlsApp/UlsSearch/licenseMarketSum.jsp?licKey=9793

http://wireless2.fcc.gov/UlsApp/UlsSearch/licenseMarketSum.jsp?licKey=10372

 

Both are AT&T, so I am probably correct in my assessments of one W-CDMA carrier and one GSM channel.

 

AJ

[digiblur]

AJ any idea what this is

 

1965 - 1970 MHz and 1971 MHz

PCS 1X is CH 425 and EVDO is CH 475.

Use the other tab it shows more data on the PC.

 

I was digging around with mine today and found the AWS frequencies that VZW hold in Baton Rouge are very active with a large carrier.