Looking for a Spectrum Analyzer, any engineers out there?

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videobruce

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The choices in ascending price and links for the spec sheet & owners manual (if available);

Protek 3201 $1375;
http://www.protektest.com/ProdInfo.asp?prodId=3201
http://www.protektest.com/ProdManual/Man_3201.pdf

Instek GSP-810 $1675 a Swept Analyzer;
http://www.instek.com/GSP-810.htm
http://www.instek.com/manual/GSP-810OM.zip

B&K 2630 around $1860;
http://www.bkprecision.com/www/np_specs.asp?m=2630
http://www.bkprecision.com/manual/2630_manua.pdf

Protek 7830 $2600 (not available yet and no manual):
http://www.gsinstrument.com/eng/pro...ure/rf_7830.htm

Avcom PSA-37XP $3230 (no link for the manual);
http://www.avcomofva.com/downloads/...ets/PSA37XP.pdf

Instek GSP-827 a FFT Analyzer under $3570;
http://www.instek.com/GSP-827.htm
http://www.instek.com/manual/GSP-827.zip

The clear choice if $$ wasn't a object would be the Instek-827 w/ 2.7GHz coverage and a LCD display, but I can't seem to justify spending that much they way I plan on using it at this point in time. I don't know just how much that will change in the future (trying to make the purchase 'furture proof').
Realistically, I'm leaning towards the Instek GSP-810 for $1675. I have the limited Service Manual (from MCM Electronics, no less). There is a 5 day return, no restocking fee offer.
The Protek 3201, while the price is nice, doesn't seem a whole lot better than the SLM with a very linited display I already own and it just doesn't offer any room to grow into. I am afraid I would outgrow the unit too fast finding what it can't do.
The B&K has a TG, but the rest of the specs seem shortchanged to me especially the very limited 20kHz & 800 kHz "IF Bandwidth" (RBW).
The Avcom big plusses are it's the only American made unit and it has a LCD display, but the cost is very close to the 827 which appears to blow away the 37XP, especially only going down to 75 kHz RBW.

Between the two major types of SAs'; 'Swept' and 'FFT' (Fast Fourier Transform), each has it's advantages and disadvantages, but from my reading the FFT is the better choice. Unfortunately, with a price to match. The question is, do I really need all of that?

How this is to be used:
1. 2-way radio spectrum monitoring
2. TV band monitoring and trap tuning (hopefully only a couple of times with the tuning)
3. Looking for sources of RF noise or interference.
4. Wireless data around 2.5GHz would be a plus, but not a priority.
5. Hopefully more as I get more confortable with it.

I am a amatuer radio operator (not active) and have a background in electronics, but no degree. I would considerate myself at a intermediate level at best.

I would appreaciate any input. Thanks.
 
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videobruce

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Update on the first post as I have refined the search;

Update on the above choices. I have found what B&K sells from another importer for around $900 less. They gave me a price of $1030 delivered where the B&K (same unit mfg. by Atten) is around $1900:
http://www.madelltech.com/m1-7.html
They also have the model w/o the tracking generator for $875 used. :eek:

I have eliminated the 'Protek' and Avcom models because of price and features.
Instead, the Instek GSP 827 would be the one of choice, but I'm back to the 'price' issue. At $3275 it is by far the best that I found in that price range;

http://www.instek.com/GSP-827.htm
 

kd7rto

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For years, two-way shops have used all-in-one communications test sets. You might want to consider an older one of these units. (Though not something REALLY old, like the Cushman CE series).

I picked up an IFR1100S on eBay for $800. Spectrum analyzer, oscilloscope, signal generator, FM/AM receiver with deviation and freq error meters, it does it all. It covers audio-1 GHz, and when used with my AR5000, gives me spectrum analysis up to 2.6 GHz.

I've owned an AOR SDU5600, AOR SDU5000, and an Avcom SDM-42A (spectrum display units), but the IFR service monitor, by far, out performs them all.
 

rescue161

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videobruce said:
Update on the first post as I have refined the search;

Update on the above choices. I have found what B&K sells from another importer for around $900 less. They gave me a price of $1030 delivered where the B&K (same unit mfg. by Atten) is around $1900:
http://www.madelltech.com/m1-7.html
They also have the model w/o the tracking generator for $875 used. :eek:

I have eliminated the 'Protek' and Avcom models because of price and features.
Instead, the Instek GSP 827 would be the one of choice, but I'm back to the 'price' issue. At $3275 it is by far the best that I found in that price range;

http://www.instek.com/GSP-827.htm

I have that exact model here. You'll be disappointed in the accuracy of the frequency read-out as it only has 6 digits. If you are trying to tune a duplexer and it needs to be 462.6250, then the display is going to read 462.6 or 462.7. I jumps back and forth when you're right in between frequencies. I have a seperate signal generator that I use in conjunction with the analyzer and it works pretty good. The sig gen that I have is a Fluke and is very good. I mostly use the analyzer to see what's going on with the duplexer. I haven't done anything else with it. The quality is sort of lacking and you'll master it in no time - kind of making you wish that you should have waited for the more expensive model.

Of the choices that you've given, I'd go with the 810 or at least do some more research on it.

If you have any questions or need me to do some tests, just let me know.
 

rescue161

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scancapecod said:
If you have a receiver with a 10.7 MHz IF output, this is an outstanding alternative for around $1100. A superb performer.

http://www.rfspace.com/sdr14.html

But are you able to inject a signal into that with a sig gen? I'd be afraid to send an rf signal into that.

Looks good for just monitoring, but for testing and duplexer adjusting, I don't think it will cut the mustard.
 

loumaag

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The following is a link that was being bandied about in the late 90's. I know some engineers who thought this was a pretty good approach; however, I don't know anyone who put it together. In any case, I let you make up your own mind. Just so you understand, the link is still good, but I don't know if the support is.

http://www.science-workshop.com/
 

mancow

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Too bad you weren't in the market a few months ago. I had an Avcom 65A for sale. They can be found as low as around $500 at times and they work great. They also have a demodulator so you can hear the audio.
 

videobruce

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I have to opportunity to test both the Atten 5101 from Madell Technologies ($750 used but in excellent condition) and the Instek GSP-810 (new $1675) from Test Equipment Depot.

5010 observations:
1. Drift. 5MHz in the first 30 minutes and 1 MHz in the next hour. It really doesn't become stable untill at least 2-3 hours, but is useable after one hour.
2. Frequency control. Done via a 'knob' that has little 'drag'. It moves the center frequency very fast (a pro & con) and there is a 'fine' tune knob, but it's hard to fine tune it.
3. Frequency readout is only to 100 kHz. Not very exact. Only one marker.
4. Sweep display is real time as in analog. No digital sampling.

810 observations:
1. Drift: Around 60 kHz in the 30" and almost none afterwards.
2. Frequency control: Direct entry or via the 'spinner' dial. Can't travel as easyly and fast as the 5010 with just one control (pros & cons here too)
3. Frequency readout is in 1 kHz. Two markers with ability to measure received signal levels on both marker. This the 5010 doesn't have.
4. Sweep display are digital samples. Unknown rate. It will 'miss' fast 'blips' depending on when they hit. This is the big difference between the two and I don't know which is better.
5. Remote readout (and control for additional $$) from a PC via a serial cable.

Where I am torn between is the way each unit displays the same signal; analog vs digital samples. I understand the difference between the two, but I'm not sure which is better.
Since these issues can apply to regular oscilloscopes, I would like to assume more have experiance with them.

Thanks again in advance.
 

videobruce

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FWIW I kept the 810 and sent back the 5010. Great price (especially since it was used), but the dual markers, stability and PC connectivity sold me on the 810.

Now the question is; how about a external noise generator to subsistute for a tracking generator. The only thing I have found is one for $400;

http://www.appliedin.com/noisesource/ns1spec.html
 

prcguy

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Have you considered a good used HP analyzer? I picked up a nice HP 8594E (2.9GHz w/tracking generator) for $1200 about 10yrs ago and it has served me well. This thing cost $25k originally and it was only about 5yrs old when surplused. I’ve used lost of low cost Avcoms and many other portable analyzers for the satellite industry and they are toys in comparison. Even the analyzer in my IFR-1200S is very limited compared to the HP. There are tons of good used analyzers on the market within the price range you mention for new “toys”. If a company completely overhauls and calibrates a used analyzer it will cost big $$, so avoid the Tucker Electronics and other reconditioning houses if you want a good deal. Another thing to consider is using an analyzer with the IF output on a scanner or receiver. As signals off to the side are tuned in to the center of the IF they get sucked out when finally lined up due to the receiver AGC acting on the signal. It’s very distracting and disappointing using an analyzer this way.
prcguy
 

videobruce

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Don't like e-bay and don't like boat anchors. Especially ones that are 50 lbs, and would cost more to get them repaired then what I would buy them for.

This instek seems to be fine though I would of rather have the 827, but at 2x the price I can't justify spending that much.

Now, what I need is a broadband noise generator (noise bridge I believe they are called) to subsistute for a tracking generator. All I found was this;
http://www.appliedin.com/noisesource/ns1spec.html
 
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