RF Explorer - 15-2700MHz Spectrum Anakyzer $269

On a sunny day (Tue, 29 Oct 2013 21:53:05 +1100) it happened snipped-for-privacy@imagenet.com wrote in :

Yes I did look at it a while back. The 25 $ or so DVB-T sticks have only 2 MHz sampling rate or so, this one claims 20 MHz bandwidth.

Did they so simply multiply the price by 10 too?

It depends on what you want / need I guess, I can scan over 20 MHz in a rather short time with my software and the DVB-T stick. Not going to buy this thing, and it was not even finished when I looked.

2.7 GHz is a bit higher than the 2.2 GHz of the DVB-T sticks, but not that much, anything interesting in that extra band except for the 2.4 GHz WifFi? There exists software that uses normal WiFi cards to scan that band, I have seen it on the web. And you can always mix down, for example I have a RF converter for the lower RF bands that adds 100 MHz to the signal so the DVB-T stick with rtl_sdr can look there too.

I just got an HP8566B 100 Hz - 22 GHz spectrum analyzer from eBay for $960 plus a somewhat-inflated freight shipping price of $350. If you have the space, boat anchors rule.

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs 
Principal Consultant 
ElectroOptical Innovations LLC 
Optics, Electro-optics, Photonics, Analog Electronics 

160 North State Road #203 
Briarcliff Manor NY 10510 USA 
+1 845 480 2058 

hobbs at electrooptical dot net 
http://electrooptical.net

I have a voltmeter.

Not associated, but may be of interest to others: As a good source of refurbished, warranteed, calibrated equipment try:

Priority Test Equipment, Inc. 888 278 2230

700 Harvest Park Drive, Suite D Brentwood, CA 94513 tel: 925-513-7300 fax: 925-513-7338

Nanette Throne is one of the owners/founders and they recently sent me a 'comprehensive' list of available equipment - containing items other than voltmeters.

On a sunny day (Tue, 29 Oct 2013 09:15:43 -0400) it happened Phil Hobbs wrote in :

That is still a very good price including the shipping. I have the space, but for what I am doing it is overkill, would be cool though.

On a sunny day (Tue, 29 Oct 2013 06:27:57 -0700) it happened RobertMacy wrote in :

how many meters is a volt?

Yeah, it's pretty much overkill for me too, except that I have this hypersonic particle detector project going, so I had an excuse. Plus I've wanted my own for the last 30 years, since I first used an 8566A in my satellite radio job before grad school.

It arrived with a dead A4A3 memory board, but I had a spare, so all was as in the Ukrainian rowboat. (*) The display is much brighter than the one on my 8568B. I'd rather have an HP70000 series like the one I had at IBM, but since those are modular they're much less likely to be in working order once they get to eBay.

Cheers

Phil Hobbs

(*) i.e. hunky dory

--
Dr Philip C D Hobbs 
Principal Consultant 
ElectroOptical Innovations LLC 
Optics, Electro-optics, Photonics, Analog Electronics 

160 North State Road #203 
Briarcliff Manor NY 10510 

hobbs at electrooptical dot net 
http://electrooptical.net

Besides frequency range, the main characteristics of a proper spectrum analyzer are spur free dynamic range, resolution, and gain flatness. If you look at the specifications: some of these are sorta specified. I haven't played with one, but my guess(tm) is that in a strong signal environment (rooftop, mountain top, or connected to a real outdoor antenna), you'll see a substantial number of mixer spurs and internally generated junk on the screen. It's fairly easy to recognize and ignore these spurs, but not easy to completely eliminate them from the display.

Note that there are several different models, designed specifically to cover various cellular and data services. Only one is a general purpose spectrum analyzer.

Currently available in six models, based on frequency range: 433M: 430-440Mhz 868M: 860-890Mhz 915M: 910-920Mhz WSub1G: 240-960MHz 2.4G: 2350-2550MHz 3G: 15-2700MHz

Current Expansion Modules available: RFEMWSub1G: 240-960MHz RFEM2.4G: 2350-2550MHz RFEMWSUB3G: 15-2700MHz

Another potential problem is the IF bandwidth. The spec sheet says: Resolution bandwidth (RBW): automatic 2.6Khz to 800Khz the model)

2.6Khz is to wide to look at modulation spectra or sweep narrow band (IF) filters.

I do quite a bit with a tracking generator. A tracking generator is promised, but currently not available.

You might want to read the HP spectrum analyzer app note 150 to see what can be done and what your missing with low end hardware. Also compare specs. 3.6MB

My boat anchorage:

--
Jeff Liebermann     jeffl@cruzio.com 
150 Felker St #D    http://www.LearnByDestroying.com 
Santa Cruz CA 95060 http://802.11junk.com 
Skype: JeffLiebermann     AE6KS    831-336-2558

Shipping boat anchors is tricky. If the packing was primo, the shipping charge may not have been that excessive. Many an Ebay deal has been screwed up by terrible packing. Packing is time consuming. Most people suck at it.

I've contemplated sending a transit case on some deals to the seller, just to insure they don't screw it up. When I make that offer, they go into uber-careful packing since they know I'm going to bitch if the shipping screws up the deal. But I'm not bluffing. I have a few transit cases I've picked up on the surplus market for situations where I need to transport instrumentation. I would send a box at my cost if the item is delicate.

Every once in a while, military grade transit cases show up by the boatload on ebay. Like they bought too many for the project.

This guy has been selling the same typecase for about two years:

They are new in the box.

The packing was indifferent. I moaned about it ahead of time, so the guy put some scrap polyurethane foam under the transit case that the SA was already in, and shipped it on a pallet. I got a freight quote for $200 for shipping it from their zipcode to mine, including a lift gate local delivery. The selling price was outrageous cheap, so I decided not to argue about the shipping in case he got mad and half-assed it on purpose.

The SA wasn't bolted into the transit case, because it didn't have rack ears. It apparently came from a shop that used to service aircraft radios, and was "secured" using two SMA coax cables wound round the handles and the rails in the case. The guy did stick some peanuts and styrofoam scraps inside the case. I wasn't too impressed.

However, after I replaced the A4A3 board, and apart from needing a bit of TLC at some point to fix an intermittent reference unlock and oven error indication, it works fine. I tested it with an 18-GHz sweeper, and the combination shows some amplitude whoopdedoos, but those are probably due to the sweeper or the gnarly RG58 cable. I'll see if I can dig up a calibrated amplitude detector someplace, or maybe an HP436A power meter and head.

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs 
Principal Consultant 
ElectroOptical Innovations LLC 
Optics, Electro-optics, Photonics, Analog Electronics 

160 North State Road #203 
Briarcliff Manor NY 10510 

hobbs at electrooptical dot net 
http://electrooptical.net

HP, as in High Price, measuring equipments are all a man could hope for, I agree. But there are other SAs available. I use one of these, http://www.sp ectran.com/, and it works. There are sometimes some spurs at every even 10M Hz or 20MHz, but for the price it is good.

Hey, at least you got a transit case in the deal. Those rack mount transit cases are reasonably priced for what you are getting, especially if shock mounted. Though as you mentioned, it does help to have your gear rack mounted. If I see something I want on ebay in a rack and it is pricey, I'd spring for the shock rack case.

Out here in the bay area, all the DoD is gone thanks to Poppy Bush's BRAC. We don't have much in the way of government liquidation. But if you are in an area that has such gear handy, the auctions are where these surplus cases enter the market.

There is a guy in Beatty Nevada that has a ammo box and transit case shop. It is all out in the open. Interesting to look at, but much of his stuff is really in poor shape. The ammo cases are from Hawthorne so I am told. No idea where he gets the transit cases. Prices are similar to ebay, but you can at least see the case.

The ones I get locally are from Mountain View Surplus in Campbell. Prices are like ebay, but their stuff is in good condition.

At those prices, you might just want to consider getting a Rigol spectrum analyzer.

May i add a word of caution concerning shipping, especially of delicate or semi-delicate items. UPS is known to destroy well-packed dishes, glassware, etc and then absolutely *refused* to pay the "insurance" claim. This has happened a number of times, and the NOT-paying is no accident. It does absolutely NO GOOD to attempt to complain, all such messages get tossed by upper management. And since their "insurance" is NOT regulated by your (or any) State, the State Insurance commissioner has no legal authority. Also, it appears that the Interstate Commerce Commission is also unconcerned. SO. If you want to have delicate stuff SAFELY transported, then *F* UPS and use a reputable company like FedEx (or DHL if item goes outside US).

The difference in quality is mostly whether you can actually see the signal, see too much clutter, and whether the measurements off the screen are accurate. There are plenty of spectrum analyzers where you can sorta see the modulation spectra and where measurement accuracy is lacking. The SA's based on TV and CATV front ends are truly abysmal. However, as you mentioned, such spectrum analyzers have their place. According to the data sheet, the device in question: seems to target the "RF Enthusiast", whatever that might be. For myself, I wouldn't mind having an uncalibrated spectrum display to take to mountaintop radio sites so I can see what manner of signals are being spewed. The latest crop of digital narrowband radios make scanning difficult or impossible. All one hears on a scanner is noise[1]. With sufficient dynamic range, good shielding, and a decent attenuator, such a low end SA can effectively be used sniffing, viewing, identification, and direction finding.

However, that wasn't the original question. It was basically what's the difference between a cheap SA and quality instrument. I believe I've answered that question or at least pointed the OP in the right direction. Whether he needs a quality instrument, or can survive with a cheap spectrum viewer, is his decision.

[1] "Any sufficiently advanced modulation scheme is virtually indistinguishable from noise." (SETI League President Richard Factor).

--
Jeff Liebermann     jeffl@cruzio.com 
150 Felker St #D    http://www.LearnByDestroying.com 
Santa Cruz CA 95060 http://802.11junk.com 
Skype: JeffLiebermann     AE6KS    831-336-2558

If the dish was well packed, it wouldn't break. We're talking pilot error here.

UPS will pay you $50 with a minimal amount of bitching, but no more. Their attitude is if it broke, you didn't pack it correctly. I agree with them. UPS, Fedex, and USPS throw packages. Expect it. Hell if I know why they toss stuff. [Why does the bagage handler throw your bag on the belt when it is just as easy to place it there?] Some ebay dealer will "foam in" your item, of course on your dime.

Trust me, Fedex is no better. Fedex ground is terrible. I won't use them. Fedex air is on par with the rest of the package companies. In fact, USPS air is essentially Fedex air, just using the same planes at different times of the day.

As an aside, "peanuts" are terrible packing material. Items can "swim" in peanuts. If you insist on use them, you need to bag the peanuts to form a cushion, then tape the bags around the item to protect. Bubble wrap is the way to go.

A nice feature for SIGINT is "infinite persistence". Think of it like a wifi site survey. Most RF devices are not CW.

The US Army blew out about 800 of these:

They went on ebay for $300 or $350. I forget. The "reconditioned" units are from a dealer that got them from the same salvage house. These are nice for satellite work, and they do have "infinite persistence" if you want to see cellular or avionics.

Yep. Peak hold, peak memory, or in the case of one of my boat anchors, storage scope persistence. If I'm desperate, I use a camera with a very long shutter speed.

One of those would be handy for the C-band receive dishes I'm currently refurbishing and aligning. Rust, corrosion, and rot everywhere: I'm getting a bit old for this kind of work.

Instead of spectrum analyzer, I'm using one of these: Works well as long as it doesn't go into oscillation, or I don't need to identify which bird it's hearing. I modified and calibrated one into a signal level meter, which is good enough for a quick sanity check. A spectrum analyzer would be nice, but a meter is good enough. I could also use the spectrum analyzer to determine if any of the channels from the bird are low in output, or are gone, which is sometimes the case. However, the receiver we're using has all that and more built in:

--
Jeff Liebermann     jeffl@cruzio.com 
150 Felker St #D    http://www.LearnByDestroying.com 
Santa Cruz CA 95060 http://802.11junk.com 
Skype: JeffLiebermann     AE6KS    831-336-2558

I've used sat finders, but I'm almost convinced a usb dvb receiver is better. I don't know about C-band though, since I think there is still some analog on those birds. But the usb receiver can find a specific bird.

The usb dvbs2 receivers are all Chinese designs are far as I know. They work, but not elegantly. The real problem is the production runs are small, so there isn't a large community for each distinct usb dvb receiver. The companies are borderline hobbies. There are units on ebay for under $50. The dvbworld units have linux hacks. Kind of interesting since you use dd to steal the firmware from the windows driver to make a file from the linux implementation. Amazing any of this works.

Something I haven't tried are the dvbs2 "finders" that are actually cheap LCD TVs. About $100 on ebay. Obviously more useful if you want to use it while on the roof.